Free and bound phenolic profiles of the bran from different rice varieties and their antioxidant activity and inhibitory effects on ɑ-amylose and ɑ-glucosidase
TL;DR: In this paper, free and bound phenolic extracts from three varieties of black, indica, and Japonica rice bran were evaluated for their compositions, antioxidant activity and inhibitory effects on amylase and glucosidase activities.
About: This article is published in Journal of Cereal Science.The article was published on 2018-07-01. It has received 53 citations till now. The article focuses on the topics: Brown rice & Black rice.
Citations
More filters
TL;DR: In this article, a review of free and bound polyphenol extraction from plant by-products is presented, which highlights the potential for use in industry, especially in pharmaceutical, nutraceutical and cosmetic applications.
Abstract: Background In recent times, research has highlighted the bioactive roles played by non-extractable polyphenols (NEP) in human health, especially from by-products of grains, fruits and vegetables. Most studies have reported on the total phenol content of samples without adequate attention paid to a major class of polyphenols referred to as NEP. This limits the scope of polyphenol studies and the extent of NEP incorporation into medicines, nutraceuticals, cosmetic and foods among other applications. Scope and approach This review introduces NEP and gives an update on recent advances in free and bound polyphenol extraction from plant by-products. Owing to the fact that most researchers are already familiar with the extraction of free polyphenols, this review emphasizes the extraction of NEP and provides a basis for the selection of appropriate techniques and applications for different plant by-product sources. It also presents suggestions for future studies into NEP extraction efficiency from complex plant sources using alternative physical approaches. Key findings and conclusions NEP from by-products have high potential for use in industry, especially in pharmaceutical, nutraceutical and cosmetic applications. To ascertain the total phenol content of extracts, both free and bound phenols must be accounted for with special attention directed at appropriate sample pretreatment and extract hydrolysis. Higher bioactive properties of NEP, coupled with their cheaper by-product sources makes them economically viable and medicinally potent. Also, structure-function relationships and the possibility to use physical means such as slow-freezing-thawing to increase hydrolytic yield of NEP is recommended.
99 citations
TL;DR: RBDF had a significantly stronger prebiotic effect on the microbes associated with diabetes and may act as important functional components that could contribute to the health benefits of whole grain dietary fiber.
Abstract: Whole-grain dietary fiber is rich in bound-form phenolics, and the biological activity of this special structural feature has attracted increasing attention. In this study, rice bran dietary fiber (RBDF) was subjected to in vitro gastrointestinal digestion and colonic fermentation to investigate the liberation of bound phenolics and their potential activities. Bound phenolics were released at a higher ratio during colonic fermentation (27.57%) than gastrointestinal digestion (2.68%). Nine phenolic compounds were detected from the fermentation supernatants. The released phenolics showed radical scavenging activity (DPPH and ABTS assays) and α-glucosidase inhibitory activity (IC50 = 19.11 μg GAE/mL). Compared with phenolics-removed RBDF (PR-RBDF), RBDF had a significantly stronger prebiotic effect on the microbes associated with diabetes (Lactobacillus spp., Akkermansia muciniphila, and Faecalibacterium prausnitzii). These findings indicate that bound phenolics may act as important functional components that could contribute to the health benefits of whole-grain dietary fiber.
57 citations
TL;DR: In this article, the effects of extrusion and fermentation on phenolic profiles and bioaccessibility, together with the antioxidant activity in defatted rice bran (DRB) were investigated.
Abstract: The effects of extrusion and fermentation on the free and bound phenolic distribution in grains and related products remain controversial. The phenolic bioaccessibility have not been comprehensively studied. Therefore, the effects of extrusion and fermentation on phenolic profiles and bioaccessibility, together with the antioxidant activity in defatted rice bran (DRB) were investigated in this study. Our results revealed extrusion and fermentation not only facilitate the release of phenolics, improve the extractability of bound phenolics in DRB. The free, bound and total phenolic content increased by 23.0%, 50.7% and 36.3% after extrusion, and by 99.4%, 40% and 71.6% after fermentation, respectively. Extrusion and fermentation changed the content and distribution of 8 detected phenolic compounds but not composition in DRB. Fermentation enhanced ORAC and CAA antioxidant activity with 1.8 and 4.1 folds increases, respectively, while extrusion had no effect on CAA. Bioaccessibile phenolics increased by 40.5 and 64.4% in extruded and fermented DRB after in vitro digestion compared with raw DRB, respectively. Scanning electron microscope analysis showed extrusion and fermentation changed the compact microstructure of DRB to loose and porous structure. Our research indicates fermented and extruded DRB (especially the former) represent potentially promising materials for developing health foods and nutraceuticals.
57 citations
TL;DR: In this paper, bound polyphenols were extracted from mung bean skin dietary fiber by acid and alkaline hydrolysis and the highest yield was 37.638 (mg FAE/g).
Abstract: In this study, bound polyphenols were extracted from mung bean skin dietary fiber by acid hydrolysis or alkaline hydrolysis. It was found that alkaline hydrolysis was more thorough than acid hydrolysis, the highest yield of bound polyphenols was 37.638 (mg FAE/g). In addition, the compositions of bound polyphenols were identified and quantified by UPLC-ESI-QTOF-MS/MS and UPLC-ESI-QqQ-MS/MS. In the study of antioxidant properties, we found that with the increase of polyphenol concentration, the scavenging rate of DPPH free radical, the absorption ability of oxygen free radical and the inhibition of ABAP were increased. Moreover, the inhibition rate of bound polyphenols on α-amylase and α-glucosidase increased in a dose dependent manner. The results could provide perspective for using the bound polyphenols in mung bean skin as the functional components of health food.
48 citations
TL;DR: This research is the first showing the potential anti-diabetic activity of R. maderensis, which decreased after the gastrointestinal digestion, possibly due to some loss of phenolics that took place during the digestion process.
Abstract: In this work, we report the in vitro inhibitory potential of Rumex maderensis methanolic extracts (leaves, flowers, and stems) towards key digestive enzymes linked to type-2 diabetes and obesity (α-amylase, α-glucosidase, pancreatic lipase). The inhibitory activity towards aldose reductase and glycation of bovine serum albumin (BSA) is also reported; in these latter assays, the effect of simulated digestion on the bioactivities was evaluated. The inhibitory activities of R. maderensis extracts were statistically compared with the inhibition produced by reference compounds for each assay. The analysed extracts exhibited significant inhibitory activities, which decreased after the gastrointestinal digestion, possibly due to some loss of phenolics that took place during the digestion process. The most important results were observed during the BSA-glycation assay, in which the analysed extracts presented higher potency than a reference compound: aminoguanidine (AMG). This research is the first showing the potential anti-diabetic activity of R. maderensis.
43 citations
References
More filters
TL;DR: A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants.
18,580 citations
TL;DR: The bran/germ fraction of whole wheat may impart greater health benefits when consumed as part of a diet, and help reduce the risk of chronic diseases.
874 citations
TL;DR: Of the 42 anthocyanin compounds observed, 9 were characterized by comparison of the spectroscopic and chromatographic properties with those of authentic standards and the remaining compounds were tentatively identified on the basis ofSpectroscopic properties and electrospray ionization mass spectra.
Abstract: 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...
685 citations
TL;DR: Both DPPH* and ABTS*(+) cation assays indicated that the black varieties (Biji and Hunan) demonstrated much higher radical scavenging activities than the pink (Fenhong) and yellow (Shuijing) varieties, which may be attributed to much higher levels of anthocyanins, flavonoids, and total phenolics in theblack varieties.
Abstract: Characterization of anthocyanins and flavonols and radical scavenging activity assays of extracts from four Chinese bayberry (Myrica rubra) varieties with different fruit colors were carried out. One dominant anthocyanin and three major flavonols were isolated by HPLC, and cyanidin-3-O-glucoside and two of three flavonols, myricetin and quercetin-3-O-rutinoside, were identified by cochromatography with authentic standards. Both DPPH• and ABTS•+ cation assays indicated that the black varieties (Biji and Hunan) demonstrated much higher radical scavenging activities than the pink (Fenhong) and yellow (Shuijing) varieties, which may be attributed to much higher levels of anthocyanins, flavonoids, and total phenolics in the black varieties. Biji and Hunan had 6.49 and 6.52 mM Trolox equivalent antioxidant capacity (TEAC) per 100 g of fresh weight, whereas the pink (Fenhong) and yellow (Shuijing) bayberries had 1.32 and 1.31 mM TEAC/100 g. Different fruit color was reflected by the surface color and pigment ext...
426 citations
TL;DR: The findings suggest that brown seaweed extracts may limit the release of simple sugars from the gut and thereby alleviate postprandial hyperglycaemia.
334 citations