Phytochemical profiles and antioxidant activity of brown rice varieties

Ferulic acid concentration in 233 maize inbreds and its processing stability in selected high-ferulic-acid lines

Unlike wheat and rice, which are typically consumed as refined grains, maize is typically consumed in whole-grain forms, making it an ideal source of whole-grain phytochemicals. This study explored the genetic diversity and processing stability of ferulic acid concentration (FAC) in 233 diverse maize inbred lines. Substantial variation in FAC was observed, ranging from 1174.7 to 4811.0 μg/g. Selected high-FAC lines demonstrated consistent FAC across five environments. FAC was not significantly correlated with kernel weight, suggesting the feasibility of producing high-FAC maize without compromising yield. More importantly, common food-processing methods such as boiling, porridge-making, and popcorn-making had minimal impact on FAC, even with slight increases observed in popcorn. These findings highlight the potential of whole grain maize as a source of natural antioxidants and lay the groundwork for developing nutritionally enhanced maize for functional food applications.

Ferulic acid identification in brown rice using untargeted metabolomics and network analysis and its effects in mitigating AFB1-induced hepatic damage

Regular consumption of brown rice has been linked to a reduction in the probability of oxidative stress-related diseases, including diabetes, Alzheimer's disease and cancer. The higher abundance of bioactive metabolites, including polyphenols and vitamins, in brown rice relative to white rice may contribute to its associated health benefits. Aflatoxin B1 (AFB1), a kind of mycotoxin widely found in grains, is recognized as a primary risk factor for hepatocellular carcinoma in humans. Therefore, the differential polyphenol metabolites between brown rice and white rice, as natural plant antioxidants, may also be able to mitigate the oxidative damage caused by AFB1. In this work, the differential polyphenol metabolites between brown rice and white rice were identified using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). The results showed that 35 differential metabolites were found and classified into phenolic acids, flavonoids, lignans and coumarins. Among them, ferulic acid (FA) was characterized as a kind of differential metabolite that could mitigate AFB1-induced oxidative damage based on the interaction network and cell experiments. Furthermore, results of the mice experiment confirmed that FA mitigated AFB1-induced hepatic injury through a potential mechanism associated with the enhancement of antioxidant capacity, restoration of mitochondrial function and attenuation of AFB1-induced apoptosis. In conclusion, FA, identified between brown rice and white rice, could effectively alleviate AFB1-induced hepatic injury in vitro and in vivo. This study provides important insight into the application of brown rice (abundant in FA) as a functional food.

Unveiling the distribution of free and bound phenolic acids, flavonoids, anthocyanins, and proanthocyanidins in pigmented and non-pigmented rice genotypes

The total phenolic content, phenolic acid profile, anthocyanins, proanthocyanidins, flavonoids, and antioxidant capacity of the whole-grain and bran portion of sixteen distinct rice genotypes that correspond to three distinct pericarp bran colors-black, red, and non-pigmented (NP)-were examined. Ten free and bound phenolic acids, as well as two flavonoids, were analyzed using HPLC-PDA. The flavonoids included kaempferol and catechin hydrate, and the free phenolic acids included gallic acid, 2,5-dihydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, chlorogenic acid, trans-cinnamic acid, trans-ferulic acid, p-coumaric acid, and sinapic acid. Trans-ferulic acid (207.39 mg/kg), p-hydroxybenzoic acid (94.36 mg/kg), and p-coumaric acid (59.75 mg/kg) were the principal bound phenolic acids in pigmented rice genotypes, whereas in NP genotypes they were trans-ferulic acid (95.61 mg/kg) and p-hydroxybenzoic acid (58.32 mg/kg). The main free phenolic acid was syringic acid (120.43 mg/kg) in all genotypes. 2,5-dihydroxybenzoic acid was also detected in NP genotypes, mainly in the bound form (4.88 mg/kg). NP genotypes Basmati 386 and Punjab Basmati 7 also displayed high content of bran flavonoids (1001 and 1028 mg CE/100 g). The bound form of phenolics had significant DPPH and ABTS + activity. This study found wide diversity in the phenolic acid profile, total phenolic constituents, and antioxidant activity in the bran and whole grain of pigmented and NP rice. The individual phenolic acids in free and bound forms in different fractions of the grain were found to exert their antioxidant activity differently. The results obtained will provide new opportunities to improve the nutritional quality of rice with enhanced levels of phytochemicals in the ongoing breeding programs. Black rice bran contains a high level of phytochemicals and thus has a potent pharmaceutical role. This information would enhance the use of whole-grain and bran of pigmented rice in food product development by food technologists. Further studies may be focused on clinical trials with respect to cancer and diabetes.

Strategies to fortify the nutritional values of polished rice by implanting selective traits from brown rice: A nutrigenomics-based approach

Whole-grain cereals are important components of a healthy diet. It reduces the risk of many deadly diseases like cardiovascular diseases, diabetes, cancer, etc. Brown rice is an example of whole grain food, which is highly nutritious due to the presence of various bioactive compounds (flavonoids, phenolics, vitamins, phytosterols, oils, etc.) associated with the rice bran layer of brown rice. White rice is devoid of the nutritious rice bran layer and thus lacks the bioactive compounds which are the major attractants of brown rice. Therefore, to confer health benefits to the public at large, the nutrigenomic potential of white rice may be improved by integrating the phytochemicals associated with the rice bran layer of brown rice into it via biofortification processes like conventional breeding, agronomic practices, metabolic engineering, CRISPR/Cas9 technology, and RNAi techniques. Thus, this review article focuses on improving the nutritional qualities of white/polished rice through biofortification processes, utilizing new breeding technologies (NBTs).

A review: The nutrition components, active substances and flavonoid accumulation of Tartary buckwheat sprouts and innovative physical technology for seeds germinating

Compared with the common grain, Tartary buckwheat enjoys higher nutritional value. Some distinctive nutrition associated with physiological activity of Tartary buckwheat is valuable in medicine. In addition, it's a good feed crop. In the paper, the main components (starch, protein, amino acid, fatty acid and mineral) and polyphenol bioactive components in Tartary buckwheat and its sprouts were reviewed, and the accumulation of flavonoids in sprouts during germination, especially the methods, synthetic pathways and mechanisms of flavonoid accumulation was summarized. The research on bioactive components and health benefits of Tartary buckwheat also were reviewed. Besides, the applications of innovative physical technology including microwave, magnetic, electromagnetic, ultrasonic, and light were also mentioned and highlighted, which could promote the enrichment of some active substances during seeds germination and growth of Tartary buckwheat sprouts. It would give a good support and benefit for the research and processing of Tartary buckwheat and its sprouts in next day.

Effects of Germination, Fermentation and Extrusion on the Nutritional, Cooking and Sensory Properties of Brown Rice Products: A Comparative Study

In this study, cooked brown rice (BR), germinated brown rice (GBR), fermented brown rice (FBR) and white rice (WR) were prepared by traditional cooking techniques, and extruded brown rice (EBR) was obtained by extrusion processing technology. The nutritional, cooking and sensory properties of different BR products were investigated. The results indicated that the soluble dietary fiber (SDF) content, free total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity (DPPH, ABTS, T-AOC) in processed BR products were significantly higher than those in cooked BR and WR. The values of SDF, free TPC, TFC and T-AOC in EBR increased by 38.78%, 232.36%, 102.01% and 153.92%, respectively, compared with cooked BR. Cooked FBR and EBR had more nutrients, required less cooking time, had a softer texture and were whiter than cooked GBR and BR, especially EBR. In addition, the water absorption rate of EBR was 14.29% and 25.41% higher than that of cooked FBR and GBR. The hardness of EBR was significantly lower than that of cooked FBR and BR, even lower than that of cooked WR. However, there was no significant difference between the hardness of cooked GBR and that of cooked BR. The flavor compounds in EBR were similar to that of cooked WR, while those in cooked GBR and FBR did not differ greatly compared to cooked BR. Collectively, cooked FBR and EBR had better nutritional value, cooking and sensory properties than cooked BR, and the comprehensive value of EBR was higher.

Effect of different doses of nitrogen fertilization on bioactive compounds and antioxidant activity of brown rice

Brown rice as a whole grain food is associated with various chronic diseases' reduced risks. In this study, the effects of different doses of nitrogen fertilization (0, 160, 210, 260, 315, and 420 kg N/ 100 m²) on bioactive compounds and antioxidant activity of brown rice (yanfeng47) were investigated. At nitrogen level of 210-260 kg N/100 m², the content of TFC (302.65 mg/100 g), β-sitosterol (1762.92 mg/100 g), stigmasterol (1358.735 mg/100 g), DPPH (74.57%), and OH free radical scavenging (74.19%) was the highest. The major phenolic acid was p-hydroxybenzoic acid. There were significant positive linear relationships between TFC (0.872, 0.843), β-sitosterol (0.896, 0.657), stigmasterol (0.543, 0.771), p-hydroxybenzoic acid (0.871, 0.875), and DPPH, OH antioxidant activity. These indicated that TFC and phytosterols were the most important components in brown rice that had strong antioxidant activity. Composite score of principal components indicated 210 Kg N/100 m² exhibited a more ideal dose of nitrogen for nutritional composition and antioxidant activity of brown rice.

Cycloartenyl Ferulate Is the Predominant Compound in Brown Rice Conferring Cytoprotective Potential against Oxidative Stress-Induced Cytotoxicity

Since brown rice extract is a rich source of biologically active compounds, the present study is aimed to quantify the major compounds in brown rice and to compare their cytoprotective potential against oxidative stress. The content of the main hydrophobic compounds in brown rice followed the order of cycloartenyl ferulate (CAF) (89.00 ± 8.07 nmol/g) >> α-tocopherol (αT) (19.73 ± 2.28 nmol/g) > γ-tocotrienol (γT3) (18.24 ± 1.41 nmol/g) > α-tocotrienol (αT3) (16.02 ± 1.29 nmol/g) > γ-tocopherol (γT) (3.81 ± 0.40 nmol/g). However, the percent contribution of CAF to the radical scavenging activity of one gram of whole brown rice was similar to those of αT, αT3, and γT3 because of its weaker antioxidant activity. The CAF pretreatment displayed a significant cytoprotective effect on the hydrogen peroxide-induced cytotoxicity from 10 µM, which is lower than the minimal concentrations of αT and γT required for a significant protection. CAF also enhanced the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation coincided with the enhancement of the heme oxygenase-1 (HO-1) mRNA level. An HO-1 inhibitor, tin protoporphyrin IX (SnPP), significantly impaired the cytoprotection of CAF. The cytoprotective potential of CAF is attributable to its cycloartenyl moiety besides the ferulyl moiety. These results suggested that CAF is the predominant cytoprotector in brown rice against hydrogen peroxide-induced cytotoxicity.

Polyphenol Composition and Antioxidant Activity of Japonica Rice Cultivars and Intake Status

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.

Metabolic Variations in Brown Rice Fertilised with Different Levels of Nitrogen

Nitrogen is a necessary element for plant growth; therefore, it is important to study the influence of N fertilisers on crop metabolites. In this study, we investigate the variability of endogenous metabolites in brown rice fertilised with different amounts of nitrogen. We identified 489 metabolites in brown rice. Compared to non-nitrogen fertilised groups, there were 59 differentially activated metabolic pathways in the nitrogen-fertilised groups. Additionally, there were significantly differential secondary metabolites, especially flavonoids, between groups treated with moderate (210 kg N/hm2) and excessive amounts of nitrogen (420 kg N/hm2). Nitrogen fertilisation upregulated linoleic acid metabolism and most steroids, steroid derivatives, and flavonoid compounds, which have antioxidant activity. The DPPH, ABTS, and hydroxyl radical scavenging rates were higher in fertilised groups than in the non-fertilised group. These findings provide a theoretical basis to enhance the health benefits of brown rice by improving fertilisation.

Comparative study of solid-state fermentation with different microbial strains on the bioactive compounds and microstructure of brown rice

The effects of solid-state fermentation (SSF) with Lactiplantibacillus plantarum, Saccharomyces cerevisiae, Rhizopus oryzae, Aspergillus oryzae, and Neurospora sitophila were determined on the bioactive compound content and grain microstructure of brown rice (BR). After SSF, the β-glucan, arabinoxylans, γ-oryzanol, thiamine, riboflavin, phenolic, and flavonoid contents increased by 147, 11.2, 30.5, 16.9, 21.1, 76%, and 49.6%, respectively, indicating a marked increase in bioactive compound content. In addition, the water-soluble dietary fiber and arabinoxylan contents, and free phenolic and flavonoid contents significantly increased (p < 0.05). These changes were consistent with the microstructural changes observed after SSF, i.e., the outer cortex was rough, cracked, porous and separated from the starch endosperm, which was also cracked and porous; this should increase the dietary bioavailability of the bioactive compounds. SSF, especially with A. oryzae and Lb. plantarum, greatly enhanced the bioactive compound content in BR and has great potential in BR processing.

Phenolic Compounds and Antioxidant Activity of Rice–Tartary Buckwheat Composite as Affected by In Vitro Digestion

The present study aimed to evaluate the phenolic compounds and antioxidant activity of rice–tartary buckwheat composite (RTBC) as affected by in vitro digestion to explore the structure-activity relationship of the release of total phenolic content (TPC) and total flavonoid content (TFC) with the antioxidant activity of RTBC during in vitro oral, gastric, and intestinal digestion stages. The release of TPC and TFC from RTBC increased significantly after in vitro digestion ( $P<0.05$ ), and the change of antioxidant activity was consistent with that of TPC and TFC. Compared with the initial stage of digestion, the antioxidant activity of RTBC was increased after digestion ( $P<0.05$ ), and there was a strong correlation between antioxidant activity and the release of TPC and TFC (0.954 < R < 0.997; $P<0.05$ ). The phenolic compounds released in the oral, gastric, and intestinal digestion stages varied, and eight phenolic compounds were identified by UPLC-Triple-TOF/MS, namely, quercetin-3-O-robinoside-7-O-sophoroside, quercetin-3-O-neohesperidoside-7-O-glucoside, forsythobiflavone A, forsythobiflavone B, quercetin-3-O-rutinoside-7-O-glucoside, rutin, isoquercetin, and ferulic acid. These results indicated that in vitro digestion significantly increases the release of phenolic compounds and flavonoids from RTBC and there is a higher antioxidant activity after digestion than before digestion. The phenolic compounds released after digestion of RTBC are beneficial to health protection.

Effect of environment and field management strategies on phenolic acid profiles of hard red winter wheat genotypes

BACKGROUND

Integrated wheat management strategies can affect grain yield and flour end-use properties. However, the effect of integrated management and its interaction with environmental factors on the phenolic acid profiles of wheat has not been reported. The phenolic acid profile has become another parameter for the evaluation of wheat quality due to its potential health benefits.

RESULTS

Year × location × management and year × management × genotype interactions were significant for the total phenolic content (TPC) of wheat samples. The year × location × management × genotype interaction was significant for the concentration of trans-ferulic acid and several other phenolic acids. Field management practices with no fungicide application (e.g., farmer's practice, enhanced fertility) may lead to increased accumulation of phenolic compounds, especially for WB4458, which is more susceptible to fungi infection. However, this effect was also related to growing year and location. Higher soil nitrogen content at sowing also seems to affect the TPC and phenolic acid concentration positively.

CONCLUSION

Wheat phenolic acid profiles are affected by genotype, field management, environment, and their interactions. Intensified field management, in particular, may lead to decreased concentration of wheat phytochemicals. The level of naturally occurring nitrogen in the soil may also affect the accumulation of wheat phytochemicals. © 2021 Society of Chemical Industry.

Identification of key phenolic compounds responsible for antioxidant activities of free and bound fractions of blackberry varieties' extracts by boosted regression trees

BACKGROUND

Free fractions of different blackberry varieties' extracts are high in phenolic compounds with antioxidant activities. However, the phenolic profiles and antioxidant activities against peroxyl radicals of bound fractions of different blackberry varieties' extracts have not been previously reported. In addition, what the key antioxidant phenolic compounds are in free and bound fractions of blackberry extracts remain unknown. This study aimed to investigate the phenolic profiles and antioxidant activities of free and bound fractions of eight blackberry varieties' extracts and reveal the key antioxidant phenolic compounds by boosted regression trees.

RESULTS

Fifteen phenolics (three anthocyanins, four flavonols, three phenolic acids, two proanthocyanidins, and three ellagitannins) were identified in blackberry by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Ferulic acid, ellagic acid, procyanidin C1, kaempferol-O-hexoside, ellagitannins hex, and gallic acid were major bound phenolics. Bound fractions of eight blackberry varieties' extracts were high in phenolics and showed great antioxidant activity. Boosted regression trees analysis showed that cyanidin-3-O-glucoside and chlorogenic acid were the most significant compounds, contributing 48.4% and 15.9% respectively to the antioxidant activity of free fraction. Ferulic acid was the most significant antioxidant compound in bound fraction, with a contribution of 61.5%. Principal component analysis showed that Kiowa was the best among the eight varieties due to its phenolic profile and antioxidant activity.

CONCLUSION

It was concluded that blackberry varieties contained high amounts of bound phenolics, which confer health benefits through reducing oxidative stress. Ferulic acid was the key compound to explain the antioxidant activities of bound fractions. © 2021 Society of Chemical Industry.

Multi-Mechanistic In Vitro Evaluation of Antihyperglycemic, Antioxidant and Antiglycation Activities of Three Phenolic-Rich Indian Red Rice Genotypes and In Silico Evaluation of Their Phenolic Metabolites

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.

White rice ethanol extract is qualitatively, but not quantitatively, equivalent to that of brown rice as an antioxidant source

The purpose of this study is to compare the potentials to exhibit biologically active antioxidant actions between white rice (WR) and brown rice (BR) in in vitro assays and a cellular model. The Trolox equivalent (TE) per 1 mg ethanol extract of WR for the 1,1-diphenyl-2-picrylhydrazyl assay was slightly higher than that of BR, whereas the TE per 1 g whole WR was much lower than that for BR. This tendency was very comparable to those for the oxygen radical absorbance capacity and total polyphenol content. Both of the ethanol extracts also similarly suppressed the hydrogen peroxide-induced cytotoxicity and enhanced the gene expression of drug-metabolizing enzymes. Based on the α-tocopherol quantity, its contribution to the cytoprotective effect of the rice extracts is very limited. Taken together, the ethanol extract of WR might be a qualitatively, but not quantitatively, equivalent source of antioxidative phytochemicals to that of BR.

Limosilactobacillus reuteri Fermented Brown Rice: A Product with Enhanced Bioactive Compounds and Antioxidant Potential

Oxidative stress has been postulated to play a role in several diseases, including cardiovascular diseases, diabetes, and stress-related disorders (anxiety/depression). Presently, natural plant-derived phytochemicals are an important tool in reducing metabolomic disorders or for avoiding the side effects of current medicinal therapies. Brown Rice (Oryza sativa L.) is an important part of Asian diets reported as a rich source of bioactive phytonutrients. In our present study, we have analyzed the effect of different lactic acid bacteria (LABs) fermentation on antioxidant properties and in the enhancement of bioactive constituents in Korean brown rice. Therefore, the antioxidant activities and phytochemical analysis were investigated for raw brown rice (BR) and different fermented brown rice (FBR). BR fermented with Limosilactobacillus reuteri, showed the highest antioxidant activities among all samples: DPPH (121.19 ± 1.0), ABTS (145.80 ± 0.99), and FRAP (171.89 ± 0.71) mg Trolox equiv./100 g, dry weight (DW). Total phenolic content (108.86 ± 0.63) mg GAE equiv./100 g, DW and total flavonoids content (86.79 ± 0.83) mg catechin equiv./100 g, DW was also observed highest in Limosilactobacillus reuteri FBR. Furthermore, phytochemical profiling using ultra-high-performance liquid tandem chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) and cell antioxidant assay (CAA) revealed L. reuteri FBR as a strong antioxidant with an abundance of bioactive compounds such as gamma-aminobutyric acid, coumarin, cinnamic acid, butanoic acid, ascorbic acid, nicotinic acid, and stearic acid. This study expanded current knowledge on the impact of fermentation leading to the enhancement of antioxidant capacity with an abundance of health-related bioactive compounds in BR. The results obtained may provide useful information on functional food production using fermented brown rice.

Phenolic acids and phytosterols in rice grains and wheat flours consumed in five regions of China

Phenolic acids and phytosterols, the main functional compounds in cereals, could promote wellbeing and reduce the risks of diet-related diseases. This study aimed to demonstrate phenolic acid and phytosterol profiles in rice grains and wheat flours, and estimate their intakes in five geographical regions and among different age groups. Phenolic acids and phytosterols mainly existed in bound form, and the whole rice grain had high amount of 161.39 to 368.74 µg/g and 37.50 to 93.31 mg/ 100 g, respectively. In total, nine phenolic acids and six phytosterols were detected with ferulic and p-coumaric acid, and β-sitosterol the most abundant. The dietary intakes of phenolic acids and phytosterols were calculated combined with the dietary foods intake data of Chinese people. The intakes of total phenolic acids and phytosterols from rice grains and wheat flours varied across different regions with Beijing the highest among the five regions. At the age of 2 to 70 years, the average intakes of phenolic acids and phytosterols from rice and wheat flours were 7.74 to 17.52 and 58.02 to 135.61 mg/sp/day, respectively. If 3-ounce of polished rice was replaced by black rice grain, the predicted intakes of total phenolic acids and phytosterols from rice grains and wheat flours would increase by at least 196% and 68%, respectively, especially for free phenolic acids and phytosterols. PRACTICAL APPLICATION: This study would help the consumers know how much phenolic acids and phytosterols they would get from 3 ounces of black rice in a reasonable intake of staple food but shift away other kinds of foods. It could also provide inspirations for food industries to explore the functional cereal foods that are rich in phenolic acids and phytosterols for different regions and different age groups.

Untargeted Metabolomics of Korean Fermented Brown Rice Using UHPLC Q-TOF MS/MS Reveal an Abundance of Potential Dietary Antioxidative and Stress-Reducing Compounds

Free radical-induced oxidative stress is the root cause of many diseases, such as diabetes, stress and cardiovascular diseases. The objective of this research was to screen GABA levels, antioxidant activities and bioactive compounds in brown rice. In this study, we first fermented brown rice with different lactic acid bacteria (LABs), and the best LAB was selected based on the levels of GABA in the fermentate. Lactobacillus reuterii generated the highest levels of GABA after fermentation. To ascertain whether germination can improve the GABA levels of brown rice, we compared the levels of GABA in raw brown rice (Raw), germinated brown rice (Germ), fermented brown rice (Ferm) and fermented-germinated brown rice (G+F) to identify the best approach. Then, antioxidant activities were investigated for Raw BR, Germ BR, Ferm BR and G+F BR. Antioxidant activity was calculated using a 2,2-diphenyl-1-picryl hydrazile radical assay, 2,2-azino-bis-(3-ethylene benzothiozoline-6-sulfonic acid) radical assay and ferric-reducing antioxidant power. In Ferm BR, DPPH (114.40 ± 0.66), ABTS (130.52 ± 0.97) and FRAP (111.16 ± 1.83) mg Trolox equivalent 100 g, dry weight (DW), were observed as the highest among all samples. Total phenolic content (97.13 ± 0.59) and total flavonoids contents (79.62 ± 1.33) mg GAE/100 g and catechin equivalent/100 g, DW, were also found to be highest in fermented BR. Furthermore, an untargeted metabolomics approach using ultra-high-performance liquid tandem chromatography quadrupole time of flight mass spectrometry revealed the abundance of bioactive compounds in fermented BR, such as GABA, tryptophan, coumaric acid, L-ascorbic acid, linoleic acid, β-carotenol, eugenol, 6-gingerol, etc., as well as bioactive peptides which could contribute to the health-promoting properties of L. reuterii fermented brown rice.

Changes in phenolic profiles and antioxidant activities during the whole wheat bread-making process

Health benefits of whole wheat products are partially attributed to their unique phenolic profiles. This study investigated the effect of bread-making processes on the phenolic profiles and antioxidant activities of four different varieties of hard red winter wheat. The fermentation process generally increased soluble phenolic content, flavonoid content, antioxidant activities, and soluble ferulic acid of whole wheat products. The baking process increased the soluble phenolic content and antioxidant activities. Some phenolic acids were incorporated into Maillard reaction products during baking. For the insoluble fraction, fermentation and baking slightly increased phenolic content, flavonoid content, and antioxidant activities of certain wheat varieties. Ferulic acid and isomers of di-ferulic acid (DFA) were not significantly affected by the baking process. Overall, the bread-making process demonstrated positive effects on the potential health benefits of whole wheat products.

In vitro digestion effect on mineral bioaccessibility and antioxidant bioactive compounds of plant-based beverages

Consumption of plant-based beverages (PBB) is a growing trend; and have been used as viable substitutes for dairy based products. To date, no study has comparatively analyzed mineral composition and effect of in vitro digestion on the bioaccessibility of different PBB. The aim of this research was to investigate the content of essential minerals (calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn)) and to estimate the effect of in vitro digestion in plant-based beverages, and their antioxidant bioactive compounds (phenolic compounds and antioxidant capacity). Moreover, the presence of antinutritional factors, such as myo-inositol phosphates fractions, were evaluated. Samples of PBB (rice, cashew nut, almond, peanut, coconut, oat, soy, blended or not with another ingredients, fortified with minerals or naturally present) and milk for comparison were evaluated. TPC ranged from 0.2 mg GAEq/L for coconut to 12.4 mg GAEq/L for rice and, the antioxidant capacity (DPPH) ranged from 3.1 to 306.5 µmol TE/L for samples containing peanut and oat, respectively. Only a few samples presented myo-inositol phosphates fractions in their composition, mostly IP5 and IP6, especially cashew nut beverages. Mineral content showed a wide range for Ca, ranging from 10 to 1697.33 mg/L for rice and coconut, respectively. The Mg content ranged from 6.29 to 251.23-268.43 mg/L for rice and cashew nut beverages, respectively. Fe content ranged from 0.76 mg/L to 12.89 mg/L for the samples of rice. Zinc content ranged from 0.57 mg/L to 8.13 mg/L for samples of oat and soy, respectively. Significant variation was observed for Ca (8.2-306.6 mg/L) and Mg (1.9-107.4 mg/L) dialyzed between the beverages, with lower concentrations of Fe (1.0 mg/L) and Zn (0.5 mg/L) in dialyzed fractions. This study provides at least 975 analytically determined laboratory results, providing important information for characterization and comparison of different plant-based beverages.

Comparative Assessment of Phenolic Profiles, Cellular Antioxidant and Antiproliferative Activities in Ten Varieties of Sweet Potato (Ipomoea Batatas) Storage Roots

Sweet potato is the sixth most important crop widely cultivated around the world with abundant varieties. Different varieties gain different phenolic profiles which has drawn researchers' attention for its unique health benefits. Our study evaluated the phenolic profiles, total and cellular antioxidant activities, antiproliferative activities, and cytotoxicity in 10 cultivated varieties of sweet potato in different colours. Among fourteen metabolites detected in our study, hyperoside, ferulic acid and caffeic acid were considered as prominent in SPSRs. According to the principle component analysis, phytochemical composition of HX22, YS15 and YS7 was quite similar. The results also evidenced that purple-fleshed varieties, such as YS43, YZ7 and YY153, have higher total phenolics content and corresponding stronger total antioxidant capacities as well as cellular antiproliferative activities against human liver cancer HepG2 cells than other varieties. The extremely significant correlation between phenolics and total antioxidant activity was also revealed by Pearson correlation analysis (p < 0.05). However, no significant relevance was found between intracellular antioxidant activity and total phenolic content or flesh colour of sweet potatoes.

Effect of In Vitro Digestion on Phytochemical Profiles and Cellular Antioxidant Activity of Whole Grains

Most of the previous in vitro digestion treatments were conducted directly to whole grains without extraction of free phenolics, thus the bioaccessible phenolics contained both free phenolics that survived the digestion and digested phenolics released by digestion. However, the profiles of digested phenolics released by digestion remain unknown. This study was designed to investigate the phytochemical contents, peroxyl radical scavenging capacities (PSCs), and cellular antioxidant activities (CAAs) of free, digested, and bound fractions of whole grains. Total phenolic contents of whole grains were highest in digested fraction, followed by free and bound fractions. The predominant phenolics were 12 phenolic acids and one flavonoid, which mostly existed in bound forms, then in digested and free forms. The digested phenolics bound to proteins were in conjugated form. The bound fractions had the highest PSCs, followed by free and digested fractions. CAAs were highest in bound fractions, followed by digested and free fractions.

Comparative Study of Phenolic Profiles, Antioxidant and Antiproliferative Activities in Different Vegetative Parts of Ramie (Boehmeria nivea L.)

Ramie (Boehmeria nivea L.) is usually cultivated as a fiber crop, but it is also well known for its potential use in animal feeding with viable commercial applications. In this study, the phenolics profile as well as cellular antioxidant and antiproliferative activities were investigated in free and bound fractions of six different vegetative parts from Boehmeria nivea L. The highest total phenolic content was observed in bud (4585 ± 320 mg GAE/100 g DW), whereas root and petiole had the lowest total phenolic contents, 442.8 ± 9.8 and 630.9 ± 27.0 mg GAE/100 g DW, respectively. Likewise, phloem had the most abundant total flavonoids (2755 ± 184 mg CE/100 g DW), whereas the lowest flavonoid contents was found in root and petiole, 636.9 ± 44.2 and 797.4 ± 87.6 mg CE/100 g DW, respectively. Xylem and bud depicted remarkable antioxidant and antiproliferative activities, which could be explained by their diverse phenolic composition, especially chlorogenic acid and epicatechin. The Boehmeria nivea L. plant might be a valuable resource for high value-added phenolic compounds used in food and non-food industries.

Process-Structure-Function in Association with the Main Bioactive of Black Rice Flour Sieving Fractions

The aim of this work was to advance knowledge on the potential use of black rice different sieving fractions for various functional applications, through proximate analysis, thermal degradation kinetics of phytochemical and characterization of the thermal behavior of the main proteins, from the perspectives of their use as a food ingredient. The results indicated that the thermal degradation of phytochemicals followed a first-order reaction kinetics for all the tested fractions. The temperature-dependent degradation was adequately modeled according to the Arrhenius equation. The calculated activation energies (E_a) and k values were different among the four studied parameters. The kinetic parameters depended on the grinding and sieving degree, the anthocyanins being the most thermolabile compounds, thus affecting the antioxidant activity. Three protein fractions were identified by electrophoresis with different molecular weight, such as albumin, globulin, and glutelin. The fluorescence spectroscopy experiments revealed the sequential character of the heat-induced conformational changes, different molecular events being suggested, such as folding in the lower temperature range and unfolding at higher temperature. The significance of the study is evidenced by the need to identify and advance the process-structure-function relationships for various biologically active compounds from the perspective of obtaining food or ingredients nutritionally optimized.

Antioxidant Activity, Quality Parameters and Grain Characteristics of Rice Varieties of Afghanistan

The present study was conducted to evaluate the antioxidant activity, grain traits and quality contents in Afghanistan’s selected rice varieties. The antioxidant capacity was measured using DPPH (1,1-diphenyl-2-picrylhydrazyl) and Reducing Power methods. Grain length, grain width and grain thickness were in the range of 5.4-7.6, 1.7-3.2, and 1.5-2.2 mm respectively. Selah Zoodras, Taram Irani and Attai-1 had the longest grain length whereas Luke was associated with high width and thickness among the varieties. Protein, amylose and lipid content varied from 6.5-9.9, 20.3-23.5, and 10-18% respectively. Barah Kunduz showed the highest protein and lipid content while Selah zoodras was associated highest amylose content. The selected rice varieties possessed moderate antioxidant activity and their physiochemical properties were not correlated with antioxidant capacity. Results of this study provided useful information on the selection and production of rice varieties with high nutritional and pharmaceutical values in Afghanistan.

Antioxidant Activity, Quality Parameters and Grain Characteristics of Rice Varieties of Afghanistan

The present study was conducted to evaluate the antioxidant activity, grain traits and quality contents in Afghanistan’s selected rice varieties. The antioxidant capacity was measured using DPPH (1,1-diphenyl-2-picrylhydrazyl) and Reducing Power methods. Grain length, grain width and grain thickness were in the range of 5.4-7.6, 1.7-3.2, and 1.5-2.2 mm respectively. Selah Zoodras, Taram Irani and Attai-1 had the longest grain length whereas Luke was associated with high width and thickness among the varieties. Protein, amylose and lipid content varied from 6.5-9.9, 20.3-23.5, and 10-18% respectively. Barah Kunduz showed the highest protein and lipid content while Selah zoodras was associated highest amylose content. The selected rice varieties possessed moderate antioxidant activity and their physiochemical properties were not correlated with antioxidant capacity. Results of this study provided useful information on the selection and production of rice varieties with high nutritional and pharmaceutical values in Afghanistan.

Redox Homeostasis and Natural Dietary Compounds: Focusing on Antioxidants of Rice (Oryza sativa L.)

Redox homeostasis may be defined as the dynamic equilibrium between electrophiles and nucleophiles to maintain the optimum redox steady state. This mechanism involves complex reactions, including nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, activated by oxidative stress in order to restore the redox balance. The ability to maintain the optimal redox homeostasis is fundamental for preserving physiological functions and preventing phenotypic shift toward pathological conditions. Here, we reviewed mechanisms involved in redox homeostasis and how certain natural compounds regulate the nucleophilic tone. In addition, we focused on the antioxidant properties of rice and particularly on its bioactive compound, γ-oryzanol. It is well known that γ-oryzanol exerts a variety of beneficial effects mediated by its antioxidant properties. Recently, γ-oryzanol was also found as a Nrf2 inducer, resulting in nucleophilic tone regulation and making rice a para-hormetic food.

Profile of phenolic compounds and antioxidant activity of finger millet varieties

The profiles of phenolic compounds and antioxidant capacities of four finger millet varieties harvested in northern Malawi were investigated. The total phenolics, flavonoids and condensed tannins in the free fractions ranged from 114.43 to 179.19 mg ferulic acid equivalent (FAE)/100 g, 90.24 to 202.94 mg catechin equivalent (CE)/100 g and 31.76 to 83.59 mg CE/100 g, respectively. Total phenolic contents of the bound fractions ranged from 58.27 to 123.23 mg FAE/100 g. Twenty phenolic compounds were identified in the free fractions including eighteen flavonoids, with catechin and epicatechin being the predominant flavonoids. Seventeen phenolic compounds were identified in the bound fractions, with ferulic acid being the predominant one. Ten of the identified polyphenols were firstly reported in finger millet. Darker colored finger millet varieties had higher phenolic contents and antioxidant properties than the lighter colored ones. Finger millet can be used as healthy food material and natural antioxidant resource.

A full utilization of rice husk to evaluate phytochemical bioactivities and prepare cellulose nanocrystals

Rice husks (RHs) as an agro-waste generated from rice production, while its application is limited. This study was designed to introduce a full utilization of rice husks, which extracted the phytochemical at first and then produced cellulose nanocrystals (CNCs) as the use of the residue. Furthermore, the phytochemicals extracted from rice husk was identified and its biological activity, including antioxidant activity, cellular antioxidant activity (CAA) and antiproliferative activity, had been detected as well. Results showed the bound fraction of rice husk had higher antioxidant than common fruit and grain. Free fraction of rice husk deserved to have further analysis in antiproliferative activity due to its low cytotoxicity. The CNCs produced by residue was using delignification process and acid hydrolysis treatments. The chemical composition of the residue obtained after phytochemical extraction was determined. CNCs morphological investigation was performed using an optical microscope and atomic force microscopy (AFM). Our strategy is to achieve a comprehensive utilization of rice husks with both economy and environment benefits.

Phytochemical Profile of Brown Rice and Its Nutrigenomic Implications

Whole grain foods have been promoted to be included as one of the important components of a healthy diet because of the relationship between the regular consumption of whole-grain foods and reduced risk of chronic diseases. Rice is a staple food, which has been widely consumed for centuries by many Asian countries. Studies have suggested that brown rice is associated with a wide spectrum of nutrigenomic implications such as anti-diabetic, anti-cholesterol, cardioprotective and antioxidant. This is because of the presence of various phytochemicals that are mainly located in bran layers of brown rice. Therefore, this paper is a review of publications that focuses on the bioactive compounds and nutrigenomic implications of brown rice. Although current evidence supports the fact that the consumption of brown rice is beneficial for health, these studies are heterogeneous in terms of their brown rice samples used and population groups, which cause the evaluation to be difficult. Future clinical studies should focus on the screening of individual bioactive compounds in brown rice with reference to their nutrigenomic implications.