Article

Impact of Alkalization on the Antioxidant and Flavanol Content of Commercial Cocoa Powders

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Abstract

Cocoa is a food ingredient that is important for the contribution of flavor to foods but is also associated with potential health benefits. The chemistry thought to be responsible for its cardiovascular health benefits is the flavanol (flavan-3-ol) antioxidants. Evidence from the literature indicates that natural cocoas are high in flavanols, but when the cocoa is processed with alkali, also known as Dutch processing or Dutching, the flavanols are substantially reduced. This paper provides a survey of the physical and chemical composition of representative natural cocoas and lightly, medium, and heavily alkalized cocoas. As part of the survey, both brown/black and red/brown alkali-processed cocoas were measured. Natural cocoa powders have an extractable pH of 5.3−5.8. Alkalized cocoa powders were grouped into lightly treated (pH 6.50−7.20), medium-treated (pH 7.21−7.60), and heavily treated (pH 7.61 and higher). The natural, nonalkalized powders had the highest ORAC and total polyphenols and flavanols (including procyanidins). These chemical measurements showed a linear decrease as the extractable pH of the cocoa powder increased. Likewise, the flavanol monomers, oligomers, and polymers all showed a linear decrease with increasing pH of the final cocoa powder. When brown/black cocoa powders were compared to red cocoa powders, similar decreases in flavanols were observed with increased alkalization. The average total flavanol contents were 34.6 ± 6.8 mg/g for the natural cocoas, 13.8 ± 7.3 mg/g for the lightly processed cocoas, 7.8 ± 4.0 mg/g for the medium processed cocoas, and 3.9 ± 1.8 mg/g for the heavily processed cocoa powders. The observed linear and predictable impact of alkalization on flavanol content is discussed with respect to other reports in the literature as well as what implications it may have on diet and food manufacturing.Keywords: Alkalization; Dutching; flavanols; flavan-3-ols; procyanidins; antioxidants; cocoa powder; cacao

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... Rheological properties were determined in rotation viscosimeter RheoStress 600 HP, Haake, using the O.I.C.C. method at the temperature of 40 ± 0.1 °C [28]. Flow curves were determined using the method of hysteresis loop within the shear rate interval 1-60 1/s. ...
... Hardness showed an inverse relationship with particle size, attributed mainly to the relative strengths of the particle-to-particle interactions within the different particulate structures of products exhibiting different PSDs [28,29]. Results of chocolate hardness, 8 days after production correlate with the results of particle size distribution. ...
... Total flavanol content in cocoa decreases by primary processing (fermentation and dying) and by further steps (roasting as well as alkalization, also called dutching) used for manufacturing semi-finished cocoa products [25]. Alkalization has shown to decrease total flavanol content up to 60% [27], which augments as the extractable pH of the cocoa powder increased [28]. ...
Chapter
Today, food not only needs to satisfy hunger and provide the necessary nutrients for the body, but also to prevent the occurrence of diseases that are related to nutrition and improve the physical and mental health of consumers. Functional foods can improve the general condition of the body, reduce the risk of some diseases and furthermore be used to treat some diseases. Given the growing popularity of functional foods and frequent consumption of confectionery products, especially chocolate, the goal of this chapter was to create innovative, functional chocolate - chocolate with soy milk. Chocolate with soy milk is composed of 8-10% soy proteins, which have a positive impact on human health. Soy milk contains more protein and less fat than cow’s milk. It is characterized by the absence of cholesterol and lactose, has a low content of saturated fatty acids, while the content of polyunsaturated fatty acids is significantly higher than in cow’s milk. This chocolate is not only interesting because of its health effects, but also because of its textural properties. The greatest impact on the thermoreological, thermal and textural properties of chocolate have the composition of the ingredients, fat content, selection of emulsifiers, solid particle size distribution and particle packing method. In milk chocolate the ratio of milk fat and cocoa butter determines the quality of chocolate and today everything about it is well known, while the ratio of soy milk - cocoa butter has not been completely defined. For this chapter, chocolate was produced in an unconventional way, i.e., in a ball mill applying variable refining time (30, 60 and 90 minutes) and pre-crystallization temperature of chocolate mass (26, 28 and 30°C). The chocolate was produced with 20% of soy milk powder. The quality of chocolate was monitored by investigating nutritive composition, polyphenol content, hardness of chocolate, solid triglyceride content (SFC), thermal characteristics, rheological parameters (Casson yield flow (Pa), Casson viscosity (Pas), the thixotropic loop area, elastic modulus and creep curves) as well as sensory properties. Results showed that chocolate with soy milk had a higher nutritional value and better antioxidant properties than chocolate with powdered milk. The proteins of the soy milk, which are capable of forming a gel if the protein concentration is greater than 8%, lead to the viscoelastic behavior of the chocolate mass. Rheology of the chocolate mass with soy milk depends solely on the soy proteins, while thermal and sensory properties and content of solid triglycerides depends on the fatty phase, i.e., soybean oil. In order to maintain optimal sensory quality, hardness as well as melting resistance of chocolate, it is necessary for the chocolate with soy milk to be refined longer in a ball mill, however also to use lower temperatures for pre-crystallization.
... flavan-3-ols, anthocyanins and proanthocyanidins), and methylxanthines (i.e. theobromine, caffeine and theophylline) (Li et al., 2012;Miller et al., 2008). ...
... As expected, alkalization greatly darkened the color of cocoa powder and rapidly increased its pH (Table 1). All alkalized cocoa powders reached a pH above 8, meaning that they were in the range of heavily alkalized powders (Miller et al., 2008). Alkalization under constant alkali concentration of NaOH 2.34% w/w, altered the color since all alkalized powders had a ΔE value substantially above 1 when compared to the non-alkalized powder, which can be visually perceived darker from consumers, as the biggest differences were observed in the L* value (Stanley et al., 2015). ...
... Based on the classification of alkalized cocoa powders, the powders treated with NaOH 0.59 and 1.17% w/w fall into the lightly alkalized range (pH 6.5-7.2), while the ones treated with NaOH 2.34 and 3.59% w/w fall into the heavily alkalized range (pH > 7.6) irrespective of the alkalization time (Miller et al., 2008). Unlike the others, the pH values of powders treated with NaOH 0.59% w/w were below 7.2, which indicates that this alkali concentration was not sufficient to fully neutralize the acidity of the natural cocoa powder. ...
Article
Full-text available
Alkalization is an important process in cocoa powder production that affects color and flavor. In this study, the impact of alkalization temperature (60, 70, 80, 90, 100 °C), NaOH concentration (0.59, 1.17, 2.34, 3.59% w/w of cocoa powder) and alkalization time (1 and 10 min) on the physicochemical properties (pH, color) and phytochemical profile (theobromine, caffeine, epicatechin, catechin) of cocoa powder were investigated, while the aroma was studied on the corresponding cocoa drinks. High-performance liquid chromatography coupled to an ultra-violet detector (HPLC-UV) was used for screening the non-volatiles and headspace solid - phase microextraction - gas chromatography - mass spectrometry (HS-SPME-GC-MS) for the aromatic compounds. Major changes of the cocoa properties occurred during the first minute of alkalization. Increase of temperature and alkali concentration generally reduced the levels of epicatechin and the lightness (L*), while the pH of the cocoa powder was affected by changing the alkali concentration. On the other hand, the reddish (a*) and yellowish (b*) color component values and theobromine levels were not significantly affected by varying temperature and alkali concentration. A higher temperature did not affect the concentration of the volatile compounds, while a decrease in certain chemical classes was observed by increasing the alkali concentration.
... Alkalization is normally carried out by adding sodium or potassium carbonate at high temperature and controlled pressure. According to the final pH, cocoa powders can be classified into natural (pH 5 to 6), light-alkalized (pH 6 to 7.2), medium-alkalized (pH 7.2 to 7.6), and strong-alkalized powders (pH > 7.6; Miller et al., 2008). Light-alkalized cocoa powders are light brown, but darker than natural ones, and their flavor is less astringent and less acidic than those of natural powders. ...
... Many articles have been published in the literature about the determination of and/or the changes produced in the different types of polyphenols and methylxanthines among several distinct cocoa products (Gabbay Alves et al., 2017;Machonis, Jones, Schaneberg, Kwik-Uribe, & Dowell, 2014;Manzano et al., 2017;Risner, 2008), in cocoa processing steps (Elwers, Zambrano, Rohsius, & Lieberei, 2009;Lacueva et al., 2008;Li et al., 2012Li et al., , 2014Miller et al., 2008;Payne, Hurst, Miller, Rank, & Stuart, 2010;Pedan, Fischer, Bernath, Hühn, & Rohn, 2017;Quiroz-Reyes & Fogliano, 2018), among different cocoa clones or varieties (Elwers et al., 2009;Niemenak, Rohsius, Elwers, Omokolo Ndoumou, & Lieberei, 2006), and so forth. Therefore, some of these studies are reviewed below. ...
... The results showed that the content of both methylxanthines and flavan-3-ols lowered as the degree of alkalization increased, whereas a higher degree of alkalization decreased TPC. Similar results were found by Miller et al. (2008), who also studied the influence of alkalization on the antioxidant capacity (ORAC method), TPC, and flavanol content of cocoa powders. For all the samples, the highest contents of all the determinations were found for natural powders. ...
Article
Cocoa (Theobroma cacao L.) and its derivatives are appreciated for their aroma, color, and healthy properties, and are commodities of high economic value worldwide. Wide ranges of conventional methods have been used for years to guarantee cocoa quality. Recently, however, demand for global cocoa and the requirements of sensory, functional, and safety cocoa attributes have changed. On the one hand, society and health authorities are increasingly demanding new more accurate quality control tests, including not only the analysis of physicochemical and sensory parameters, but also determinations of functional compounds and contaminants (some of which come in trace quantities). On the other hand, increased production forces industries to seek quality control techniques based on fast, nondestructive online methods. Finally, an increase in global cocoa demand and a consequent rise in prices can lead to future cases of fraud. For this reason, new analytes, technologies, and ways to analyze data are being researched, developed, and implemented into research or quality laboratories to control cocoa quality and authenticity. The main advances made in destructive techniques focus on developing new and more sensitive methods such as chromatographic analysis to detect metabolites and contaminants in trace quantities. These methods are used to assess cocoa quality; study new functional properties; control cocoa authenticity; or detect frequent emerging frauds. Regarding nondestructive methods, spectroscopy is the most explored technique, which is conducted within the near infrared range, and also within the medium infrared range to a lesser extent. It is applied mainly in the postharvest stage of cocoa beans to analyze different biochemical parameters or to assess the authenticity of cocoa and its derivatives.
... Cocoa powder is the most important raw material of confectionery products, chocolate-flavoured bakeries, ice-creams and drinks (Miller et al., 2008). Apart from technologic properties, cocoa (Theobroma cacao L.) and its derived products are well considered for being a rich source of methylxanthines and polyphenols (Langer, Marshall, Day, & Morgan, 2011). ...
... medium-alkalised (MAC) (pH 7.2-7.6), strong-alkalised (SAC) (pH > 7.6) and black powders (BC) (pH > 7.6 and very low L values) (Miller et al., 2008). ...
... The 86 cocoa powders were physico-chemically characterised and divided into five categories according to their extractable pH values and colour (Miller et al., 2008). By contemplating these values, 23 cocoa samples were classified as natural, 19 as light-alkalised, 21 as mediumalkalised, 19 as strong-alkalised and 4 as black powders. ...
... This procedure involves using an alkali (generally potassium carbonate) in combination with oxygen, water and high temperatures. These extreme conditions provoke, among others, Maillard reactions and polyphenol oxidations and polymerizations, which end up with flavor and color modifications from light brown (natural) to red, dark brown or extremely black (Li et al., 2012;Miller et al., 2008). ...
... After decreasing temperature to 20-25 C in a cold bath, sample pH was measured with a digital pHmeter (Crison Instruments, S.A., Barcelona, Spain) previously calibrated with 3 buffer solutions: pH 4.01, pH 7.0 and pH 9.21 (T ¼ 25 C). According to pH value, samples were classified in four different categories: natural cocoa powders (5 < pH < 6), light alkalized (6 < pH < 7.2), medium alkalized (7.2 < pH < 7.6) and strong alkalized powders (pH > 7.6) (Miller et al., 2008). ...
... The different natural cocoas are found in the negative region, whereas the alkalinized samples are distributed across the negative and positive regions. These differences could be due to alkali, the stage in which it has been alkalized (bean or cake), and the degree of alkalinization that can produce different color changes (red or dark brown) (Miller et al., 2008). The second PC explains 20% of variability and might be related to the percentage of cocoa powder in the sample. ...
Article
Cocoa powder is a highly valuable global product that can be adulterated with low-cost raw materials like carob flour as small amounts of this flour would not change the color, aroma and taste characteristics of the final product. Rapid methods, like NIR technology combined with multivariate analysis, are interesting for such detection. In this work, unaltered cocoa powders with different alkalization levels, carob flours with three different roasting degrees, and adulterated samples, prepared by blending cocoa powders with carob flour at several proportions, were analyzed. The diffuse reflectance spectra of the samples of 1100–2500 nm were acquired in a Foss NIR spectrophotometer. A qualitative and a quantitative analysis were done. For the qualitative analysis, a principal component analysis (PCA) and a partial least squares discriminant analysis (PLS-DA) were performed. Good results (100% classification accuracy) were obtained, which indicates the possibility of distinguishing pure cocoa powders from adulterated samples. For the quantitative analysis, a partial least squares (PLS) regression analysis was performed. The most robust PLS prediction model was obtained with one factor (LV), a coefficient of determination for prediction (RP²) of 0.974 and a root mean square error of prediction (RMSEP) of 3.2% for the external set. These data allowed us to conclude that NIR technology combined with multivariate analysis enables the identification and determination of the amount of natural cocoa powder present in a mixture adulterated with carob flour.
... The highest concentrations were found in the C sample, with more than 7 mg GAE/g of polyphenols, as in Belšcak et al. [27], although the literature mentions very variable polyphenol contents, depending on the geographical origin of the beans, degree of maturation, processing, and packaging [7,9,11,29,46]. The content in theobromine and caffeine of the C sample under study ( Table 2) was coherent with what was reported by Jalil and Ismail [60], whilst the pH value ( [61], since this sample may be considered as quite alkalized cocoa, showing a pH value greater than 8.00. The alkalization of cocoa powder causes a decrease in the total polyphenols and an increase in pH up to 8.0. ...
... medium treatment (pH 7.2-7.6), and heavy treatment (pH 7.6 and above) [61]. ...
... Therefore, despite chocolates having a high fat content (Table 3), the lipid oxidation at the end of storage ( Figure 1A) was very slow. Both the lyophobic and the lyophilic antioxidants were supposed to perform a continuously protective activity towards fats [14,69] due to their well-known biological effects [3,16,17,27,53,60,61,73,74]. ...
Article
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Background: While there has been an increasing interest in the health properties of chocolate, limited research has looked into the changes of antioxidants occurring in the time span from production to the best before date, which was a period of 18 months in this study. Methods: Humidity, ash, pH, acidity, fiber, carotenoids, retinols, tocopherols, sugars, proteins, theobromine, caffeine, polyphenols, fats, the peroxide value, organic acids, and volatile compounds, along with the sensory profile, were monitored at 18-week intervals for 18 months under conditions simulating a factory warehouse or a point of sale. Results: At the end of the storage period, more polyphenols were lost (64% and 87%) than vitamin E (5% and 14%) in cocoa mass and cocoa powder, respectively. Conversely, a greater loss in vitamin E (34% and 86%) than in polyphenols (19% and 47%) was shown in the hazelnut paste and gianduja chocolate, respectively. The sensory profiling of cocoa mass, cocoa powder, and hazelnut paste revealed increases in grittiness and astringency, as well as decreases in melting, bitterness, and toasted aroma. Moreover, in the hazelnut paste and gianduja chocolate, oiliness increased with a toasted and caramel aroma. Furthermore, dark chocolate was more gritty, acidic, and bitter. Milk chocolate lost its nutty aroma but maintained its sweetness and creaminess. Conclusions: These results should contribute an important reference for companies and consumers, in order to preserve the antioxidants and understand how antioxidants and sensory properties change from the date of production until the best before date.
... Several researchers have demonstrated the detrimental impact of alkalization on the phytochemical content of cocoa (Gu et al., 2006;Li et al., 2014;Miller et al., 2008;Payne et al., 2010;Quelal-Vásconez et al., 2020;Stanley et al., 2015;Todorovic et al., 2017;Valverde et al., 2020), whereas some others attempted to study the impact of alkalization conditions on the final cocoa flavor (Alasti et al., 2020;Huang & Barringer, 2010Li et al., 2012;Mohamadi Alasti et al., 2019;Serra Bonvehí & Ventura Coll, 2002). However, the minor flavonoids have not been investigated thus far and their presence in cocoa powder might affect its orosensory properties. ...
... According to the classification of alkalized cocoa powders, the powder treated with NaOH 1.17% w/w is assorted into the medium-alkalized range (pH 6.5-7.2), whereas the one treated with NaOH 2.34 % w/w is assorted into the highalkalized range (pH >7.6) (Miller et al., 2008). ...
... Apart from the epimerization, other processes must have taken place since the total level of procyanidin B1 and B2 also decreased when a more intense alkalization is applied. Several studies reported a similar reduction in total procyanidin content (monomers, dimers, trimers, up to oligomers and/or polymers) after alkalization (Andres-Lacueva et al., 2008;Gu et al., 2006;Miller et al., 2008;Stanley et al., 2015). However, in the current study, no higher procyanidin oligomers were quantified. ...
Article
Alkalization is a process to improve color, dispersibility and flavor of cocoa powder but is likely to have a negative effect on the phytochemicals. Hereto, the impact of alkalization degree (none, medium and high) on the potential mood-enhancing compounds corresponding to the four levels of the mood pyramid model (flavanols, methylxanthines, biogenic amines and orosensory properties) was investigated. The phytochemical content, analyzed via UPLC-HRMS, showed reduction of specific potential mood-enhancing compounds upon alkalization, implying a decrease in bitterness and astringency. Moreover, volatile compounds analysis via HS-SPME-GC-MS indicated that alkalization reduced the levels of volatile compounds, responsible for acidity, fruity, floral and cocoa aromas. With respect to the orosensory properties, the cocoa powder palatability was suggested to be increased due to reduced acidity, bitterness, and astringency, while the desired volatile compounds were reduced. However, sensorial analysis is required to link the volatile results with the overall effect on the flavor perception.
... Samples were classified into different alkalization levels by following the classification by Miller: natural (pH 5-6), slight (pH 6-7.2), medium (pH 7.2-7.6) and strong alkalized (pH > 7.6) (Miller et al., 2008). ...
... With NaOH, values lowered to 58% and 80% for catechin and epicatechin, respectively, when samples were treated with the strongest processing variables. These results agree with other authors in line with two facts: (1) cocoa alkalization leads to general polyphenols degradation (Gültekin-Özgüven et al., 2016;Miller et al., 2008;Gu et al., 2006;Jolić et al., 2011;Zhu et al., 2002); (2) (-)-epicatechin is more sensitive to alkalization than (+)-catechin (Gültekin-Özgüven et al., 2016;Andres-Lacueva et al., 2008). ...
Article
Polyphenols, a group of secondary metabolites, have well-known relevant effects on human health. During traditional alkalization, this content dramatically lowers. We aimed to evaluate an alternative alkalization method based on extrusion on cocoa functional characteristics. The results showed that the antioxidant capacity and total phenolic values increased as alkali concentration and temperature did, and these values doubled under less extreme conditions. Comparing the functional properties between extruded and traditionally produced powders revealed that catechin, epicatechin and dimers B1 and B2 contents were 43%, 33%, 54% and 34% lower in the extruded samples, respectively. However, this reduction was partially balanced by increased clovamide content up to 50%. Thus the total phenol content and antioxidant capacity of the extruded samples were statistically above those of the commercial one. Hence extrusion alkalization should be considered a new processing alternative to avoid markedly reducing functional properties.
... This is owing to its rich content of natural antioxidants, having been reported to exhibit greater antioxidant capacity than many other flavanol-rich foods and food extracts including red wine, blueberry, garlic, strawberry and green and black tea . Reported numbers of antioxidants in cocoa and its products (621) triple those in green tea, double those in red wine and are far higher than those in blueberries which are known to be a great source of antioxidants (Cooper et al., 2008;Miller et al., 2008). Nutritionally, cocoa powder is a rich source of protein (22%), contain useful amounts of vitamin A, riboflavin and nicotinic acid, several minerals including iron, calcium, copper, magnesium, phosphorus, potassium, sodium and zinc (Steinberg et al., 2003). ...
... A preliminary study to ascertain consumers' preference for the powders in the yoghurt was carried out and actual studies were thereafter done using the alkalized powder since preference for yoghurts made with the alkalized powder was higher, probably due to the astringent flavour of the natural powder which is usually reduced during alkalization process. Alkalization also reduces bitterness and improves solubility and these factors are important for beverage product applications (Miller et al., 2008). ...
Article
Full-text available
Increasing awareness of health benefits of plant-based food/drinks has resulted in increased preference of consumers for functional beverages as compared to conventional sugar-laden drinks/beverages which only quench thirst but provide little or no nutritional or health benefits. However, most commercially-available functional drinks/beverages are often expensive and not affordable for most people especially low-income earners in developing countries. This study aims to develop low-cost functional yoghurt from milk-cocoa powder blends so as to provide alternative to expensive commercially-available functional drinks and enhance direct consumption of bioactive-rich cocoa powder. Cocoa powder was used to partially replace milk in yoghurt at levels of 10-50%. Standard procedures were used to evaluate triplicate samples of yoghurts for proximate and mineral composition, vitamins, radical-scavenging abilities and phenolic content. Sensory attributes of the yoghurts were evaluated using trained and untrained panels. pH, acidity and brix ranged from 4.29-4.34, 0.67-0.88% and 12-13.5%, respectively. Cocoa powder inclusion significantly increased crude protein (33.7-38.89% DW), fat (0.07-0.14%), ash (0.71-1.01%), fibre (0.1-0.21%), Ca, Mg, K, Zn, Fe, vitamins A, B 1 , B 2 , B 3 , C and E; while vitamin D reduced from 1.64 to 0.72-1.08 mg/L. Similarly phenolic and flavonoid contents, DPPH, FRAP and ABTS increased; values ranged from 0.03-0.16 mg/gGAE; 0.03-0.06 mg/gQUE, 40.12-72.72%, 0.43-1.17 mg/g and 22.49-26.09 mmol/ml, respectively. While the trained panel preferred 50:50 milk-cocoa yoghurt, untrained panel preferred 90:10 milk-cocoa yoghurt, indicating both panels' preference for milk-cocoa yoghurts as compared to the plain yoghurt. Organoleptically acceptable, nutritionally-rich, low-cost functional yoghurt high in bioactive compounds can be developed from milk and cocoa powder. Its production requires no sophisticated machines since yoghurt is already being produced by both rural and urban dwellers/processors in Nigeria. This milk-cocoa yoghurt provides a cheaper alternative not only packed with bioactive compounds from cocoa powder but also high in protein and micro and macronutrients.
... pH was used to classify samples into different categories according to Miller's scale (Miller et al., 2008). Those cocoas with a pH between 5 and 6 were considered natural cocoas, those with a pH between 6 and 7.2 were taken as lightly alkalized, between 7.2 and 7.6 were moderately alkalized, and those over 7.6 were strongly alkalized. ...
... Coef. used to classify cocoa into different categories (Miller et al., 2008). pH also conditions sample color because its increases the enzyme activity of polyphenol oxidase (Misnawi, Jamilah, & Nazamid, 2003;Rodríguez et al., 2009) and enhances several chemical reactions that darken cocoa (Germann, Stark, & Hofmann, 2019a, 2019b). ...
Article
Traditional alkalization, essential for darkening color, modifying flavor and increasing cocoa powder solubility, is a discontinuous time-consuming technique that employs considerable energy. We herein propose extrusion as a promising alternative to improve and increase the sustainability of the traditional process. The aims of this work were twofold: on the one hand, to characterise the effects of extrusion on alkalised cocoa physico-chemical features; on the other hand, to determine if alkalized powders possess similar characteristics to those obtained by conventional treatment. The results showed that alkali was the main variable to increase pH and to diminish color. Compared to commercial samples, the developed cocoas had darker colors than, and similar sensory properties to, their reference commercial cocoas. These findings confirm that extrusion is suitable for producing high sensory acceptable alkalized products quickly, sustainably and continuously.
... Some manufacturers include an additional step of alkalization, also known as Dutching, which is applied to the cocoa beans, cocoa liquor or cocoa powder (Miller et al. 2008) to obtain the desirable dark brown color, reduce bitterness and astringency, and prevent the sinking of cocoa powder in cocoa-based drinks (Miller et al. 2008). When cocoa is alkalized, after heating in a closed mixing vessel, a warm alkali solution is added for a specific reaction time, and excess moisture is removed by heating or drying (Li et al. 2014). ...
... Some manufacturers include an additional step of alkalization, also known as Dutching, which is applied to the cocoa beans, cocoa liquor or cocoa powder (Miller et al. 2008) to obtain the desirable dark brown color, reduce bitterness and astringency, and prevent the sinking of cocoa powder in cocoa-based drinks (Miller et al. 2008). When cocoa is alkalized, after heating in a closed mixing vessel, a warm alkali solution is added for a specific reaction time, and excess moisture is removed by heating or drying (Li et al. 2014). ...
Article
Full-text available
Cocoa beans, the seeds of the tree Theobroma cacao L., are the key raw material for chocolate production that implies an extensive post-harvest process. Chocolate properties can vary depending on cocoa origin, composition and manufacturing procedure, which will give unique sensory properties to the final product. On the other hand, the high global consumption of cocoa products, long recognized as a major source of dietary polyphenols with important health benefits, has increased interest in tracking the geographical origin of cocoa and authenticating chocolate to guarantee product quality and reveal possible commercial fraud. However, the sustainable production of high-quality cocoa is still far from reality, and the cocoa sector continues to face many challenges in this field. This review provides an update on the progress toward the authenticity, traceability and sustainability of cocoa products, issues that chocolate producers still need to resolve.
... These researchers reported that the previous characteristics reduced by 87%, 83%, and 50%. These losses were similar to those reported by Miller et al. (2008) in commercial cocoa powders, which were 89% for flavanols in highly alkalized cocoa, by Gu, House, Wu, Ou, and Prior (2006) in commercial cocoa powders, which were 51% for antioxidant activity and 78% for procyanidins, and by Jolić, Redovniković, Marković, Šipušić, and Delonga (2011) in commercially alkalized cocoa nibs, which were 64% for total phenolic content, 59% for total procyanidins, and 39% for antioxidant activity. In another work, Zhu et al. (2002) simulated the alkaline conditions of the lower gut and found an 85% loss in flavanols and procyanidins at pH 7.4 after 24 h, and a 100% loss at pH 9 after 4 hr. ...
... Andres-Lacueva et al., 2008;Rodríguez et al., 2009;Miller et al., 2008;Gültekin-Özgüven et al., 2016;Jolić et al., 2011;Zhu et al., 2002;Gu et al., 2006;Todorovic et al., 2017;Hurst et al., 2011;Kofink et al., 2007;Ortega et al., 2008;Stark and Hofmann, 2006; Peterson, 2005, 2007;Zhang et al., 2014;Germann et al., 2019a and2019b;Todorovic et al., 2017 Methylxanthines• Theobromine and caffeine are reduced Theobromine interacts with bases and forms saltsLi et al., 2012;Oduns and Longe, 1998 ...
Article
Alkalization, also known as “Dutching,” is an optional, but very useful, step taken in the production chain of cocoa to darken its color, modify its taste, and increase natural cocoa solubility. Over the years, various attempts have been made to design new and more effective alkalization methods. Moreover, different authors have attempted to elucidate the impact of alkalization on the physicochemical, nutritional, functional, microbiological, and sensory characteristics of alkalized cocoa. The aim of this review is to provide a clear guide about not only the conditions that can be applied to alkalize cocoa, but also the reported effects of alkalization on the nutritional, functional, microbiological, and sensory characteristics of cocoa. The first part of this review describes different cocoa alkalization systems and how they can be tuned to induce specific changes in cocoa properties. The second part is a holistic analysis of the effects of the alkalization process on different cocoa features, performed by emphasizing the biochemistry behind all these transformations.
... Elevated TPC and TFC values observed following natron treatment could therefore, be explained by the fact that trace amounts of metals that might be present in the natron could form complexes with the substances in the mixture, thereby increasing the absorbance values obtained for TPC and TFC (Psotová et al., 2003).Transition metals are also believed to play a potential role as catalysts of oxidative processes by enhancing the formation of hydroxyl radicals and hydroperoxide decomposition during the Fenton reaction (Halliwell et al., 1997). Miller et al. (2008) also report that an alkaline treatment can compromise the content phenolic compounds and antioxidant properties of cocoa (Theobroma cacao). Alkaline pH was also found to have adverse effect on the antioxidant properties of both Rosemanirus officinalis, Thymus vulgaris and Origanum majorana (Gawlik-dziki and Świeca, 2007). ...
... According to Fig. 2, some MAC samples may have similar volatile profiles to LACs: these similarities could be attributed to the process stage in which alkalization was performed (Miller et al., 2008). During the alkalization process, volatile compounds can be better conserved depending on the process method, conditions (temperature and alkali levels), products (alkali types) and the presentation of the cocoa product to be alkalized: beans, cake or powder. ...
Article
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A total of 56 key volatile compounds present in natural and alkalized cocoa powders have been rapidly evaluated using a non-target approach using stir bar sorptive extraction gas chromatography mass spectrometry (SBSE-GC-MS) coupled to Parallel Factor Analysis 2 (PARAFAC2) automated in PARADISe. Principal component analysis (PCA) explained 80% of the variability of the concentration, in four PCs, which revealed specific groups of volatile characteristics. Partial least squares discriminant analysis (PLS-DA) helped to identify volatile compounds that were correlated to the different degrees of alkalization. Dynamics between compounds such as the acetophenone increasing and toluene and furfural decreasing in medium and strongly alkalized cocoas allowed its differentiation from natural cocoa samples. Thus, the proposed comprehensive analysis is a useful tool for understanding volatiles, e.g., for the quality control of cocoa powders with significant time and costs savings.
... This process aims at reducing fermented almonds acidity, increasing the solubility of cocoa powder and contributing to the taste and flavor of cocoa-based products. Furthermore, alkalization provides products with different colors and tonalities, such as light brown, red or even dark black (Gültekin-Özgüven et al., 2016;Li et al., 2012;Miller et al., 2008;Minifie, 1999). The type of alkalis and the alkalization conditions, including alkali concentration (1-6%), temperature (60°C to 120°C) and process time (30-150 min) are highly diverse and dependent on the desired sensorial and technological properties of final products (Bispo, 1999;Bispo et al., 2005;Li et al., 2014;Minifie, 1999). ...
... However, alkalization influences loss of methyl xanthine compounds [13]. Raw cacao had shown the second most amount of theobromine, as it is the initial stage of cacao processing and taken directly from cacao pod [14]. ...
Article
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Theobroma cacao seed is the major ingredient in all types of chocolate products and contains Theobromine. Theobromine is a bitter alkaloid beneficial in the treatment of hypertension, arteriosclerosis and angina pectoris. Of all chocolate brand samples, Sample J containing 70% Cacao had the highest amount of theobromine. Sample A containing 11% Cacao had the least amount of theobromine. The 100% Cacao Chocolate Bar had the highest concentration of theobromine in comparison to roasted cocoa having the lowest concentration of theobromine. Quantitative analysis of Theobromine was completed on the Thermo Scientific UHPLC and LTQ Orbit rap Discovery equipped with an ESI ion source. A three-minute gradient method with a flow rate of 300 μL/min was developed on the UHPLC-HRMS using HPLC-grade water and acetonitrile. Ethyl ether was used to remove cacao fats and water was used to isolate theobromine. To obtain the precision of the theobromine extraction process, the recovery analysis was 86%.
... Natural cocoa contains approximately 35 mg/g theobromine, medium processed cocoa contains approximately 8 mg/g, and heavily processed cocoa only approximately 4 mg/g. 16 Unlike most other MX species, T. cacao contains more theobromine than caffeine. Cocoa beans are very rich in polyphenols such as catechins and proanthocyanidins, though fermentation, drying and roasting results in considerably lower concentrations in processed cocoa. ...
Article
In general, preparations of coffee, teas, and cocoa containing high levels of polyphenols, L-theanine and other bioactive compounds selectively enhance mood and cognition effects of caffeine. This review summarizes the bioactive components of commonly consumed natural caffeine sources (e.g. guayusa, mate and camellia teas, coffee and cocoa) and analyzes the psychopharmacology of constituent phytochemicals: methylxanthines, polyphenols, and L-theanine. Acute and chronic synergistic effects of these compounds on mood and cognition are compared and discussed. Specific sets of constituent compounds such as polyphenols, theobromine and L-theanine appear to enhance mood and cognition effects of caffeine and alleviate negative psychophysiological effects of caffeine. However, more research is needed to identify optimal combinations and ratios of caffeine and phytochemicals for enhancement of cognitive performance.
... Elevated TPC and TFC values observed following natron treatment could therefore, be explained by the fact that trace amounts of metals that might be present in the natron could form complexes with the substances in the mixture, thereby increasing the absorbance values obtained for TPC and TFC (Psotová et al., 2003).Transition metals are also believed to play a potential role as catalysts of oxidative processes by enhancing the formation of hydroxyl radicals and hydroperoxide decomposition during the Fenton reaction (Halliwell et al., 1997). Miller et al. (2008) also report that an alkaline treatment can compromise the content phenolic compounds and antioxidant properties of cocoa (Theobroma cacao). Alkaline pH was also found to have adverse effect on the antioxidant properties of both Rosemanirus officinalis, Thymus vulgaris and Origanum majorana (Gawlik-dziki and Świeca, 2007). ...
Research
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Guiera senegalensis is among the medicinal herbs traditionally used for the management of maternal conditions in Katsina State, Nigeria. In the course of its preparation, G. senegalensis is, in most cases, mixed with Ipomoea asarifolia and Euphorbia balsamifera. Small amount of natron is often added in order to enhance the palatability of the herbal preparation. In this study, we investigated the impact of these two phenomena on the antioxidant properties of G.senegalensis.Phenolic antioxidant contents were assessed using Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) calorimetric assays. Antioxidant activity on the other hand was evaluated using 2,2 ꞌ-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, Ferric Reducing Antioxidant Power (FRAP) and Total Antioxidant Capacity (TAC) assays. Herbal combination and natron addition were found to significantly (P <0.05) affect the antioxidant properties of G. senegalensis.High antioxidant properties were observed when G. senegalensis was extracted alone compared to when extracted in combination with either I. asarifolia or E. balsamifera or both. Although it increased the TPC and TFC values, natron addition was also found to be detrimental to the antioxidant activities of G. senegalensis.
... A total of 30 g fine particles of bagasse was poured in 500 mL KOH solution (10 %) and stirred for one night. Addition of KOH solution to bagasse particles facilitated the elimination of colorants, organic acids, lipids and proteins in the cellulosic structure of bagasse, and mostly important alkalized the surface of particles (27,28). The alkalized particles were then washed with sufficient water until pH 7 in the eluate solution was achieved. ...
Article
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Background: The implementation of a safety program is one of the most effective factors in increasing productivity. A look to safety from the perspective of efficiency can indicate necessary investment in safety for all, especially the managers of companies. Objectives: The aim of this study was to evaluate the effect of safety costs on some indicators of productivity and quality in industrial companies. Methods: This study was a retrospective analysis and was implemented in five steel companies in Ahvaz. The data relating to the safety costs such as staffing costs and total safety costs, and productivity and quality indicators were collected in five years. This information and data were collected according to statistics from documents and archives of safety, accounting, and production sectors of companies. Costs as well as numbers and figures of variables were expressed in the form of per capita and percentage to make the data comparable. Linear and generalized regression models and Wald Chi-Square test were used by the SPSS 22 software to determine the relationships between them. Results: Safety costs such as capita labor safety costs and capita total safety costs or percentage safety labor costs to labor costs, showed a significant positive effect on labor productivity, labor competitiveness, total factor productivity, quality index and production rates (in some cases, P = 0.001). Conclusions: The total safety cost and safety labor compensation generally, regardless of the nature and quality of the safety management system, can impact productivity, quality and quantity of production in addition to other factors of production. Surely if safety programs are targeted and codified, the effect of the investment will be doubled.
... Cacao, a tropical crop which grows best with humid climate and adequate rainfall, is a highly-valued crop among equatorial regions. (Miller et al., 2008). While the Philippines used to be a top producer of cacao, poor pests and disease management in the 1980s led to the fall of its cacao market (Hebbar, 2007;Ploetz, 2007). ...
Article
Pest control strategies for crop diseases highly depend on visual inspection to assess the severity of the infection, which usually lead to inconsistencies: either over or under assessment. These inconsistencies could be attributed to the limitations of humans to perceive small differences. A more precise disease assessment is needed for better pest management decision, which will result to a more efficient utilization and allocation of resources for farm inputs. This translates to a better income for cacao farmers. This paper introduces a mobile application named AuToDiDAC or Automated Tool for Disease Detection and Assessment for Cacao Black Pod Rot (BPR). AuToDiDAC automatically detects, separates, and assesses the infection level of BPR in cacao through image processing and machine learning techniques. It gives the farmers the capacity to objectively monitor and report the infection level of the BPR compared to the common visual rating for plant disease level of infection. Pixel-level accuracy test of the tool showed an average of 84% accuracy on an independent test set of ten cacao pod images.
... The regulation of nitric oxide (NO) production by the flavanols present in dark chocolate could explain its effects on insulin sensitivity. [10] Daily dark chocolate consumption of 20 grams per day helps to increase the sensitivity to insulin. This is important for blood glucose control. ...
... Comparing the contents of proanthocyanidins of dried cocoa beans after both processes, a higher level was revealed for the OF-F. A possible reason is a lower pH of the cotyledon, indicated by the lower pulp pH measured at the end of the OF-F, as polyphenols in cocoa powder have been described to remain stable at acidic pH but decompose at alkali pH (Miller et al. 2008). Furthermore, the influence of seasonal variation might have contributed to the different polyphenolic contents, as observed by Camu et al. (2008a) in Ghana. ...
Article
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Lab-scale systems modelling the spontaneous cocoa bean fermentation process are useful tools to research the influence of process parameters on the fermentation and the final bean quality. In this study in Honduras, a 1-kg lab-scale fermentation (LS-F) was compared to a 300-kg on-farm fermentation (OF-F) in a multiphasic approach, analysing microbial counts, microbial species diversity, physico-chemical parameters, and final dried bean quality. Yeast and total aerobic counts of up to 8 log CFU/g during the LS-F were comparable to the OF-F, while counts for lactic acid bacteria and acetic acid bacteria were up to 3 log CFU/g lower during the LS-F than during the OF-F. While species of the genera Hansenia, Saccharomyces, and Acetobacter dominated most of the fermentation processes, the genera dominating the drying phases were Pichia, Trichosporon, Pediococcus, and Acetobacter. Dried beans resulting from the LS-F, compared to the OF-F, were similar in contents of acetic acid, 6 times lower in lactic acid, up to 4 times higher in residual sugars, and 3–12 times higher in polyphenols. Dried beans processed at LS showed a similar flavour profile in terms of astringency, bitterness, acidity, and brown, fine, and cocoa flavours, but 2 units higher off-flavours than OF processed beans. With 81%, the share of well-fermented beans from the LS-F complied with industrial standards, whereas 7% over-fermented beans were above the threshold. Conclusively, the 5-day model fermentation and subsequent drying successfully mimicked the on-farm process, providing a high-throughput method to screen microbial strains to be used as starter cultures.
... Besides being highly appetizing, the scientific literature is also prolific in the description of cocoa virtues [4]. Cocoa beans are highly enriched in fat and polyphenols [5] including flavanols, which act as natural antioxidants with several described beneficial effects on human health [6][7][8]. Benefits attributed to the consumption of cocoa include reduction in blood pressure, anti-stress, anti-tumoral and anti-obesity properties, increase in cerebral blood flow, enhancement of cognitive performance, and reduction in the probability of stroke attacks [4,9,10]. On the other hand, little is known about the potential risks of excessive chocolate consumption to human health [11][12][13]. ...
Article
While the consumption of caffeine and cocoa has been associated to a variety of health benefits to humans, some authors have proposed that excessive caffeine intake may increase the frequency of epileptic seizures in humans and reduce the efficiency of antiepileptic drugs. Little is known, however, about the proconvulsant potential of the sustained, excessive intake of cocoa on hippocampal neural circuits. Using the mouse as experimental model, we examined the effects of chronic consumption of food enriched in cocoa-based dark chocolate on motor and mood-related behaviours as well as on the excitability properties of hippocampal neurons. Cocoa food enrichment did not affect body weights or mood-related behaviours but rather promoted general locomotion and improved motor coordination. However, ex vivo electrophysiological analysis revealed a significant enhancement in seizure-like population spike bursting at the neurogenic dentate gyrus, which was paralleled by a significant reduction in the levels of GABA-α1 receptors thus suggesting that an excessive dietary intake of cocoa-enriched food might alter some of the synaptic elements involved in epileptogenesis. These data invite for further multidisciplinary research aiming to elucidating the potential deleterious effects of the chocolate abuse on behaviour and brain hyperexcitability.
... A total of 30 g fine particles of bagasse was poured in 500 mL KOH solution (10 %) and stirred for one night. Addition of KOH solution to bagasse particles facilitated the elimination of colorants, organic acids, lipids and proteins in the cellulosic structure of bagasse, and mostly important alkalized the surface of particles (27,28). The alkalized particles were then washed with sufficient water until pH 7 in the eluate solution was achieved. ...
... Type B proanthocyanidins are formed from (+)catechin and (-)-epicatechin, with the oxidative coupling occurring between the C 4 of the heterocycle and the C 6 or C 8 positions of the adjacent unit to create oligomers and polymers. Individual procyanidins that have been identified in cocoa include the B 1 , B 2 , B 4 and B 5 dimers, the C 1 trimer and tetramers such as cinnamtannin A 1 (Figure 7.2; Haslam 1998), although longer chain polymers comprising seven or more monomer units seemingly predominate (Haslam 1998;Hammerstone et al. 1999;Gu et al. 2006;Miller et al. 2008). Some dimeric epicatechin glycosides as the 3-O-arabinoside and the 3-O-galactoside conjugates of (+)-epicatechin-(2␣→7,4␣→8)-(+)-epicatechin (Figure 7.2) have also been reported in T. cacao (Buckingham 1994). ...
... This result was mirrored by the findings of Dagdemir et al. (2004) and Ozdemir et al (2015). Depending on the impact of alkalization in cocoa production, the pH levels of cocoa powders vary between 6.50 and 7.61 (Miller et al. 2008). For this reason, the pH of samples with cocoa was higher than that of plain samples. ...
Article
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Citation: Arslaner A., Salik M.A., Özdemir S., Akköse A. (2019): Yogurt ice cream sweetened vith sucrose, stevia and honey: Some quality and thermal properties. Czech J. Food Sci., 37: 446-455. Abstract: This study investigated the effects of some sweeteners (sucrose, honey and stevia) on the quality and thermal properties of plain (P) and cocoa (C) yogurt ice cream. For this purpose, six different yogurt ice cream samples were prepared with sucrose (control: AP, AC), with honey (BP, BC) and with stevia (CP, CC). The highest values of protein, ash, fat, lactose ratios and lightness (L *) were measured in samples with stevia. The addition of honey increased the b * values. The addition of cocoa increased pH and viscosity, but decreased overrun ratios. Although the addition of stevia reduced the lactic acid bacteria (LAB) counts, in all samples the LAB count was above 6 log CFU/g during storage. Results of the thermal and melting analysis showed that the use of stevia had a positive effect on the ice cream stability by increasing the freezing and melting point peak temperatures (T f , T m), the enthalpy (ΔH f , ΔH m), and the initial ice crystal melting temperatures (T' m).
... The beans are then broken to separate the nib from its shell and subsequently sterilized. This is followed by alkalization process by an alkali solution of potassium or sodium carbonate at a temperature of 80-100 Celsius [30]. Subsequently, the alkalized product is roasted and ground to reduce the nibs to liquor or pressed to separate the fat content from the powder and eventually to produce cocoa powder and butter [31]. ...
Article
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Cocoa and its products are rich sources of polyphenols such as flavanols. These compounds exert antioxidant and anti-inflammatory activities, accountable for cocoa health-promoting effects. However, cocoa polyphenols are poorly absorbed in the intestine, and most of them cannot reach the systemic circulation in their natural forms. Instead, their secondary bioactive metabolites are bioavailable, enter the circulation, reach the target organs, and exhibit their activities. In fact, once reaching the intestine, cocoa polyphenols interact bidirectionally with the gut microbiota. These compounds can modulate the composition of the gut microbiota exerting prebiotic mechanisms. They enhance the growth of beneficial gut bacteria, such as Lactobacillus and Bifidobacterium, while reducing the number of pathogenic ones, such as Clostridium perfringens. On the other hand, bioactive cocoa metabolites can enhance gut health, displaying anti-inflammatory activities, positively affecting immunity, and reducing the risk of various diseases. This review aims to summarize the available knowledge of the bidirectional interaction between cocoa polyphenols and gut microbiota with their various health outcomes.
... improves the dispersibility of cocoa powder to be used, especially in beverages (Miller et al., 2008). However, alkalization is not applicable in this study. ...
Article
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There is an increase in cocoa utilisation as an alternative to espresso coffee due to its lower caffeine content (17% less) than coffee. The polyphenols, theobromine is a good source of antioxidant contributed to the flavor and aroma in cocoa products. Different fat content and grinding levels were evaluated in producing a concentrated cocoa drink with a close resemblance to espresso coffee. Concentrated cocoa drink made of cocoa bean with 20% fat, grind at level 50 showed better caffeine content (3.31 µg/mL), theobromine content (34.26 µg/mL), antioxidant capacity (1726.3 μM TE), and TPC (193.57 mg/mL GAE). Five different classes of volatile compounds were detected from fresh‐brewed concentrated cocoa drinks responsible for the unique aroma properties, including alcohols, aldehyde, ketones, esters, acids, and pyrazines. These findings are significant to the cocoa industries, where the concentrated cocoa drink may act as an alternative cocoa drink with improved nutritional content.
... Cocoa flavanols are present in good amounts in dark chocolate, with a content of catechin and epicatechin (estimated to be approximately 20 times higher than in tea [70]) that was reported to have some beneficial effects on glucose metabolism. Furthermore, a meta-analysis of 42 randomized controlled trials with acute or chronic consumption of chocolate or cocoa reported an improvement in insulin sensitivity associated with a decrease in serum insulin [71]. ...
Article
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Type 2 diabetes is an increasing health concern worldwide. Both genetic and environmental risk factors as improper dietary habits or physical inactivity are known to be crucial in the pathogenesis of type 2 diabetes. Polyphenols are a group of plant-derived compounds with anti-inflammatory and antioxidant properties that are associated with a low prevalence of metabolic conditions characterized by insulin resistance, including obesity, diabetes, and hypertension. Moreover, there is now full awareness that foods that are rich in phytochemicals and polyphenols could play an important role in preserving human cardiovascular health and substantial clinical evidence indicates that regular dietary consumption of such foods affects favorably carbohydrate metabolism. This review briefly summarizes the evidence relating dietary patterns rich in polyphenols with glucose metabolism and highlights the potential benefits of these compounds in the prevention of type 2 diabetes.
... Cocoa powder levels for flavanol monomers, procyanidin and methylxanthines (caffeine, theobromine) were measured by high-performance liquid chromatography (HPLC) as described previously [51,52]. Total levels of polyphenols were also assessed by a Folin-Ciocalteu reagent calorimetric assay as described previously [53]. The dose of flavanol monomers used in the present study is in line with previous studies, shown to be safe and effective in modifying human endothelial function in young healthy adults [33,34,54]. ...
Article
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Mental stress has been shown to induce cardiovascular events, likely due to its negative impact on vascular function. Flavanols, plant-derived polyphenolic compounds, improve endothelial function and blood pressure (BP) in humans, however their effects during stress are not known. This study examined the effects of acute intake of cocoa flavanols on stress-induced changes on vascular function. In a randomised, controlled, double-blind, cross-over intervention study, 30 healthy men ingested a cocoa flavanol beverage (high-flavanol: 150 mg vs. low-flavanol < 4 mg (−)-epicatechin) 1.5 h before an 8-min mental stress task). Forearm blood flow (FBF), BP, and cardiovascular activity were assessed pre- and post-intervention, both at rest and during stress. Endothelial function (brachial flow-mediated dilatation, FMD) and brachial BP were measured before the intervention and 30 and 90 min post-stress. FMD was impaired 30 min post-stress, yet high-flavanol cocoa attenuated this decline and remained significantly higher compared to low-flavanol cocoa at 90 min post-stress. High-flavanol cocoa increased FBF at rest and during stress. Stress-induced cardiovascular and BP responses were similar in both conditions. Flavanols are effective at counteracting mental stress-induced endothelial dysfunction and improving peripheral blood flow during stress. These findings suggest the use of flavanol-rich dietary strategies to protect vascular health during stress.
... Even though the processing with alkali in commercial cocoa powder manufacturing is known to reduce the phenolics substantially compared to unprocessed natural cocoa powder [59][60][61][62], there are some evidence that show about 40% of the natural level of flavanols is retained on average for lightly Dutched powders, and an average of 22% is retained in even moderately alkali processed cocoa powders [63]. Therefore, we thought to determine the TP, TF and the antioxidant activity of our cocoa powder as we attributed these beneficial effects of cocoa to cocoa polyphenols. ...
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BACKGROUND: Cocoa, one of the richest dietary sources of polyphenols has been studied for its health promoting effects, but how long-term consumption of cocoa affects age-associated health and lifespan is not well defined. OBJECTIVE: The objective of this study was to determine the effects of long-term cocoa consumption on age-associated health and lifespan in C. elegans METHODS: The standard E. coli OP50 diet of wild type C. elegans was supplemented with cocoa powder starting from L1 stage until they die. Body length and area were measured as indicators of worm nutrition. Age associated health was determined at different stages of life as day 4, day 8 and day 12 using worm locomotion, thermotolerance, cognition and mitochondrial function. In addition, lifespan was evaluated. RESULTS: Cocoa improved age-associated decline in neuromuscular function. Both mean and median lifespan were extended by cocoa supplementation. However, maximum lifespan was not affected. Cocoa showed beneficial effects on thermotolerance at all ages (more prominent effects at young (day 4) and middle (day 8) age. Further, consumption of cocoa improved age-related learning deficits, short-term memory loss and mitochondrial dysfunction. CONCLUSIONS: Long-term cocoa consumption seemed to improve age-associated health and extends lifespan in C. elegans
... The benefits of cocoa and cocoa products depend on polyphenol content. Cocoa flavanols can be found in dark chocolate, with a content estimated to be five times higher than that in milk chocolate [16]; the content of catechin and epicatechin is approximately 20 times higher than in tea. ...
Article
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Obesity remains a major public health problem due to its increasing prevalence. Natural products have become common as adjunct therapeutic agents for treating obesity and preventing metabolic diseases. Cocoa and its products are commonly consumed worldwide. Dark chocolate, a rich source of polyphenols, has received attention lately for its beneficial role in the management of obesity; however, conflicting results are still being reported. This scoping review aims to provide a comprehensive understanding of the existing literature on the relationship and effects of cocoa and dark chocolate intake among obese adults. We searched multiple databases for research investigating the consumption of cocoa and/or dark chocolate in managing obesity among adults. This review includes epidemiological and human studies that were published in English over the last 10 years. Our review of the current literature indicates that epidemiological and human trials with obese adults have shown inconsistent results, which may be due to the different populations of subjects, and different types of cocoa products and doses used for intervention. Studies among obese adults are mainly focusing on obese individuals with comorbidities, as such more studies are needed to elucidate the role of cocoa polyphenols in weight control and preventing the risk of chronic diseases among obese individuals without comorbidities as well as healthy individuals. Careful adjustment of confounding factors would be required. The effects of cocoa and dark chocolate intake on obese adults were discussed, and further research is warranted to identify the gaps.
... A similar dose of (−)-epicatechin could be achieved through diet by consuming foods rich in flavanols, particularly apples, black grapes, blackberries, cherries, raspberries, pears, pulses, green tea and red wine 62 . Total levels of polyphenols in the powders were assessed by a Folin-Ciocalteu reagent calorimetric assay as described previously 63 . Individual monomer levels and procyanidin levels as well as levels of methylxanthines, were confirmed by HPLC as described previously 64,65 . ...
Article
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Cocoa flavanols protect humans against vascular disease, as evidenced by improvements in peripheral endothelial function, likely through nitric oxide signalling. Emerging evidence also suggests that flavanol-rich diets protect against cognitive aging, but mechanisms remain elusive. In a randomized double-blind within-subject acute study in healthy young adults, we link these two lines of research by showing, for the first time, that flavanol intake leads to faster and greater brain oxygenation responses to hypercapnia, as well as higher performance only when cognitive demand is high. Individual difference analyses further show that participants who benefit from flavanols intake during hypercapnia are also those who do so in the cognitive challenge. These data support the hypothesis that similar vascular mechanisms underlie both the peripheral and cerebral effects of flavanols. They further show the importance of studies combining physiological and graded cognitive challenges in young adults to investigate the actions of dietary flavanols on brain function.
... The colour of the final product is important for its reception by a consumer. Thus, a dark colour suggests strong taste and aroma, and a lighter colour is associated with milder aroma (Miller et al. 2008). Darker products are alkalised, and their taste and aroma are fixed during the process. ...
Article
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Volatile aromatic substances are the main factors contributing to the acceptability of cocoa products. The beneficial effect of fat-free ingredients of cocoa beans on human health has been scientifically proven. This encourages the consumption of cocoa products as well as further research on improving their processing technology. The aim of this study was to analyse changes in the composition of volatile compounds and their impact on the sensory characteristics of an agglomerated cocoa powder mixture with modified composition for the raw material. The basic mixture was composed of 20% cocoa and 80% sucrose. Changes in mixture composition involved partial or total replacement of sucrose with maltodextrin or a mixture of glucose and fructose. Mixing and agglomeration were carried out in a fluid bed agglomerator. The analysis of volatile compounds was carried out using a gas chromatograph coupled with mass spectrometer, and 1,2-dichlorobenzene was used as an internal standard. The analysis showed the presence of over 70 various chemical compounds. Such volatile compounds as acetic acid, 2,3-butanediol, nonanal, and pentanoic acid, were found in almost all tested products. The highest content of acetic acid was determined in cocoa powder. In the case of the investigated cocoa beverages, the raw material composition and agglomeration affected their volatile compounds content. The analyses demonstrated a reduction in the content of volatile compounds caused by agglomeration.
... Cocoa powder which is used for non-confectionary products, e.g., beverages, is usually alkalized to improve solubility and sensory properties. However, by alkalization, flavan-3-ols are largely destroyed, thereby reducing total flavan-3-ol content up to 80%, depending on the extent of alkalization [14][15][16]. Moreover, alkalization of cocoa powder induces an epimerization of (−)-epicatechin to (−)-catechin, an atypical stereoisomer that is also generated by roasting of cocoa beans. ...
Article
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Flavan-3-ols are claimed to be responsible for the cardioprotective effects of cocoa. Alkalized cocoa powder (ALC), commonly used for many non-confectionary products, including beverages, provides less (+)-catechin, (−)-epicatechin, and procyanidins and more (−)-catechin than nonalkalized cocoa powder (NALC). This may affect the plasma appearance of monomeric flavan-3-ol stereoisomers after consumption of NALC vs. ALC. Within a randomized, crossover trial, 12 healthy nonsmokers ingested a milk-based cocoa beverage providing either NALC or ALC. Blood was collected before and within 6 h postconsumption. (+)-Catechin, (−)-catechin, and epicatechin were analyzed in plasma by HPLC as sum of free and glucuronidated metabolites. Pharmacokinetic parameters were obtained by a one-compartment model with nonlinear regression methods. For epicatechin in plasma, total area under the curve within 6 h postconsumption (AUC0–6h) and incremental AUC0–6h were additionally calculated by using the linear trapezoidal method. After consumption of NALC and ALC, (+)-catechin and (−)-catechin were mostly not detectable in plasma, in contrast to epicatechin. For epicatechin, total AUC0–6h was different between both treatments, but not incremental AUC0–6h. Most kinetic parameters were similar for both treatments, but they varied strongly between individuals. Thus, epicatechin is the main monomeric flavan-3-ol in plasma after cocoa consumption. Whether NALC should be preferred against ALC due to its higher (−)-epicatechin content remains unclear with regard to the results on incremental AUC0–6h. Future studies should investigate epicatechin metabolites in plasma for a period up to 24 h in a larger sample size, taking into account genetic polymorphisms in epicatechin metabolism and should consider all metabolites to understand inter-individual differences after cocoa intake.
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In septic condition, the skin normal flora Staphylococcal spp. may trigger local and sistemic skin infection. In this study antibacterial activity of cocoa ethanolic extract (CEE) against Staphylococcus aureus and Staphylococcus epidermidis infections was observed in vitro and in vivo. Ethanolic extract from unfermented cocoa beans was prepared as solution in the in vitro testing, while for in vivo testing the extract was prepared as cream. Agar well diffusion assay showed that CEE ranging from 7.8 mg/mL to 1000 mg/mL demonstrated inhibitory activity against growth of either S. aureus and S. epidermidis. Inhibitory activity of CEE was in concentration dependent manner, and was less potential than either cephalexin 4 x 10 -3 mg/mL or cefotaxime 8 x 10 -3 mg/mL. Linear regression of CEE concentration plotted against inhibition zone values ha dpredicted the minimum inhibitory concentrations (MIC) of CEE towards S. aureus and S. epidermidis were at 341.9 mg/mL and 359.7 mg/mL, respectively. Topical application of cream containing CEE at several concentrations (2%, 4%, and 8%) demonstrated healing properties towards incision wound infected with S. aureus and S. epidermidis cultures in rabbit-skin model. CEE cream promoted wound contraction and higher recovery rate than of base cream (negative control) but lower than mupirocin 2% cream. In S. aureus and S. epidermidis infected wound models, CEE cream 8% improved wound recovery to 72.7% and 86.1% from original rates of 23.5% and 34.7% (base cream application). Catechin and procyanidis are suggested playing roles in alleviation of wound inflammation and stimulation of extracellular matrix accumulation, thus accelerate the wound healing process. This study proposes utilization of cocoa bean as source of active ingredient for skin care products.
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Shigella dysenteriae is a gastrointestinal pathogen which shows resistance to antibiotics. A study has been conducted to investigate alternative antibacterial agents, due to the emerging resistance of S. dysenteriae to ciprofloxacin and other antibiotic classes. In this study, antibacterial properties of cocoa ethanolic extract (CEE) and its impact on growth and morphology of S. dysenteriae were evaluated. The effect of CEE on bacterial growth was assayed by using agar-well diffusion method and by observing morphological changes of bacterial cells through the use of scanning electron microscopy (SEM). Furthermore, CEE was also applied orally to mice infected with S. dysenteriae. The intestinal fluids was cultured in selective medium to evaluate growth of S. dysenteriae colonies. This study demonstrated that CEE at concentrations of 15.6 mg/mL inhibited S. dysenteriae growth, and at concentrations of 500 mg/mL and 1,000 mg/mL exhibited equal activity to 6.5 g/mL of ciprofloxacin. SEM showed that S. dysenteriae cells had formed filaments, indicating that CEE caused cellular stress to S. dysenteriae. In in vivo assay, CEE showed suppression of S. dysenteriae colony in the mice intestine. This research suggests that CEE could potentially be used as antibacterial agent againsts S. dysenteriae.
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Contamination with filamentous fungi during cocoa bean fermentation and drying reduces the quality of cocoa beans and poses a health risk for consumers due to the potential accumulation of mycotoxins. The aim of this study was to develop anti-fungal lactic acid bacteria (LAB)-yeast co-cultures by selecting anti-fungal strains best adapted to the cocoa bean fermentation process from 362 LAB and 384 yeast strains isolated from cocoa bean post-harvest processes. The applied multiphasic screening approach included anti-fungal activity tests in vitro and in vivo and assessment of the carbon metabolism and stress tolerance of the anti-fungal strains in a cocoa pulp simulation medium. The anti-fungal strains, Lactobacillus fermentum M017, Lb. fermentum 223, Hanseniaspora opuntiae H17, and Saccharomyces cerevisiae H290, were selected based on their high fungal growth inhibition capacity and their well-adapted metabolism. Up to seven filamentous fungal strains of the genera Aspergillus, Penicillium, and Gibberella were inhibited on average by 63 and 75% of the maximal inhibition zone by M017 and 223, respectively, and by 25 and 31% by the strains H17 and H290, respectively. Both Lb. fermentum strains converted the medium's glucose, fructose, and citric acid into 20.4–23.0 g/l of mannitol, 3.9–6.2 g/l acetic acid, and 8.6–10.3 g/l lactic acid, whereas the two yeast strains metabolized glucose and fructose to produce 7.4–18.4 g/l of ethanol. The Lb. fermentum strains were further characterized as particularly tolerant towards ethanol, acetic acid, and heat stress and both yeast strains tolerated high amounts of ethanol and lactic acid in the medium. Finally, the anti-fungal in vivo assays revealed that the two Lb. fermentum strains completely inhibited growth of the citrinin-producing strain, P. citrinum S005, and the potentially fumonisin-producing strain, G. moniliformis S003, on the surface of cocoa beans. Furthermore, growth of the aflatoxin-producer A. flavus S075 was inhibited after 10-14 days by all four selected anti-fungal strains, i.e. Lb. fermentum M017, Lb. fermentum 223, H. opuntiae H17, and Sacc. cerevisiae H290, at 51–95% when applied as single cultures and at 100% when the strains were combined into four co-cultures, each composed of a Lb. fermentum and one of the two yeast strains. As a conclusion, these four LAB-yeast co-cultures are recommended for future applications to limit the growth of filamentous fungi and the concomitant mycotoxin production during the fermentation of cocoa beans.
Article
Cheshire, Britain, and the towns of Widnes and St. Helens, where many of the world's first chemical factories and towns were created in the nineteenth century, is an especially important place to study historical responses to industrial pollution and its social costs. This paper, based on newly recovered archival sources about the Victorian alkali industry, explores the role of visual imagery, particularly drawings and lantern slides, in materializing the connection between labor in chemical trades, the disposal of waste, and poor health outcomes for diverse communities in the late nineteenth century. The paper will focus on the writer Robert Sherard's article “White Slaves of England” (1897), a work that, more than many of its time, drew national attention to the plight of nineteenth-century chemical workers by pictorializing the ways that work in heavy chemical industries, many of them involving waste and its disposal, affected individual workers and their lives. The paper concludes with critical reflections on the current state of scholarship on images, waste, and labor, areas for more needed work, and paths forward.
Chapter
Cocoa (Theobroma cacao), from the health viewpoint, is an important commodity in the world due to the high contents of polyphenols which are its main antioxidant-active fraction, particularly flavonoids. Polyphenols also confer astringent and bitter taste, also contributing to the fruity and green flavors of cocoa liquors. There are three main groups of flavonoids in cocoa: catechins (flavan-3-ols), anthocyanins, and proanthocyanidins. Other minor polyphenols also present in cocoa include flavones, phenolic acids, clovamide, dideoxyclovamide, resveratrol, and piceid. The content and composition of polyphenols in cocoa and its derived products vary strongly depending on genotype, cultivar, origin, agricultural practices, post-harvest practices, and bean processing. Fermentation of cocoa beans is considered to be one of the major steps that affect polyphenol content. Anthocyanins usually disappear rapidly during this process being hydrolyzed to anthocyanidins, which polymerize along with simple catechins to form complex tannins. During the drying process, the oxidation reactions that started in fermentation continue, the phenol degradation increasing with temperature. Alkalinization of the nibs, liquor, or powder also originates considerable losses of cocoa polyphenols. Therefore, given the functional effects of the polyphenols above mentioned, it is vital analyzing the total phenolic content and the composition and quantity of individual polyphenols in both cocoa beans and cocoa-derived products, being chocolate the most representative of these latter. The quantitative determination of total polyphenols in cocoa and chocolate usually includes the assessment of the total phenol (TPC) or flavonoid (TFC) contents with Folin-Ciocalteu reagent, the measurement of the flavan-3-ols content by the vanillin and pdimethylaminocinnamaldehyde (p-DAC) assays or the determination of proanthocyanidins by the butanol/HCl assay. The analysis of the polyphenols profile has usually been accomplished by liquid chromatography (HPLC) with different detectors. Nevertheless, nowadays liquid chromatography-mass spectrometry (HPLC-MS) or liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) are among the most widely used techniques for both structural characterization and quantification of both low and high molecular weight polyphenols in cocoa. In the last years, there have been significant improvements in HPLC technique with the development of ultraperformance liquid chromatography (UPLC) and today, the number of studies focusing on the analysis of polyphenols by using UPLC coupled to MS (UPLC-MS/MS) is increasing. In this chapter, the different current available methodologies for analysis, quantification, isolation, purification, and structure elucidation of polyphenols in cocoa and cocoaderived products are reviewed. Taking into account that there is evidence that demonstrates that the bioactivity of flavanols is significantly influenced by their stereochemical configuration, enantioselective methods have also been included such as chiral capillary electrophoresis (CCE), micellar electrokinetic chromatography (MEKC) or UPLC.
Article
Many factors can influence antioxidative and antimicrobial characteristics of plant materials. The quality of cocoa as functional food ingredient is influenced through its processing. The main aim of this study was to test if there is difference in polyphenol content, antioxidant capacity, and antimicrobial activity between nonalkalized and alkalized cocoa powders. To estimate polyphenol and flavonoid content in cocoa samples the spectrophotometric microassays were used. Flavan-3ols were determined with reversed-phase high-performance liquid chromatography (RP-HPLC). Antimicrobial activity against 3 Gram positive bacteria, 4 Gram negative bacteria and 1 strain of yeast was determined using broth microdilution method. Total polyphenol content was 1.8 times lower in alkalized cocoa samples than in natural ones. Epicatechin/catechin ratio was changed due to the process of alkalization in favor of catechin (2.21 in natural and 1.45 in alkalized cocoa powders). Combined results of 3 antioxidative tests (DPPH, FRAP, ABTS) were used for calculation of RACI (Relative Antioxidant Capacity Index) and GAS (Global Antioxidant Score) values that were consistently higher in natural than in alkalized cocoa extracts. Obtained results have shown significant correlations between these values and phenolic content (0.929 ࣘ r ࣘ 0.957, P < 0.01). Antimicrobial activity varied from 5.0 to 25.0 mg/ml (MICs), while Candida albicans was the most sensitive tested microorganism. Cocoa powders subjected to alkalization had significantly reduced content of total and specific phenolic compounds and reduced antioxidant capacity (P < 0.05), but their antimicrobial activity was equal for Gram-positive bacteria or even significantly enhanced for Gram-negative bacteria. Practical Application: In this article, phenol content, antioxidant, and antimicrobial activity of alkalized and nonalkalized cocoa powders were described. Since the cocoa powder is very often the object of alkalization, the results here collected demonstrated epimerization flavan-3ols, reduction of phenol content, and antioxidant activity but equal or even enhanced antimicrobial activity of alkalized cocoa powders. Considering antioxidant and antimicrobial properties of analyzed cocoa powders, there are clear opportunities for the development of new cocoa-based functional foods.
Article
Cocoa and chocolate are widely consumed by humans, and habitual intake is associated with benefits to cardiovascular health, which has been attributed to its polyphenolic content. Classically, in the processing of cacao beans, a final brown color has been preferred over the natural red-violet hues present in raw beans as a marker of proper processing and the development of the characteristic chocolate aroma and flavors. Recently, the industry has shown a renewed interest in the purple-red hues of cacao since the introduction of ruby chocolate to the market. Here, we present a processing method to preserve the composition of flavan-3-ols and procyanidins and to retain pink-red hues in powders produced from unfermented cocoa beans, in which polyphenol-degrading enzymes were first inactivated at 95 °C followed by fast soaking in 1.5 M citric acid and immediate dehydration and grinding to obtain powders with nearly 150 mg/g flavan-3-ols and procyanidins and stable pink-red hues according to CIE L*a*b* color measurements. These procyanidin-rich cacao powders could be added to chocolate products to reach the desired health properties of eating polyphenol-rich chocolates in the new context of the preferred pink shades of the so-called fourth chocolate.
Article
Alkalization modifies the color and flavor of the cocoa products. The aim of the present survey was to determine how different types and dosage of alkaline relate to the color quality, total polyphenol amount and alkylpyrazine content of cocoa powder. Cameroon cacao beans were used to produce cocoa nibs. The nibs were alkalized with the solutions of NaOH, K2CO3, and NH4HCO3 at their different concentrations and combinations. The browning index (OD460/OD525) and alkylpyrazine content were changed significantly (p ≤ 0.01) with changing the type and the concentration of the alkali solution. The browning index, moisture, ash, and acid-insoluble ash content increased as the concentration of the alkali increased. In general, the not-alkaline products had more polyphenol and ratio of tetramethylpyrazine to trimethylpyrazine than the alkalized ones. Besides, the polyphenol and alkylpyrazine amounts decreased as the concentration of the alkali increased (p ≤ 0.01). At the same concentration, alkalization with a NaOH solution produced a higher polyphenol and alkylpyrazine content, but lower OD460/OD525 value than that with a K2CO3 solution. The samples with a high concentration of alkaline solution had the lowest ratio of monomer anthocyanins to yellow and brown polymers content (F1/F3) value.
Article
Four cocoa powder varieties processed in different European countries (Germany, Poland, Romania and Bulgaria) were subjected to physicochemical, phytochemical and microbiological analysis. The cocoa powders were extensively characterized by recording their pH and titratable acidity, respectively, the polyphenols and also the methylxantine derivatives content (theobromine and caffeine). The cocoa powders pH ranged between 5.37 and 8.23, while the titratable acidity was 3.2–4.3 miliequivalent (100 g)−1 of cocoa powder. Their total polyphenols content ranged between 0.986 ÷ 2.003 g GAE/(100 g)−1. The methylxanthine derivatives (theobromine and caffeine) were analyzed by the HPLC method and ranges of 0.992–1.174% for theobromine and 0.096–0.369% for caffeine were obtained. Thermal analysis (TG–DTA) combined with mass spectrometry (MS) elucidated the decomposition processes and the volatile substances (CO, CO2, H2O, NO, theobromine, caffeine). The thermal analysis revealed transformations in the cocoa powders composition: drying and water loss; decomposition of pectic polysaccharides; lipids, amino acids and proteins, crystalline phase transformations and carbonizations. The microbiological analysis tested the degree of preservation of the cocoa powders across time, specifically immediately after unwrapping and after 14 days.
Article
Bone loss resulting in increased risk for osteoporosis is a major health issue worldwide. Chocolate is a rich source of antioxidant and antiinflammatory flavonoids and dietary minerals with the potential to benefit bone health. However, other chocolate constituents such as cocoa butter, sugar, and methylxanthines may be detrimental to bone. Human studies investigating the role of chocolate consumption on serum bone markers and bone mineral density (BMD)have been inconsistent. A contributing factor is likely the different composition and thereby the nutrient and bioactive content among chocolate types. White and milk chocolate are high in sugar and low in flavonoids and most minerals. Dark chocolate (45–85% cocoa solids)is high in flavonoids, most minerals, and low in sugar with ≥70% cocoa solids resulting in higher fat and methylxanthine content. The aim of this review was to examine the relationship between chocolate consumption and its constiuents, including flavonoid content, on bone health and osteoporosis risk. Studies showed postmenopausal women had no bone effects at moderate chocolate intakes, whereas adolescents consuming chocolate had greater longitudinal bone growth. Based on flavonoid and mineral content, unsweetened cocoa powder appeared to be the best option followed by dark chocolate with higher cocoa content in terms of supporting and preserving bone health. Determining dietary recommendations for chocolate consumption relative to bone health is important because of the growing popularity of chocolate, particularly dark chocolate, and an expected increase in consumption owing to suggestions of health benefits against various degenerative diseases.
Article
Although cocoa powder alkalization (Dutching) is a widely used industrial process to improve taste, dispersibility, and coloring of the final product, nevertheless knowledge about the compounds causing a change in coloring is fragmentary. By means of alkaline model reactions starting from the major cocoa polyphenol monomers, (+)-catechin or (?)-epicatechin, eight chromophores were derived from the first rearrangement product catechinic acid. LC-MS/MS analysis, one- and two dimensional-NMR, and electron paramagnetic resonance (EPR) spectroscopy led to the unequivocal identification of 6′-hydroxycatechinic acids (1a, 2a) and their radical states (1b, 2b), which were highlighted as main red chromophores. Six new dehydrocatechinic acid dimers (dehydrocatechinic acid-C-6′B/C-8D-(2R,3S)-catechin (3), dehydrocatechinic acid-C-6′B/C-6D-(2R,3S)-catechin (4, 5), dehydrocatechinic acid-C-6′B/C-8D-(2R,3R)-epicatechin (6), and dehydrocatechinic acid-C-6′B/C-6D-(2R,3R)-epicatechin (7, 8)) were also characterized as chromophores. 1-8 as well as their precursors were detected and quantified in alkalized cocoa powders via LC-MS/MS. With the increasing grade of alkalization, a decrease in catechin and epicatechin together with an increase in catechinic acid was observed. Compounds 1b, 2b, and 3-8 also showed a decrease in concentration by Dutching, which correlates to the accumulation of/to higher ordered chromophore oligomers and underlined the increase of the high molecular weight fraction. These findings give a first insight into the formation of structures causing the red coloring of cocoa, which offers the opportunity to optimize the alkalization process toward a better color design of cocoa powders.
Conference Paper
Several studies have been reported on the potential health benefits of cocoa polyphenols. However, drying has an inhibitory effect on the substantial recovery of cocoa polyphenols. This is majorly because of the high degradation of polyphenol compounds as well as the enhanced activity of polyphenol oxidases; a precursor for browning of polyphenols during drying. Pre-treatment technique such as water blanching (70°, 80° and 90°C for 5 min, 10 min and 15 min exposure times respectively) can inactivate the polyphenol oxidases enzyme and promote high percent of the polyphenol recovery in dried cocoa bean. The results for dried fresh cocoa beans showed an optimal level of polyphenol recovery (119 mg GAE/g) when blanched at 90°C for 5 minutes duration. The antioxidant activity was also observed using 2.2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay.
Article
Alkalization is a crucial process during cocoa processing to reduce its bitterness, improve solubility and develop color. Alkalization can be performed out at several points of the process (nib or cake), with different agents and at various intensities. All these variables may affect cocoa properties, but also physico-chemical and sensory properties of derived products (i.e. cakes). This work aims to evaluate the impact of alkalization type (nib vs. cake), alkalizing agent (K2CO3, NaHCO3 and KOH) and process intensity (mild and strong) on the physico-chemical and sensory properties of sponge cakes. For this aim, 8 different alkalized powders were industrially produced and used in the preparation of sponge cakes. Alkalizing conditions significantly affected cocoa properties (pH, color, sensory properties) and those of the corresponding cakes (cake doughs color and rheology, as well as baked cake color and texture). In general, doughs prepared with cocoas alkalized under strong conditions were a 55 % darker and a 15 % less elastic. After baking, the corresponding cakes were a 17 % darker (L*) and a 12 % harder in texture. Despite these differences, all the cakes were equally rated by consumers in sensory terms demonstrating that for this application, alkalization variables do not condition consumer acceptability.
Chapter
Of all confections, chocolate arguably has the longest history, having been already cultivated thousands of years ago in the reign of the Olmec. After Spanish explorers brought cocoa beans back to Europe, its usage slowly expanded. Used initially to create a drink, chocolate gradually developed into the smooth, creamy product we know today as a result of a series of technological advances. The history of chocolate cultivation and development has been the subject of numerous treatises (see, for example, Coe and Coe 2007).
Chapter
The raw materials used for chocolate production provide a source of proteins, carbohydrates, fats, minerals, and vitamins, which are essential for growth and development. Dark chocolate is also rich in polyphenolic compounds, originating from dark solids of cocoa beans. Milk chocolate contains less cocoa bean solids and thus less polyphenolic compounds comparing to dark chocolate. On the other hand, white chocolate contains only cocoa butter and thus lack bioactive components that have a positive impact on human health. Cocoa bean contains several minerals, some of which are found in high amounts in processed chocolate. The amount of retained minerals depends on the content of cocoa bean solids in chocolate. Accordingly, dark chocolate typically has a higher amount of minerals than milk or white chocolate. It is also known that unprocessed cocoa bean presents a good source of dietary fiber, mostly insoluble fiber, which is significantly reduced when removing the cocoa husk. Dark chocolate does not contribute significantly to dietary fiber intake, but, however, contains a higher amount of dietary fiber compared to milk chocolate. This research examined and compared the content of total polyphenols, minerals (potassium, calcium, magnesium, iron, zinc, copper, manganese), total dietary fiber and soluble dietary fiber in in different chocolate products collected from the market: white chocolate (25% of cocoa solids - cocoa butter), milk chocolate (25% of cocoa solids), baking chocolate containing 44% of cocoa solids, and dark chocolates containing 58%, 75%, 88%, and 100% of cocoa solids.
Article
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Background: Small, short-term, intervention studies indicate that cocoa-containing foods improve endothelial function and reduce blood pressure. We studied whether habitual cocoa intake was cross-sectionally related to blood pressure and prospectively related with cardiovascular mortality.Methods: Data used were of 470 elderly men participating in the Zutphen Elderly Study and free of chronic diseases at baseline. Blood pressure was measured at baseline and 5 years later, and causes of death were ascertained during 15 years of follow-up. Habitual food consumption was assessed by the cross-check dietary history method in 1985, 1990, and 1995. Cocoa intake was estimated from the consumption of cocoa-containing foods.Results: One third of the men did not use cocoa at baseline. The median cocoa intake among users was 2.11 g/d. After adjustment, the mean systolic blood pressure in the highest tertile of cocoa intake was 3.7 mm Hg lower (95% confidence interval [CI], −7.1 to −0.3 mm Hg; P = .03 for trend) and the mean diastolic blood pressure was 2.1 mm Hg lower (95% CI, −4.0 to −0.2 mm Hg; P = .03 for trend) compared with the lowest tertile. During follow-up, 314 men died, 152 of cardiovascular diseases. Compared with the lowest tertile of cocoa intake, the adjusted relative risk for men in the highest tertile was 0.50 (95% CI, 0.32-0.78; P = .004 for trend) for cardiovascular mortality and 0.53 (95% CI, 0.39-0.72; P < .001) for all-cause mortality.Conclusion: In a cohort of elderly men, cocoa intake is inversely associated with blood pressure and 15-year cardiovascular and all-cause mortality.
Article
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Monomeric and oligomeric procyanidins present in cocoa liquors and chocolates were separated and quantified in four different laboratories using a normal-phase high-performance liquid chromatography (HPLC) method with fluorescence detection. Procyanidin standards through decamers were obtained by extraction from cocoa beans, enrichment by Sephadex LH-20 gel permeation chromatography, and final purification by preparative normal-phase HPLC. The purity of each oligomeric fraction was assessed using HPLC coupled to mass spectrometry. A composite standard was then prepared, and calibration curves were generated for each oligomeric class using a quadratic fit of area sum versus concentration. Results obtained by each of the laboratories were in close agreement, which suggests this method is reliable and reproducible for quantification of procyanidins. Furthermore, the procyanidin content of the samples was correlated to the antioxidant capacity measured using the ORAC assay as an indicator for potential biological activity. Keywords: HPLC; procyanidins; cocoa; chocolate; quantification; antioxidant
Article
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Polyphenols have become an intense focus of research interest because of their perceived health-beneficial effects, such as anti-carcinogenic, anti-atherogenic, anti-inflammatory, anti-microbial, etc. Polyphenols in green and black tea, grape seeds, grapes and (red) wine have raised much attention but chocolate has not been investigated intensively up to now. This review is concerned with polyphenols in Theobroma cacao, the change in composition and quantity during fermentation, drying, and the manufacture of chocolate, as well as with analytical methods for isolation, characterisation and quantification. Cocoa beans are rich in polyphenols in particular catechins and proanthocyanidins. However, a sharp decrease in quantity occurs during fermentation and drying of cocoa beans and further retention has been reported during roasting. Characterisation and in particular quantification of polyphenols in chocolate has only been developed relatively recently. This work reviews further on the literature on the available methodology for analysis, quantification, isolation, purification, and structure elucidation of polyphenols in cocoa components and other commodities. Concerning the analytical methods main emphasis is put on HPLC as it is usually the method of choice due to its high resolution, high efficiency, high reproducibility and relatively short analysis time without restriction on sample volatility. Moreover, HPLC can be coupled to a variety of detectors such as UV–Vis, photodiode array (PDA), fluorescence, electrochemical (ECD), and mass spectrometry (MS). However, TLC as a screening method and capillary electrophoresis (CE) as a promising tool is taken into consideration as well. The characterisation and quantification of the polyphenol composition is amongst the first steps to be done to evaluate a putative contribution of chocolate to human health.
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Epidemiologic studies have shown inverse associations between dietary polyphenols and mortality from coronary heart disease. However, the basis for this protective association is uncertain. Food polyphenols reportedly have antioxidant properties and decrease platelet function in vitro. This study sought to evaluate whether consumption of a polyphenol-rich cocoa beverage modulates human platelet activation and primary hemostasis. Peripheral blood was obtained from 30 healthy subjects before and 2 and 6 h after ingestion of a cocoa beverage (n = 10), a caffeine-containing control beverage (n = 10), or water (n = 10). Platelet activation was measured in terms of expression of activation-dependent platelet antigens and platelet microparticle formation by using fluorescent-labeled monoclonal antibodies and flow cytometry. Primary platelet-related hemostasis was measured with a platelet function analyzer. Ex vivo epinephrine- or ADP-stimulated expression of the fibrinogen-binding conformation of glycoprotein IIb-IIIa was lower 2 and 6 h after consumption of cocoa than before consumption. Cocoa consumption also decreased ADP-stimulated P-selectin expression. In contrast, epinephrine-induced platelet glycoprotein IIb-IIIa expression increased after consumption of the caffeine-containing beverage but not after water consumption. Platelet microparticle formation decreased 2 and 6 h after cocoa consumption but increased after caffeine and water consumption. Primary hemostasis in response to epinephrine in vitro was inhibited 6 h after cocoa consumption. The caffeine-containing beverage inhibited ADP-induced primary hemostasis 2 and 6 h after consumption. Cocoa consumption suppressed ADP- or epinephrine-stimulated platelet activation and platelet microparticle formation. Cocoa consumption had an aspirin-like effect on primary hemostasis.
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Epidemiologic studies have linked flavonoid-rich foods with a reduced risk of cardiovascular mortality. Some cocoas are flavonoid-rich and contain the monomeric flavanols (-)-epicatechin and (+)-catechin and oligomeric procyanidins formed from these monomeric units. Both the monomers and the oligomers have shown potential in favorably influencing cardiovascular health in in vitro and preliminary clinical studies. Although previous investigations have shown increasing concentrations of (-)-epicatechin in human plasma after cocoa consumption, no information is available in the published literature regarding the presence of procyanidins in human plasma. This study sought to determine whether procyanidins can be detected and quantified in human plasma after acute consumption of a flavanol-rich cocoa. Peripheral blood was obtained from 5 healthy adult subjects before (baseline, 0 h) and 0.5, 2, and 6 h after consumption of 0.375 g cocoa/kg body wt as a beverage. Plasma samples were analyzed for monomers and procyanidins with the use of reversed-phase HPLC with coulometric electrochemical array detection and liquid chromatography-tandem mass spectrometry. Procyanidin dimer, (-)-epicatechin, and (+)-catechin were detected in the plasma of human subjects as early as 0.5 h (16 +/- 5 nmol/L, 2.61 +/- 0.46 micro mol/L, and 0.13 +/- 0.03 micro mol/L, respectively) after acute cocoa consumption and reached maximal concentrations by 2 h (41 +/- 4 nmol/L, 5.92 +/- 0.60 micro mol/L, and 0.16 +/- 0.03 micro mol/L, respectively). Dimeric procyanidins can be detected in human plasma as early as 30 min after the consumption of a flavanol-rich food such as cocoa.
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The effects of chocolate on cardiovascular health are still a matter of debate. Chocolate may adversely affect cardiovascular risk because of its effects on glucose, lipids, and body weight or potentially favour cardiovascular health through antioxidative effects of chocolate ingredients, such as flavonoids (present in dark but not white chocolate). Endothelial dysfunction and platelet activation are cornerstones in the pathogenesis of atherothrombosis, leading to vasoconstriction, thrombus formation, and inflammation. Smoking is a major cardiovascular risk factor. The mechanisms promoting atherothrombosis in smokers primarily include increased oxidative stress that enhances proatherogenic processes such as low density lipoprotein oxidation and inactivation of endothelium derived nitric oxide. Platelets contribute both to acute coronary syndromes and to the progression of atherothrombosis. Both active and passive cigarette smoking has consistently been shown to induce endothelial dysfunction. Therefore, smokers serve as an ideal model to study the beneficial vascular effects of antioxidant strategies such as dark chocolate.1 The goal of the present study was to investigate whether the beneficial antioxidant effect of polyphenol-rich dark chocolate can induce an improvement of endothelial and platelet function in healthy volunteers with known endothelial dysfunction and platelet hyperreactivity. Twenty five male smokers were enrolled in the study after giving written informed consent. Women were excluded for known sex hormone induced differences in vascular tone and reactivity. All study participants did not take any medication, including vitamins or dietary supplements. The local institutional ethical review board approved the protocol. To assess the effect of dark …
Article
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Small, short-term, intervention studies indicate that cocoa-containing foods improve endothelial function and reduce blood pressure. We studied whether habitual cocoa intake was cross-sectionally related to blood pressure and prospectively related with cardiovascular mortality. Data used were of 470 elderly men participating in the Zutphen Elderly Study and free of chronic diseases at baseline. Blood pressure was measured at baseline and 5 years later, and causes of death were ascertained during 15 years of follow-up. Habitual food consumption was assessed by the cross-check dietary history method in 1985, 1990, and 1995. Cocoa intake was estimated from the consumption of cocoa-containing foods. One third of the men did not use cocoa at baseline. The median cocoa intake among users was 2.11 g/d. After adjustment, the mean systolic blood pressure in the highest tertile of cocoa intake was 3.7 mm Hg lower (95% confidence interval [CI], -7.1 to -0.3 mm Hg; P = .03 for trend) and the mean diastolic blood pressure was 2.1 mm Hg lower (95% CI, -4.0 to -0.2 mm Hg; P = .03 for trend) compared with the lowest tertile. During follow-up, 314 men died, 152 of cardiovascular diseases. Compared with the lowest tertile of cocoa intake, the adjusted relative risk for men in the highest tertile was 0.50 (95% CI, 0.32-0.78; P = .004 for trend) for cardiovascular mortality and 0.53 (95% CI, 0.39-0.72; P < .001) for all-cause mortality. In a cohort of elderly men, cocoa intake is inversely associated with blood pressure and 15-year cardiovascular and all-cause mortality.
Article
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Proanthocyanidins (PAs) have been shown to have potential health benefits. However, no data exist concerning their dietary intake. Therefore, PAs in common and infant foods from the U.S. were analyzed. On the bases of our data and those from the USDA's Continuing Survey of Food Intakes by Individuals (CSFII) of 1994-1996, the mean daily intake of PAs in the U.S. population (>2 y old) was estimated to be 57.7 mg/person. Monomers, dimers, trimers, and those above trimers contribute 7.1, 11.2, 7.8, and 73.9% of total PAs, respectively. The major sources of PAs in the American diet are apples (32.0%), followed by chocolate (17.9%) and grapes (17.8%). The 2- to 5-y-old age group (68.2 mg/person) and men >60 y old (70.8 mg/person) consume more PAs daily than other groups because they consume more fruit. The daily intake of PAs for 4- to 6-mo-old and 6- to 10-mo-old infants was estimated to be 1.3 mg and 26.9 mg, respectively, based on the recommendations of the American Academy of Pediatrics. This study supports the concept that PAs account for a major fraction of the total flavonoids ingested in Western diets.
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Dietary flavonoids may have beneficial cardiovascular effects in human populations, but epidemiologic study results have not been conclusive. We used flavonoid food composition data from 3 recently available US Department of Agriculture databases to improve estimates of dietary flavonoid intake and to evaluate the association between flavonoid intake and cardiovascular disease (CVD) mortality. Study participants were 34 489 postmenopausal women in the Iowa Women's Health Study who were free of CVD and had complete food-frequency questionnaire information at baseline. Intakes of total flavonoids and 7 subclasses were categorized into quintiles, and food sources were grouped into frequency categories. Proportional hazards rate ratios (RR) were computed for CVD, coronary heart disease (CHD), stroke, and total mortality after 16 y of follow-up. After multivariate adjustment, significant inverse associations were observed between anthocyanidins and CHD, CVD, and total mortality [RR (95% CI) for any versus no intake: 0.88 (0.78, 0.99), 0.91 (0.83, 0.99), and 0.90 (0.86, 0.95)]; between flavanones and CHD [RR for highest quintile versus lowest: 0.78 (0.65, 0.94)]; and between flavones and total mortality [RR for highest quintile versus lowest: 0.88 (0.82, 0.96)]. No association was found between flavonoid intake and stroke mortality. Individual flavonoid-rich foods associated with significant mortality reduction included bran (added to foods; associated with stroke and CVD); apples or pears or both and red wine (associated with CHD and CVD); grapefruit (associated with CHD); strawberries (associated with CVD); and chocolate (associated with CVD). Dietary intakes of flavanones, anthocyanidins, and certain foods rich in flavonoids were associated with reduced risk of death due to CHD, CVD, and all causes.
Article
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Regular intake of cocoa-containing foods is linked to lower cardiovascular mortality in observational studies. Short-term interventions of at most 2 weeks indicate that high doses of cocoa can improve endothelial function and reduce blood pressure (BP) due to the action of the cocoa polyphenols, but the clinical effect of low habitual cocoa intake on BP and the underlying BP-lowering mechanisms are unclear. To determine effects of low doses of polyphenol-rich dark chocolate on BP. Randomized, controlled, investigator-blinded, parallel-group trial involving 44 adults aged 56 through 73 years (24 women, 20 men) with untreated upper-range prehypertension or stage 1 hypertension without concomitant risk factors. The trial was conducted at a primary care clinic in Germany between January 2005 and December 2006. Participants were randomly assigned to receive for 18 weeks either 6.3 g (30 kcal) per day of dark chocolate containing 30 mg of polyphenols or matching polyphenol-free white chocolate. Primary outcome measure was the change in BP after 18 weeks. Secondary outcome measures were changes in plasma markers of vasodilative nitric oxide (S-nitrosoglutathione) and oxidative stress (8-isoprostane), and bioavailability of cocoa polyphenols. From baseline to 18 weeks, dark chocolate intake reduced mean (SD) systolic BP by -2.9 (1.6) mm Hg (P < .001) and diastolic BP by -1.9 (1.0) mm Hg (P < .001) without changes in body weight, plasma levels of lipids, glucose, and 8-isoprostane. Hypertension prevalence declined from 86% to 68%. The BP decrease was accompanied by a sustained increase of S-nitrosoglutathione by 0.23 (0.12) nmol/L (P < .001), and a dark chocolate dose resulted in the appearance of cocoa phenols in plasma. White chocolate intake caused no changes in BP or plasma biomarkers. Data in this relatively small sample of otherwise healthy individuals with above-optimal BP indicate that inclusion of small amounts of polyphenol-rich dark chocolate as part of a usual diet efficiently reduced BP and improved formation of vasodilative nitric oxide. clinicaltrials.gov Identifier: NCT00421499.
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Die im internationalen Sprachgebrauch verwendeten Worte „Kakao und Schokolade“ leiten sich aus der Aztekensprache ab. (H. Fincke 1932, W. T. Clarke 1953). „Kakao“ entstammt der aztekischen Bezeichnung für Kakaokern „kakauatl“, Schokolade aus den Bezeichnungen „xococ“ -sauer, herbwürzig- „atl“ -wasser-, zusammengesetzt zu „xocoatl“.
Article
Three polyphenols of chocolate were separated by chemical fractionation and paper chromatography after different steps in the manufacturing process. These polyphenols were characterized by color tests and by ultraviolet and infrared spectra. One was identified as (-)-epicatechin; the other two are apparently similar compounds. Roasting diminished the concentration of (-)-epicatechin, and alkalizing or conching caused stereochemical changes in its structure. The other two compounds also underwent stereochemical changes during roasting; no further change occurred with alkalization, but conching reversed the change caused by roasting.
Article
An improved method of oxygen radical absorbance capacity (ORAC) assay has been developed and validated using fluorescein (3',6'-dihydroxyspiro[isobenzofuran-1[3H],9'[9H]-xanthen]-3-one) as the fluorescent probe. Our results demonstrate that fluorescein (FL) is superior to B-phycoerythrin. The oxidized FL products induced by peroxyl radical were identified by LC/MS, and the reaction mechanism was determined to follow a classic hydrogen atom transfer mechanism. In addition, methodological and mechanistic comparison of ORAC(FL) with other widely used methods was discussed. It is concluded that, unlike other popular methods, the improved ORAC(FL) assay provides a direct measure of hydrophilic chain-breaking antioxidant capacity against peroxyl radical.
Article
Cocoa flavanols and procyanidins possess wide-ranging biological activities. The present study investigated the stability of the cocoa monomers, (-)-epicatechin and (+)-catechin, and the dimers, epicatechin-(4beta-8)-epicatechin (Dimer B2) and epicatechin-(4beta- 6)-epicatechin (Dimer B5), in simulated gastric and intestinal juice and at different pH values. The dimers were less stable than the monomers at both acidic and alkaline pH. Incubation of Dimer B2 and Dimer B5 in simulated gastric juice (pH 1.8) or acidic pH resulted in degradation to epicatechin and isomerization to Dimer B5 and Dimer B2, respectively. When incubated in simulated intestinal juice or at alkaline pH, all four compounds degraded almost completely within several hours. These results suggest that the amount, and type, of flavanols and procyanidins in the gastrointestinal tract following the consumption of cocoa can be influenced by the stability of these compounds in both acidic and alkaline environments.
Article
We recently reported the improved oxygen radical absorbance capacity (ORAC) assay using fluorescein (FL) as the fluorescent probe. The current ORAC(FL) assay is limited in hydrophilic antioxidant due to the aqueous environment of the assay. Lipophilic antioxidants mainly include the vitamin E family and carotenoids, which play a critical role in biological defense systems. In this paper, we expanded the current ORAC(FL) assay to lipophilic antioxidants. Randomly methylated beta-cyclodextrin (RMCD) was introduced as the water solubility enhancer for lipophilic antioxidants. Seven percent RMCD (w/v) in a 50% acetone-H(2)O mixture was found to sufficiently solubilize vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). This newly developed ORAC assay (abbbreviated ORAC(FL-LIPO)) was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrate that the ORAC(FL-LIPO) assay is reliable and robust. For the first time, by using 6-hydroxy-2,5,7,8-tetramethyl-2-carboxylic acid as a standard (1.0), the ORAC values of alpha-tocopherol, (+)-gamma-tocopherol, (+)-delta-tocopherol, alpha-tocopherol acetate, tocotrienols, 2,6-di-tert-butyl-4-methylphenol, and gamma-oryzanol were determined to be 0.5 +/- 0.02, 0.74 +/- 0.03, 1.36 +/- 0.14, 0.00, 0.91 +/- 0.04, 0.16 +/- 0.01, and 3.00 +/- 0.26, respectively. The structural information of oxidized alpha-tocopherol obtained by liquid chromatography/mass spectrometry reveals that the mechanism for the reaction between the vitamin E and the peroxyl radical follows the hydrogen atom transfer mechanism, which is in agreement with the notion that vitamin E is the chain-breaking antioxidant.
Article
Purpose of review: Cardiovascular benefits for cocoa are being claimed in the scientific literature with growing intensity. To date, excitement over the potential health benefits of flavonoids has been driven mostly by epidemiological studies of tea and red wine, but raw cocoa contains specific flavonoids in concentrations far exceeding those from most other sources. Early evidence supports cocoa's enhancement of endothelial function via improvement of nitric oxide synthesis. However, many new studies have brought more confusion than clarity to the enterprise. This review provides guidelines for legitimate research in this promising field. Topics of discussion: Evidence generated from epidemiological studies, linking an increase in flavonoid ingestion to a reduction in cardiovascular events, is less convincing than data from controlled clinical trials. Whereas a few trials have shown evidence for an enhancement of endothelial function, inhibition of platelet adhesion and low-density lipoprotein oxidation, many studies have ignored scientific principles. Tremendous variability in cocoa processing, flavonoid content, measurement and dosing threatens the field. Valid research depends upon the precise identification and measurement of compounds of interest, which are probably the flavanols catechin and epicatechin, their oligomers and metabolites. These measures depend upon reliable methods of separation and quantification. Whether the monomers, dimers or larger flavanol oligomers, or their metabolites, are responsible for biological efficacy remains to be determined. Final questions surround bioavailability and dosing frequency. Conclusions: Evidence is mounting to support cardiovascular health benefits from the consumption of flavanol-rich cocoa. This review hopes to illuminate sound scientific principles by which future research in the field can be guided.
Article
In the United States, commercially available foods, including cocoa and chocolate, are being marketed with statements referring to the level of antioxidant activity and polyphenols. For cocoa-containing foods, there has been no comprehensive survey of the content of these and other chemistries. A survey of cocoa and chocolate-containing products marketed in the United States was conducted to determine antioxidant activity and polyphenol and procyanidin contents. Commercially available samples consisted of the top market share products in each of the following six categories: natural cocoa, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized using four different methods: oxygen radical absorbance capacity (ORAC), vitamin C equivalence antioxidant capacity (VCEAC), total polyphenols, and procyanidins. All composite lots were further characterized for percent nonfat cocoa solids (NFCS) and percent fat. Natural cocoas had the highest levels of antioxidant activities, total polyphenols, and procyanidins followed by baking chocolates, dark chocolates and baking chips, and finally milk chocolate and syrups. The results showed a strong linear correlation between NFCS and ORAC (R (2) = 0.9849), total polyphenols (R (2) = 0.9793), and procyanidins (R (2) = 0.946), respectively. On the basis of principal component analysis, 81.4% of the sample set was associated with NFCS, antioxidant activity, total polyphenols, and procyanidins. The results indicated that, regardless of the product category, NFCS were the primary factor contributing to the level of cocoa antioxidants in the products tested. Results further suggested that differences in cocoa bean blends and processing, with the possible exception of Dutching, are minor factors in determining the level of antioxidants in commercially available cocoa-containing products in the United States.
Article
Cocoa and chocolate products from major brands were analyzed blind for total antioxidant capacity (AOC) (lipophilic and hydrophilic ORAC(FL)), catechins, and procyanidins (monomer through polymers). Accuracy of analyses was ascertained by comparing analyses on a NIST standard reference chocolate with NIST certified values. Procyanidin (PC) content was related to the nonfat cocoa solid (NFCS) content. The natural cocoa powders (average 87% of NFCS) contained the highest levels of AOC (826 +/- 103 micromol of TE/g) and PCs (40.8 +/- 8.3 mg/g). Alkalized cocoa (Dutched powders, average 80% NFCS) contained lower AOC (402 +/- 6 micromol of TE /g) and PCs (8.9 +/- 2.7 mg/g). Unsweetened chocolates or chocolate liquor (50% NFCS) contained 496 +/- 40 micromol of TE /g of AOC and 22.3 +/- 2.9 mg/g of PCs. Milk chocolates, which contain the least amount of NFCS (7.1%), had the lowest concentrations of AOC (80 +/- 10 micromol of TE /g) and PCs (2.7 +/- 0.5 mg/g). One serving of cocoa (5 g) or chocolate (15 or 40 g, depending upon the type of chocolate) provides 2000-9100 micromol of TE of AOC and 45-517 mg of PCs, amounts that exceed the amount in a serving of the majority of foods consumed in America. The monomers through trimers, which are thought to be directly bioavailable, contributed 30% of the total PCs in chocolates. Hydrophilic antioxidant capacity contributed >90% of AOC in all products. The correlation coefficient between AOC and PCs in chocolates was 0.92, suggesting that PCs are the dominant antioxidants in cocoa and chocolates. These results indicate that NFCS is correlated with AOC and PC in cocoa and chocolate products. Alkalizing dramatically decreased both the procyanidin content and antioxidant capacity, although not to the same extent.
Article
Dark chocolate has potent antioxidant properties. Coronary atherosclerosis is promoted by impaired endothelial function and increased platelet activation. Traditional risk factors, high oxidative stress, and reduced antioxidant defenses play a crucial role in the pathogenesis of atherosclerosis, particularly in transplanted hearts. Thus, flavonoid-rich dark chocolate holds the potential to have a beneficial impact on graft atherosclerosis. We assessed the effect of flavonoid-rich dark chocolate compared with cocoa-free control chocolate on coronary vascular and platelet function in 22 heart transplant recipients in a double-blind, randomized study. Coronary vasomotion was assessed with quantitative coronary angiography and cold pressor testing before and 2 hours after ingestion of 40 g of dark (70% cocoa) chocolate or control chocolate, respectively. Two hours after ingestion of flavonoid-rich dark chocolate, coronary artery diameter was increased significantly (from 2.36+/-0.51 to 2.51+/-0.59 mm, P<0.01), whereas it remained unchanged after control chocolate. Endothelium-dependent coronary vasomotion improved significantly after dark chocolate (4.5+/-11.4% versus -4.3+/-11.7% in the placebo group, P=0.01). Platelet adhesion decreased from 4.9+/-1.1% to 3.8+/-0.8% (P=0.04) in the dark chocolate group but remained unchanged in the control group. Dark chocolate induces coronary vasodilation, improves coronary vascular function, and decreases platelet adhesion 2 hours after consumption. These immediate beneficial effects were paralleled by a significant reduction of serum oxidative stress and were positively correlated with changes in serum epicatechin concentration.
Article
Major brands of cocoa powder products present in the Spanish market were analyzed for monomeric flavanols [(+)-catechin and (-)-epicatechin] and flavonols [quercetin-3-glucuronide, quercetin-3-glucoside (isoquercitrin), quercetin-3-arabinoside, and quercetin]. In addition, the influence of the manufacturing process of cocoa powder products, in particular, the alkalinization treatment ( Dutching), on the original content of these flavonoids has been studied. (-)-Epicatechin was in the range of 116.02-730.26 microg/g, whereas (+)-catechin was in the range of 81.40-447.62 microg/g in the commercial cocoa products studied. Among flavonols, quercetin-3-arabinoside and isoquercitrin were the major flavonols in the cocoa powder products studied, ranging from 2.10 to 40.33 microg/g and from 3.97 to 42.74 microg/g, respectively, followed by quercetin-3-glucuronide (0.13-9.88 microg/g) and quercetin aglycone (0.28-3.25 microg/g). To our knowledge, these results are the first quantitative data in relation to the content of individualized flavonol derivatives in commercial cocoa powder products. The alkalinization treatment resulted in 60% loss of the mean total flavonoid content. Among flavanols, (-)-epicatechin presented a larger decline (67%, as a mean percentage difference) than (+)-catechin (38%), probably because of its epimerization into (-)-catechin, a less bioavailable form of catechin. A decline was also confirmed for di-, tri-, and tetrameric procyanidins. In the case of flavonols, quercetin presented the highest loss (86%), whereas quercetin-3-glucuronide, quercetin-3-arabinoside, and isoquercitrin showed a similar decrease (58, 62, and 61%, respectively). It is concluded that the large decrease found in the flavonoid content of natural cocoa powder, together with the observed change in the monomeric flavanol profile that results from the alkalinization treatment, could affect the antioxidant properties and the polyphenol biovailability of cocoa powder products.
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