Bioactive compounds and antioxidant activity of wheat bran and barley husk in the extracts with different polarity

Wheat debranning: effects on mycotoxins, phenolic content, and antioxidant activity

The debranning process, at an industrial scale, was applied to grains of two wheat cultivars to determine its effect on Fusarium mycotoxin content and antioxidant activity. Grain samples from the BRS Marcante and BRS Reponte wheat cultivars, naturally contaminated by Fusarium, were used in the study. The dry wheat samples were processed on the polisher once or twice and evaluated by hardness index, chemical composition (moisture, protein, and ash), deoxynivalenol (DON) and zearalenone (ZON) levels, phenolic content, and antioxidant activity. In the BRS Marcante cultivar, the debranning process only slightly reduced the DON and ZON contents in whole-wheat flours compared with the previous cleaning treatment (no-debranned). In the BRS Reponte cultivar, the DON concentration decreased by 36% at a debranning ratio of 5%, obtained by polishing, compared with prior cleaning treatment (no-debranned). In addition, the polishing reduced the ZON level by 56% compared with the cleaned wheat. The debranning process did not reduce the antioxidant capacity. Therefore, debranning is a suitable technology to obtain safer and healthier food by minimizing the mycotoxin content and retaining antioxidant capacity.

Solid-state fermentation using wheat bran to produce glucose syrup and functional cereal bars

Wheat bran is one of the most abundant by-products from grain milling, which can be used as substrate for solid-state fermentation (SSF) to obtain enzymes able to convert this agro-industrial waste into glucose syrup, which in turn can be applied for the production of different food products. The present study aimed to determine centesimal composition of wheat bran, obtain enzymatic extract that converts wheat bran into wheat glucose syrup (WGS), produce rice flakes cereal bars (RFCB), and evaluate their nutritional composition and the presence of functional compounds, as well as their antioxidant potential. Determination of centesimal composition of wheat bran demonstrated its nutritional potential. Enzymatic extract was obtained and it converted wheat bran into WGS, which were applied to rice flakes producing RFCB. These cereal bars proved to be a source of dietary fiber (1.8 g) and soluble protein (7.2 g) while RCFB produced with corn glucose syrup did not present these nutritional components. In addition, RFCB produced with WGS showed polyphenolic compounds, among them flavonoids, which exhibited antioxidant activity by DPPH and ABTS radical scavenging (47.46% and 711.89 μM Trolox Equivalent/g, respectively), and iron ion reduction (71.70 μM Trolox equivalent/g). Final product showed a decrease in caloric value and sodium content. Therefore, the present study showed that the bioprocess of SSF yields a nutritional, ecological, and functional food product, which might be of great interest for food industry, adding nutritional and functional value to a well-stablished product.

Total Phenols and Flavonoids in Germinated Barley Using Different Solvents

Sprouts are a source of secondary metabolites as phenolic compounds. Germination and the use of solvents can affect their content. The aim of this work was to identify the total content of phenols and flavonoids in ungerminated and germinated (3, 5, and 7 days) Esmeralda and Perla barley. Different solvents (water, 50 % acetone, 80 % methanol, 80 % ethanol) were used to recover total phenols and flavonoids. The 7-day germination proved to be ideal for total phenol and flavonoid obtention from Esmeralda barley and the highest total phenol and flavonoid content in Perla variety was observed at 5 and 7 days of germination, respectively. Methanol and ethanol (80 %) yielded the highest extraction percentage of total phenols; 50 % acetone recovered the highest flavonoid concentrations in Esmeralda barley and 80 % methanol in Perla barley. The highest total phenol concentration was obtained from Perla samples at 13.60 mg GAE/g, and the highest total flavonoids were observed in Esmeralda barley at 1.73 mg QE/g. A high correlation was found between the concentration of phenols (0.995) and total flavonoids (0.780) with the radicle size in the Esmeralda samples.

Functional and Nutritional Characteristics of Natural or Modified Wheat Bran Non-Starch Polysaccharides: A Literature Review

Wheat bran (WB) consists mainly of different histological cell layers (pericarp, testa, hyaline layer and aleurone). WB contains large quantities of non-starch polysaccharides (NSP), including arabinoxylans (AX) and β-glucans. These dietary fibres have long been studied for their health effects on management and prevention of cardiovascular diseases, cholesterol, obesity, type-2 diabetes, and cancer. NSP benefits depend on their dose and molecular characteristics, including concentration, viscosity, molecular weight, and linked-polyphenols bioavailability. Given the positive health effects of WB, its incorporation in different food products is steadily increasing. However, the rheological, organoleptic and other problems associated with WB integration are numerous. Biological, physical, chemical and combined methods have been developed to optimise and modify NSP molecular characteristics. Most of these techniques aimed to potentially improve food processing, nutritional and health benefits. In this review, the physicochemical, molecular and functional properties of modified and unmodified WB are highlighted and explored. Up-to-date research findings from the clinical trials on mechanisms that WB have and their effects on health markers are critically reviewed. The review points out the lack of research using WB or purified WB fibre components in randomized, controlled clinical trials.

Implication of solvent polarities on browntop millet (Urochloa ramosa) phenolic antioxidants and their ability to protect oxidative DNA damage and inhibit α-amylase and α-glucosidase enzymes

Phenolics of browntop millet extracted in solvents with varying polarities [water, methanol, acetone (80%), ethanol (70%)] were comparatively assessed for their phenolic profiles, antioxidant activities, DNA damage protection and enzyme inhibitory properties. Results indicated that acetone (80%) and ethanol (70%) were most effective in extracting millet phenolics than other solvents. Gallic, caffeic and ferulic acids were the major phenolic acids, myricetin and kaempferol were the most abundant flavonoids detected in all the extracts of browntop millet. Phenolics extracted in 80% acetone and 70% ethanol offered noticeable contributions toward several antioxidant mechanisms and prevented the oxidative DNA damage than water and methanol extracts. All the millet extracts exhibited potent inhibition towards α-glucosidase than α-amylase activities. These results suggest that the solvents and their polarities impacted the extraction and bioactivities of millet phenolics and provided useful information for the effective utilization of browntop millet as a functional food ingredient to manage hyperglycemia.

Polyphenol Profile and In Vitro Antioxidant and Enzyme Inhibitory Activities of Different Solvent Extracts of Highland Barley Bran

Five different solvent extracts of highland barley bran were analyzed and compared for their polyphenol profile, antioxidant activity, and α-glucosidase and α-amylase inhibitory activities. The highland barley bran acetone extract had the highest total phenolic content, total flavonoid content, and antioxidant capacity. It was followed by the methanol and ethanol extracts, while n-butanol and ethyl acetate extracts exhibited lower measured values. Diosmetin, luteolin, protocatechuic acid, vanillic acid, ferulic acid, phlorogucinol, diosmin, isoquercitrin, catechin, and isovitexin were among the most abundant phenolic compounds identified in different solvent extracts, and their concentrations varied according to the solvent used. The highest α-glucosidase and α-amylase inhibitory activity were observed in the ethyl acetate extract of highland barley bran, followed by the acetone and methanol extracts. In contrast, n-butanol and ethanol extracts exhibited lower measured values. The different solvent extracts were effective inhibitors for α-glucosidase and α-amylase with activity reaching to 34.45-94.32% and 22.08-35.92% of that of positive control acarbose, respectively. There were obvious correlations between the phenolic content and composition of different solvent extracts and their in vitro antioxidant activity, α-glucosidase inhibition activity and α-amylase inhibition activity. Black barley bran is an excellent natural raw material for developing polyphenol-rich functional foods and shows good antioxidant and hypoglycemic potential to benefit human health.

Extraction and characterization of cereal bran cell wall in relation to its end use perspectives

The main objective of the current research was to explore the physicochemical, microbial and sensorial attributes of cereals bran cell wall (CBCW) enriched bread. In 1st phase, the cell wall wasextracted from different cerealsbran and characterized for its dietary fiber profile and antioxidant activity. In addition, bread was prepared with the additionof CBCW at different ratios and explored for physicochemical, microbialand sensorial characteristics. Current results showed that total dietary fiber contents of CBCW were 59.1 ± 0.2%, 61.2 ± 0.03% and 68.8 ± 0.2% in wheat, maize and oat bran respectively. Furthermore, maize bran cell wall showed higher antioxidant activityof ferric reducing antioxidant power (FRAP), DPPH and ABTS were 52.5 ± 0.12, 28.4 ± 0.07 and 18 ± 0.05 µmol TE/g as compared to wheat and oat bran cell wall. Additionally, CBCWimproved the bread quality in terms of physicochemical, microbial and sensorial characteristics.Moreover, CBCW-enriched bread showed higher loaf volume, loaf height, the specific volume of loaf and weight of bread as compared to control due to less baking loss. Furthermore, maize bran cell wall enriched bread exhibited less growth after 4 days as compared to other treatments. Moreover, CBCW-enriched bread showed higher sensorial properties score than C0.Convulsively, CBCW-enriched bread has good physicochemical, microbial and sensorial properties as compared to control bread.

Pulses-derived proteins for the plant-based market: opportunities to reduce postharvest loss and waste

Pulses are one of the main global food sources and have become even more essential after the enormous growth of the plant-based food market. Among the losses and waste throughout the supply chain, postharvest ones and industrial sidestreams from protein processing are of special interest. In this review, we present the main reasons for postharvest losses, and strategies to reduce them. We also describe how to value the waste fractions generated from obtaining pulses' proteins and ways to enhance the proteins' functionalities. Fermentation and the use of enzymes were emphasized as biotechnological tools to develop new food ingredients and products.

Antioxidant and Cytoprotective Capacities of Various Wheat (Triticum aestivum L.) Cultivars in Korea

Whole wheat (Triticum aestivum L.) is a rich source of bioactive compounds with health benefits such as antioxidant, anti-inflammatory, and anti-proliferative activities. In this study, we evaluated the antioxidant and cytoprotective capacities of 41 wheat cultivars. The antioxidant capacities of whole wheat grain extracts (WWE) from various wheat cultivars were evaluated using total phenolic content and ABTS and DPPH radical-scavenging activities. The relative antioxidant capacity index (RACI) was calculated to integrate different chemical methods of antioxidant capacity. The cytoprotective capacity of the WWE was investigated using hepatocytes (HepG2), myoblasts (C2C12), and endothelial (EA.hy926) cells. The RACI was the highest and lowest for Dajoong (1.71) and Topdong (−1.96), respectively. Pearson correlation tests were conducted to determine the correlation between the antioxidant and cytoprotective activities. However, no significant correlations between RACI and the cytoprotective capacities were ascertained. Principal component analysis revealed that the first two components represented 68.93% of the total variability. Hierarchical cluster analysis classified WWE into three groups based on measured parameters. The results of this study highlight the variation in the antioxidant and cytoprotective capacities of 41 different wheat cultivars. This study provides basic information that can guide decisions in wheat breeding programs for the development of functional food crops and new dietary ingredients.

Ionizing Radiation Technologies to Increase the Extraction of Bioactive Compounds from Agro-Industrial Residues: A Review

Due to the growing demand in society for healthier foods, scientific communities are searching and developing new ingredients. In this context, agro-industrial residues, which can have a negative impact on the environment, represent a natural source for bioactive compounds and their recovery can contribute to economic and environmental sustainability. Ionizing radiation is a clean and eco-friendly technology that can be used to improve the extraction of bioactive compounds. The aim of this review, after presenting general aspects about bioactive compounds in agro-industrial residues and radiation technologies, is to focus on the effects of ionizing radiation on the extraction of bioactive compounds from these residues and related bioactive properties. Irradiated residues were demonstrated to have enhanced bioactive characteristics that turn the prepared extracts suitable for applications in food industry, resulting in high-added-value products as well as reducing adverse impacts on the environment.

Purification, structural analysis, and stability of antioxidant peptides from purple wheat bran

Protein derived from purple wheat bran was hydrolyzed sequentially using alcalase proteases for the production of antioxidant peptides. Purple wheat bran protein (PWBP) hydrolysates were fractionated using size-exclusion (G-25) and ion-exchange chromatography methods to identify the structure of antioxidant peptides. The free radical scavenging activity of peptides purified from PWBP hydrolysates was evaluated using superoxide anion radical-scavenging activity and determination assays of Trolox equivalent antioxidant capacity (TEAC). Results demonstrated that purple wheat bran peptide F4-4 exhibited the highest antioxidant activity among other hydrolysates. F4-4 was further identified as Cys-Gly-Phe-Pro-Gly-His-Cys, Gln-Ala-Cys, Arg-Asn-Phe, Ser-Ser-Cys, and Trp-Phe by high performance liquid chromatography (HPLC) spectrometer coupled with Orbitrap Elite™ mass spectrometer (LC–MS/MS). Antioxidant peptides 2 and 4 showed improved stability when the temperature was lower than 80 °C. These peptides also demonstrated good digestive stability in vitro system by simulating gastrointestinal digestion.

Advances on the Valorisation and Functionalization of By-Products and Wastes from Cereal-Based Processing Industry

Cereals have been one of the major food resources for human diets and animal feed for thousands of years, and a large quantity of by-products is generated throughout the entire processing food chain, from farm to fork. These by-products mostly consist of the germ and outer layers (bran) derived from dry and wet milling of the grains, of the brewers' spent grain generated in the brewing industry, or comprise other types obtained from the breadmaking and starch production industries. Cereal processing by-products are an excellent low-cost source of various compounds such as dietary fibres, proteins, carbohydrates and sugars, minerals and antioxidants (such as polyphenols and vitamins), among others. Often, they are downgraded and end up as waste or, in the best case, are used as animal feed or fertilizers. With the increase in world population coupled with the growing awareness about environmental sustainability and healthy life-styles and well-being, the interest of the industry and the global market to provide novel, sustainable and innovative solutions for the management of cereal-based by-products is also growing rapidly. In that respect, these promising materials can be valorised by applying various biotechnological techniques, thus leading to numerous economic and environmental advantages as well as important opportunities towards new product development (NPD) in the food and feed industry and other types such as chemical, packaging, nutraceutical (dietary supplements and food additives), cosmetic and pharmaceutical industries. This review aims at giving a scientific overview of the potential and the latest advances on the valorisation of cereal-based by-products and wastes. We intended it to be a reference document for scientists, technicians and all those chasing new research topics and opportunities to explore cereal-based by-products through a circular economy approach.

Pilot-scale ohmic heating-assisted extraction of wheat bran bioactive compounds: Effects of the extract on corn oil stability

Recent studies introduced ohmic heating-assisted extraction (OHAE) as a promising emerging technology at laboratory-scales. The objectives of the present study were, first, to investigate the applicability of OHAE at pilot-scale for extraction of bioactive compounds from wheat bran immersed in a polar solvent (salted water containing 0.1% NaCl) at the electric field strengths (EFS) of 4.28, 7.90, and 15.71 V/cm and, second, to evaluate the effects of the wheat extracts on the corn oil stability during 30 days of storage at 45 °C. The results showed that OHAE saved 63% of energy consumption compared with the conventional extraction method. Also, the scaled-up OHAE unit yielded extracts with high quantities of bioactive compounds (110-460 ppm total phenolics) and higher antioxidant activities (antioxidant effectiveness of 56-84%) than those of the extract obtained through the conventional extraction method, i.e., 95 ppm total phenolics with antioxidant effectiveness of 51%. Increasing the EFS increased total phenolics and antioxidant effectiveness of extracts. The incorporation of 250 ppm of the extract obtained at the highest EFS effectively postponed the oxidation of corn oil during one month of storage (peroxide value of 7 vs. 19 meq/kg compared with the control sample) and extended the half-life of oil from 11 to 26 days. Besides, mathematical models proposed in this study well-predicted the oxidation stability of the oil samples mixed with the extract.

Chemical and microbial evaluation of biscuits made from wheat flour substituted with wheat sprouts

The aim of this work was to produce biscuits from wheat flour substituted with different amounts of wheat sprout powder (2.5-7.5%). The biscuits were subjected to chemical, phytochemical, and microbial evaluations. The crude protein, fat, and ash contents and the energy value of the biscuits increased with increasing percentage of wheat sprout powder. Adding sprouts resulted in higher values of phenolics, alpha-tocopherol, and antioxidant activity. There was no statistically significant difference in the contents of total phenolics and alpha-tocopherol between biscuits supplemented with 5% sprouts and biscuits substituted with 7.5% sprouts. The phenolic content in biscuits containing 7.5% sprouts was 245 mg gallic acid equivalents (GAE)/100 g dm compared with 110 mg GAE/100 g dm in control biscuits. Antioxidant activity was the highest in biscuits substituted with 7.5% sprouts. All levels of substitution of wheat flour with wheat sprouts had an effect on the nutritional properties of biscuits, but the substitution level of 2.5-5% is recommended for the improvement of their sensorial properties. The biscuits produced had a low microbial load and were microbiologically safe. Escherichia coli, Salmonella spp., and sulfite-reduction clostridia were not detected in any sample during the period of investigation from 2 to 60 days of storage.

Distribution of β-Glucan, Phenolic Acids, and Proteins as Functional Phytonutrients of Hull-Less Barley Grain

Two hull-less barley varieties were roller-milled, and breaks (B) and reduction flours (C), shorts, and bran were collected. Shorts, which mainly originate from endosperm cells with a smaller amount of the outer layers, had the largest yield (48.87–51.54%). Ash (0.82–3.10%) and protein (9.95–14.8%) increased from flours toward shorts and bran, while starch decreased (82.31–48.69%). In contrast to clear distribution differences in protein content (bran > shorts > C > B), albumins/globulins content was lowest in bran (0.78–0.90 g/100 g_dw), and their distribution between fractions was uneven and genotype dependent. Distribution of hordeins (6.69–10.49 g/100 g_dw) was more distinct and generally decreased in order from bran > B > shorts > C. The proportion of nutritionally poor C-hordeins in total hordeins varied from 28.33% to 30.24%, without significant differences between fractions. The β-glucan content varied from 0.80% to 7.49% with decreasing content in the order bran, shorts > C > B. Shorts and bran could be classified as moderate and high β-glucan flour (5.70–7.22%). The total phenolic and antioxidant activities ranged from 0.91 to 2.21 mg GAE/g_dw and 28.81–72.06%, respectively. Ferulic and sinapic acids determined by high-performance liquid chromatography (HPLC) were major contributors to the antioxidant activity (45.16–1026.91 ug/g_dw and 18.93–206.52 ug/g_dw), respectively. The yield and high content of phytonutrients make hull-less barley shorts suitable for the production of health-promoting food and food supplements.

HPLC-ESI-qTOF-MS/MS Characterization, Antioxidant Activities and Inhibitory Ability of Digestive Enzymes with Molecular Docking Analysis of Various Parts of Raspberry (Rubus ideaus L.)

The anti-oxidative phenolic compounds in plant extracts possess multiple pharmacological functions. However, the phenolic characterization and in vitro bio-activities in various parts of raspberry (Rubus idaeus L.) have not been investigated systematically. In the present study, the phenolic profiles of leaves (LE), fruit pulp (FPE), and seed extracts (SE) in raspberry were analyzed by HR-HPLC-ESI-qTOF-MS/MS method, and their antioxidant activities and digestive enzymes inhibitory abilities were also investigated. The molecular docking analysis was used to delineate their inhibition mechanisms toward type II diabetes related digestive enzymes. Regardless of LE, FPE, or SE, 50% methanol was the best solvent for extracting high contents of phenolic compounds, followed by 50% ethanol and 100% methanol. The LE of raspberry displayed the highest total phenolic content (TPC) and total flavonoid content (TFC). A total of nineteen phenolic compounds were identified. The quantitative results showed that gallic acid, ellagic acid, and procyanidin C3 were the major constituents in the three extracts. The various parts extracts of raspberry all exhibited the strong antioxidant activities, especially for LE. Moreover, the powerful inhibitory effects of the three extracts against digestive enzymes (α-glucosidase and α-amylase) were observed. The major phenolic compounds of the three extracts also showed good inhibitory activities of digestive enzyme in a dose-dependent manner. The underlying inhibitory mechanisms of the main phenolic compounds against digestive enzymes were clarified by molecular docking analysis. The present study demonstrated that the various parts of raspberry had strong antioxidant activities and inhibitory effects on digestive enzymes, and can potentially prevent oxidative damage or diabetes-related problems.