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Effects of Roasting Temperature on the Aroma Components of Carob (Ceratonia siliqua L.)
Abstract
The analysis of the volatile fraction of carob bean pulp during a roasting process between 10 and 60 min was performed. In all, 137 components (comprising ca. 98.0% of the total isolate) were positively identified. Acids, alcohols, and aldehydes represent 91.4% of the total of the identified compounds in raw carob. The levels of these compounds decreased steeply during the roasting process, representing 51.2% of the total as a result of the increasing amounts of furans, esters, and pyrroles in roasted carob, whose odor is more pleasant than that of raw carob and reminiscent of chocolate or cocoa and which could be used in foods as a flavoring agent. Keywords: Carob; Ceratonia siliqua L.; roasting process; volatiles
... In carob powder, propanoic acid, 2-methyl, butanoic acid, pentanoic acid, hexanoic acid, furfural, and heptanoic acid were previously detected with SPME/GC-MS analysis (Farag and El-kersh 2017) and with in-tube extraction (ITEX) coupled with GC-MS (Racolta et al. 2014). In general, the present results are in Benzaldehyde (C, CP) CP (Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butane Table 1. The most abundant volatile chemical groups that distribute to the aroma of carob powder are acids followed by esters and aldehydes/ketones (Fig. 3b). ...
... , 2-methyl-, methyl ester (C, CP) Butanoic acid, ethyl ester (C, CP) 2-Hexanone (C, CP) Propanoic acid, 2-methyl (C, CP) CP(Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butanoic acid (C, CP) CP(Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butanoic acid, 2-methyl, -ethyl ester (C, CP) Furfural (CP) CP(Cantalejo 1997;Racolta et al. 2014; Farag and El-1997;Racolta et al. 2014) Propanoic acid, 2-methyl-, 2-methylpropyl ester (CP)Hexanoic acid, methyl ester (C, CP)3-Hepten-2-one (C, CP) CP(Cantalejo 1997) Hexanoic acid, ethyl ester (C, CP) ...
... , 2-methyl-, methyl ester (C, CP) Butanoic acid, ethyl ester (C, CP) 2-Hexanone (C, CP) Propanoic acid, 2-methyl (C, CP) CP(Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butanoic acid (C, CP) CP(Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butanoic acid, 2-methyl, -ethyl ester (C, CP) Furfural (CP) CP(Cantalejo 1997;Racolta et al. 2014; Farag and El-1997;Racolta et al. 2014) Propanoic acid, 2-methyl-, 2-methylpropyl ester (CP)Hexanoic acid, methyl ester (C, CP)3-Hepten-2-one (C, CP) CP(Cantalejo 1997) Hexanoic acid, ethyl ester (C, CP) ...
Biogenic volatile organic compounds (VOCs) contribute to the communication, growth, breeding, and defense of plant; their role in plant kingdom is vital. Carob tree is cultivated mainly in Middle East and eastern European countries (e.g., Spain, Italy, Greece, Cyprus) and lately in Australia, the USA, and South Africa. Therefore, it is examined as a case study for its volatile emissions in the environment. Apart from the VOCs emitted from carob flowers and fruit, carob is considered of great interest for the food industry (carob powder), not only for its health benefits but also due to its characteristic strong aroma, which can be maintained even after processing (roasting). Solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) analyses of carob flowers, fruit, and powder (commercial samples) were performed and the detected VOCs are presented and discussed. The most prominent chemical classes emitted from carob fruit and powder appeared to be acids followed by esters and aldehydes/ketones, whereas from carob flowers the terpenoids. The strongest VOCs both in carob fruits and powder were propanoic acid, 2-methyl (isobutyric acid) and in flowers ethanol. The uniqueness of carob benefits is well known in the agriculture, pharmaceutical, cosmetic, and food sector and is closely related to the agro-economy and long history of eastern Mediterranean countries.
... temperature and time, can increase the total phenolic content and total antioxidant activity due to the formation of Maillard reaction products and enhancement of the polyphenol solubility. 22,23 As for the sensory quality, roasting treatment not only decreases the amount of aliphatic acids which impart an undesirable smell, 24,25 but also increases the amount of furans and esters which impart a pleasant odour close to that of chocolate or cocoa. 25 The carob tree has been considered a potential candidate in the reforestation programmes in dry regions to mitigate the effects of environmental degradation and to increase the economic revenues of agricultural practices. ...
... 22,23 As for the sensory quality, roasting treatment not only decreases the amount of aliphatic acids which impart an undesirable smell, 24,25 but also increases the amount of furans and esters which impart a pleasant odour close to that of chocolate or cocoa. 25 The carob tree has been considered a potential candidate in the reforestation programmes in dry regions to mitigate the effects of environmental degradation and to increase the economic revenues of agricultural practices. 26,27 Accordingly, the carob tree has been given focus either for the purpose of conservation 28,29 or to preserve this organic traditional local food ingredient and develop it further by means of processing and production. ...
... The reason behind this finding is attributed to pyridines, pyrazines, aldehydes and ketones which are associated with roast aroma and flavour and were found to increase in carob powder upon roasting. 25,26 KSR also obtained the highest ratings for the caramel odour attribute. Fadel et al. 57 found that cocoa substitute [mixture of chicory roots and roasted carob pods (1:2 w/w)] contains cyclotene, maltol, furaneol and furans which were linked to the odour quality of caramel because they provide a warm and sugary flavour note. ...
Background:
This work aimed at formulating a carob-based milk beverage and assessing its chemical and sensory properties. Six varieties of carob pods, each processed into roasted and unroasted powders, were used to develop twelve prototypes of the beverage. Chemical and physicochemical analyses (moisture, ash, fiber, protein, sugars, total-phenolics, total-antioxidants, water activity and color) and sensory tests were conducted.
Results:
Variety of carob pod had a significant effect on all chemical variables in carob powders(p<0.01), except for sugars, and when incorporated in the beverage, on moisture, total-phenolics, total-antioxidant activity and color parameters (L, a, b;p's<0.001). Roasting treatment significantly increased fiber, total-phenolics, total-antioxidant activity(p's<0.001), fructose, glucose(p's<0.05), and a-value levels(p<0.01), significantly lowered moisture (p<0.05), water activity, L and b-values(p's<0.001) in carob powders; and significantly increased the beverage's total-phenolics,a-value(p's<0.001) and total-antioxidant activity (p<0.01).Roasting treatment significantly increased the beverage's acceptability ratings. Beverages formulated with roasted carob powder had higher ratings for level of residue, color, caramel odor, mocha odor and flavor, roasted coffee odor and flavor, viscosity mouthfeel and bitter aftertaste. Principal component analysis was conducted: PC1 and PC2 separated attributes according to roasting treatment and variety of carob pods, respectively.
Conclusion:
It is recommended to use AKR and BIKR to formulate a carob-based milk beverage.
... Nowadays, there is a growing interest in supplements derived from natural, traditional and non-traditional foods as possible sources of biologically active substances with proven health properties for inclusion in the human diet (Baumel et al., 2018). About that, carob (Ceratonia siliqua L.) holds potentially significant importance for the food industry due to its phytochemical constituents with functional properties (Goulas et al., 2016), flavouring properties (Foundation & Aue, 1997), and nutrition benefits (Papaefstathiou & Agapiou, 2018). The carob tree grows up to 8-17 m high, with a broad semispherical crown and a thick trunk with brown, rough bark and sturdy branches ( Fig. 1a; Tous & Antoni, 2013). ...
... The roasting step is crucial to attaining the product's stability throughout storage, affecting its chemical composition (Boublenza et al., 2017;Červenka et al., 2019b;Vitali Č epo et al., 2014). In this last aspect, sugar caramelisation and Maillard reaction favour the production of furans, esters and pyrroles that recall cocoa's aroma (Foundation & Aue, 1997). Moreover, the release of phenolics occurs through the ruptured of high-molecular complexes from the carob matrix or the partial degradation of phenolics, which results in the production of different types of antioxidant molecules (Boublenza et al., 2017). ...
Background
Carob (Ceratonia siliqua L.) is an evergreen tree that belongs to the Leguminosae family and is typical of the Mediterranean basin. It is well known for its valuable locust bean gum obtained from carob seeds. However, the food industry can obtain different carob products from carob fruit after processing. Carob products are good sources of dietary fibre, sugars, and a range of bioactive compounds such as polyphenols and D-pinitol.
Scope and approach
Bioactive compounds present in carob fruit and its derived products help control many health problems such as diabetes, heart diseases, and gastrointestinal disorders due to their anti-hyperglycaemic, antioxidant, and anti-inflammatory activities. So, carob products have a great potential to be used as a functional food ingredient.
Key findings and conclusions
This article focuses on carob characteristics and processing, chemical composition, health benefits, and applications in food formulations to explore the potential of carob in developing a wide variety of health-beneficial food products.
... The seeds contribute to more than 60% of the pod market price and are used for the production of locust bean gum, which is obtained from the endosperm. 3 Locust bean gum forms a viscous solution at relatively low concentration and is added as a thickener or stabilizer in many food products. The carob pulp has lower value and, up to now, is mainly used for animal feed and the production of sugar syrup. ...
... [11][12][13][14][15][16] The chemical composition of the pulp strongly depends on the cultivar, origin and harvesting time. 3,17 Due to the high free sugar content (>48% of which more than 65% sucrose), the pulp is gaining popularity as a natural sweetener in foods, with a flavor profile and appearance similar to cocoa powder. 18 In this vein, carob pulp is used as an alternative ingredient in some chocolate products leveraging on the peculiarity that it does not contain psychostimulants such as caffeine and the obromine. ...
Carob is the fruit obtained from Ceratonia siliqua L. and it is a source of bioactive compounds that have been linked to several health promoting effects, including lowering blood cholesterol concentration. The objective of this study was to connect the physicochemical changes of carob flour occurring during roasting with its capacity to bind glycoconjugates of bile acids. Carob flour samples were roasted for different times at 150°C and chemically characterized by measuring the concentrations of tannins and polyphenols. Data showed that carob flour binds high amounts of bile acids: 732.6 µmol of bound bile acid per g of carob flour which is comparable to the 836.2 µmol per g bound by cholestyramine, a known cholesterol lowering drug. The carob flour ability to bind cholesterol decreases up to 40% during roasting. Data suggested that tannins and insoluble components play a major role in binding bile salts, as a result of hydrophobic interactions.
... In carob powder, propanoic acid, 2-methyl, butanoic acid, pentanoic acid, hexanoic acid, furfural, and heptanoic acid were previously detected with SPME/GC-MS analysis (Farag and El-kersh 2017) and with in-tube extraction (ITEX) coupled with GC-MS (Racolta et al. 2014). In general, the present results are in Benzaldehyde (C, CP) CP (Cantalejo 1997;Racolta et al. 2014;Farag and El-kersh 2017) Butane Table 1. The most abundant volatile chemical groups that distribute to the aroma of carob powder are acids followed by esters and aldehydes/ketones (Fig. 3b). ...
... , 2-methyl-, 2-methylpropyl ester (CP) Hexanoic acid, methyl ester (C, CP) 3-Hepten-2-one (C, CP) CP(Cantalejo 1997) Hexanoic acid, ethyl ester (C, CP) ecology. The VOCs presented in ...
The original publication of this paper contains an error.
... During the roasting process, important chemical reactions occur including sugar caramelization and Maillard reaction, which cause significant changes in the chemical and sensory profile of carob flour and affect its final taste, color and aroma [48,50]. Several studies reported that cocoa-like aroma could be generated in roasted carob pulp and the effect of roasting conditions on carob aroma has been investigated [51][52][53]. The cocoa-like and caramel aromas have been attributed to the thermal degradation of the high sugar content of carob and secondarily to the subsequent formation of some potent odorants via the Maillard reaction [52]. ...
... Furthermore, in the sensory evaluation the carob-based milks containing the roasted carob powders showed the highest acceptability in terms of color, roasted coffee odor and flavor, caramel odor, mocha odor and flavor, viscosity mouth-feel and bitter aftertaste [50]. That was attributed to pyridines, pyrazines, aldehydes, and ketones, which associated with roast aroma and flavor and were found to increase upon roasting [51,52]. The improved chocolate-like flavor in carob-based milk containing roasted carob powder instead of non-roasted, was also addressed in another study of sensory evaluation [192]. ...
Cocoa originates from the beans of the cocoa tree (Theobroma cacao L.). It is an important commodity and the main ingredient in chocolate manufacture. Its value and quality are related to complex flavors and to its distinct sensory properties. The increasing demand for cocoa and its rising price urges the research for cocoa substitutes. A potential substitute for cocoa is carob. Carob is the fruit of an evergreen tree (Ceratonia siliqua L.) cultivated in the Mediterranean area, well known for its valuable locust bean gum and also for carob powder and syrup that are obtained from carob pulp. Cocoa beans and carob pods contain various phytochemicals including polyphenols, proteins and amino acids, fatty acids, carbohydrates and fiber. Phytochemicals represent an important source of nutrients and compounds that are beneficial to human health. In this review, phytochemicals in cocoa beans and carob pods and their impact on human health are reviewed. The bioactive compounds that are present in carob, in conjunction with the cocoa-like flavors and unique sensory properties that are enhanced by carob powder roasting, underline carob’s potential to substitute cocoa in various food products. These food applications are discussed in this review.
... Roasting also modifies the volatile fraction of the carob flour, reducing the percentage of acids, alcohols and aldehydes and increasing the level of furans, pyrroles and esters. This leads to an enhancement of the aroma of the flour making it more similar to chocolate or cocoa (Cantalejo 1997). ...
... Taking into account consumer observations, LT cake was considered overly dark and with a bitter taste. It is known that as the degree of roasting is increased the content in phenolic compounds and particularly in furans and pyrrols is increased, partly down to Maillard reactions (Cantalejo 1997;Cepo et al. 2014;Sahin et al. 2009). Even though those compounds can look alike, to a certain extent, the flavour of other roasted products such as chocolate or cacao, and excess of these compounds can give rise to bitter tastes in those products. ...
Carob flour is a product rich in fibre obtained from by-products of the locust bean gum extraction processing. The flour is commercialised with different degrees of roasting in order to improve its organoleptic characteristics. In this study, carob flour with three different roasting degrees was used to replace rice flour (15%) in gluten-free cakes and cookies. The influence of this replacement was studied on the psychochemical characteristics and acceptability of the final products. The incorporation of carob flour increased the viscosity of cake batters and increased the solid elastic-like behaviour of the cookie doughs, indicating a stronger interaction among the formula ingredients. The inclusion of carob flour, with a low time of roasting, did not lead to any significant differences in the specific volume and hardness of the cakes, but reduced cake staling and the thickness and width of the cookies. Darker colours were obtained when carob flour was incorporated into the product. The acceptability of cakes was only reduced with the addition of highly roasted carob flour, while in the case of cookies there was a decline in the acceptability of all carob flour cookies, which was mostly perceived with the highest roasting degree, something mainly attributed to the bitter taste of the products.
... In terms of its health benefits, C. siliqua exhibits a myriad of biological effects including antibacterial, antidiarrheal, antidiabetic, anti-hypercholestrolemic, and hepatoprotective [2][3][4][5]. Additionally, Carob pods, roasted and unroasted are widely used in manufacturing of sugar syrups, molasses, and beverage [6] or as a cocoa substitute in candy products and cakes [7]. Roasting of carob pod along with sugar is thought to enhance or intensify the aroma. ...
... The metabolite loading plot for PC1 (Fig. 3B), which clears the significant components with respect to scattering behavior, showed higher volatile levels in unroasted pod and with no detection of novel peaks in roasted specimen. Our results fall in agreement with previous report on roasting effect on C. siliqua analyzed using steam distillation and revealing a steep decrease in its volatiles [6]. Pentanoic and hexanoic acid (caproic acid) contributed the most positively along PC1, being more fortified in unroasted fruit. ...
... As already described for several medicinal plants [6][7][8], in vitro, and in vivo studies of the antioxidant capacities of carob proved their inhibiting potential, related to their phenolic compounds [9][10][11]; moreover, carob has a great potential to be used in agrifood industries due to its phytochemical constituents with functional, flavoring properties through its characteristic strong aroma, which persists even after treatment [12]. This exceptional quality may be clarified by the presence of acids, esters, and aldehydes/ketones produced from carob fruit and powder, which are biogenic volatile organic composites that promote plant growth, breeding, protection [13,14] and nutrition benefits [15]. In addition, it has been confirmed to possess remarkable bioactivity and is considered dietary fiber in the food industry [16,17], wherein it is used for the preparation of soft drinks, confectionery products, and baked goods and as a substitute for cocoa or chocolate [18]. ...
The present work was designed to investigate the effects of different extraction processes, namely ultrasonic-assisted, supercritical fluid, microwave-assisted and Soxhlet applied to carob pods. The total phenolic quantification and the antioxidant activity were assessed by the means of rapid in vitro spectrophotometric assays; the phenolic profile was identified using ultra-high performance liquid chromatography coupled to mass spectrometry. The results revealed that the phenolic compounds and the antioxidant capacity varied significantly with the nature of the extraction process. The content of total phenolic compounds ranged from 11.55 to 34.38 mg GAE/g DW; the content of total flavonoids varied from 3.50 to 10.53 mg QE/g DW, and the content of condensed tannins fluctuated from 3.30 to 6.55 mg CE/ g DW. All extracts performed differently on antioxidant activity when determined by the DPPH assay producing a dose-dependent response, with IC50 extended from 11.33 to 6.07 µg/mL. HPLC analysis enabled the identification of nine compounds. As a function of the studied extraction methods, the phenolic compound contents were positively correlated with antioxidant activity.
... It is worth noting that some compounds were also sensitive to temperature and easily decomposed or degraded in the presence of high temperature, which causes some volatile compounds to be lost or weakened in the heated sample. This finding agreed with Salum et al. [52] and Cantalejo et al. [66] that a slight aroma loss occurs during prolonged hightemperature processing. Consequently, it was important to demonstrate the changes in aroma precursors during processing [67]. ...
The present study aimed to ascertain how the volatile compounds changed throughout various processing steps when producing a smoke-flavored sea bass (Lateolabrax maculatus). The volatile compounds in different production steps were characterized by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). A total of 85 compounds were identified, and 25 compounds that may be considered as potential key compounds were screened by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Results indicated that aldehydes were the major volatile compounds throughout the processing. The characteristic volatile compound in fresh samples was hexanol, and curing was an effective method to remove the fishy flavor. The concentration of volatile compounds was significantly higher in dried, smoked, and heated samples than in fresh and salted samples. Aldehydes accumulated because of the drying process, especially heptanal and hexanal. Smoke flavoring was an important stage in imparting smoked flavor, where phenols, furans and ketones were enriched, and heating leads to the breakdown of aldehydes and alcohols. This study will provide a theoretical basis for improving the quality of smoke-flavored sea bass products in the future.
... This is supported by the increase in both fructose and glucose from the oral to the gastric phase, for CF ≤ 100 μm. The larger particle fractions (>100 μm) presented less sugar content when compared to ≤100 μm CF; this is possible since the larger particle fractions might be resulting mostly from the seed part of the carob pod, which exhibits less sugar content than that of pulp and is more difficult to mill, leading to larger particles [12,46]. The results obtained for all sugars were affected by the particle size and the GIT phase (p < 0.05). ...
Carob fruit is native to the Mediterranean region and produced mainly in Portugal, Italy, Morocco and Turkey. The production of the carob fruit in Portugal is highly extensive and sustainable. Currently, carob flour (CF) production is mainly achieved after pulp separation, despite it having been demonstrated that the seeds improve the extraction efficiency of bioactive compounds such as polyphenols, promoting human health. This study aimed to produce an integral CF through an innovative process and assess its physicochemical and bioactive properties at different particle sizes throughout simulated gastrointestinal tract (GIT) digestion. The sugar content profile obtained throughout GIT digestion indicated that sucrose, the sugar present at the highest concentration in undigested CF, was digested and broken down into simple sugars, namely glucose and fructose. The total phenolic content (TPC) and antioxidant activity obtained for the ≤100 µm fraction were in accordance and gastric digestion promoted an increase in the TPC value compared to the undigested sample. The >100 µm fractions displayed a distinct profile from the ≤100 µm fraction. This study showed that the particle size affects the sugar, antioxidant and total phenolic content of CFs and also their gastrointestinal tract digestion. The ≤100 µm fraction demonstrated the most suitable profile as a functional food ingredient.
... 91.4% of the identified compounds in raw carob contained acids, alcohols, and aldehydes. During the roasting process, the amount of these compounds decreased sharply, showing 51.2% of the total as a result of the increasing amounts of other volatile compounds in roasted carob, whose smell is more pleasant than that of raw one 33 . Although, roasting is the main process done on carob, extraction of phenolic compounds and D-pinitol compound have been studied, through different methods and conditions. ...
... Further to the metabolites that influence taste, volatiles also play a critical role in shaping the overall flavor of the carob pulp. A limited number of studies have been performed to decipher the VOCs profile of the carob intact pod, kibbled pulp or powder, focusing mainly on the aroma characterization of mature carobs from different origins or reporting the effect of roasting on the carob VOCs profile (4,14,(21)(22)(23). The major categories of VOCs detected in mature carob according to the above studies were acids, esters, aldehydes, ketones, alcohols, furans/pyrans, and hydrocarbons. ...
Carob powder is increasingly valued as a substitute for cocoa and as a flavor-enhancing component of processed foods. However, little is known about the impact of preharvest factors such as fruit maturity, genotype and altitude on its volatile organic compounds (VOCs) composition. The current study examined the VOCs composition of powder milled from pods of two genotypes cultivated at 15 and 510 m altitude and harvested at six progressive stages of maturity, ranging from fully developed immature green (RS1) to late ripe (RS6). Fifty-six VOCs categorized into acids, esters, aldehydes, ketones, alcohols, furans, and alkanes were identified through HS-SPME GC-MS analysis. Maturity was the most influential factor, followed by altitude and least by genotype. Aldehydes and alcohols correlated positively ( r = 0.789; p < 0.001), both accumulated in immature carobs and decreased with progressive ripening, resulting in the attenuation of green grassy aroma. Conversely, acids increased with ripening and dominated the carob volatilome at full maturity, correlating negatively with aldehydes and alcohols ( r = −0.835 and r = −0.950, respectively; p < 0.001). The most abundant VOC throughout ripening (17.3-57.7%) was isobutyric acid, responsible for the characteristic cheesy-acidic-buttery aroma of carob powder. The pleasurable aroma detected at the immature stages (RS2 and RS3) was traced to isobutyrate and methyl isobutyrate esters, rendering unripe green carob powder a potential admixture component for improving the aroma of novel food products. Lower altitude favored the accumulation of acids linked to less pleasant aroma, whereas isobutyric acid was more abundant at higher altitude. This constitutes a significant indication that higher altitude enhances the characteristic carob-like aroma and sensory quality of carob powder.
... In the case of pulp processing, it can be kibbled to various grades (pieces/kibbles, and flour/powder) for animal feed. Moreover, the pulp can be roasted to improve its organoleptic characteristics, obtaining, when together with other food ingredients, a taste very similar to cocoa [3]. After this, it is common to include grinding and sieving steps to obtain carob flour, a product often used in different food preparations for human consumption. ...
Carob (Ceratonia siliqua L.) pod is a characteristic fruit from the Mediterranean regions. It is composed by seeds, the valuable part due to the extraction of locust bean gum, and the pulp, considered a by-product of the fruit processing industry. Carob pulp is a mixture of macro- and micronutrients, such as carbohydrates, vitamins and minerals, and secondary metabolites with functional properties. In the last few years, numerous studies on the chemical and biological characteristics of the pulp have been performed to encourage its commercial use. Its potential applications as a nutraceutical ingredient in many recipes for food and beverage elaborations have been extensively evaluated. Another aspect highlighted in this work is the use of alternative processes or conditions to mitigate furanic production, recognized for its toxicity. Furthermore, carob pulp’s similar sensorial, chemical and biological properties to cocoa, the absence of the stimulating alkaloids theobromine and caffeine, as well as its low-fat content, make it a healthier potential substitute for cocoa. This paper reviews the nutritional and functional values of carob pulp-based products in order to provide information on the proclaimed health-promoting properties of this interesting by-product.
... According to the literature, VOCs from carobs have been studied using solvent extraction and GC-MS technique [22,23]. SPME-GC-MS was also employed to analyze the VOCs released by Ceratonia siliqua roasted and unroasted pods; in total, 31 odorous compounds were reported [12]. ...
Ceratonia siliqua L. is quite popular for the sweetness of its fruit (“natural chocolate”) and the strong, persistent, characteristic odor that associates not only carob fruit, but also its traditional food products. This is due to the emission of an array of volatile organic compounds (VOCs). The released odor is a complex mixture, and therefore, needs to be separated prior detected, especially when its origin varies and is engaged. Therefore, Headspace–Solid-Phase Microextraction–Gas Chromatography–Mass Spectrometry (HS–SPME–GC–MS) analysis was performed in ground carob pods from three different European countries to decode their released aroma. The method was applied to Cypriot (Kountourka, Koumpota, Tilliria), Spanish (Negra, Rojal, Matalafera) and Italian (Saccarata, Racemosa, Gibiliana) cultivars, and the released volatile species were further processed with multivariate data analysis (MDA). The chromatographic separation highlighted 54 common VOCs in the grounded carob pods; the most abundant appeared to be propanoic acid 2-methyl (isobutyric acid), acetic acid, butanoic acid, hexanoic acid, and propanoic acid 2-methyl-methyl ester. The quantitative results for acetic acid, propanoic acid 2-methyl, butanoic acid, furfural and pentanoic acid revealed their emission in the low ppbv levels. The engage of MDA on the obtained results showed a clear differentiation of the carobs based on their geographical and botanical origin. The combination of HS–SPME–GC–MS and chemometrics contributes to the quality characterization of carobs and highlights their authenticity markers.
... 22 Ethyl acetate, which is the ester formed from ethanol and acetic acid, was one of the most abundant compounds in carob honey after ethanol, methanol, and acetic acid. Some studies have focused on the volatile compounds found in carob; 23,24 however, only one published article focused on the volatile characteristics of carob honey, which is mainly characterized by nonanal and octanal. 25 Heather, citrus, wildflower honey from Sivas, and wildflower honey from Kırşehir also had high amounts of ethyl acetate. ...
Background:
Honey has a very important commercial value for producers as a natural product. Honey aroma is formed from the contributions of several volatile compounds, which were influenced by nectar composition, botanical origins and locations. Selected ion flow tube mass spectrometry (SIFT-MS) is a technique that quantifies volatile organic compounds simply and rapidly even in low concentrations. In this study, the headspace concentration of eight monofloral (chestnut, rhododendron, lavender, sage, carob, heather, citrus, and pine) and three multiflower Turkish honeys were analyzed using SIFT-MS. Soft independent modeling of class analogy (SIMCA) was used to differentiate honey samples based on their volatiles.
Results:
This study focused on 78 volatile compounds, which were selected from previous studies of selected honeys. A very clear distinction was observed between all honeys. Interclass distances greater than 8 indicate that honeys were significantly different. Methanol and ethanol, were abundant in the honeys. Chestnut honey collected from the Yalova region had the highest total concentration of volatiles followed by heather honey and chestnut honey collected from the Düzce region.
Conclusion:
Honeys with different botanical and geographical origin showed differences in their volatile profile based on chemometric. Between the honey samples, methanol, ethanol, acetoin, ethyl acetate, and isobutanoic acid had the highest discriminating power and also methanol and ethanol, and then acetic acid, were the volatiles at the highest concentration in most honeys. This article is protected by copyright. All rights reserved.
... According to the literature, several studies were conducted on the identification of volatile compounds of carob pods [43][44][45][46][47]; however, there is no information about the volatile or aroma profile of carob molasses. Therefore, the present study presents the first report that describes the volatile profile of Tunisian carob molasses. ...
Carob molasses is widely consumed in many Mediterranean countries, including Tunisia where it is known as ‘Rub El Kharroub’. The main objective of the present study was to evaluate the physicochemical properties and biological activities of both commercial and homemade Tunisian carob molasses. The physicochemical characterization revealed that the main parameters (color and HMF concentration) were related to non-enzymatic browning reactions occurring during juice concentration. The phytochemical analysis proved that the presence of bioactive compounds (volatile compounds, phenolic substances and products of non-enzymatic browning reactions) in carob molasses samples justify their biological effects (antioxidant and antibacterial activities). Accordingly, such characteristics may qualify Tunisian carob molasses (both homemade and commercial) as nutritious and healthy food that could be directly consumed or used a functional ingredient in food and pharmaceutical industry.
... 91.4% of the identified compounds in raw carob contained acids, alcohols, and aldehydes. During the roasting process, the amount of these compounds decreased sharply, showing 51.2% of the total as a result of the increasing amounts of other volatile compounds in roasted carob, whose smell is more pleasant than that of raw one 33 . Although, roasting is the main process done on carob, extraction of phenolic compounds and D-pinitol compound have been studied, through different methods and conditions. ...
The carob is a dome-shaped evergreen tree that is a member of the pea family (Fabaceae). Its fruit has been used for human consumption and as animal feed in the Mediterranean countries for centuries and was also widely used as a herbal remedy in traditional folk’s medicine. In this paper, an in-depth literature review was conducted about this species discussing its history, origins, main current uses, components (both nutrient and bioactive), biological activities, and potential applications as the source of sustainable ingredients and products. Among the many bioactive compounds that were found in carob, the most well studied are polyphenols. The levels of these compounds were found to vary depending on many factors, such as the variety, plant part, geographic location, roasting and extraction conditions, and even analysis methods. In the light of these researches, it was recognized that carob offers several biological activities including antioxidant, anticancer, and anti-diabetic due to the presence of a high quantity of pinitol and antibacterial. Rich in sugars, proteins, and minerals, the carob has a vast range of industrial applications such as cacao substitute, sugars substitute, free from gluten making it cereal-derived foods for celiac people.
... On one side, sugar caramelisation and Maillard reaction favour the production of furans, esters and pyrroles that recall the aroma of cocoa. 14 On the other hand, the release of phenolics takes place through the ruptured of high-molecular complexes from carob matrix or the partially degradation of phenolics which results in the production of different types of antioxidant molecules. 15,16 The products of these chemical reactions, such as phenolic compounds and Maillard Reaction Products (MRPs), contribute to the antioxidant capacity and for the beneficial health properties of carob products. ...
BACKGROUND
The production of the traditional carob liquor from Algarve (Portugal) depends on numerous factors such as carob processing, variety and maceration conditions. An experimental design with 36 runs was created to evaluate the effect of the roasting temperature, particle size, variety of carob and time of maceration on several parameters of carob liquors as gallic acid and total phenolic content, the furanic composition (furfural and 5‐(hydroxymethyl)furfural), browning index and in vitro antioxidant capacity.
RESULTS
The results revealed that carob variety was the independent variable with the greatest effect on antioxidant capacity, total phenolic and gallic acid content. In particular, AIDA liquors presented the highest results, mainly those prepared with unroasted carob. Meanwhile, Galhosa and Mulata liquors showed the greatest concentrations when the carob pulp was roasted at 150 °C. The furanic composition and browning index were greatly influenced by the carob roasting degree.
CONCLUSION
The levels of the main toxic furanics present in carob liquors, furfural and 5‐(hydroxymethyl)furfural, suggest a safe consumption of these beverages even in samples of carobs with the maximum roasting degree. The smallest carob particle size favoured the highest phenolic extraction, while the longest maceration periods decreased the concentration of the toxic furanic compounds studied.
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... For all the 72 possible cocoa-carob combinations, three different levels of adulteration were prepared: low adulteration LA (0e20%), medium adulteration MA (20e40%) and high adulteration HA (40e60%). The upper limit (60%) was set by considering that above this concentration, adulteration would become evident due to the characteristic carob aroma (Cantalejo, 1997). The specific adulteration percentage at a given level was determined randomly from a uniform distribution (each adulteration percentage had the same probability of being selected), following the Latin Hypercube Strategy (LHS) (Helton & Davis, 2003). ...
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.
... During roasting, more than 50 % of them are evaporated, mostly those that have unpleasant odors. 126 Later study discovered 169 compounds with clear dominance of short chain acids (77.5 %). 127 Use of advanced isolation and detection method (headspace solid-phase micro extraction, HD-SPME) revealed new yet known volatile compounds in pods, that were not reported in ref. 126, 127. ...
... Roasting at 150°C for 60 min was found to be the most appropriate heat treatment to improve the desirable characteristics of carob powder along with improvement in the flavor profile by reducing the concentration of isobutyric acid, which has an undesirable flavor (Berna and others 1997). Improvement in the aroma of the roasted carobs can also be attributed to a reduction in acids, alcohols, and aldehydes, amounting to 91.4% of the total 137 aroma components identified, and an increase in the amounts of furans, esters, and pyrroles (Cantalejo 1997). Fadel and others (2006) demonstrated that a cocoa substitute with similar characteristics to cocoa can be produced via Maillard technology by using a mixture of milled chicory roots and carob pods. ...
Carob (Ceratonia siliqua L.) is well known for its valuable locust bean gum obtained from the carob seeds. Separation of seeds from the pod leaves behind the carob kibble which is a good source of dietary fiber, sugars, and a range of bioactive compounds such as polyphenols and pinitol. Bioactive compounds present in carob kibble have been found to be beneficial in the control of many health problems such as diabetes, heart diseases, and colon cancer due to their antidiabetic, antioxidant, and anti-inflammatory activities. Carob kibble has substantial potential to be used as a food ingredient. This article focuses on the composition, health benefits, and food applications of carob kibble.
... ln mature stage, carob pod has an elongated shape up to 10-20 cm, straight or curved, with 1-4 cm of width and constituted by epicarp (tough), mesocarp (fleshy and sugary pulp) and seeds. The mesocarp is separated by 7 mm-cells, which correspond to 4-16 seeds per pod and c. 5000 seeds per kg of pods (Foury 1954, Bolanos 1955, Metro & Sauvage 1955, INRA 1965, Piotto & Piccini 1996, Cantalejo 1997. Carob seeds have 8-10 mm of length, 7-8 mm of width and 3-5 mm ofthickness (Batlle & Tous 1997 The carob species represent the Ceratonia genera of Caesalpinoideae, Leguminosae, Angiospermae, Spermatophyta (Tutin et al. 1990/93). ...
The survey of floral variability of carob tree (Ceratonia siliqua L.) from the Province of Chefchaouen (NW of Morocco) marks an unsteady floral mosaic. The determinate and the indeterminate inflorescences development is not controlled by environmental conditions in the study area. In carob tree, the indeterminate inflorescences rate is generally higher than the determinate inflorescences one. The particular inflorescence types have been observed. Inflorescence length and flowers number per inflorescence would not related to environmental conditions. Inflorescence length is superior in male trees when compared to female ones (5.71 cm vs. 4.45 cm). Flowers number per inflorescence in male trees is superior to the one in female trees (42 flowers vs. 30 flowers). In male carob tree, seven flower types have been distinguished differing by sepals and stamens numbers and filament length. In female carob tree, three flower types have been defined in terms of pistil form. The grafting of male or female trees in the domesticated areas affects the sex-ratio in this species. Pollen grains diameter and potential fertility show a high variability and could not be explained by the studied factors. The diameter of pollen grains is 28.3±2.43 µm. The aborted pollen rate has been estimated to 15 %.
... ln mature stage, carob pod has an elongated shape up to 10-20 cm, straight or curved, with 1-4 cm of width and constituted by epicarp (tough), mesocarp (fleshy and sugary pulp) and seeds. The mesocarp is separated by 7 mm-cells, which correspond to 4-16 seeds per pod and c. 5000 seeds per kg of pods (Foury 1954, Bolanos 1955, Metro & Sauvage 1955, INRA 1965, Piotto & Piccini 1996, Cantalejo 1997. Carob seeds have 8-10 mm of length, 7-8 mm of width and 3-5 mm ofthickness (Batlle & Tous 1997 The carob species represent the Ceratonia genera of Caesalpinoideae, Leguminosae, Angiospermae, Spermatophyta (Tutin et al. 1990/93). ...
A pomological survey of two types of carob tree from the Province of Chefchaouen, NW of Morocco (productive "dkar" and "lanta") shows that pods of productive "dkar" type (spontaneous type) present the high yield in seeds (20.5±7.74%) and are more straight than pods of "lanta" type (grafted type) and pod curvature is inversely proportional to tree age. Trees of productive "dkar" type promote endosperm (carob bean gum) content of seeds (47.6±4.53%). The tegument and the embryo-cotyledons complex (carob germ) constitute respectively 22.7% and 19.9% of seed dry weight (dw). According to the provenance, these components would attain in aged grafted-type 23.0% and 21.0% in the same order. Other morphometric parameters of pods and seeds are commented in these carob tree types and especially compared to the Mediterranean cultivars or varieties.
The possibility of producing carob brandy was investigated, focusing on the fermentation of carob and the preliminary characterization of the volatile components in the obtained distillates. Fermentations were carried out in carob mash with or without added nutrients by five Saccharomyces cerevisiae strains at three different temperatures. The obtained wine was subjected to fractional distillation in a copper still to produce carob spirit. Analysis of sugars and fermentation products was performed by high performance liquid chromatography. Gas chromatography and gas chromatography coupled with MS detection was used to analyze the volatile components of carob wine and brandy. Carob flour and the strains used can be efficiently used for the fermentation process to produce carob wine with ethanol content ranging from 46.4 to 50.5 gL−1 and corresponding yield coefficients ranging from 0.45 to 0.49 gg−1. More than ninety compounds detected in carob spirit; ethyl 2-methyl butanoate, ethyl 2-methyl propanoate, ethyl cinnamate, ethyl hexanoate, beta-ionone, ethyl butanoate and ethyl octanoate, largely contribute to the bouquet of the spirit. Thus, a novel volatile spirit may be an additional product in the carob processing chain and represent a new potential, especially for small carob growers.
The aim of this study was to examine the effects of increasing and decreasing gluten content on the physical, chemical and rheological properties of dough obtained from different types of wheat flour. For the research, samples of three types of flour were used: T-500, T-710 and T-850, obtained by milling the wheat variety Falado. Corrections were made to the gluten content based on the content of wet gluten in the wheat flour samples, as follows: by increasing it to 33% by adding vital gluten and by decreasing it to 22% by adding wheat starch. After adjusting the gluten content, the total of nine flour samples were obtained. Physico-chemical analyses included the determination of moisture, ash, protein, wet and dry gluten content, titrable acidity, sedimentation value and quality of gluten by visual evaluation. Rheological analyses included those performed on a farinograph: flour water absorption, dough development, stability, degree of softening, quality number and quality group, and those performed on an extensograph: area under extensograph curve, dough resistance, extensibility, R/E ratio. The statistical analysis showed a significant influence of flour type and gluten content on all physical, chemical and rheological parameters, except on the dough development. The results showed that the vital gluten addition increased and that the wheat starch addition decreased protein, ash and wet gluten content, acidity and sedimentation value, flour water absorption, degree of softening, area under extensograph curve and extensibility of dough in the samples of all types of flours with certain exceptions (samples T 500/22, T 710/33 and T 850/33).
The impact of roasting temperatures (100, 120, 150 and 180° for 25 min) on the bioactive compounds, sensory and physicochemical properties of carob pods powder as well as the polycyclic aromatic hydrocarbons content (PAHs) were studied. The study also investigated whether roasting the dried carob pods (PO) or dried carob powder (CPW) is better used in the food industry. Increasing roasting temperatures resulted in several changes in the chemical composition of carob pods powder, as evidenced by significantly lower water content, protein, fat, total sugar and pH values. This increase also was accompanied by a significant increase in ash, fibers, total polyphenols, total flavonoids, and condensed tannins contents. Raw carob powder and roasted powder at 180°C showed the least acceptable organoleptic properties while roasting powders at 120 and 150°C showed the best results in terms of taste, color, odor, texture, and overall acceptability. PAHs ranged from 3.37 to 22.59 µg/kg, and carcinogenic PAHs ranged from 1.38 to 10.16 µg/kg of roasted carob powder. The difference among the detected levels in different roasting degrees was significant (P ≤ 0.5). Carob powder roasted at 180°C had a total PAHs content higher than other samples roasted at lower temperatures. Roasting at higher temperatures was not acceptable and not applicable due to the occurred partial carbonization and undesired sensorial characteristics formation.
Scientific monograph about taxonomy, ethnobotany, ecology, genetic variability, phytochemical characteristics and utilization of carob tree (Ceratonia siliqua L.) and bay laurel in Croatia.
Metabolomics, can be defined as little molecule -omics. Nowadays, the elucidation of the molecular mechanism of any disease with genome analysis
and proteome analysis is not sufficient. Instead of these, a holistic assessment including metabolomic studies provides rational and accurate results.
The application of metabolomics includes the identification of biomarkers, enzyme-substract interactions, drug-activity studies, metabolic pathway
analysis and some other studies related with the system biology. Metabolomics is the cheap and correct separation, definition and measurement of all
metabolites in cells, tissues or biological fluids in short amounts of time with high throughput technologies such as NMR, GC-MS and LC-MS. It is the
quantitative measurement of the metabolic profile of the living being to characterize the genetics and the phenotypic response to nutritional status of it.
Data comprehensive approach with the ability to collect high volume quantities, aims to improve our understanding of health and disease, nutrition and
food role. The aim of this review; is to emphasize some potential applications of metabolomics in food and nutrition research, to investigate the effects
of metabolomics on nutrition and to present scientific literature on these subjects.
Keywords : Metabolomics, food, nutrition
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This study explores the evolution of key aroma compounds and the chemical changes of their precursors, including reducing sugars, free amino acids, free fatty acids, thiamine and proximate compositions in Beijing roasted duck during roasting for 0-80 min. The results showed that the amounts and contents of 9 key aroma compounds in roasted ducks first quickly increased (p <0.05) and subsequently remained constant (p >0.05) after 50 min, except for a slight decrease between 70 and 80 min. Cysteine, cystine and methionine were the main free amino acids and could react with glucose and ribose to generate 2-furfurylthiol, dimethyl trisulfide and methional. Linoleic acid, α-linolenic acid and arachidonic acid had important effects on the increase of hexanal, octanal and nonanal together with the emergence and formation of heptanal, (E, E)-2,4-decadienal and 1-octene-3-ol. However, thiamine might not be the main precursor of the key aroma compounds in Beijing roasted duck.
Botanical origin and antibacterial activity of Hedysarum coronarium and Citrus honey against Pseudomonas aeroginosae, Staphylococcus aureus and Klebsiella pneumonia
Messaouda BELAID *1, Arezki MOHAMMEDI 1, Salima KEBBOUCHE-GANA 1, Fatma ACHEUK 1,Nora CHAHBAR 1 AND Malika ABBAD-BENNOUR 2
1. Laboratory of Valorisation and conservation of biological resources (VALCOR). Faculty of Sciences, University M’Hamed Bougara of Boumerdes, Algeria
2. Faculty of Biological and Agricultural Sciences Mouloud Mammeri of Tizi Ouzou, Algeria
*Corresponding author: belaidfo@yahoo.fr
ABSTRACT
Honey has always been regarded as a food which is advantageous for one’s health and as a product which has healing qualities. The purpose of the study was to evaluate the antibacterial activity of Hedysarum coronarium and Citrus honey against Pseudomonas aeroginosae, Staphylococcus aureus and Klebsiella pneumonia. To test the antibacterial activity, the agar well diffusion methods was employed. For the palynological analysis, we used the methodology proposed by Louveaux et al (1978); a minimum of 1200 pollen grains was counted par sample. Commonly, monofloral honeys were made up of nectar belonging to a single plant in an extent of at least 45%. These were general guidelines but many pollen types were under represented (such Citrus honey) or over represented (for example Eucalyptus honey). The results showed that the Citrus honey exhibited the highest inhibition against Klebsiella pneumonia and Pseudomonas aeroginosae comparatively of the Hedysarum coronarium honey.
Keywords: Hedysarum coronarium Honey, Citrus honey, pollen analysis, antibacterial activity
The effects of hot air, microwave, and combined microwave/hot air roasting on physical and chemical properties of carob powder were determined. The comparison of different roasting processes was evaluated whether the combined microwave/hot air roasting could be an alternative to other roasting methods or not. The moisture content (2.86%–5.03%), water activity (0.20–0.35), and pH (4.94–5.12) values of the carob powder decreased by increasing microwave power and roasting time; whereas total phenolic content (10.13–13.74 mg/g dm), total antioxidant activity (0.69–1.53 g/mg DPPH), browning index (23.57–70.30), and UV absorbance (427.41–701.05) increased. Hunter L (41.54–55.28) and b (16.45–20.91) values of the carob powder decreased after roasting while color value a (8.88–20.91) increased. The main sugar was sucrose (317.54–347.68 mg/kg), followed by fructose (80.98–90.11 mg/kg), and glucose (45.16–62.19 mg/kg). Roasting process reduced the sugar content while increased the d‐pinitol (62.41–76.71 mg/kg) content. The main volatile was isobutyric acid (acidic/butter odor). Hot air and the combined microwave/hot air roasted samples showed similar volatile and sensorial profile. According to the results, the combined microwave/hot air roasting consumed 50% less energy than the hot air roasting and got the best sensory scores. The effects of microwave, hot air, and the combined microwave/hot air roasting processes on the properties of carob powder were first investigated. d‐pinitol content of carob was increased by roasting processes. Different roasting processes increased organoleptic properties of carob powder. Total phenolic content and antioxidant activity of carob powder increased by roasting. The combined microwave/hot air roasting consumed 50% less energy than the hot air roasting and it is recommended to produce carob powder with preferable product quality.
The main objective of this research was to compare physicochemical parameters, antioxidant activity, lipid composition, and sensory analysis of initial and roasted carob pod powder ( Ceratonia siliqua L.) obtained at different roasting temperatures. The roasted products became darker and the average moisture content, water activity, oil content, and sweetness values decreased at higher temperatures. Total polyphenol content and antioxidant activity increased with increasing roasted temperature. Oleic acid, linoleic acid, and palmitic acid were the main fatty acids present in carob oil. Results showed that the roasted carob pod powders are sweeter, have more caramel-like taste, and have more cacao-like aroma at lower roasting temperatures but have more astringent taste, coffee-like aroma, and roasted aroma at higher roasting temperatures.
Ceratonia siliqua is a legume tree of considerable commercial importance for the flavor and sweets industry cultivated mostly for its pods nutritive value and or several health benefits. Despite extensive studies on C. siliqua pod non-volatile metabolites, much less is known regarding volatiles composition which contributes to the flavor of its many food products. To gain insight into C. siliqua aroma, 31 volatile constituents from unroasted and roasted pods were profiled using headspace solid-phase micro extraction (HD-SPME) analyzed via quadruple mass spectrometer followed by multivariate data analyses. Short chain fatty acids amounted for the major volatile class at ca. (71-77%) with caproic acid (20%) and pentanoic acid (15-25%) as major components. Compared to ripe pod, roasted ripe pod was found less enriched in major volatile classes i.e., short chain fatty acids and aldehydes, except for higher pyranone levels. Volatiles mediating for unheated and hot carob fruit aroma is likely to be related to its (E)-cinnamaldehyde and pyranone content, respectively. Such knowledge is expected to be the key for understanding the olfactory and taste properties of C. siliqua and its various commercial food products.
Changes in furan and other volatile compounds in the headspace of sliced carrot (Daucus carota ssp. Sativus) during air-drying were studied using selected ion flow tube-mass spectrometry. Drying temperatures of 93 to 133C were applied to study how the volatiles change during heat treatment. Furan concentration did not change significantly until the moisture content was below 40%. At less than 7% moisture content, the furan content increased with increasing drying temperature and decreasing moisture content. Furan concentration tended to increase exponentially with drying temperature and Hunter L-value. Changes in some major volatiles during drying were monitored. Many aldehydes, alcohols and terpenes decreased 60–90% during the early stages of drying; however, significant increases in (E)-2-octenal, 2,3-butanedione, 2-methylbutanal, acetone, bornyl acetate, butanal, butanone, furfural, furaneol and sotolon, hexanal, methyl acetate, monoterpenes, norfuraneol, undecane, β-caryophyllene, β-ionone, p-cymene, and p-cymenene were found at the end of drying.
Furan is a possible carcinogen, but data in dried fruits and vegetables are limited. Furan was formed in the headspace of dehydrated carrots, but it only formed significantly at higher temperatures of 113 to 133C, especially at moisture content less than 4%, so typical commercial drying conditions, at temperatures below 100C, will not be a concern for significant furan formation. Some volatile flavor compounds were formed and others lost during drying, which could be used to aid processors in limiting major flavor changes.
α,β-Unsaturated ketones can be prepared by reaction of differently substituted β-keto acids and aldehydes. The reaction is carried out under organocatalysis (β-alanine, 0.5 equiv.) and generates the enones with high E selectivity (>95 %). This version of the Verley–Doebner modification of the Knoevenagel reaction is a practical alternative to the classic Horner–Wadsworth–Emmons (HWE) reaction without the formation of high molecular weight byproducts. The process makes use of simple reagents and can be applied to large-scale synthesis under conditions compatible with atom-economy principles. Differently substituted aliphatic, aromatic, or heteroaromatic α,β-unsaturated ketones can be prepared. An example of a hydroformylation/Verley–Doebner Knoevenagel telescoped process is also described.
The Aroma Scanner A32 S, which mimics the human olfactory system, is based on conducting polymer sensor technology. The design of this electronic nose (capable of detecting and recognizing odours) is described. Two different products, earth-almond and carob (raw, and roasted for different lengths of time), were analysed by means of this electronic nose and by gas chromatography-mass spectrometry (GC-MS), in order to establish a basis of comparison between the two methods. After having analysed and compared the results obtained from both products, the Aroma Scanner was found to be a suitable method for monitoring the earth-almond roasting process, but not so effective at controlling carob roasting, as the correlation between sensor and GC-MS data was lower in the case of carob (R
2=0.74) than with earth-almond (R
2=0.98). This may be due to the inherent nature of the sample, as well as to the choice of signal processing technique. Therefore, the Aroma Scanner A32 S can be used as an efficient tool complementary to GC-MS analyses in recognizing aroma components of different products if the values concerning the volatiles formed in the roasting process do not appear very close to each other (Euclidean distance ≥0.5).
Studies with 13C-2 labeled glycine in model systems containing 3-hydroxy-2-butanone or glyceraldehyde have indicated that the β-dicarbonyl compounds, the immediate precursors of pyrazoles, are produced in Maillard model systems through two pathways. One pathway involves dehydration of α,β-dihydroxy carbonyl compounds with elimination of the α-hydroxyl group and the other through aldol condensation of an α-hydroxy carbonyl compound with simple aldehydes to produce α,β-dihydroxy carbonyl moiety that can undergo the above-mentioned dehydration to produce β-dicarbonyl structures. The conversion of β-dicarbonyls into pyrazoles can be achieved through 1,3-diimine formation by reaction with either two ammonia molecules or with a primary amine and an ammonia. After imine–enamine isomerizations the resulting dienamine can be oxidized to form pyrazole rings similar to the oxidation of two thiol moieties into disulfide linkages. The α-dicarbonyl species can serve as hydrogen acceptors since in their absence no pyrazole formation was detected. Glycine/3-hydroxy-2-butanone system generated 3,4,5-trimethyl-pyrazole (associated with the aroma of tequila) and 1,3,4,5-tetramethyl-pyrazole whereas, glycine/glyceraldehyde generated 1,5-dimethyl and 1,3,5-trimethyl-pyrazoles.
Free and glucosidic bound leaf volatiles of Degenia velebitica were isolated and fractionated simultaneously into H(2)O-soluble, H(2)O-insoluble, and highly volatile compounds by hydrodistillation-adsorption (HDA) and analyzed by GC/MS. Among the 24 constituents identified, the main compounds obtained by the HDA method were S- and/or N-atom containing compounds, i.e., 6-(methylsulfanyl)hexanenitrile (10; 26.78%), dimethyl trisulfide (6; 26.35%), 3,4,5-trimethylpyrazole (17; 13.33%), hex-5-enenitrile (2; 10.11%), dimethyl tetrasulfide (8; 4.93%), and pent-4-enyl isothiocyanate (7; 4.45%). In addition, O-glycosidically bound volatiles and free volatiles were isolated by solvent extraction. Sixteen volatile O-aglycones and twelve free volatile components were identified. The main O-aglycones were eugenol (19; 24.15%), 2-methoxy-4-vinylphenol (11; 11.50%), and benzyl alcohol (20; 9.49%), and the main free volatiles were (9Z,12Z)-octa-9,12-dienic acid (38.35%), hexadecanoic acid (22.64%), and phytol (5.80%). The H(2)O-soluble volatile fraction obtained by HDA, containing mostly glucosinolate degradation products and 3,4,5-trimethylpyrazole (17), was evaluated for antimicrobial activity by determining inhibition zones with the diffusion method as well as minimal inhibitory concentrations (MIC) and minimal microbicidal concentrations (MMC) with the micro-dilution method. The fraction expressed activity against the tested Gram-positive and Gram-negative bacteria as well as against yeast, with MIC values equal to or lower than 16.7 μg/ml.
Solid phase microextraction (SPME) was used in conjunction with GC-MS to monitor the changes in some major volatile flavors during drying of plums. The aroma profile was significantly modified during the process and substantial loss of the original volatile flavors was observed. The generation of some compounds was shown to be due to the thermal decomposition of carbohydrates. This paper discusses the importance of aroma profiling in detecting the progress of the chemical (degradation) reactions and identifying marker volatiles in quality control of the product.
A general and convenient synthesis of beta-ketols and alpha,beta-alkenones has been achieved by a Knoevenagel condensation of a beta-ketoacid with an aldehyde in aqueous medium. Saponification of a beta-ketoester by an aqueous KOH 10% solution gives the potassium salt of the beta-ketoacid, which is condensed in situ with an aldehyde at pH 7.8-8.0, at 60 degrees C for 5-6 h. The intermediate beta-ketocarboxylate is smoothly decarboxylated in the reaction medium, giving the beta-ketol in high yield (75-90%). Acidification of the reaction mixture at pH 1 and heating at 70 degrees C under vigorous stirring for 6 h, leads directly to the corresponding alpha,beta-unsaturated ketone in good yield (65-75%).
The seeds of the main Italian carob varieties, Latinissima and Tantillo, and those of two selected accessions of Latinissima were evaluated in terms of yield, rheological properties, and sugar composition of the endosperm (LBG). The separation of the seed components in Latinissima and its seedlings yielded meanly 52.2% gum, 17.4% germ, and 30.5% tegument, whereas Tantillo furnished a lower gum yield (38.5%) and a higher yield of tegument (45.8%). The viscosity of 1% LBG aqueous solutions was measured at different shear rates (3-60 rpm), pH values (3.0-6.0), and temperatures (10-60 degrees C). The best results were shown by Latinissima, whereas Tantillo provided always the poorest thickening capacity. The content of free simple sugars and sucrose in the raw flours, the total monosaccharide residues after acidic hydrolysis, the mannose/galactose ratio, and the distribution of polysaccharides by size exclusion chromatography accounted for the observed viscosities. The seeds of Latinissima showed the highest technological potential.
Vacuum distillation of heat-treated carobs gave an aqueous, colorless, sweet-smelling distillate which was tested over a wide range of concentrations and found to be highly attractive to adultOryzaephilus surinamensis (L.). The materials responsible for the aroma were isolated from the distillate by saturating with sodium chloride and extracting into diethyl ether as separate acidic, neutral, and basic fractions. The extraction efficiency was checked by recombining portions of the three fractions and replacing the diethyl ether with water to give a "reconstituted distillate;" this was almost as attractive as the original distillate. Bioassay of aqueous solutions of the three separate fractions showed that the acidic was attractive, while the neutral and basic had little effect. The five major components of the acidic fraction were found to be acetic, isobutyric,n-butyric, 2-methylbutyric, and hexanoic (caproic) acids. Bioassay of these in aqueous solution, both separately and combined, showed that hexanoic acid was the most attractive and may be responsible for both the longer-lasting attractive effect of the carob distillate and for the effectiveness of carobs themselves used in bait bags to detect stored product insects.
Volatile components of carob beans were analysed using established procedures. In all, 169 components (ca 97.4% of the total isolate) were positively identified, of which 163 are reported as carob bean volatiles for the first time. A further eight components (ca 0.5 %) were partially characterized. Seven aliphatic acids represented an extraordinarily high level (77.5%) of the isolate, the major contributors being methylpropanoic acid (45.0%) and hexanoic acid (19.0%). The non-acid volatiles contained 25 aliphatic esters (10.52%), most of which derived from the above acids, together with a range of classic volatile products deriving largely from the high sugar content and the lower protein and lipid content of mature carobs.
This review covers the occurrence of pyrrole derivatives in food systems as well as their formation in model systems and organoleptic properties.
Methionine and methionine sulfoxide were mixed with or without glucose in distilled water, individually. These solutions were heated in closed sample cylinders at 180 degrees C for 1 h. The volatile compounds generated were extracted using methylene chloride and analyzed by GC and GC-MS. Pyrazine compounds, especially 2,5-dimethyl-, 2-ethyl-5-methyl-, trimethyl-, and methylpyrazines were the predominant compounds among those generated from thermal interactions of glucose and methionine or methionine sulfoxide. The formation of methional or those compounds derived from methional was found to be more favorable from the thermal degradation of methionine, whereas the formation of dimethyl polysulfides, especially dimethyl disulfide and dimethyl trisulfide, was found to be more favourable from the thermal degradation of methionine sulfoxide. Glucose was found to have a catalytic effect on the formation of volatile compounds from the thermal degradation of methionine or methionine sulfoxide.
The effect of residual amide levels in wheat gluten on the thermal generation of aromas and the formation of brown color was studied. This was accomplished by deamidating native wheat gluten to different levels and heating each fraction with glucose in a closed system at 150 degrees C for 60 min. The volatiles from the resulting reactant mixtures were then isolated and identified by GC/MS. Brown color development was measured spectrophotometrically. It was found that the Maillard-derived aromas decreased as amide levels decreased, as did the formation of brown color. Explanations for these trends are discussed.
Chemical analyses of the fruit of two carob varieties were made during 1969 at fortnightly intervals during the six months preceding harvest.
The sugar content of the pods increased rapidly from the end of May onwards while the crude protein and crude fibre contents decreased. Sucrose increased from about 2·5% in late March to about 35% at harvest in mid-August. The main increase in sugar content occurred after the pod had attained its full size in late May.
The composition of mesquite pods (Prosopis pallida L) (PP), a legume cultivated in the large desert areas of Peru, was studied. These fruits have at the present time very little practical or commercial use. Taking into account the morphological and compositional similarities to Mediterranean carob pods (Ceratonia siliqua L) (CS), which are widely used in the food industry, some applications of PP are considered. PP shows better nutritional properties than CS, mainly owing to its lower polyphenolic content and higher protein digestibility.
Determination of the tannins, pectins, hemicellulose, cellulose, nitrogen, mineral elements, total and reducing sugars and fat contents was carried out on carob pods from Mallorca, Spain. The results are compared with data from the literature. A survey of papers on the composition and practical applications of carob pods is included.
The ethyl acetate-soluble phenolic compounds were isolated from mature and ripened samples of four new pear selections. Phenolic spectra were related to textural parameters of shear analysis and sclereid development and tendency to undergo oxidative browning. Anomalous textural parameters were associated with low phenolic content, notably of chlorogenic acids, and tendency to brown was associated with higher levels of chlorogenic acid on ripening.
Near-infrared (NIR) reflectance spectroscopy was used to develop calibration equations to measure chemical composition (dry matter, crude protein and reducing sugars) in carob samples. Calibration equations were obtained by multiple linear regression of conventional laboratory analysis values on NIR spectra from 75 samples and verified with 20 additional samples from the original population, collected on the Spanish Mediterranean littoral in different years. A Tecnichon Infra Alyzer model 450 monochromator interfaced with an IBM PS2 microcomputer was used for the study. Two alternative calibrations were chosen using three and six wavelengths. The coefficients of multiple correlation ranged from 0·91 to 0·95 and the standard errors of calibration ranged from 0·38 to 1·62. The study showed that NIR analysis can be used for predicting the chemical composition of carob pulp.
Sample preparation techniques for gas-liquid chromatographic analysis of biologically derived aromas
- T H Parliment
Parliment, T. H. Sample preparation techniques for gas-liquid chromatographic analysis of biologically derived aromas. In Biogeneration of Aromas; Parliment, T. H., Croteau, R., Eds.; American Chemical Society: Washington, 1986; pp 34-52.
The amino acid profile of carob). Ind. Obst-Gemueseverw-ertung
- N Artik
- S Erbas
- Das
Artik, N.; Erbas, S. Das Aminosä ureprofil von Johannisbrot (The amino acid profile of carob). Ind. Obst-Gemueseverw-ertung 1988, 73 (3), 83-86.
La carruba: Attuali e potenziali utilizzi nell' alimentazione umana (The carob fruit: Actual and potential use for human nutrition). Riv. Ital. Sostanze Grasse
- A Lanzani
Lanzani, A. La carruba: Attuali e potenziali utilizzi nell' alimentazione umana (The carob fruit: Actual and potential use for human nutrition). Riv. Ital. Sostanze Grasse 1982, 54, 344-348.
Eight-Peak Index of Mass Spectra
- Mass Spectrometry Data
- Center
Mass Spectrometry Data Center. Eight-Peak Index of Mass Spectra; MSDC: Nottingham, U.K., 1974; Vol. 1-3.
Compilation of Mass Spectra of Volatile Compounds in Food; Central Institute for Nutrition and Food Research-TNO: Zeist, The Netherlands, 1979. Canellas, J.; Pou, J.; Mulet, A Protein enrichment of carob kibbles after sugar extraction
- N Braw
- J Bowman
- A C Tas
- G F Lavos
Braw, N.; Bowman, J.; Tas, A. C.; LaVos, G. F. Compilation of Mass Spectra of Volatile Compounds in Food; Central Institute for Nutrition and Food Research-TNO: Zeist, The Netherlands, 1979. Canellas, J.; Pou, J.; Mulet, A Protein enrichment of carob kibbles after sugar extraction. Food Sci. Technol. (London) 1989, 22, 73-77.
Taking the headache out of chocolate. Bakers' Rev. 1984, 38-39, 43. Haslam, H. Plant Polyphenols
- C Harvey
Harvey, C. Taking the headache out of chocolate. Bakers' Rev. 1984, 38-39, 43. Haslam, H. Plant Polyphenols; Cambridge University Press: Cambridge, 1989; p 11.
Pá rká nyi, C. Mechanisms of formation of hetero-cyclic compounds in Maillard pyrolysis reactions
- G Vernine
Vernine, G.; Pá rká nyi, C. Mechanisms of formation of hetero-cyclic compounds in Maillard pyrolysis reactions. In The
Saura-Calixto, F. Composition and potential uses of mesquite pods (Prosopis pallida L.): Comparison with carob pods (Ceratonia siliqua L.)
- L Bravo
- N Grados
Bravo, L.; Grados, N.; Saura-Calixto, F. Composition and potential uses of mesquite pods (Prosopis pallida L.): Comparison with carob pods (Ceratonia siliqua L.). J. Sci. Food Agric. 1994, 65, 303-306.
Carob as a food: A historic review
- W A Carlson
Carlson, W. A. Carob as a food: A historic review. Food Sci. Technol. (London) 1980, 13, 51-52.
Techniques of analysis of flavors In Food Flavours, Part A. Introduction
- D A Cronin
Cronin, D. A. Techniques of analysis of flavors. In Food Flavours, Part A. Introduction; Morton, I. D., MacLeod, A. J., Eds.; Elsevier Science Publishers Co.: New York, 1982; pp 15-48.
The Carob (Ceratonia siliqua): A Report to Tate & Lyle Ltd
- K Mitrakos
Mitrakos, K. The Carob (Ceratonia siliqua): A Report to Tate & Lyle Ltd; Institute of General Botany, University of Athens: Athens, Greece, 1968; pp 1-29.
- Parliment T. H.
Institute of General Botany
- K Mitrakos