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Phenolics characterization and antioxidant activity of six different pigmented Oryza sativa L. cultivars grown in Piedmont (Italy)
... This last variety has two major subspecies: Oryza sativa L. spp japonica, rife in South-East Asia, Japan, Europe, and the U.S., and Oryza sativa L. spp indica, which is primarily consumed in India and Southern China. Italy is the main producer of rice (Oryza sativa L.) in Europe; approximately 90% of its production is concentrated in two Northern regions-Piedmont and Lombardy [1]. Even though white rice varieties are the most consumed, pigmented rice became more popular in the last few years due to their antioxidant properties and phenolic content, and the potential beneficial effects on the human health [2]. ...
... Cyanidin-3-O-glucoside and peonidin-3-O-glicoside were tentatively identified by comparison with retention times of individual authentic standard molecules and their UV-Vis spectra; the quantification was performed on the basis of calibration curves obtained with the corresponding standards. Cyanidin-3-O-rutinoside and peonidin-3-O-rutinoside were identified based on chromatographic characteristics determined in our previous study [1] and were quantified as glucoside equivalents. In the Supplementary material file, the chromatogram of the standards and, as an example, the chromatogram of a "risotto" rice sample are reported. ...
... In fact, all the studies reports that cyanidin-3-O-glucoside is the main anthocyanin, followed by peonidin-3-glucoside [1,8,9,25,[27][28][29]. This is confirmed for the Artemide black rice analyzed in this work; cyanidin-3-O-glucoside was the highest content anthocyanin (3623 ± 126 µg/g d.w.), accounting for about 89% of the identified most abundant anthocyanins, followed by peonidin-3-glucoside (323 ± 9 µg/g d.w.). ...
The consumption of black rice has grown in recent years due to its particular organoleptic properties and high content of antioxidant polyphenols, which make it a sort of natural functional food. However, heat treatment applied during cooking can influence the content and the composition of antioxidant components, particularly anthocyanins, the main compounds of black rice, responsible for its color. The aim of this work was to evaluate the impact of different cooking techniques (boiling, microwaves oven, under pressure pot and risotto preparation) on the chemical and nutritional composition of the Italian Artemide black rice. Different cooking methods had significant and different impact on rice composition. Proximate composition was not affected by cooking, except for moisture, which increased, and fiber content, which decreased. Total polyphenols, total anthocyanin content, and antioxidant capacity were reduced; moreover, anthocyanins and phenolic acids determined by HPLC-DAD generally decreased, with the only exception of protocatechuic acid. The risotto preparation was the most useful cooking technique to preserve anthocyanins and antioxidant activity. Our results demonstrated the importance to study cooking methods and to evaluate their impact on rice characteristics, in order to preserve its nutritional and beneficial properties.
... More recently, the interest in pigmented rice and its consumption have also grown in Western countries. This can be attributed to the present of bioactive compounds, including anthocyanins, flavonoids and phenolic acids [2][3][4][5][6]. Thanks to these molecules, several biological activities associated with rice consumption were shown, such as antiatherosclerosis [7][8][9], antioxidant, anti-inflammatory and inhibitory properties against α-glucosidase and α-amylase [10]. ...
... g gallic acid/kg in Artemide rice and it ranged from 8.22 to 11.88 g gallic acid/kg in the Venere rice batches (Figure 1a). These contents agree with those of a recent study conducted by Bordiga et al. [5] that found TPI values of 11.87 ± 1.16 g gallic acid/kg for the Artemide rice and 6.20 ± 0.82 g gallic acid/kg for the Venere rice. In Carnaroli, TPI assay detected a very low amount of phenolics present in the outer layers of the caryopsis. ...
... As expected, anthocyanins were not detected in Carnaroli cultivar. The obtained values were higher than those reported in Bordiga et al. [5], in which the total anthocyanin contents were 1.40 ± 0.33 g/kg for Artemide and 0.78 ± 0.17 g/kg for Venere. The differences can be attributed both to the agronomic variability of rice in different years and the different methods used to assess the total anthocyanin content. ...
Pigmented rice cultivars, namely Venere and Artemide, are a source of bioactive molecules, in particular phenolics, including anthocyanins, exerting a positive effect on cardiovascular systems thanks also to their antioxidant capacity. This study aimed to determine the total phenol index (TPI), total flavonoids (TF), total anthocyanins (TA) and in vitro antioxidant capacity in 12 batches of Venere cultivar and two batches of Artemide cultivar. The rice was cooked using different methods (boiling, microwave, pressure cooker, water bath, rice cooker) with the purpose to individuate the procedure limiting the loss of bioactive compounds. TPI, TF and TA were spectrophotometrically determined in both raw and cooked rice samples. Rice samples of Artemide cultivars were richer in TPI (17.7–18.8 vs. 8.2–11.9 g gallic acid/kg in Venere rice), TF (13.1 vs. 5.0–7.1 g catechin/kg rice for Venere rice) and TA (3.2–3.4 vs. 1.8–2.9 g Cy-3glc/kg for Venere rice) in comparison to those of Venere cultivar; as well, they showed higher antioxidant capacity (46.6–47.8 vs. 14.4–31.9 mM Trolox/kg for Venere rice). Among the investigated cooking methods, the rice cooker and the water bath led to lower and comparable losses of phenolics. Interestingly, the cooking water remaining after cooking with the rice cooker was rich in phenolics. The consumption of a portion of rice (100 g) cooked with the rice cooker with its own cooking water can supply 240 mg catechin and 711 mg cyanidin 3-O-glucoside for Venere rice and 545 mg catechin and 614 mg cyanidin 3-O-glucoside for Artemide rice, with a potential positive effect on health.
... Pigmented rice grains are rich in a variety of antioxidant compounds, including flavones, flavonols, isoflavones, anthocyanins, procyanidins, phenolics, tannins, tocols, sterols, γ-oryzanols, vitamins, amino acids, and essential oils [5,6,14,15]. Black rice is particularly rich in anthocyanins (cyanidin 3-galactoside, cyanidin 3,5-diglucoside, cyanidin 3-glucoside, cyanidin 3-rutinoside, peonidin 3-glucoside, etc.), whereas red rice contains higher levels of procyanidins [16,17]. ...
... Pigmented rice, especially BR varieties, contain higher levels of flavonoids, anthocyanins, and phenolic acids and possess diverse pharmacological attributes, e.g., antidiabetic, anti-hyperlipidemia, antioxidant, anticancer, cardioprotective, anti-osteosclerosis, antiallergic, etc., [6,7,9,11,12,14,34]. Herein, we found that over 170 MDA metabolites, including flavones, flavanones, flavonols, isoflavones, anthocyanidins, chalcones, phenolic acids, alkaloids, quinones, lignans, coumarins, and terpenoids, have higher contents in BR, followed by RR. ...
Pigmented rice grains are important resources for health and nutritional perspectives. Thus, a thorough dissection of the variation of nutrients and bioactive metabolites in different colored rice is of global interest. This study applied LC–MS-based widely targeted metabolite profiling and unraveled the variability of metabolites and nutraceuticals in long grain/non-glutinous black (BR), red (RR), green (GR), and white rice (WR) grains. We identified and classified 1292 metabolites, including five flavonoid compounds specific to BR. The metabolite profiles of the four rice grains showed significant variation, with 275–543 differentially accumulated metabolites identified. Flavonoid (flavone, flavonol, and anthocyanin) and cofactor biosynthesis were the most differentially regulated pathways among the four rice types. Most bioactive flavonoids, anthocyanidins (glycosylated cyanidins and peonidins), phenolic acids, and lignans had the highest relative content in BR, followed by RR. Most alkaloids, amino acids and derivatives, lipids, and vitamins (B6, B3, B1, nicotinamide, and isonicotinic acid) had higher relative contents in GR than others. Procyanidins (B1, B2, and B3) had the highest relative content in RR. In addition, we identified 25 potential discriminatory biomarkers, including fagomine, which could be used to authenticate GR. Our results show that BR and RR are important materials for medicinal use, while GR is an excellent source of nutrients (amino acids and vitamins) and bioactive alkaloids. Moreover, they provide data resources for the science-based use of different colored rice varieties in diverse industries.
... Black rice starch is said to reduce the true digestibility of the protein and increases the digestibility of the starches because of the reason that it is extremely rich in phenolics (Rini et al 2019), flavonoids, and anthocyanins. It shows higher antioxidant activity when compared to white and other pigmented rice varieties (Bordiga et al., 2014). The higher protein and anthocyanin content in black rice starch increases its nutritional and antioxidant properties, which are beneficial to health (Sati & Singh, 2019). ...
... In a study conducted by Zhou et al. (2014) for understanding the changes in starch characteristics, phenolics, flavonoids, antioxidant, and proanthocyanidin, it was found that all the pigmented rice starches follow a similar pattern of degradation only the degree differences in different landraces, for brown and black rice starch the aging process induces a change in the amount of phenolics, flavonoids, and proanthocyanidins. 7.10 Application and advantages of black rice starch over other sources 7.10.1 Health effects associated with black rice starch Black rice varieties contain a rich heterogeneous mixture of phytochemicals which may provide a basis for the potential health benefits (Bordiga et al., 2014). It has been reported by Ngo et al., (2022) that the digestibility of the starch of black rice is affected by black rice anthocyanin which confers a dose-dependent reduction in starch digestibility, and its use in food formulations affects the overall digestibility not only through enzyme inhibition but also changes in food microstructure. ...
The nutritional and functional quality of starch in black rice cultivars varies differently with different landraces for which efforts should be made to maintain the geographic identity, value chain, and utilization of the same. Black rice starch is found to have a better physicochemical and nutritional profile in terms of its thermal, rheological, and presence of bioactive compounds as compared to conventional starch sources such as white rice and wheat. It has more resistant starch content and the starch profile tends to have a bit longer cooking time, moderate gruel solid loss, low water uptake ratio, and swelling capacity while cooking. In this chapter, the nutritional, physicochemical characteristics, functionality, isolation, modification, and applications of black rice starch have been studied in detail with a focus on Indian black rice.
... (from white to black) (Bordiga et al., 2014). Fig. 3 illustrates the range of SPC detected in pigmented and non-pigmented rice originating from different parts of the world. ...
... Results are expressed as mg equivalents of gallic acid (GAE)/g (n = 6 for Orange samples; n = 9 for Ermes rice; n = 3 for other samples). Fig. 3. Comparison between literature data (Bordiga et al., 2014;Melini et al., 2019) and results from the present study on the SPC. correlated with their antioxidant capacity. ...
... These compounds are beneficial to human health and play an important role in antioxidant activity and reducing the risk of cancer, diabetes, cardiovascular and neurodegenerative diseases [64][65][66]. Many previous studies have found that black and red rice have higher levels of total phenols than white rice, and black rice has higher levels of phenolic acid than red rice [65,67,68]. Pengkumsri et al. [69] studied bioactive compounds and antioxidant properties of Chiang Mai black rice, Suphanburi-1 brown rice, and Mali red rice from the northern part of Thailand. ...
... Brown red jasmine (BRJ) rice showed higher DPPH activity than Kam Leum Pua (KLP) black rice and Japanese brown rice (JBR) [21]. Both Chiang Mai Black rice (CBLR) and Mali Red rice (MRR) had the highest antioxidant activity, while Suphanburi-1 Brown rice (SBrR) showed the lowest antioxidant activity [67]. Waewkum and Singthong [50] described that most red and black rice had higher antioxidants than non-pigmented rice, with Red Hom Mali (RHR) showing higher antioxidant activity than Riceberry (RBR), Homnil (HNR), and Hom Mali (HR) respectively. ...
The objective of this study was to investigate the physical characteristics, phytochemical contents, and antioxidant activity of 10 organic-pigmented rice varieties including Tubtim Chumpae, Niaw Daeng, Nieng Guang, Mali Daeng, Hom Nil, Niaw Dam, Riceberry, Mali Gomain Surin, Malinil Surin, and Pa Ga Am Puen (obtained from Tapthai organic villages, Tha-mo, Prasat, Surin province, Thailand in June, 2021). The physical characteristics investigated included grain length, width, shape, and color in both paddy and unpolished rice. The results revealed that the mean length and width of paddy rice grain varieties ranged from 6.58 to 10.85 mm and 2.12 to 3.27 mm, respectively, while the length and width of unpolished rice grain were 5.94 to 7.53 mm and 1.74 to 2.61 mm, respectively. Most organic-pigmented rice varieties had a slender shape except for Nieng Guang and Niaw Dam, which were moderately shaped. There were 5 colors of paddy rice, including straw, purple, purple straw, black and black furrow on straw background and light purple straw while unpolished rice showed red, dark purple, black, purple, and light brown color. The anthocyanin content, total phenolic compounds and antioxidant activity of different rice varieties showed a significant difference in the range of 4.38 to 77.96 mg/100 g DW, 42.94 to 341.19 mg GAE/100 g DW and 2.71 to 34.77 mM TE/100 g DW, respectively. Niaw Dam exhibited the highest anthocyanin concentrations. The highest total phenolic content was found in Mali Daeng and Nieng Guang, resulting in high antioxidant activity. This study suggested that pigmented rice is rich in phytochemicals and antioxidants. Nieng Guang, in particular, could be promoted for cultivation and beneficial use in the food, pharmaceutical, and cosmetic industries. HIGHLIGHTS Surin province is one of the principal regions with diverse indigenous and commercial rice varieties in Thailand The grain shape of eight varieties of rice, including Tubtim Chumpae, Niaw Daeng, Mali Daeng, Hom Nil, Riceberry, Mali Gomain Surin, Malinil Surin and Pa Ga Am Puen were slender while that of Nieng Guang and Niaw Dam varieties were moderate. The physical aspects of rice indicate its quality, market value and have essential role in selecting, handling, storing, and processing of rice Niaw Dam black rice had a high content of anthocyanin while Mali Daeng and Nieng Guang red rice had the highest content of total phenols, resulting in higher antioxidant activity than the other Pa Ga Am Puen brown rice had the lowest anthocyanin content, total phenolic content and antioxidant activity The basic information of this study might be useful for selecting rice varieties for future rice breeding and provide pigmented rice nutrition information especially indigenous pigmented rice which has potential in the food, pharmaceutical and cosmetic industries GRAPHICAL ABSTRACT
... Purple rice is rich in bioactive micronutrients, particularly polyphenols, which have antithrombotic, anti-inflammatory, and antioxidant properties (Ed Nignpense et al., 2019;Ed Nignpense et al., 2020;Rao et al., 2018). Anthocyanins are a group of polyphenols that produce a dark colour and have been shown to express bioactive capabilities (Bordiga et al., 2014;Zhou et al., 2020). These anthocyanins are primarily responsible for the free radical scavenging and anti-inflammatory activities of purple rice and other coloured rice varieties (Callcott et al., 2019). ...
... Only the identification of VA (P5), C3G (P4), P3G (P7), and PCA (P1) was consistent with the previous investigations by Rao et al. (2018). Rutin and quercetin were detected in this study using standards and consistent with literature studying pigmented rice (Bordiga et al., 2014;Peanparkdee et al., 2020Peanparkdee et al., , 2021. Sriseadka et al. (2012) reported myricetin-7-O-glucoside, dihydroquercetin and isoquercetin as rice flavonoids in Thai black rice varieties using UHPLC-ESI-MS analysis. ...
Polyphenol-rich purple rice has been shown to exhibit a wide range of health properties including antioxidant activity. This study aimed to determine the impact that gastrointestinal digestion of purple rice had on its phenolic bioaccessibility and antioxidant activity. Our results demonstrated a significant difference (p < 0.01) in bioaccessible phenolic content level and antioxidant activity between simulated gastric and intestinal digestion. However, mass spectrometry and ultra-high-performance liquid chromatography (UHPLC) coupled with online ABTS•+ scavenging activity demonstrated a significant loss in the number of polyphenols that were bioaccessible after digestion. Interestingly, substantial free radical scavenging activity was retained after digestion due to the bioaccessibility of bioactive compounds such as tryptophan and protocatechuic acid. Hence, purple rice may be considered as a source of bioaccessible phenolic and antioxidant compounds.
... Their healthy properties, such as anticancer [3,4] and anti-inflammatory activities [5,6], are due to their antioxidant composition [7][8][9]. Several bioactive compounds, mainly belonging to the class of phenolic compounds, have been in fact identified in the coloured caryopses [8,10,11]. Anthocyanins, since they accumulate in the grains during maturation, are the most abundant antioxidant compounds occurring in pigmented rice [12], especially cyanidin-3-glucoside [13]. Prevention of cardiovascular diseases [14], retinal protection activity, inhibition of cholesterol adsorption [15] and neuroprotective effect [15,16] are among the other beneficial biological activities of dietary anthocyanins investigated and reported in literature. ...
... 'Violet Nori' rice, in particular, presents an anthocyanin content generally higher or at least comparable with that in other best known black cultivar ('Venere', 'Artemide' and 'Nerone') [1] and it has been demonstrated [2] that even when subjected to the effect of cooking, 'Violet Nori' preserves an amount of anthocyanins still higher or equal to the values reported in the fruits and vegetables generally considered as the best sources of dietetic anthocyanins (cranberries, black plums, red raspberries and eggplants) [17]. The dark purple colour of 'Violet Nori' rice, as well as that of other black rice cultivar, is precisely due to the presence of a high content of anthocyanins in its pericarp layer [10]. Other classes of flavonoids contribute to the health-promoting activities of pigmented rice too, especially the most abundant groups of flavonols and flavones [8]. ...
Oryza sativa L. ‘Violet Nori’ is an Italian cultivar of spontaneous growing aromatic purple rice which is particularly rich in polyphenolic compounds, especially anthocyanins, conferring it an excellent antioxidant capacity. The present study aimed at increasing the extraction yields of its antioxidant compounds with green strategies and it is divided into two steps. The first step concerned a solubility study of the targeted polyphenols in different ethanol:water mixtures by means of a theoretical prediction method, using the simulation program COSMO-RS, and the subsequently confirmation of the computational results by practical experiments. Once the best extraction mixture was identified, the second step of the work was performed, with the purpose of intensifying the extraction yield. Therefore, various innovative green extraction techniques, including ultrasound, using both the probe system and the ultrasonic bath, bead milling, microwave and accelerated solvent extractions were tested and compared to conventional maceration.
Results, expressed in terms of total phenolic and total monomeric anthocyanin contents, showed that the best extracting solvent for ‘Violet Nori’ rice was the mixture ethanol:water (60:40 v/v), being COSMO-RS computational predictions in good correlation with the experimental results. Moreover, the most efficient techniques to extract the antioxidant compounds resulted to be both ultrasound-assisted extraction probe and bead milling, that in only 5 minutes got the same extractive efficiency obtained after 3 hours of conventional maceration.
... Italy is the main rice producer in Europe, particularly in the area between the Piedmont and Lombardy regions, where a large collection of registered varieties characterized by different nutritional and technological features is maintained. The main popular registered varieties of black rice grown in Italy, and in particular in the Piedmont region, are Artemide, Venere and Nerone, while those of red rice are represented by Ermes and Ris Rus with a great culinary appreciation by the Italian population [56]. Additionally, the Italian brand "Riso Scotti" has created an all-Italian value chain, marketing the versatile black rice Venere, suited for preparation of "risotto", pasta, cous cous, cakes and other snacks. ...
Cereals are the basis of much of the world’s daily diet. Recently, there has been considerable interest in the beneficial properties of wholegrains due to their content of phytochemicals, particularly polyphenols. Despite this, the existing data on polyphenolic composition of cereal-based foods reported in the most comprehensive databases are still not updated. Many cereal-based foods and phenolic compounds are missing, including pigmented ones. Observational epidemiological studies reporting the intake of polyphenols from cereals are limited and inconsistent, although experimental studies suggest a protective role for dietary polyphenols against cardiovascular disease, diabetes, and cancer. Estimating polyphenol intake is complex because of the large number of compounds present in foods and the many factors that affect their levels, such as plant variety, harvest season, food processing and cooking, making it difficult matching consumption data with data on food composition. Further, it should be taken into account that food composition tables and consumed foods are categorized in different ways. The present work provides an overview of the available data on polyphenols content reported in several existing databases, in terms of presence, missing and no data, and discusses the strengths and weaknesses of methods for assessing cereal polyphenol consumption. Furthermore, this review suggests a greater need for the inclusion of most up-to-date cereal food composition data and for the harmonization of standardized procedures in collecting cereal-based food data and adequate assessment tools for dietary intake.
... Pigmented rice varieties include black, red, deep-purple, brown-reddish, etc., resulting from the accumulation of natural pigments in the seed coat, pericarp, and aleurone [4]. Pigmented rice grains are rich in a variety of nutraceuticals, including flavones, flavonols, isoflavones, anthocyanins, procyanidins, phenolics, tannins, tocols, sterols, γ-oryzanols, vitamins, amino acids, and essential oils compared to white rice [3][4][5][6]. Accordingly, most studies have focused on comparing the pigmentation processes and quality characteristics of white and pigmented rice [3,7,8]. In contrast, comparative metabolic explorations concerning the quality differences between common and glutinous rice are scarce, limiting rice quality improvement and value addition. ...
Interest in glutinous rice consumption has been expanding in East Asia. However, the extent of metabolite variation between common and glutinous rice has not been fully explored to identify metabolic targets for rice quality improvement. Thus, the objective of this study was to provide insights into the variation of metabolites and nutraceuticals between common and glutinous rice. Two black rice (common rice, BL-N, and glutinous rice, BL-G) and two white rice (common rice, WH-N, and glutinous rice, WH-G) types were analysed via LC-MS-based widely targeted metabolic profiling. We identified 441 and 343 types, including 160 key overlapping differentially accumulated metabolites between BL-N_vs_BL-G and WH-N_vs_WH-G, respectively. Glutinous rice showed a higher relative content of most categories of metabolites, except for quinones (in BL-N) and tannins (in WH-N). Seven vitamins, including B6, B3, B5, B13, isonicotinic acid, N-(beta-D-glucosyl)nicotinate, and 4-pyridoxic acid-O-glucoside, were significantly up-regulated in BL-G compared to BL-N. The biosynthesis of cofactors, zeatin biosynthesis, citrate cycle, amino acid metabolism, alpha-linolenic acid metabolism, and glyoxylate and dicarboxylate metabolism was the most differentially regulated pathway. Key differential metabolites in citrate cycle include citrate, isocitrate, fumarate, malate, succinate, and 2-oxoglutarate; in amino acid metabolism (L-serine, L-cysteine, L-lysine, L-glutamine, L-methionine, and L-tryptophan); and in glycolysis (UDP-glucose, D-glucose-1P, D-glucose-6P, and D-fructose-6P). The data resources in this study may contribute to a better understanding of the function and nutritional value of glutinous rice.
... Better retrogradation properties have been observed in pigmented rice, which increases the resistant starch content (Jayaraman et al., 2019). Owing to all the facts stated above, many researchers have attempted to study black rice types for their rich and diverse variety of phytochemicals, which serves as a foundation for possible health advantages (Bordiga et al., 2014). It has been shown to be effective in reducing the risk of lifestyle disorders such as diabetes, cholesterol, hypertension, obesity, allergy, anti-atherosclerosis and increased glycemic index (Deng et al., 2013). ...
Twelve aromatic black-pigmented rice landraces collected from different districts of Assam and Manipur were
analyzed for physicochemical, nutritional, and cooking properties along with phytochemical and starch characteristics. Chakhao black rice varieties are well known from Manipur, but it is not the case for Assam black rice
landraces and is largely unknown. In the current study, different characterization parameters were combined,
correlated, and analyzed by performing Pearson correlation, unweighted pair group method with arithmetic
mean (UPGMA) based clustering and principal component analysis (PCA) for selection of better performing
landraces based on loading factors of all component’s v/s principal components. Results showed that Darrang
(DR) black rice landrace contained the highest amount of protein (12.62%), whereas the fat content was almost
similar in all the landraces. Cooking time of all landraces ranged from 21 to 27 min. EI and TH (Chakhao
poreiton) recorded maximum levels of anthocyanin content (171.05 and 171.97 mg C3G/100 g) followed by
Golaghat (GG; 168.37). Physically, the kernels varied significantly in size and shape. Highest levels of total
phenolic were observed in WI (Chakhao amubi- 175.08 mg GAE /100 g). The amylose content of all the landraces
was in the range of waxy and low. The resistant starch ranged from 4.72% to 21.17% in raw rice and
3.28–15.38% in gelatinized rice. Elemental distribution was found to be higher in aleurone layer of all landraces
than that of endosperm. The statistical analysis highlighted that Assam landraces, especially the ones from upper
Assam are equally competent as Manipur black rice for the desired quality.
... The individual anthocyanins in methanolic rice extracts were quantified with RP-HPLC by Agilent Technologies by using RP C18 column (150 mm x 4.6 mm, 2.7 μm particle size, Ascentis Express, USA) under gradient conditions by the procedure described by Bordiga et al. [25]. The column was injected with rice extracts and eluted with the help of a mobile phase made up of solvent A, 0.1% Formic acid, and solvent B, 100% Acetonitrile as follows: 5 min, 95% A and 5% B; 25 min, 95% A, and 5% B; 5 min, 95% A and 5% B with of 1 ml/min. ...
The study was conducted to investigate the effects of bioprocessing by germination and hydrothermal treatment of pigmented red (Jyothi) and black (Chak hao) rice paddy on nutrients, nutraceuticals and antioxidant activities in unpolished rice and comparison with the raw unpolished rice. The results of bioprocessing in the red sample showed an increase in gamma-aminobutyric acid (GABA)(117%), γ-oryzanol (46%), soluble phenolics such as gallic acid (GA)(194%), t-cinnamic acid (80%), bound phenolics like GA (1104%), protocatechuic acid (PCA)(66%) and vanillic acid (VA)(55%) and NO scavenging activity (35%) compared to control. In contrast, the black variety showed an increase in GABA (68%), γ-oryzanol (13%), and soluble phenolics like catechin (CAT)(47%), syringic acid (SYN)(148%), PCA (78%), t-cinnamic acid (590%) and bound phenolics like GA (242%), SYN (260%), caffeic acid (CAF)(115%), campesterol (12%) and β-sitosterol (17%) compared to control. Bioprocessing and hydrothermal treatment in red showed no change in GABA and phytosterols, while an increase in γ-oryzanol (39%), total anthocyanin (62%), bound phenolics such as PCA (30%), CAF (17%) and t-cinnamic acid (35%), and NO scavenging activity (13%) compared to bioprocessed rice. In contrast, black showed an increase in GABA (17%), bound phenolics like CAT (167%), t-cinnamic acid (64%), ferulic acid (FA)(79.5%), campesterol (14%), stigmasterol (29%) and β-sitosterol (13%), and NO scavenging activity (26%) compared to bioprocessed rice. Significant retention of total phenolics, flavonoid, γ-tocotrienol, γ-tocopherol, α-tocopherol and phytosterols content, and DPPH radical scavenging and total antioxidant activity in both the samples was observed in-spite of processing compared to control. Changes in the contents of nutrients and nutraceuticals are variety-specific. Bioprocessing and hydrothermal treatment resulted in nutraceutical-rich pigmented whole red and black rice, which can be used to develop functional foods to prevent lifestyle disorders.
... Black rice is mainly produced in Southeast Asia, but in recent years its cultivation in Italy has been gaining ground because of a greater culinary appreciation by the Italian population. The main varieties of black rice grown in Italy, and in particular in the Piedmont region, are Artemide, Venere and Nerone [8]. Artemide black rice is a pigmented variety obtained from the hybridization between Venere black rice and a white indica variety; it is particularly rich in healthy polyphenols, mainly anthocyanins and phenolic acids. ...
The aims of this study were to evaluate: (i) the chemical and nutritional composition of rice before and after cooking and (ii) postprandial glycemic impacts in children and adolescents with type 1 diabetes (T1D) after eating two different types of rice (“Gigante Vercelli” white rice and “Artemide” black rice) or white rice cooked “risotto” style or boiled using an advanced hybrid closed loop (AHCL) system (Tandem Control-IQTM). General composition and spectrophotometric analyses of raw and cooked rice were performed. Eight T1D subjects (four males and four females, aged 11 ± 1.4 years), two with celiac disease (CD), using an AHCL system were enrolled. “Gigante Vercelli” white rice cooked as risotto or boiled and boiled “Artemide” rice were prepared by the same cook on two evenings. Continuous glucose monitoring metrics were evaluated for 12 h after meal consumption. Total dietary fiber was higher for both rice types after cooking compared with raw rice. Cooking as risotto increased polyphenols and antioxidants (p < 0.05) in both rice varieties, and total starch decreased after boiling (p < 0.05) in white rice. There was a significant peak in glycemia after consuming risotto and boiled white rice (p < 0.05), while the mean glycemic peak remained <180 mg/dL in individuals eating boiled Artemide rice. There were no significant differences in automatic basal or auto-bolus insulin deliveries by the AHCL according to different types of rice or cooking method. Our findings suggest that glycemic trends are impacted by the different chemical and nutritional profiles of rice but are nevertheless well controlled by AHCL systems.
... [10] The colour of bakery products is affected by ingredients, process, and ingredient process interactions, such as Maillard or caramelization reactions . [11] The colour of the black rice added muffin was brown in colour and was appealing to eye like chocolate muffins ...
Black rice has been consumed from antique times by the people of Southeast Asian countries. It is said to be a nutrient-rich rice variety among all species of rice. The Phytochemicals present in it are the reason for its health-promoting properties. Muffins were prepared from black rice and refined wheat flour. The nutrient composition, anthocyanin content, and shelf-life stability were assessed. The prepared black rice muffin contained 81.89 % carbohydrates, 2.35% protein, and 3.25% fat. The shelf-life stability of the nutrients decreased on the eighth day from 81.89 to 77.56% carbohydrate and from 3.25% fat to 2.88%. Sensory analysis of the muffin by the panel gave an overall acceptance rate of 4.57 on a hedonic scale of 5 points. Muffins made of black rice and refined flour is a low-gluten snack that can be relished by all. No doubt muffins made of black rice can be guaranteed as a health-promoting functional food.
... The free radicals produced can be neutralized in the presence of antioxidants, so it can prevent oxidative damage in the human body [5]. Many studies have reported that rice is rich in antioxidants [7][8][9][10][11][12]. In addition, rice bran is a by-product obtained after milling and also is rich in antioxidants, but previously it was used only as animal feed [13][14][15][16]. ...
Rice (Oryza sativa L.) is a primary food that is widely consumed throughout the world, especially in Asian countries. The two main subspecies of rice are japonica and indica which are different in physical characteristics. In general, both indica and japonica rice consist of three types of grain colors, namely white, red, and black. Furthermore, rice and rice by-products contain secondary metabolites such as phenolic compounds, flavonoids, and tocopherols that have bioactivities such as antioxidants, antimicrobial, cancer chemopreventive, antidiabetic, and hypolipidemic agents. The existence of health benefits in rice bran, especially as antioxidants, gives rice bran the opportunity to be used as a functional food. Most of the bioactive compounds in plants are found in bound form with cell wall components such as cellulose and lignin. The process of releasing bonds between bioactive components and cell wall components in rice bran can increase the antioxidant capacity. Fermentation and treatment with enzymes were able to increase the total phenolic content, total flavonoids, tocotrienols, tocopherols, and γ-oryzanol in rice bran.
... Anthocyanins were absent in red (Ermes and Russ) and white (Selenio) cultivars. Artemide, Venere, and Nerone show the predominance of cyanidin-3-glucoside Bordiga et al., 2014 ness, obesity, aging, and diabetes, based on in vitro, animal, and human research investigations. However, additional study is needed to identify anthocyanins' real effects in humans by conducting clinical trials. ...
In all cereals, particularly maize, rice, barley, and wheat have colored varieties that
consist of significant levels of pigments and anthocyanins. Using whole grain components produced from colored cereals in the development of functional foods is
thus a potential strategy or approach to follow. In the current study, the findings of
investigation on content, and types of pigments (anthocyanins) found in colored grains
were summarized.
... In the same manner, flavonoids are mainly located in the outer layers of rice bran, and their content significantly decreases after milling (Ma, Yi, Wu, & Tan, 2020). The most common flavonoids in rice are flavones, such as tricin, luteolin, apigenin (Goufo & Trindade, 2014), but also flavonols and flavanols and/or their corresponding glycosides are also found (Bagchi et al., 2021;Bordiga et al., 2014). Using legume seed coats could be a way to enhance the polyphenolic profile of rice-based snacks (Figs. 1 and 2). ...
This study investigated the impact of seed coats from peas (PC) and chickpeas (CC) (at 15% and 30% levels) on rice-based co-extruded snacks. Using PC and CC reduced the content of soluble (29%) and cell-wall bound phenolic acids (21%), but it enhanced the amount and the profile of flavonoids of rice-based snacks (up to 16 times with PC), resulting in significantly higher antioxidant activity (134%). Snacks with 15% CC showed a higher section area (about 335 versus 191 mm²) and a lower average pore radius (20.1 versus 23.9 mm) than PC-snacks; however, such features did not affect either texture or porosity. At 30% level, PC resulted in a more porous structure (porosity: 73.1 versus 66.7%) with smaller pores (17.2 versus 27.3 mm) and high firmness (55.9 versus 40.1 N). Consumers’ acceptability evaluation revealed that samples containing pulse seed coat were comparable and preferred to the control (i.e., 100% polished rice).
... Aromatic rice varieties have long been popular in the Asia and Southeast Asian, and therefore most of the trade in aromatic rice has traditionally been centered around India, Pakistan, and Thailand. In the 1990s, the popularity of aromatic rice increased in Europe, North America, and South America (Singh et al., 2000), when studies with black pericarp aromatic rice grown in Italy (Bordiga et al., 2014), Della from the US (Lin et al., 1990), and aromatic rice IAC (500) grown in Brazil (Dias et al., 2021), started to be reported. ...
The objective of this work was to investigate and characterize new rice cultivars still little explored and never reported in the literature but of nutritional and economic potential. For this, the Brazilian cultivars IAC 500 (aromatic) and IAC 2157 (non-aromatic) were analyzed and compared regarding their proximate composition, amylose content, fatty acid composition, vitamin E content, and glycemic and insulinemic responses. An additional goal of the work was to analyze the influence of the planting month on the contents of minerals, phytosterols, and free phenolic compounds from the cultivars planted under the same conditions at four different months of the year. This work presents the first report of the chemical characterization of the Brazilian aromatic rice IAC 500, that present higher ash, protein, lipid, α-tocopherol, and unsaturated fatty acid levels compared with the Brazilian non-aromatic rice IAC 2157. The planting time quantitatively influenced the bioactive compounds, but there was no consensus regarding the best planting time to maximize the content of the analyzed compounds. The main finding of the study is that the ingestion of aromatic rice resulted in a lower insulinemic response compared to non-aromatic rice. Future research is needed to investigate the observed difference in pancreatic insulin release after consumption of aromatic rice.
... Phenolic extraction was carried out by the method of Bordiga et al. (2014). Red rice flours (0.1 g) were extracted with 2.5 ml of solvent mixture of methanol: water: formic acid (50:48:5:1.5 v/v). ...
... Among these factors, pH and heat significantly affected the degradation of anthocyanins (Sadilova et al. 2007). Hence, it is necessary to consider various factors that could affect the quality and yield of anthocyanins such as the nature of extraction process, solvent system, and time of extraction for the development of natural food supplement and possible synthesis of potent drugs (Bordiga et al. 2014). ...
This study aimed to optimize different process parameters for the extraction of anthocyanins from black rice bran using Response Surface Methodology (RSM). To determine its degradation profile, the stability of crude anthocyanin extract (CAE) against selected biologically relevant buffers was also evaluated. Two-level full factorial and Box-Behnken designs were employed in the screening and optimization of extraction
parameters, respectively. CAE was prepared from black rice bran using conventional and optimized methods, and the resulting extract was determined for their phytochemical content and antioxidant scavenging activities. Stability of the optimized CAE was further evaluated using biologically relevant buffers for 48 h. Results showed that the optimum conditions for the extraction of anthocyanins were 60% ethanol, 0.2% hydrochloric acid, and 215 min of extraction. The CAE obtained from the optimized method was 4 times higher in anthocyanins, 2.3 times higher in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical
scavenging activity, 1.7 times higher in phenolics and ferric reducing antioxidant power (FRAP) values, and 1.5 times higher in flavonoids than that obtained from the conventional method. In terms of its stability, the optimized CAE did not undergo substantial degradation at pH 1, while significant degradation was observed
at pH 7.4. Addition of 10% newborn calf serum had no significant effect on the stability of anthocyanin. The half-life of anthocyanins from the optimized CAE ranged from 29.0 to 32.5 h based on first order kinetics. The study suggests that RSM is a practical and effective statistical tool that can be used to optimize the best conditions in extracting anthocyanins from black rice bran.
... Both companies identified black rice extract as a common adulterant based on comparison of the anthocyanin fingerprint with authentic black rice extract ( Figure 3 (Table 1). 68,69 While other adulterants were detected in some of the bulk extracts, the identities of these ingredients were not determined. Additionally, several commercial elder berry bulk extracts and dietary supplement products were highly diluted or did not contain any detectable anthocyanins at all. ...
As the popularity of elder berry dietary supplements continued to rise during the COVID-19 pandemic due to consumers’ increased interest in herbal ingredients with purported immunomodulatory and antiviral effects, shipments of some elder berry ingredients were delayed due to manufacturing closures in China and India and disruptions in transportation and material processing at customs. In response, concerns about demand outpacing supply have been raised, and that some of the elder berry bulk extracts and finished dietary supplements offered during the pandemic were of low quality or adulterated. However, no data explicitly reporting adulteration of elder berries or elder berry extracts could be retrieved in the published scientific literature.
In order to assess the current market situation with regard to the authenticity of commercial bulk elder berry extracts and finished products, a request for analytical data was sent to manufacturers of elder berry dietary supplements and contract analytical laboratories. The data obtained represent a total of 532 samples, although some of the same samples may have been tested at several laboratories. Test samples included bulk extracts, bulk whole or powdered elder berries, and finished dietary supplement products. A total of 58 (10.9%) of the 532 samples failed the identity test specifications due to differences in the analytical fingerprint when compared to authentic samples.
The results of this investigation indicate that responsible manufacturers of herbal dietary supplements have to remain vigilant and actively establish quality control assays that help to detect issues with adulteration, such as the undisclosed fraudulent substitution, dilution, and/or spiking of products, which is particularly important during times of extraordinary sales increases or sudden supply chain dislocations and shortages.
... Cyanidin-3-glucoside (C3G) and peonidin-3-glucoside (Pn3G) are the most common forms of anthocyanins found in black rice [11]. Other forms of anthocyanins observed in black rice are cyanidin-3,5-diglucoside, cyanidin-3-rutinoside, cyanidin-3-gentiobioside, malvidin-3glucoside, and peonidin-3-rutinoside [12,13]. Anthocyanins are distributed in all parts of black rice seeds but are mostly accumulated in the bran. ...
Anthocyanins are an important micro-component that contributes to the quality factors and health benefits of black rice. Anthocyanins concentration and compositions differ among rice seeds depending on the varieties, growth conditions, and maturity level at harvesting. Chemical composition-based seeds inspection on a real-time, non-destructive, and accurate basis is essential to establish industries to optimize the cost and quality of the product. Therefore, this research aimed to evaluate the feasibility of near-infrared hyperspectral imaging (NIR-HSI) to predict the content of anthocyanins in black rice seeds, which will open up the possibility to develop a sorting machine based on rice micro-components. Images of thirty-two samples of black rice seeds, harvested in 2019 and 2020, were captured using the NIR-HSI system with a wavelength of 895–2504 nm. The spectral data extracted from the image were then synchronized with the rice anthocyanins reference value analyzed using high-performance liquid chromatography (HPLC). For comparison, the seed samples were ground into powder, which was also captured using the same NIR-HSI system to obtain the data and was then analyzed using the same method. The model performance of partial least square regression (PLSR) of the seed sample developed based on harvesting time, and mixed data revealed the model consistency with R² over 0.85 for calibration datasets. The best prediction models for 2019, 2020, and mixed data were obtained by applying standard normal variate (SNV) pre-processing, indicated by the highest coefficient of determination (R²) of 0.85, 0.95, 0.90, and the lowest standard error of prediction (SEP) of 0.11, 0.17, and 0.16 mg/g, respectively. The obtained R² and SEP values of the seed model were comparable to the result of powder of 0.92–0.95 and 0.09–0.15 mg/g, respectively. Additionally, the obtained beta coefficients from the developed model were used to generate seed chemical images for predicting anthocyanins in rice seed. The root mean square error (RMSE) value for seed prediction evaluation showed an acceptable result of 0.21 mg/g. This result exhibits the potential of NIR-HSI to be applied in a seed sorting machine based on the anthocyanins content.
... An ultrasonic assisted phenolic extraction protocol by Bordiga et al. (2014) was followed in this study. Briefly, lyophilized brown rice flour samples (0.1 g) were extracted with 2.5 mL of solvent mixture of methanol: water: formic acid in the ratio 50:48.5:1.5 v/v and subjected to ultrasonication (Branson Bransonic® Digital Bath 5800, USA) for 10 min at 50 • C. The extracts were then centrifuged (Sorvall, ST 8R, Thermo Fisher Scientific, Germany) at 2,500 g at 5 • C for 5 min. ...
The study reports the in vitro antihyperglycemic potential of Bamboo seed rice/BSR, a brown rice from Bambusa arundinacea species in comparison to a traditional Indian brown rice - Garudan samba/GS from Oryza sativa species using an integrated approach. Untargeted phenolic profiling using Q-TOF-LC-MS/MS confirmed sixty-three phenolic metabolites in BSR and thirty-nine in GS. The most abundant phenolics in BSR and GS were gallic acid, 4-hydroxybenzaldehyde, caffeic acid 4-O-glucoside and p-coumaric acid. Additionally, eriocitrin was abundant in BSR and cirsimaritin in GS. Predicted glycemic index determined using an in vitro starch digestibility technique indicated BSR to be a low GI variety and GS a moderate GI variety. In terms of antihyperglycemic enzyme inhibitory potential, BSR exhibited better α-amylase inhibition, whereas GS exhibited greater inhibition of dipeptidyl peptidase IV. This was further confirmed using molecular docking techniques which revealed that eriocitrin and cirsimaritin were strong inhibitors of α-amylase and DPP IV enzymes. The study thus revealed brown rice varieties from both Bambusa sp. and Oryza sp. as healthier options to white rice in the dietary management of diabetes and as good sources of several bioactive phenolic compounds.
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... Among the aromatic varieties of rice, the most popular, sold in world trade are Basmati of India and Pakistan and Jasmine of Thailand. In addition to these, other varieties have been planted and explored worldwide, such as Indonesian aromatic rice (Rojolele, Pandan Wangi and Mentik Wangi) (Setyaningsih, Majchrzak, Dymerski, Namieśnik, & Palma, 2019), Japanese aromatic rice (Towanishi-ki) (Shinoda et al., 2020), taro-scented Japonica rice (TaiNung 71) from Taiwan (Chen & Chiu, 2011), aromatic rice grown in Bangladesh (Kalizira, Kataribhog, Bagun Bichi, BRRI dhan-34, BRRI dhan -37 and BRRI dhan -50) (Asaduzzaman et al., 2013), black pericarp aromatic rice grown in Italy (Bordiga et al., 2014), aromatic rice IAC (500) grown in Brazil (Dias, Duarte, Mariutti, & Bragagnolo, 2019), among others. ...
During cooking, aromatic rice has a pleasant and characteristic aroma, a relevant factor to add sale value and attract consumer interest. This work studied the volatile compounds of aromatic rice (IAC 500) aiming at identifying those responsible for the aroma and flavor of the cooked rice. The description of the aromatic notes of the IAC 500 rice was carried out by a trained and selected sensory panel, followed by olfactometry (OSME) and identification by GC-MS of the rice volatile compounds extracted by SPME. A total of 80 volatiles was sensorially perceived and/or detected in the chromatographic effluent, of which 65 were identified, 44 presented some odor, and 36 were odorless. Among the odorous compounds, 15 were not detected by GC-FID or GC-MS. This study confirmed the compound 2-acetyl-1-pyrroline as the impacting volatile compound to the aroma of aromatic rice since it presented a very low percentage of area in the chromatogram and a high odor intensity. Other 43 compounds presented odor in lower intensities, but also contributed to the overall aroma of IAC 500 rice. From the 11 aromatic notes mentioned by the trained panel (cooked vegetable/seed, corn, hominy, green, porridge, popcorn, fresh baked cake/bread, milk, caramel, tapioca flour and flower), eight were related to the volatile compounds responsible for their aroma.
... The highest increase in the antiradical capacity was measured after the ingestion of Artemide rice, in the case of the DPPH assay, while, for the ABTS assay, the consumption of Venere rice determined the highest values of activity. This difference could be due to the diverse phytochemical composition of the pigmented rice cultivars [15]. Therefore, the different content of water-and lipid-soluble compounds in the cultivars could determine their diverse reactivity towards the chromophores used for the test, the radical DPPH and the cation radical ABTS [16][17][18]. ...
Health-promoting effects of plant foods have been emphasized in the last few decades and ascribed to the bioactive phytochemicals present therein-in particular, phenylpropanoids. The latter have been investigated for a number of preclinical biological activities, including their antioxidant power. Due to the paucity of human studies, in this randomized intervention trial, we investigated whether the acute intake of pigmented rice could increase the plasma bioactive levels and antiradical power in twenty healthy subjects. A crossover randomized controlled clinical trial was conducted on 19 volunteers. Artemide and Venere black rice cultivars were tested, while brown rice Carnaroli was used as a control. Each patient received randomly one serving (100 g) of rice on three different experimental days, separated by a 7-day washout period. After baseline blood withdrawal, time-course changes of plasma polyphenols, flavonoids and radical-scavenging capacity were determined at 30, 60, 120 and 180 min post rice intake. Compared to Carnaroli rice, the two black rice cultivars significantly increased the plasma levels of polyphenols and flavonoids at 60 and 120 min and, correspondingly, the plasma antiradical power at 60 min after consumption. Pigmented rice consumption can contribute to diet-related health benefits in humans.
... In Italy, rice weed control has mirrored global and EU history, with a few additional considerations. Italian rice is often cultivated in monoculture across a large area located mostly in the northern regions of Piemonte, Lombardia, and Veneto (Bordiga et al. 2014). The territory represents about 90% of the total Italian rice area (about 219,300 ha in 2018) (Ente Nazionale Risi 2019) and is characterized by common environmental conditions, and by farms with specialized labor organization and equipment (Ferrero and Vidotto 2010). ...
Weed control in rice fields has become particularly difficult because of the increased occurrence of herbicide resistance. The objective of the study was to assess in field conditions, in Italy, if repeated applications of the same herbicides on Echinochloa spp. populations already showing an initial level of resistance would increase their level of resistance over a short time. Repeated applications of penoxsulam and cyhalofop-butyl were performed at different rates, either alone, in combination, or in sequence for one, two or three consecutive years (2010-2012) in the same plots. Confirmation of resistance was performed in greenhouse on plants derived from untreated plots and from those that survived the field treatments. Penoxsulam efficacy was lower than that obtained with cyhalofop-butyl. The average efficacy across herbicide treatments declined over time as it was 52%, 32%, and 13% at 28 days after treatments in plots treated for one, two and three years, respectively. The treatments performed in greenhouse confirmed the low herbicide efficacy observed in the field. Study results highlighted that repeated applications of ALS and ACCase inhibitor herbicides can accelerate resistance selection in Echinochloa, and even herbicide rotation, sequencing, or mixing might not be effective if applied at time intervals of insufficient length.
... Quercetin and QUG were only found in free fraction of black rice (28.38 and 12.15 μg/g). Bordiga et al. (2014) reported lower quercetin content (1.9-5.9 μg/g) and similar QUG content (1.0-14.3 μg/g) in colored rice. ...
The phytochemical contents, peroxyl radical scavenging capacities (PSCs) and cellular antioxidant activities (CAAs) of free and bound fractions of rice were reported. Black rice had the highest total phenolic content and total flavonoid content in free and bound fractions, followed by red rice, brown rice, and polished rice. Black rice contained much more free phenolic compounds than other rice samples, such as cyanidin-3-glucoside, protocatechuic acid, and vanillic acid. Tocopherols and tocotrienols contents were highest in red rice, then in black rice, brown rice, and polished rice. PSCs and CAAs of free and bound fractions were in the order: black rice > red rice > brown rice > polished rice, except that bound CAA of red rice was higher than that of black rice. The cellular uptake rate of free phenolics was highest in red rice, while cellular uptake rates of bound phenolics were highest in brown rice and polished rice.
... Quercetin and QUG were only found in free fraction of black rice (28.38 and 12.15 μg/g). Bordiga et al. (2014) reported lower quercetin content (1.9-5.9 μg/g) and similar QUG content (1.0-14.3 μg/g) in colored rice. ...
The phytochemical contents, peroxyl radical scavenging capacities (PSCs) and cellular antioxidant activities (CAAs) of free and bound fractions of rice with different colors were reported. Black rice had the highest total phenolic content and total flavonoid content in free and bound fractions, followed by red rice, brown rice, and polished rice, except that black rice had lower bound flavonoid content than red rice. Trans-ferulic acid was the predominant phenolic acid in rice. Black rice contained much more free phenolic compounds than other rice samples, such as cyanidin-3-glucoside, protocatechuic acid, and vanillic acid. Tocopherols and tocotrienols contents were highest in red rice, follow by black rice, brown rice, and polished rice. The PSCs and CAAs of free and bound fractions of rice followed the order: black rice > red rice > brown rice > polished rice, except that bound CAA of red rice was higher than that of black rice.
... Additionally, several studies conducted on other major crop plants have also revealed an association between the seed color and phenolic components (Zhang et al. 2010;Shao et al. 2011;Wang et al. 2015). Although higher flavonoid content was reported in the seed coats than in the embryos of soybean and rice (Bordiga et al. 2014;Min et al. 2015), it has been emphasized that the type and quantity of flavonoids in seed coats and embryos may be related to plant genotype (Hou et al. 2017). Furthermore, Shen et al. (2009) andShao et al. (2014) found that black-and red-colored rice grains contain higher flavonoid content than white-colored grains. ...
Buckwheat is an important grain crop known for its nutritional value and content of bioactive compounds, particularly rutin. In this study, we characterized diverse Fagopyrum esculentum Moench germplasm for the diversity of agro-morphological characteristics and the rutin and quercetin content in seeds under the spring cultivation. Of the 251 germplasm accessions assessed, 193 had red stems, 182 had a pale brown seed coat color, and 238 had ovate seeds. The times taken to reach 50% flowering and 80% maturity ranged from 38-45 to 73-95 days, respectively. The 1000-seed weight (TSW) varied from 21 to 42 g. Overall, the content of rutin and quercetin ranged from 7.22-47.86 to 0-1.22 mg/100 g DW, respectively. The number of days to flowering and maturity showed negative correlations with TSW and rutin and quercetin content. However, we found that at 73-80 days after sowing, early-maturing germplasm had significantly higher mean rutin content than either intermediate-or late-maturing germplasm. The TSW weight showed a positive correlation with the content of rutin and quercetin. We identified promising accessions based early maturity (\ 80 days), higher seed weight (C 35 g) and higher content of rutin (C 35 mg/100 g DW) and quercetin (C 1 mg/100 g DW). These accessions will help to enhance grain yield and the rutin and quercetin content in existing buckwheat cultivars for spring cultivation.
... The stationary phase employed was a Zorbax Eclipse XDB-C18 Narrow-Bore (150 mm × 2.1 mm; 3.5 µm particle size) column, while the mobile phase consisted of solvent A (water/formic acid/acetonitrile, 87:10:3, v/v/v) and solvent B (acetonitrile/water/formic acid, 50:40:10, v/v/v). The elution profile was (time, % of solvent B): 0 min, 3%; 10 min, 15%; 35 min, 40% B; 39-41 min, 100% B, and 47 min, 3% B [60]. The flow rate was 0.190 mL min −1 and the column temperature was set at 40 • C while the injection volume was 20 µL. ...
Peumus boldus Mol., is a Chilean medicinal tree used for gastrointestinal and liver diseases. Such medicinal properties are associated with the presence of bioactive flavonoids and aporphine alkaloids. In this study, a new green and efficient extraction method used seven natural deep eutectic solvents (NADES) as extraction media. The extraction efficiency of these NADES was assessed, determining the contents of boldine and total phenolic compounds (TPC). Chemical profiling of P. boldus was done by high-performance liquid chromatography coupled to photo diode array detector and electrospray ion-trap mass spectrometry (HPLC-PDA-ESI-IT/MS) and electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (HPLC-ESI-QTOF-MS). Among the NADES tested, NADES4 (choline chloride-lactic acid) and NADES6 (proline-oxalic acid) enable better extraction of boldine with 0.427 ± 0.018 and 2.362 ± 0.055 mg of boldine g-1 of plant, respectively. Extraction of boldine with NADES4 and NADES6 was more efficient than extractions performed with methanol and water. On the other hand, the highest TPC were obtained using NADES6, 179.442 ± 3.79 mg of gallic acid equivalents (GAE g-1). Moreover, TPC in extracts obtained with methanol does not show significant differences with NADES6. The HPLC-PAD-MS/MS analysis enable the tentative identification of 9 alkaloids and 22 phenolic compounds. The results of this study demonstrate that NADES are a promising green extraction media to extract P. boldus bioactive compounds and could be a valuable alternative to classic organic solvents.
Cereal food crops like maize (Zea mays), rice (Oryza sativa), sorghum (Sorghum bicolor) and wheat (Triticum aestivum) are members of the grass family (Poaceae). Together with bioenergy grasses, they play essential roles in agriculture and biorefinery, comprising an important component of bio-economy. Grasses accumulate a unique range of flavonoids (a class of plant-specific specialized metabolites) that contribute to defense responses, fertility, pigmentation and cell wall lignification. This review summarizes the distribution, functions, biosynthesis and regulation of flavonoids, including flavanones, tricin and flavone O-conjugates, flavone C-glycosides, 3-deoxyanthocyanidins, phlobaphenes, anthocyanins, proanthocyanidins (condensed tannins) and flavonols, in grasses focusing on model cereal grasses. In particular, the constitutive, predominant and widespread tricin-lignin, flavone O-conjugates and flavone C-glycosides as well as the inducible and/or lineage-specific sakuranetin (a flavanone), maysin (a flavone C-glycoside), 3-deoxyanthocyanidins and phlobaphenes, are highlighted. Finally, the impacts and importance of cereal grass flavonoids on scientific research, agricultural production, food and health, and biorefinery are discussed.
In recent years, consumers have been concentrating on the health benefits and nutrition from food to preserve a healthy lifestyle. They are looking for colorants derived from natural sources to enhance the nutritional and antioxidant value of foods. Coloured cereals (wheat, rice, barley, oat, maize, sorghum, and millets) contain many phytochemicals, including anthocyanins and carotenoids associated with numerous health benefits. This book presents a comprehensive overview of the bioactive potential, food applications, and health benefits of coloured cereal grains. Novel approaches to the integration of coloured grain into food in the food processing industries are included, reviewing high-value pigments in the bran layer which can easily be extracted and utilized as functional foods and natural colorants.
Aimed at researchers carrying out innovative studies, food regulatory and safety authorities and food processing industries who are trying to minimize synthetic food colorants and dyes, this book provides a novel approach to the use of substitute synthetic dyes which can improve the nutritional value, appearance, texture, flavour, and storage properties of food products.
Japonica rice is produced mainly in northeast China, Japan, and the Korean Peninsula. Polyphenols and flavonoids are the main antioxidants in japonica rice. This study reported the polyphenol content and antioxidant activity of nine brown and white japonica rice cultivars. The total phenolic and flavonoid contents of brown rice were in the ranges of 241.98–296.76 GAE mg/100 g, and 225.30–276.80 RE mg/100 g, respectively. These values were significantly higher than that of white rice by 118.98–206.06% and 135.0–217%, respectively. The bound fraction from phenolics and flavonoids contributed 41.1–63.6% and 62.22–78.19% of the total phenolic and flavonoid content in brown rice, respectively, while these ranges were 55.5–73.5% and 46.07–66.83% in white rice, respectively. p-Hydroxybenzonic acid was the predominant phenolic acid in japonica rice. All four antioxidant capacities of brown rice (DPPH, ABTS, OH, FRAP) were higher by up to 1.68–2.85 times than those of white rice. The PZ21 (Yanfeng 47) japonica rice variety has outstanding antioxidant capacity based on the weights of each antioxidant index. According to the differences of functional substances among varieties, it can provide guidance for consumers and theoretical basis for the production of healthy food.
The controversy and ambiguity related with chemical additives, allied to sporadic scares, have paved the way for natural additives to gain interest and funding. Today, most consumers prefer foods added with natural additives, rather than artificial ones, which is seen by the food industry as an opportunity to find new and more efficient natural-based solutions, while fighting to reduce the overall use of additives, producing minimally processed goods. The benefits of natural additives are endless, their synergy and effectiveness are a great leap over artificial additives that carry out, in most
cases, only one effect over the food.
The plant and fungi kingdoms are great sources of bioactive compounds, that can be
used to develop natural food ingredients. These natural compounds can be added as extracts, taking advantage of the synergistic effects between compounds, or as individual molecules, after purification, thus adding the most bioactive ones to the foodstuff. Although quite promising, natural additives still face some drawbacks and limitations, availability of natural resources, exhaustive and not very efficient extraction methods, and several intrinsic and extrinsic factors that can affect the stability, availability, and bioactivity of natural compounds. Therefore, an important research topic is the discovery of new alternative sources of natural additives fulfilling the different classes: preservatives (antimicrobials, antioxidants, and anti-brownings), nutritional additives, coloring agents, flavoring agents, texturizing agents, and miscellaneous agents.
In order to address the advantages and challenges the use of natural additives in foods, an enormous amount of work, divided into three review and 15 original articles, involving diverse expert teams of from different parts of the world, embodied this book “Natural Additives in Foods”, where current issues on natural additives are discussed and explored. Briefly, topics on alternatives for sustainable obtaining of bioactive molecules from agro-food byproducts, an important cheap source of added value compounds, which can contribute to total exploration of natural source, and for reduction of environmental impact, are presented and discussed in some studies. Likewise, optimized extraction techniques, aiming at greater extraction efficiency with less use of natural resources, are proposed by for some authors. Several potential natural colorants to replace artificial
ones are covered in topics that discuss their main sources and bioactivities; and the sustainable production methods and the chemical stability of these compounds for later commercial use. In addition, interesting studies approach the valorization of wild species to obtain molecules with biological proprieties, both for human health and for addition in foods. And, finally, the production of foodstuff healthier than the traditional, is proposed through the use of natural ingredients rich in phytochemicals and through processes that aim to minimize the absorption of compounds harmful to health.
Brown rice, an important material of whole-grain food, is increasingly popular for its health benefits. Thus, seven varieties of brown rice from southern China were analyzed in this study, concerning the free and bound phenolic compounds in the extract. The phenolic profiles of different brown rice were obtained and compared by the combination of HPLC and LC-MS analysis, in which eleven phenolic acids were identified. It was indicated that the total phenolic contents of different brown rice varied from 92.32 to 196.54 mg of gallic acid equivalent (GAE)/100 g DW. Ferulic acid and p-coumaric acid, free and bound, dominated within the phenolic acids. To be mentioned, the total phenols of Luotiangongmi (a kind of red rice) were significantly higher than the other six varieties. The high phenolic content of brown rice can further guide us to explore the functional properties of the crops.
The study evaluated the antidiabetic potential of three traditional Indian red rice genotypes/RR (Kattuyanam/KA, Chennangi/CH & Karungkuruvai/KU) using a combination of in vitro, metabolomics (Quadrupole-Time of Flight-Liquid chromatography-Mass spectrometry/Q-TOF-LC-MS/MS), and in silico techniques. In terms of antihyperglycemic potential, KA exhibited the highest inhibitory activity against α-amylase; CH against α-glucosidase; and KU against DPPIV and PTP1B enzymes. KA exhibited the highest antioxidant activity (DPPH, FRAP, and ABTS) and greater inhibition of protein glycation compared to other RR indicating its potential to mitigate diabetic complications. The metabolomic analysis confirmed the presence of 99 phenolics in the sample extracts (KU-71, KA-70, CH-68). Molecular docking studies revealed seven metabolites to be good inhibitors of the four target enzymes and activators of insulin receptor substrate/IRS. The antihyperglycemic and oxidation-glycation reduction composite index revealed KA to have the highest overall antidiabetic potential. Hence, the RR could be utilized in functional foods with a multi-barrelled strategy for diabetes prevention/management.
This study aimed to investigate physicochemical and functional properties as well as bioactive compounds from Thai pigmented brown rice flours from four varieties of indigenous kinds of rice in Thailand, namely Hom mali (HR), Red hom mali (RHR), Riceberry (RBR) and Homnil (HNR). The results showed that all Thai pigmented brown rice flours contained high contents of carbohydrate, protein, vitamins and minerals. The highest amylose content was present in RHR. All Thai pigmented brown rice flours have low RAG (rapid available glucose) and GI (glycemic index), especially RHR. The pasting properties were slightly altered when heated. The gelatinization temperature was high, but the enthalpy was non-significant. These flours have good water and oil absorption, swelling, solubility, emulsion, and foaming properties. In addition, these flours have a high syneresis during storage at low temperatures. The study of bioactive compounds demonstrated that all Thai pigmented brown rice flours contained significant total amount of total phenolic compounds, flavonoids, and antioxidant activities, especially in RHR. The morphology study revealed that all samples are in polyhedral shape and varied in sizes.
This study arose from the need to meet the request of consumers for healthy, ready-to-eat foods. The behavior of pigmented rice was investigated during extrusion in terms of nutritional (i.e., phenolic acids, anthocyanins and antioxidant capacity (AC)) and physical (i.e., starch pasting properties, texture, porosity and biometric indices) properties. Snacks were produced from brown, red, and black rice, by means of a co-rotating twin-screw extruder, and their features were compared with those of snacks from white rice. Although the soluble and cell-wall bound phenolic acid contents of pigmented and brown rice did not differ, the red and black rice both resulted in a higher AC after extrusion. Black rice showed the highest anthocyanin and AC contents, even after extrusion. Furthermore, the high phenolic compound content of black rice affected the starch pasting properties, and led to a lower viscosity and higher snack porosity than those of brown rice. Nevertheless, considering both the biometric and textural properties, the best results were obtained from red rice. Optimizing the extrusion conditions will help reduce the loss of anthocyanins in snacks made of pigmented rice, increase the nutritional value and improve the physical properties of the product.
Anthocyanins are antioxidants used as natural colorants and are beneficial to human health. Anthocyanins contribute to reactive oxygen species detoxification and sustain plant growth and development under different environmental stresses. They are phenolic compounds that are broadly distributed in nature and are responsible for a wide range of attractive coloration in many plant organs. Anthocyanins are found in various parts of plants such as flowers, leaves, stems, shoots, and grains. Considering their nutritional and health attributes, anthocyanin-enriched rice or pigmented rice cultivars are a possible alternative to reduce malnutrition around the globe. Anthocyanin biosynthesis and storage in rice are complex processes in which several structural and regulatory genes are involved. In recent years, significant progress has been achieved in the molecular and genetic mechanism of anthocyanins, and their synthesis is of great interest to researchers and the scientific community. However, limited studies have reported anthocyanin synthesis, transportation, and environmental conditions that can hinder anthocyanin production in rice. Rice is a staple food around the globe, and further research on anthocyanin in rice warrants more attention. In this review, metabolic and pre-biotic activities, the underlying transportation, and storage mechanisms of anthocyanins in rice are discussed in detail. This review provides potential information for the food industry and clues for rice breeding and genetic engineering of rice.
Black rice is recognized for managing diabetes in Chinese folk medicine. Therefore, the present study investigates the effect of thermal treatments and the succeeding cooking on black rice physicochemical properties, phenolic composition, total antioxidant activity (TAA), enzymes and glycation inhibition in addition to starch digestibility. Thermal decomposition of anthocyanin and cyanidin-3-glucoside was evident across all processing methods and reflected in increasing levels of protocatechuic acid, while proanthocyanidins (TPAC) were susceptible to cooking. Roasting of grains sustained total phenolics (TPC), flavonoids (TFC), TPAC, and antilipase activity. Additionally, the combined effect of frying and cooking diminished TFC, TPAC, and α-glucosidase inhibition. The thermally treated grains showed pronounced activity against α-amylase, α-glucosidase, and glycation, whereas their cooked counterparts reduced the estimated glycemic index (eGI), and enhanced resistant starch (RS). Processed grains chrominance, TAA, and apparent amylose content (AAC) showed a significant correlation with phenolics. These findings are demonstrating that black rice processing is favorable for the dietary management of metabolic disorders such as diabetes and hyperlipidemia.
Until today, numerous studies evaluated the topic of anthocyanins and various types of cancer, regarding the anthocyanins’ preventative and inhibitory effects, underlying molecular mechanisms, and such. However, there is no targeted review available regarding the anticarcinogenic effects of dietary anthocyanins on skin cancers. If diagnosed at the early stages, the survival rate of skin cancer is quite high. Nevertheless, the metastatic form has a short prognosis. In fact, the incidence of melanoma skin cancer, the type with high mortality, has increased exponentially over the last 30 years, causing the majority of skin cancer deaths. Malignant melanoma is considered a highly destructive type of skin cancer due to its particular capacity to grow and spread faster than any other type of cancers. Plants, in general, have been used in disease treatment for a long time, and medicinal plants are commonly a part of anticancer drugs on the market. Accordingly, this work primarily aims to emphasize the most recent improvements on the anticarcinogenic effects of anthocyanins from different plant sources, with an in-depth emphasis on melanoma skin cancer. We also briefly summarized the anthocyanin chemistry, their rich dietary sources in flowers, fruits, and vegetables, as well as their associated potential health benefits. Additionally, the importance of anthocyanins in topical applications such as their use in cosmetics is also given.
The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker’s yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs.
The term “red rice” refers to the color of rice kernel, including weedy, wild, or cultivated rice. Weedy rice are de-domesticated plants from cultivated rice, which compete with this crop and reduce yield. Wild rice are any Oryza species other than cultivated ones. Cultivated red rice are grown in restricted regions, where they have a cultural, ceremonial, or medicinal value. Red rice is consumed as whole grain, rich in proteins, lipids, dietary fibers, minerals, vitamins, and phenolic compounds, including phenolic acids and flavonoids. The flavonoids are proanthocyanidins, which are beneficial not only as antioxidant and anti-inflammatory but have also immunomodulatory, anticancer, cardioprotective, and antithrombotic properties. These human health-promoting properties led red rice to regain prestige. Red rice is also used as an antiaging ingredient, in the cosmetic industry, and is tolerant and resistant to several stresses in the field. They can be grown under seasonal environmental conditions to which modern cultivars are not adapted. Despite these features, there is still a lack of high-yielding red rice cultivars. In Brazil, Embrapa and Epagri recently included grains other than white in their rice breeding programs and have already released three cultivars, which have higher yield and resistance to diseases as enhanced features.
The major flavonoids in rice leaves were analyzed via LC-MS/MS after their total flavonoid extracts were hydrolyzed. The most
abundant flavones were apigenin, luteolin, and tricetin. Of these, tricetin was methylated at its 3′ and 5′-hydroxyl group
to form tricin, which was probablyO-glycosylated. Both 3′-O-methylated luteolin and luteolin were found in theC-glycosylated form while apigenin wasC-glycosylated. We also cloned and characterizedOsFNS, which catalyzes the reaction from flavanone (naringenin) to flavone (apigenin). Analysis of the reaction product with recombinant
OsFNS showed that it indeed converts naringenin to apigenin.
Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with lambda(max) of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G.
Flavanol-anthocyanin complexes were isolated by successive use of Amberlite XAD-7 chromatography, Sephadex LH-20 gel filtration and preparative HPLC from acidified, methanolic extract of strawberries (Fragaria ananassa Dutch.). These purple minor pigments were characterized by UV-Vis spectroscopy, 1D and 2D NMR techniques, and electrospray mass spectrometry to be catechin(4alpha --> 8)pelargonidin 3-O-beta-glucopyranoside (1), epicatechin(4alpha --> 8)pelargonidin 3-O-beta-glucopyranoside (2), afzelechin(4alpha --> 8)pelargonidin 3-O-beta-glucopyranoside (3) and epiafzelechin(4alpha --> 8)pelargonidin 3-O-beta-glucopyranoside (4). The stereochemistry at the 3- and 4-positions of the flavan-3-ol units was based on assumption of R-configuration at C-2. Each of the four pigments occurred in the NMR solvent as a pair of rotamers. Proved by cross-peaks in the 1H-1H NOESY NMR spectra of 1, 2 and 4, the two conformations within each rotameric pair were in equilibrium with each other. Even though 1 and 2 are based on a different aglycone, their structures may be similar to tentatively identified pigments, which have been assumed to contribute to the colour of red wines.
Proanthocyanidins are oligomeric and polymeric end products of the flavonoid biosynthetic pathway. They are present in the fruits, bark, leaves and seeds of many plants, where they provide protection against predation. At the same time they give flavor and astringency to beverages such as wine, fruit juices and teas, and are increasingly recognized as having beneficial effects on human health. The presence of proanthocyanidins is also a major quality factor for forage crops. The past 2 years have seen important breakthroughs in our understanding of the biosynthesis of the building blocks of proanthocyanidins, the flavan-3-ols (+)-catechin and (-)-epicatechin. However, virtually nothing is known about the ways in which these units are assembled into the corresponding oligomers in vivo. Molecular genetic approaches are leading to an understanding of the regulatory genes that control proanthocyanidin biosynthesis, and this information, together with increased knowledge of the enzymes specific for the pathway, will facilitate the genetic engineering of plants for introduction of value-added nutraceutical and forage quality traits.
With the aim of monitoring the formation of anthocyanin-derived pigments and contributing to the study of their chromatic properties, stability and relative contribution to the colour of red wines, a method for fractionation of the colouring material was set up. The method was based on the distinct reactivity of the different pigment families towards bisulfite (hydrogen sulfite). The wine, acidified and bleached with NaHSO3, was placed in a Toyopearl® HW-40(s) gel column and submitted to elution with ethanol. Two fractions with different pigment compositions were collected and analysed by liquid chromatographay diode array detection-mass spectrometry. Compounds present in each fraction were identified according to their UV-visible and MSn mass spectra, showing that the first one was mostly constituted of pyranoanthocyanins, whereas the second basically contained anthocyanins and anthocyanin-flavanol condensation products. A large variety of new pigments were detected, some of which had not been previously reported in red wines, as far as we know. Characteristic MS2 and MS3 fragmentation patterns were observed within each family of compounds, which could be further applied for characterisation of unknown pigments in other wines.
The composition of fatty acids, minerals, total dietary fiber and vitamin , in pigmented rice varieties were determined. Proximate composition and color were also compared among pigmented rice varieties. Crude protein contents of black rice were higher than those of red and brown rice, especially, Suwon 415 had the highest protein content. There were no significant differences in lipid and crude ash contents between pigmented rice and brown rice. Black rice showed lower Hunter value L, a and b value compared with red and brown rice. Most mineral contents of pigmented rice except Fe, Zn and Mn were higher than those of brown rice. Pigmented rice showed the higher contents in total dietary fiber, vitamin compared to brown rice. The major fatty acids of pigmented rice were palmitic acid, oleic acid and linoleic acid. The contents of oleic acid was similar to that of linoleic acid in brown rice. Oleic acid contents was lower than linoleic acid in black rice, but higher in red rice.
The use of pyrogallol as trapping reagent in proanthocyanidin (PA) analysis was investigated. PAs are antioxidants and disease-preventing agents, the efficiency of which depends on their composition and size. Different nucleophilic compounds are usually used for acid-catalyzed depolymerization of proanthocyanidins: benzyl mercaptan, phloroglucinol, and cysteamine. Each nucleophile has different characteristics and typical reaction temperatures that ranges from 50 to 90 °C. Pyrogallol is more reactive than these compounds, so it was possible to apply a minor reaction temperature that was finally reduced from 50 to 30 °C, compared to phloroglucinol, but maintaining a significant yield. The results, compared to those obtained using phloroglucinol as trapping nucleophile, indicated that pyrogallol is an effective and interesting reagent for this analysis.
The polymeric proanthocyanidin (PAs) composition of skins and seeds from Vitis vinifera L. cv during ripening was evaluated. Six grape varieties (Cabernet Sauvignon, Malvasia bianca, Moscato bianco, Nascetta, Nebbiolo and Pinot bianco) cultivated in Piedmont (vintage 2008) were collected at five different ripening stages (from 6 to 20°Brix). Polymeric proanthocyanidins were determined both by vanillin assay and by phloroglucinolysis; these analytical methods were compared showing a significant correlation (r=0.8321, p
Polyetherimide (PEI) substrate for next-generation high density optical data storage is fabricated and characterized. Cover-layer incident or first-surface recording configurations do not require optical properties of the substrate, which are the prerequisite conditions for the conventional material of polycarbonate (PC). Instead of the optical properties, good mechanical properties with a sufficient transcribability are required. Even though PEI has higher glass transition temperature than that of PC, a microscopic transcribability of PEI is comparable with PC by laminating a thermal insulation layer on the backside of a stamper to retard the heat flow. A macroscopic warpage of PEI substrate is smaller than that of PC substrates, which reduces tilt and servo burden. The lowest critical speed coupled with the flutter of PEI substrate is larger than that of PC substrate because of the mechanical properties of PEI. POLYM. ENG. SCI., 48:97–101, 2008. © 2007 Society of Plastics Engineers
The anthocyanin content of 23 grass species (Poaceae) belonging to five subfamilies has been determined. Altogether 11 anthocyanins were identified; the 3-(6″-malonylglucosides) and 3-glucosides of cyanidin, peonidin and delphinidin, the 3-(3″,6″-dimalonylglucoside), 3-(6″-rhamnosylglucoside) and 3-(6″-glucosylglucoside) of cyanidin, in addition to peonidin 3-(dimalonylglucoside) and delphinidin 3-(6″-rhamnosylglucoside). Anthocyanins acylated with one and/or two malonic acid moieties dominated the anthocyanin profiles of all the species in the subfamilies Pooideae and Panicoideae. On the other hand, the 3-glucoside and 3-rutinoside of cyanidin were the major anthocyanins in Sinarundinaria murielae (subfamily Bambusoideae) and Molinia caerulea (subfamily Arundinoideae), while the 3-glucosides of cyanidin and peonidin were the principal anthocyanins in rice, Oryza sativum (subfamily Oryzoideae). Pelargonidin derivatives and free anthocyanidins have previously been reported to occur in several Poaceae species, however, not identified in any of the species included in this survey.
Pigments resulting from the direct condensation of anthocyanins and flavanols are usually associated with reactions taking place during processing and storage of plant-derived foods and beverages and have been particularly studied in aged red wines. In this paper, small amounts of flavanol–anthocyanin condensed pigments are found in different plant extracts. Structures are suggested for 10 such condensed pigments detected in extracts of strawberry, runner beans, purple corn and grape skins, based on their MSn fragmentation patterns, following analyses by electrospray tandem mass spectrometry. All of them correspond to dimers containing a flavan-3-ol [either (epi)afzelechin, (epi)catechin or (epi)gallocatechin] as the upper unit carbon–carbon linked to a lower anthocyanin unit consisting of different delphinidin, cyanidin, pelargonidin, peonidin or malvidin derivatives. The detection of these pigments in plant extracts may suggest that they are natural pigments and not products exclusively formed during storage and ageing of processed foods and beverages, as was previously assumed.
Systematic identification and structural characterization of flavonoids and their glycosides in bran extracts of seven Thai black rice varieties were performed by sequential uses of reversed-phase HPLC with a photodiode array detector and a combined electrospray ionization tandem mass spectrometer. Eleven flavonoids were detected, and six of these were found for the first time in rice bran. These are taxifolin-7-O-glucoside, myricetin-7-O-glucoside, isorhamnetin-3-O-acetylglucoside, isorhamnetin-7-O-rutinoside, 5,6,3',4',5'-pentahydroxyflavone-7-O-glucoside and 5,3',4',5'-tetrahydroxyflavanone-7-O-glucoside. The quantitative results revealed that different rice varieties possessed flavonoids in different concentrations. The most abundance glycoside derivative of flavonoids widely distributed among the rice varieties was mono glucoside, such as quercetin-3-O-glucoside, isorhamnetin-3-O-glucoside and myricetin-7-O-glucoside.
With the aim of monitoring the formation of anthocyanin-derived pigments and contributing to the study of their chromatic properties, stability and relative contribution to the colour of red wines, a method for fractionation of the colouring material was set up. The method was based on the distinct reactivity of the different pigment families towards bisulfite (hydrogen sulfite). The wine, acidified and bleached with NaHSO3, was placed in a Toyopearl® HW-40(s) gel column and submitted to elution with ethanol. Two fractions with different pigment compositions were collected and analysed by liquid chromatographay diode array detection-mass spectrometry. Compounds present in each fraction were identified according to their UV-visible and MSn mass spectra, showing that the first one was mostly constituted of pyranoanthocyanins, whereas the second basically contained anthocyanins and anthocyanin-flavanol condensation products. A large variety of new pigments were detected, some of which had not been previously reported in red wines, as far as we know. Characteristic MS2 and MS3 fragmentation patterns were observed within each family of compounds, which could be further applied for characterisation of unknown pigments in other wines.
Antioxidants are important because they prevent lipid oxidation in food, and decrease the adverse effects of reactive species on normal physiological functions in humans. A wide variety of in vitro chemical models have been developed to assess the ability to prevent oxidative damages; amongst the chemical tests that measure radical scavenging capacity, the DPPH assay is one of the most widely employed method. EC50 (concentration required to obtain a 50% antioxidant capacity) is typically employed to express the antioxidant activity and to compare the antioxidant capacity of various samples; however its measurement requires some care, because of the non-linear relation between antioxidant concentration and antiradical activity. In this work a statistical software was developed in order to apply different linearising transformations in the study of DPPH-scavenging properties of antioxidants. The software was also implemented to perform the determination of outliers, the calculation of the EC50 values and the comparison of the curves, and of their corresponding straight lines, obtained from the regression analysis of the data. First, the analysis of the DPPH-scavenging activity was performed on standard molecules and then applied to different food extracts. The regression models employed in this work (probit, logit and angular regressions) appeared to be equivalent and to fit well the antiradical activity curves obtained for both standard molecules and food extracts; probit regression was finally chosen to discuss the results and to introduce a new parameter characterising these curves.
Extraction-dependent methods were used to evaluate the antioxidant capacity up to now. The extraction conditions applied before the measurement represent a source of variations among laboratories and in some cases are not reliable. The direct procedure described in this paper skips all time-consuming solvent extraction and hydrolysis steps. A review of the solubility and localization of food antioxidant compounds was provided as base to understand the advantage of the direct procedure with respect to the extraction protocols present in the literature. The application of the procedure to some case-studies was also illustrated.
Phytochemicals and antioxidants in whole grains have not received as much attention as the phytochemicals in fruits and vegetables although the increased consumption of whole grains and whole grain products has been associated with reduced risk of developing chronic diseases such as cardiovascular disease, type 2 diabetes, some cancers and all-cause mortality. Recent research has shown that the total phytochemical content and antioxidant activity of whole grains have been commonly underestimated in the literature, and that whole grains contain more phytochemicals than was previously reported. Most whole grain phenolics are in bound form, 85% in corn, 76% in wheat, and 75% in oats. In addition, whole grains contain unique phytochemicals that complement those in fruits and vegetables when consumed together. The beneficial effects associated with whole grain consumption are in part due to the existence of the unique phytochemicals of whole grains. The majority of phytochemicals of whole grains that are beneficial for health are present in the bran/germ fraction. In whole wheat flour, the bran/germ fraction contributed 83% of total phenolic content, 79% of total flavonoid content, 78% of total zeaxanthin, 51% of total lutein, and 42% of total β-cryptoxanthin. The bran/germ fraction of whole wheat may therefore impart greater health benefits when consumed as part of a diet, and help reduce the risk of chronic diseases. This paper will review recent research on the phytochemicals and antioxidant activity of whole grains and their unique contribution to the health benefits of whole grains.
The application of an improved method of extraction and purification has allowed the characterization of anthocyanins and free anthocyanidins in beans, Phaseolus vulgaris L. using LC-MS determination.HPLC analysis of the final extract showed the existence of seven compounds when 520 nm was the selected wavelength. Major peaks were identified, according to their retention times and UV–Vis spectra, as cyanidin and pelargonidin monoglucosides when they were compared to those of the in-house library. Taking into account mass spectrometric data, together with elution time and spectral features, it was possible to identify peaks corresponding to cyanidin and pelargonidin diglucosides. As far as we know, these anthocyanins have not been detected in P. vulgaris L. before.The last three peaks in the chromatograms were thought to be acylated anthocyanins, due to their smaller polarity. However, MS spectra showed signals at m/z 287, 301 and 271, which would be in accordance with molecular ions corresponding to anthocyanidins: cyanidin, peonidin and pelargonidin, respectively. Moreover, these compounds had the same retention times and UV–Vis spectral features as those of aglycones arising from acid hydrolysis of the final extract.These results demonstrate, for the first time, the presence, in natural form, of free aglycones in vegetable samples. Until now, the bibliographical data have indicated that, in nature, this type of compound is only found in heteroside forms.
Red wines made from Garnacha Tintorera grapes (also known as Alicante Bouschet and one of the few so-called teinturier Vitis vinifera grape cultivars, because its berry flesh is also red-colored) are usually blended with other red wines as a natural way for enhancing the color intensity of red wines. The phenolic composition of Garnacha Tintorera grapes showed already described interesting features such as the occurrence of unusual anthocyanins (pelargonidin-based anthocyanins and a peonidin dihexoside) that had not been previously described in V. vinifera cultivars. The isolation and further structure elucidation (GC-MS analysis of sugar moieties, UV-vis, LC-MS(n), and (1)H and (13)C NMR spectroscopic data) have allowed the identification of the aforementioned peonidin dihexoside as peonidin 3,7-β-O-diglucoside. This peonidin derivative, in combination with the previously reported pelargonidin-type anthocyanins, can be suggested as a suitable chemical marker for this singular V. vinifera grape cultivar and the wines made totally or partially from this grape cultivar.
A whole grain consists of the intact, ground, cracked, or flaked caryopsis, whose principal anatomical components--the starchy endosperm, germ, and bran--are present in the same relative proportions as they exist in the intact caryopsis. Whole grain food products can be intact, consisting of the original composition of bran, germ, and endosperm, throughout the entire lifetime of the product, or reconstituted, in which one or more of the original components of a whole grain is recombined to the relative proportion naturally occurring in the grain kernel. Increased consumption of whole grains has been associated with reduced risk of major chronic diseases including cardiovascular disease, type II diabetes, and some cancers. Whole grain foods offer a wide range of phytochemicals with health benefits that are only recently becoming recognized. The unique phytochemicals in whole grains are proposed to be responsible for the health benefits of whole grain consumption. In this paper, whole grain phytochemicals and the health benefits associated with their consumption are reviewed.
The health benefits of whole grain consumption have been attributed to their content of complex carbohydrates, vitamins, minerals, and other phytochemical constituents. Wild rice is a whole grain finding applications in gourmet foods due to its nutritional value and unique taste. However, little is known about its antioxidant properties and phytochemical components. The objectives of this study were to evaluate the antioxidant properties of wild rice. Eleven commercial wild rice samples (raw, mixed, and processed) were extracted with acetone and fractionated using a Sephadex LH-20 column. 2,2-Diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity, oxygen radical absorbance capacity (ORAC), and total phenolic content were evaluated to determine the antioxidant properties of wild rice. The antioxidant activity of wild rice was found to be 30 times greater than that of the control white rice. Significant differences (p < 0.05) in antioxidant activities were found among raw, mixed, and processed samples. For raw samples, DPPH radical scavenging activities and ORAC values ranged from 611 to 917 μmol of Trolox equivalent (TE)/100 g and from 4069 to 6064 μmol of TE/100 g, respectively. For mixed and processed wild rice, DPPH radical scavenging activities were 373 and 441 μmol of TE/100 g, respectively. The corresponding ORAC values were 2284 and 2557 μmol of TE/100 g. Total phenolic content (TPC) of raw wild rice varied from 2472 to 4072 mg of ferulic acid equivalent (FAE)/kg, higher than that of the mixed sample (1460 mg of FAE/kg) and processed sample (2076 mg of FAE/kg). TPC was highly correlated with total antioxidant activity of wild rice (r = 0.92). Tandem mass spectrometric techniques revealed the antioxidants identified in wild rice to be flavonoid glycosides (diglucosyl apigenin, glucosyl-arabinosyl apigenin, and diarabinosyl apigenin) in factions 2 and 3 and flavan-3-ols (catechin, epicatechin, and oligomeric procyanidin) in fractions 4 and 5.
Petit Verdot grape skins by solid-phase extraction using a combination of reverse-phase and ion-exchanging materials. This procedure allowed us to separate a fraction of anthocyanin-free flavonol 3-O-glycosides that was further split into neutral and acidic subfractions, thus facilitating flavonol identification. By means of semipreparative reverse-phase high-performance liquid chromatography, we isolated several of these flavonol 3-O-glycosides for structural elucidation. The identification of different flavonol 3-O-glycosides was based on liquid chromatography-diode array detection-electrospray ionization-tandem mass spectrometry and NMR data when available. The results suggest that red grape flavonol 3-O-glycosides comprise three different complete series, according to the nature of the sugar moiety linked to the C-3 position. The 3-O-glucosides were the main derivative of the six possible flavonol aglycones (kaempferol, quercetin, isorhamnetin, myricetin, laricitrin, and syringetin), whereas the 3-O-galactoside derivatives were found as minor compounds for all of the flavonol aglycones. The 3-O-glucuronides are the third kind of red grape flavonol derivatives and normally account as minor compounds for all of the flavonol aglycones, with the exception of quercetin 3-O-glucuronide, which was as abundant as quercetin 3-O-glucoside. In addition, the presence of quercetin 3-O-(6"-rhamnosyl)-glucoside (rutin) was also detected as a trace compound in the skins of Petit Verdot grapes.
Two novel tocotrienols were isolated from stabilized and heated rice bran, apart from the known alpha-, beta-, gamma-, and delta-tocopherols and tocotrienols. These new tocotrienols were separated by HPLC, using a normal phase silica column. Their structures were determined by ultraviolet, infrared, nuclear magnetic resonance, circular dichroism, and high-resolution mass spectroscopies and established as desmethyl tocotrienol [3, 4-dihydro-2-methyl-2-(4,8,12-trimethyltrideca-3'(E),7'(E), 11'-trienyl)-2H-1-benzopyran-6-ol] and didesmethy tocotrienol [3, 4-dihydro-2-(4,8,12-trimethyltrideca-3'(E),7'(E), 11'-trienyl)-2H-1-benzopyran-6-ol]. These tocotrienols significantly lowered serum total and LDL cholesterol levels and inhibited HMG-CoA reductase activity in chickens. They had much greater in vitro antioxidant activities and greater suppression of B16 melanoma cell proliferation than alpha-tocopherol and known tocotrienols. Results indicated that the number and position of methyl substituents in tocotrienols affect their hypocholesterolemic, antioxidant, and antitumor properties.
The antioxidant activities of vitamin E (alpha-tocopherol, alpha-tocotrienol, gamma-tocopherol, and gamma-tocotrienol) and gamma-oryzanol components (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, and campesteryl ferulate) purified from rice bran were investigated in a cholesterol oxidation system accelerated by 2,2'-azobis(2-methylpropionamidine) dihydrochloride. All components exhibited significant antioxidant activity in the inhibition of cholesterol oxidation. The highest antioxidant activity was found for 24-methylenecycloartanyl ferulate, and all three gamma-oryzanol components had activities higher than that of any of the four vitamin E components. Because the quantity of gamma-oryzanol is up to 10 times higher than that of vitamin E in rice bran, gamma-oryzanol may be a more important antioxidant of rice bran in the reduction of cholesterol oxidation than vitamin E, which has been considered to be the major antioxidant in rice bran. The antioxidant function of these components against cholesterol oxidation may contribute to the potential hypocholesterolemic property of rice bran.
The distribution of chemical constituents is known not to be even within a rice kernel. To improve the eating quality of rice or to give it some special traits by adjusting the milling intensity, we investigated the distribution of amylose, nitrogen (N), and specific minerals (P, K, Mg, Ca, and Mn) in rice kernels of 11 cultivars with various characteristics cultivated under similar conditions. The distributions of these constituents were determined using flour samples prepared consecutively by abrasive milling from the outer to the inner portions of hulled rice. In all the cultivars tested, N and the minerals were found to be more abundant in the outer than in the inner portion, but amylose was rich in the inner portion. P, Mg, K, and Mn were extremely rich in the outer portion, while N and Ca were only relatively rich there. Koshihikari, which is the most popular cultivar in Japan because of its excellent eating quality, showed the highest Mg/K ratio in the outermost portion of polished rice. The color of flour samples became pure white going from outside portions toward the center of the kernel, even if the sample was from red rice or purple-black rice because only the surface of hulled rice contains pigments. These findings suggest that the outer portion contains various compounds other than starch and the inner portion contains relatively pure starch. Rice palatability and other characteristics can be improved through controlling the degree of milling using the biased distribution of chemical constituents within a rice kernel.
The extracts from white-, black-, and red-hulled rice were prepared by sequential extraction with six different polar solvents, and their radical-scavenging activities were measured by methods using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH*) and tert-butyl hydroperoxyl radical (t-BuOO*). The extracts prepared with highly polar solvents, methanol and deionized water, exhibited higher DPPH* and t-BuOO* scavenging activities in all three cultivars. In addition, the acetone extract from red-hulled rice exhibited a high DPPH* and t-BuOO* scavenging activity, while no such activity was detected for the acetone extracts from white- and black-hulled rice. The major components responsible for the radical scavenging in the acetone extract from red-hulled rice were identified as procyanidins by acidic hydrolysis, vanillin assay, and Sephadex LH-20 chromatography. GPC analysis of the acetylated procyanidins revealed that the average molecular weight is about 5000, in a range of about 500-18,000.
The fragmentation behavior of 18 chlorogenic acids that are not substituted at position 1 has been investigated using LC-MS(4) applied to a methanolic coffee bean extract and commercial cider (hard cider). Using LC-MS(3), it is possible to discriminate between each of the three isomers of p-coumaroylquinic acid, caffeoylquinic acid, feruloylquinic acid, and dicaffeoylquinic acid, and a hierarchical key has been prepared to facilitate this process when standards are not available. MS(4) fragmentations further support these assignments, but were not essential in reaching them. The distinctive behavior of 4-acyl and 3-acyl chlorogenic acids compared with the 5-acyl chlorogenic acids is a key factor permitting these assignments. The fragmentation patterns are dependent upon the particular stereochemical relationships between the individual substituents on the quinic acid moiety. Fragmentation is facilitated by 1,2-acyl participation and proceeds through quinic acid conformers in which the relevant substituents transiently adopt a 1,3-syn-diaxial relationship. Selected ion monitoring at m/z 529 clearly indicated the presence in coffee of six caffeoylferuloylquinic acid isomers, whereas previously only two or three had been demonstrated. The hierarchical key permitted specific structures to be assigned to each of the six isomers. These assignments are internally consistent and consistent with the limited data previously available.
Anthocyanins, present in fruits and vegetables as natural colorants, have been well characterized to possess bioactive properties. Anthocyanin components extracted from black rice (Oryza sativa L. indica) separated by gel filtration and identified using LC-MS were cyanidin 3-glucoside and peonidin 3-glucoside. A standardized extract of black rice pigmented fraction (BRE) containing known proportions of cyanidin 3-glucoside and peonidin 3-glucoside exhibited marked antioxidant activities and free radical scavenging capacities in a battery of in vitro model systems. Significant (p < 0.05) prevention of supercoiled DNA strand scission induced by reactive oxygen species (specifically, peroxyl radical and hydroxyl radicals) and suppression of the oxidative modification of human low-density lipoprotein was obtained with BRE. In addition, BRE reduced (p < 0.05) the formation of nitric oxide by suppressing inducible nitric oxide synthase expression in murine macrophage RAW264.7 cells, without introducing cell toxicity. The results of this study show that black rice contains anthocyanin pigments with notable antioxidant and anti-inflammatory properties for potential use in nutraceutical or functional food formulations.
Anthocyanins are naturally occurring compounds that impart color to fruits, vegetables, and plants. They are probably the most important group of visible plant pigments besides chlorophyll. Apart from imparting color to plants, anthocyanins also have an array of health-promoting benefits, as they can protect against a variety of oxidants through a various number of mechanisms. However, anthocyanins have received less attention than other flavonoids, despite this. This article reviews their biological functions and pre-clinical studies, as well as the most recent analytical techniques concerning anthocyanin isolation and identification.
The anthocyanic composition of some pigmented cereals is still not well established, neither in relation to some of their components, nor from the quantitative point of view. Nonetheless, the use of analytical techniques, such as diode array spectroscopy and mass spectrometry (MS, PDMS, MALDI) coupled or not to liquid chromatography, are permitting, in recent years, the confirmation of the structure of some of the principal anthocyanins and a knowledge of those which are present in minor proportion. In this article, firstly, a review of the principal methods of analysis of anthocyanins is made. This is followed by a review of the most significant advances achieved in the last years in the field of the identification and quantification of these pigments in cereals and the present uses of the commercial extracts of anthocyanins obtained from these sources and the perspectives for their use is included.
Anthocyanins and proanthocyanidins were characterized by HPLC-ESI-MS/MS coupled with a diode array and/or fluorescent detector in seven cultivars of Ribes nigrum (black currant) and Ribes rubrum (red currant, Red Lake), six cultivars of Ribes grossularia (gooseberries), Aronia melanocarpa(chokeberry), and Sambucus nigra (elderberry). Thirty-one different anthocyanins were detected in these berries, but not every anthocyanin was observed in each berry. A number of minor anthocyanins were identified from these berries for the first time. The concentrations of individual anthocyanins in all of the berries were quantified using relevant anthocyanidin 3-glucoside standards. Among the berries studied in this paper and in berries in general, chokeberry has the highest total anthocyanin concentrations [1480 mg/100 g of fresh weight (FW)], whereas the lowest total anthocyanin concentration in the berries studied was found in the gooseberry cv. Careless, which contained only 0.07 mg/100 g of FW. Two cultivars of gooseberries (Marigold and Leveller) did not contain any anthocyanins. Total proanthocyanidin concentrations in the berries studied ranged from 23 to 664 mg/100 g of FW in elderberry and chokeberry, respectively. Procyanidin or prodelphinidin polymers were the predominant components (>65% w/w) in most of the berries. The lipophilic and hydrophilic antioxidant capacities were measured by the oxygen radical absorbance capacity (ORAC(FL)) procedure. The total antioxidant capacity varied from 21 micromol of TE/g of FW in Careless gooseberry to 161 micromol of TE/g of FW in chokeberry. Total phenolics in the berries in general paralleled hydrophilic antioxidant capacity.
A systematic method for anthocyanin identification using tandems mass spectrometry (MS/MS) coupled to high-performance liquid chromatography (HPLC) with photo-diode array detection (PDA) was developed. Scan for the precursor ions of commonly found anthocyanidins (cyanidin, delphinidin, malvidin, pelargonidin, petunidin, and peonidin) using LC/MS/MS on a triple quadrupole instrument allows for the specific determination of each category of anthocyanins. Further characterization of each anthocyanin was performed using MS/MS product-ion analysis, common-neutral-loss analysis, and selected reaction monitoring (SRM). The method was demonstrated for analysis of anthocyanins in black raspberries, red raspberries, highbush blueberries, and grapes (Vitis vinifera). Previous reported anthocyanins in black raspberries and red raspberries are confirmed and characterized. Common-neutral-loss analysis allows for the distinction of anthocyanin glucosides or galactoside and arabinosides in highbush blueberries. Separation and identification of anthocyanin glucosides and galactosides were achieved by LC/MS/MS using SRM. Anthocyanin isomers such as cyanidin sophoroside and 3,5-diglucoside were differentiated by their fragmentation pattern during product-ion analysis. Fifteen anthocyanins (all possible combinations of five anthocyanidins and three sugars) were characterized in highbush blueberries. Pelargonidin 3-glucoside and pelargonidin 3,5-diglucoside were detected and characterized for the first time in grapes. The present approach allows mass spectrometry to be used as a highly selective detector for rapid identification and characterization of anthocyanins and can be used as a sensitive procedure for screening anthocyanins in fruits and vegetables.
Anthocyanin pigments from a wide variety of edible and ornamental black, blue, pink, purple, red, and white wheat, barley, corn, rice, and wild rice were identified and quantified to evaluate their potential as natural colorants or functional food ingredients. The total anthocyanin contents varied significantly and exhibited a range of 7-3276 microg/g. Some grains, such as red rice and black rice, contained a limited number of pigments, whereas others, such as blue, pink, purple, and red corns, had complex anthocyanin profiles. Of the 42 anthocyanin compounds observed, 9 were characterized by comparison of the spectroscopic and chromatographic properties with those of authentic standards. The remaining compounds were tentatively identified on the basis of spectroscopic properties and electrospray ionization mass spectra. The most abundant anthocyanins were cyanidin 3-glucoside in black and red rices and in blue, purple, and red corns, pelargonidin 3-glucoside in pink corn, and delphinidin 3-glucoside in blue wheat.
The main flavonols found in seven widespread Vitis vinifera red grape cultivars include the 3-glucosides and 3-glucuronides of myricetin and quercetin and the 3-glucosides of kaempferol and isorhamnetin. In addition, the methoxylated trisubstituted flavonols, laricitrin and syringetin, were predominantly found as 3-glucosides. As minority flavonols, the results suggest the detection of the 3-galactosides of kaempferol and laricitrin, the 3-glucuronide of kaempferol, and the 3-(6' '-acetyl)glucosides of quercetin and syringetin. The flavonol profiles based on the eight above-mentioned flavonols allowed the cultivar differentiation of the grape samples. With regard to flavonol biosynthesis in the berry skin, quercetin 3-glucuronide predominated at véraison, followed by quercetin 3-glucoside, and only trace amounts of trisubstituted flavonols were detected. The proportion of quercetin 3-glucoside remained almost constant during berry ripening, whereas the proportion of quercetin 3-glucuronide decreased and the other flavonols, especially myricetin 3-glucoside, increased their importance. In wines, flavonol 3-glycosides coexisted with their corresponding free aglycones released by hydrolysis. The presence of laricitrin, syringetin, and laricitrin 3-glucoside in red wines is reported here for the first time. The extent of hydrolysis was widely variable among wines made from the same grape cultivar, and the results suggest the influence of the type of aglycone and glycoside on the rate of hydrolysis. Due to hydrolysis, the differentiation of single-cultivar wines gave acceptable results only when aglycone-type flavonol profiles were used.
Although most rice cultivars have whitish kernel, some varieties have a red testa. Aim of this work was to compare the total antioxidant capacity (TAC) and the antioxidant chemical composition (namely tocols, gamma-oryzanols, and polyphenols) of red and white rices. In addition, the effect of milling and cooking on antioxidants was investigated in both rices. Dehulled red rice showed a TAC more than three times greater than dehulled white rice and its high TAC was essentially characterized by the presence of proanthocyanidins (PA) and associated phenolics. Milling caused a significant loss of TAC, even if red rice maintained a higher TAC. Cooking caused a further loss of antioxidants, but when there was a full uptake of cooking water by the grains ("risotto") this loss was limited. Thus, the consumption of whole or partially milled rice cooked as risotto would be preferred to preserve its nutritional properties.
the structural composition of flavan-3-ol oligomers and polymers, an acid-catalyzed depolymeriza-tion method was used. Depolymerization in the presence of acid and References Anthocyanin composition in black, blue, pink, purple, and red cereal grains
- Afterward Abdel-Aal
- E S M Young
- J C Rabalski
Afterward, in order to better evaluate the structural composition of flavan-3-ol oligomers and polymers, an acid-catalyzed depolymeriza-tion method was used. Depolymerization in the presence of acid and References Abdel-Aal, E. S. M., Young, J. C., & Rabalski, I. (2006). Anthocyanin composition in black, blue, pink, purple, and red cereal grains. Journal of Agricultural and Food Chemistry, 54, 4696–4704.
Optimization of proanthocyanidins analysis using Pyrogallol as nucleophile. NMR adducts characterization
- E García-Romero
- N Castillo-Muñoz
- I Hermosín-Gutiérrez
- A M Inarejos-García
- M V Gómez
- S Gómez-Alonso
García-Romero, E., Castillo-Muñoz, N., Hermosín-Gutiérrez, I., Inarejos-García, A.M.,
Gómez, M. V., & Gómez-Alonso, S. (2012). Optimization of proanthocyanidins analysis using Pyrogallol as nucleophile. NMR adducts characterization. Proceedings of the
4th International Macrowine Conference 2012, Bordeaux, France.
R: A language and environment for statistical computing
- R Development
- Core Team
R Development Core Team (2008). R: A language and environment for statistical computing.
Vienna, Austria: R Foundation for Statistical Computing.
Proanthocyanidins -A final frontier in flavonoid research
- R A Dixon
- D Y Xie
- S B Sharma
Dixon, R. A., Xie, D. Y., & Sharma, S. B. (2005). Proanthocyanidins -A final frontier in flavonoid research? New Phytologist, 165, 9-28.