Cereal Bran Research Articles

Protective effects of insoluble dietary fiber from cereal bran against DSS-induced chronic colitis in mice: From inflammatory responses, oxidative stress, intestinal barrier, and gut microbiota.

Insoluble dietary fiber (IDF) is a crucial component of cereals, and IDF from cereal bran (IDF-CB) has been reported to have multiple biological activities. However, the effect of IDF-CB on chronic colitis remains underexplored. The study aimed to investigate the impact of IDFs from wheat bran (WBIDF), rice bran (RBIDF), millet bran (MBIDF) and oat bran (OBIDF) on chronic colitis induced by dextran sulfate sodium (DSS). Our findings demonstrated that IDFs-CB supplementation mitigated DSS-induced weight loss and reduced lesions in the colon and spleen. Levels of proinflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) and oxidative stress markers (MPO, iNOS and MDA)were decreased, and anti-inflammatory cytokine (IL-10) and T-SOD activity were increased after IDF-CB inclusion. Furthermore, IDFs-CB restored intestinal barrier function by regulating gene expression (up-regulated Muc-2, ZO-1 and Occludin, and down-regulated Claudin-1 and Claudin-4). Additionally, we analyzed the gut microbiota and SCFAs composition. WBIDF, MBIDF and OBIDF inhibited the growth of Muribaculaceae_unclassified, Bacteroides and Parasutterella. Conversely, IDFs-CB promoted the growth of Candidatus_Saccharimonas and norank_f__norank_o__Clostridia_UCG-014. Notably, WBIDF enhanced the abundance of Allobaculum, while MBIDF and OBIDF increased the abundance of Lachnospiraceae_NK4A136. Moreover, supplementation with IDFs-CB significantly elevated certain SCFA concentrations-particularly acetic acid and isohexanoic acid. Our results suggested that IDF-CB effectively alleviated DSS-induced chronic colitis; among them，WBIDF exhibited superior efficacy followed by OBIDF，MBIDF，and RBIDF. This study provides a theoretical foundation for dietary recommendations for patients suffering from inflammatory bowel disease.

Characterization and end-use perspectives of modified cereal brans: a step towards waste valorization

Characterization and end-use perspectives of modified cereal brans: a step towards waste valorization

Unexplored Opportunities of Utilizing Food Waste in Food Product Development for Cardiovascular Health.

Global food production leads to substantial amounts of agricultural and food waste that contribute to climate change and hinder international efforts to end food insecurity and poverty. Food waste is a rich source of vitamins, minerals, fibers, phenolic compounds, lipids, and bioactive peptides. These compounds can be used to create food products that help reduce heart disease risk and promote sustainability. This review examines the potential cardiovascular benefits of nutrients found in different food waste categories (such as fruits and vegetables, cereal, dairy, meat and poultry, and seafood), focusing on animal and clinical evidence, and giving examples of functional food products in each category. Current evidence suggests that consuming fruit and vegetable pomace, cereal bran, and whey protein may lower the risk of cardiovascular disease, particularly in individuals who are at risk. This is due to improved lipid profile, reduced blood pressure and increased flow-mediated dilation, enhanced glucose and insulin regulation, decreased inflammation, as well as reduced platelet aggregation and improved endothelial function. However, the intervention studies are limited, including a low number of participants and of short duration. Food waste has great potential to be utilized as cardioprotective products. Longer-term intervention studies are necessary to substantiate the health claims of food by-products. Technological advances are needed to improve the stability and bioavailability of bioactive compounds. Implementing safety assessments and regulatory frameworks for functional food derived from food waste is crucial. This is essential for maximizing the potential of food waste, reducing carbon footprint, and improving human health.

Modifications and in vitro absorption of 5-heptadecyresorcinol from cereals using digestion and ussing chamber models

5-Heptadecylresorcinol (AR-C17), a homologue of alkylresorcinols (ARs) and mainly observed in cereal brans, has stronger physiological functions compared with its homologues. However, not only is its content rare but also the purification low. Besides, few researches on its digestion characteristics and bioavailability limits its maximum applications. Here, we mainly relied on solid-state fermentation, embedment, in vitro models to systematically evaluate processing technologies, digestion and absorption characteristics of AR-C17. We showed that the highest content of AR-C17 was 57.6 μg/g extracted from triticale bran fermented by Saccharomyces cerevisiae relying on ultrasound-assistance. Additionally, AR-C17 was chiefly absorbed in duodenum and jejunum, and its apparent absorption increased by around 2.1 times when quercetin was added as the synergistic agent, which was higher than other phenolics in bran extract. Furthermore, AR-C17 embedded by β-cyclodextrin avoided the decomposition of in strong acidic environment, enhancing the retention rate to 96 % in in vitro digestion. According to the results above, we mixed AR-C17 with the quercetin, and embedded the mixture by β-cyclodextrin, which maximized the apparent absorption of AR-C17, reaching 19.8 % when the ratio of quercetin and AR-C17 was 1:1.

In situ fortification of cereal by-products with vitamin B12: An eco-sustainable approach for food fortification

Vitamin B12 deficiency poses significant health risks, especially among populations with limited access to animal-based foods. This study explores the utilisation of cereal bran by-products, wheat (WB) and oat bran (OB), as substrates for in situ vitamin B12 fortification through solid-state fermentation (SSF) using Propionibacterium freudenreichii. The impact of various precursors addition, including riboflavin, cobalt, nicotinamide and DMBI on vitamin B12 production, along with changes in microbial growth, chemical profiles, and vitamin B12 yields during fermentation was evaluated. Results showed that WB and OB possess favourable constituents for microbial growth and vitamin B12 synthesis. The substrates supplemented with riboflavin, cobalt, and DMBI demonstrated enhanced B12 production. In addition, pH levels are essential in microbial viability and cobalamin biosynthesis. Monosaccharides and organic acids play a crucial role, with maltose showing a strong positive association with B12 production in OB, while in WB, citric acid exhibits significant correlations with various factors.

Causal benefits of 25 dietary intakes on epigenetic ageing: a Mendelian randomisation study

DNA methylation GrimAge acceleration (DMGA) and intrinsic epigenetic age acceleration (IEAA) are important physiological markers for assessing the ageing process. Evidence from cross-sectional studies suggests that some dietary intake is associated with DMGA and IEAA. However, the causal relationship between them has yet to be elucidated. This Mendelian randomisation study uses genetic variants associated with different dietary intakes as instrumental variables to explore the causal benefits of multiple dietary intakes on DMGA and IEAA. Cheese intake, dark chocolate intake, average weekly red wine intake, dried fruit intake, fresh fruit intake, porridge intake, cereal intake, and liver intake had a negative causal association with DMGA, and poultry intake and doughnut intake had a positive causal association with DMGA (p < 0.05). Muesli and bran cereal intake had a negative causal association with IEAA, and pineapple intake had a positive causal association with IEAA (p < 0.05). Dietary intake positively causally associated with IEAA or DMGA may have accelerated biological ageing; conversely, dietary intake negatively causally associated with IEAA or DMGA may have contributed to delaying biological ageing. Based on genetic evidence, this study demonstrated some significant causal benefits of dietary intake on DMGA and IEAA, suggesting the possibility of intervening in DNA methylation acceleration and epigenetic age acceleration by adjusting these food intakes, thereby promoting health and delaying ageing. However, the findings of this study are exploratory and preliminary and need to be supported and validated by evidence from further clinical studies and mechanistic studies.

Resistant starch content of Australian foods

SummaryThe existing literature on resistant starch analysis in Australian foods has predominantly relied on older testing methods. Thus, our study aimed to address this gap by assessing the resistant starch content of selected Australian foods using the validated Association of Analytical Chemists 2002.02 testing method. Forty commonly consumed and available foods were tested in duplicate. The resistant starch content of foods varied from 0 to 13.72 g/100 g. Foods with the highest resistant starch were Hi‐maize flour pancakes, red kidney beans, Lebanese bread, and Cornflakes cereal, which ranged from 2.30 to 13.72 g/100 g, respectively. The lowest resistant starch foods included beetroot, rice crackers, All Bran cereal, and Nutri‐grain cereal, which ranged from 0 to 0.04 g/100 g, respectively. This is the first known Australian study to evaluate the resistant starch content of foods using the AOAC 2002.02 method. This data can be used to assess resistant starch consumption in the Australian population, inform gut microbiome research, and guide clinical practice recommendations for fibre intake.

Correction: Phytochemical characterization and end use evaluation of native and fermented cereal brans

Correction: Phytochemical characterization and end use evaluation of native and fermented cereal brans

Enhancing nutritional quality and bioactivity of wheat bran through acid and alkaline pretreatments

The effect of chemical processing, such as acid and alkaline pretreatments, on the phenolic profile, lipid components, and hydrosoluble protein content (HPC) in wheat bran (WB) was investigated. After acid pretreatment, the results provided an increase of over twofold in total reducing sugar (TRS). The sugars that have been identified are maltose, glucose, and fructose. After acid pretreatment, the total phenolic content increased by 41.95% compared with the untreated sample. Antioxidant potential, as assessed by the DPPH assay, significantly increased from 95.08 ± 1.13 μM TE/g DW in the untreated sample to 575.83 ± 2.41 μM TE/g DW following acid pretreatment. In the alkaline-treated sample, the total HPC increased to 16.58 ± 0.38 mg/100 g DW from 4.01 ± 0.17 mg/100 g DW. The fatty acid profile confirmed the presence of oleic acid (C18:1, n-9), linoleic acid (C18:2, n-6), and palmitic acid (16:0) as major components in analyzed samples. Chemical pretreatments significantly influenced all 13 identified phenolic compounds in WB, including avenanthramides, cinnamic acids (e.g., p-coumaric acid, ferulic acid, synaptic acid), and benzoic acids (e.g., vanillic acid). The study provides valuable insights into the development of sustainable approaches for using cereal bran to produce bioactive compounds with potential health benefits.

Intracellular removal of acetyl, feruloyl and p-coumaroyl decorations on arabinoxylo-oligosaccharides imported from lignocellulosic biomass degradation by Ruminiclostridium cellulolyticum

BackgroundXylans are polysaccharides that are naturally abundant in agricultural by-products, such as cereal brans and straws. Microbial degradation of arabinoxylan is facilitated by extracellular esterases that remove acetyl, feruloyl, and p-coumaroyl decorations. The bacterium Ruminiclostridium cellulolyticum possesses the Xua (xylan utilization associated) system, which is responsible for importing and intracellularly degrading arabinoxylodextrins. This system includes an arabinoxylodextrins importer, four intracellular glycosyl hydrolases, and two intracellular esterases, XuaH and XuaJ which are encoded at the end of the gene cluster.ResultsGenetic studies demonstrate that the genes xuaH and xuaJ are part of the xua operon, which covers xuaABCDD’EFGHIJ. This operon forms a functional unit regulated by the two-component system XuaSR. The esterases encoded at the end of the cluster have been further characterized: XuaJ is an acetyl esterase active on model substrates, while XuaH is a xylan feruloyl- and p-coumaryl-esterase. This latter is active on oligosaccharides derived from wheat bran and wheat straw. Modelling studies indicate that XuaH has the potential to interact with arabinoxylobiose acylated with mono- or diferulate. The intracellular esterases XuaH and XuaJ are believed to allow the cell to fully utilize the complex acylated arabinoxylo-dextrins imported into the cytoplasm during growth on wheat bran or straw.ConclusionsThis study reports for the first time that a cytosolic feruloyl esterase is part of an intracellular arabinoxylo-dextrin import and degradation system, completing its cytosolic enzymatic arsenal. This system represents a new pathway for processing highly-decorated arabinoxylo-dextrins, which could provide a competitive advantage to the cell and may have interesting biotechnological applications.

Distribution of cereal phytochemicals and micronutrients in whole grains: A review of nutraceutical, industrial, and agricultural implications

AbstractBackground and ObjectivesThere is mounting evidence that whole cereal grains are a source of many micronutrients and phytochemicals that confer several health benefits. This work aimed to investigate the distribution patterns and related implications of selected bioactive compounds from various cereal grains and discuss the techniques used to study their distribution.FindingsHand dissection and imaging techniques are the methods used to locate bioactive compounds in whole grains with high accuracy. Pearling and milling are methods of industrial importance. Phenolic compounds are concentrated in cereal bran, whereas the germ is rich in carotenoids and tocols (particularly tocopherols). Knowing the distribution pattern of compounds allows a better understanding of their bioaccessibility and associated bioactivity, as well as developing means to recover them and enhance their occurrence in the aleurone layer.ConclusionsGradient patterns exist in the distribution of phytochemicals and micronutrients derived from cereal grains. This knowledge can be translated into a number of purposeful and practical applications.Significance and NoveltyThis study employed a comparative approach to examine the repartition of various compounds in whole grains of assorted cereals with an emphasis on minor crops. The implications are relatable and applicable in diverse sectors to ultimately improve the well‐being of cereal consumers.

Changes in chemical properties and microbial communities' composition of a forest litter-based biofertilizer produced through aerated solid-state culture under different oxygen conditions.

Fermented forest litter (FFL) is a bioproduct used as biofertilizer for several decades in Eastern Asia and Latin America. It is locally handcrafted by farmers in anaerobic conditions by fermenting forest litter added with agricultural by-products such as whey, cereal bran, and molasses. The aim of this study was to characterize the FFL process and product through gas and liquid chromatography analyses. It also provides some highlights on the influence of O2 on this solid-state culture. Under anoxic condition, a maximum CO2 production rate (CDPR) of 0.41mL/h∙g dry matter (dm) was reached after 8days. The main volatile organic compounds (VOCs) were ethanol and ethyl acetate, with a production rate profile similar to CDPR. After 21days of culture, no residual sucrose nor lactose was detected. Lactic and acetic acids reached 58.8mg/g dm and 10.2mg/g dm, respectively, ensuring the acidification of the matrix to a final pH of 4.72. A metabarcoding analysis revealed that heterolactic acid bacteria (Lentilactobacillus, Leuconostoc), homolactic acid bacteria (Lactococcus), and yeasts (Saccharomyces, Clavispora) were predominant. Predicted genes in the microbiome confirmed the potential link between detected bacteria and acids and VOCs produced. When O2 was fed to the cultures, final pH reached values up to 8.5. No significant amounts of lactic nor acetic acid were found. In addition, a strong shift in microbial communities was observed, with a predominance of Proteobacteria and molds, among which are potential pathogens like Fusarium species. This suggests that particular care must be brought to maintain anoxic conditions throughout the process.

Phytochemical characterization and end use evaluation of native and fermented cereal brans

Phytochemical characterization and end use evaluation of native and fermented cereal brans

Novel cereal bran based low-cost liquid medium for enhanced growth, multifunctional traits and shelf life of consortium biofertilizer containing Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp.

The present study was carried out to valorise cereal (rice and wheat) bran for the development of low-cost liquid consortium bioformulation. Different concentrations of bran-based liquid media formulations were evaluated for the growth of consortium biofertilizer cultures (Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp.). Among the bran-based formulations, wheat bran-based formulation WB5, exhibited the highest viable cell of 10.68 ± 0.09 Log10 CFU/ml and 12.63 ± 0.04 Log10 CFU/ml for Azotobacter chroococcum and Bacillus subtilis whereas for Pseudomonas sp., rice bran based bioformulation RB5 recorded maximum viability (12.71 ± 0.05 Log10 CFU/ml) after 72 h of incubation. RB51RB1: 1:10 (Rice bran: distilled water)RB2: 1:10 (Rice bran: distilled water)RB3: 1:10 (Rice bran: distilled water)RB4: 1:10 (Rice bran: distilled water)RB5: 5:10 (Rice bran: distilled water)1 and WB52WB1: 1:10 (wheat bran: distilled water)WB2: 2:10 (wheat bran: distilled water)WB3: 3:10 (wheat bran: distilled water)WB4: 4:10 (wheat bran: distilled water)WB5: 5:10 (wheat bran: distilled water)2liquid formulations were further optimized for enhanced shelf life using 5, 10 and 15 mM of trehalose, 0.05 and 0.1% carboxymethyl cellulose, and 0.5 and 1.0% glycerol. Following the peak growth at 72 h of incubation, a gradual decrease in the viable population of consortium biofertilizer cultures was observed in all the liquid formulations. The WB5 and RB5 formulations with 15 mM trehalose and 0.1% CMC, not only recorded significantly highest cell count of consortium biofertilizer cultures, but also maximally supported multi-functional traits i.e., phosphate and zinc solubilization, ammonia and IAA production up to 150 days. Further evaluation of seedling emergence and growth of wheat (PBW 826) under axenic conditions recorded WB5 amended with 15 mM trehalose-based consortium bioformulation to exhibit maximum emergence and growth of wheat seedlings. This low-cost liquid formulation can be used for large-scale biofertilizer production as a cost-effective liquid biofertilizer production technology.

Exploring the cholesterol-lowering effects of cereal bran cell wall-enriched diets.

Cell wall polysaccharides (dietary fiber) in cereal grains contribute to health benefits. The novelty of the current study was an effort to explore the invivo therapeutic potential of different cereal bran cell walls against hypercholesterolemia. For this purpose, the cell walls were isolated from different cereal brans (wheat, maize, oats, and barley), and the intake of these cereal bran cell walls was evaluated for their anti-lipidemic activity in normal and hypercholesterolemic rats. The serum taken from the rats was tested for cholesterol, lipid, and triglyceride profiles before and after treatment. The outcomes of the current study have shown that the cereal cell wall has a significant hypercholesterolemia effect. The biochemical parameters of the control animals were within the normal clinical ranges, indicating that the experimental diets were safe. Among cereal bran cell walls, barley bran significantly decreased cholesterol (56.35 ± 1.35 mg/dL), low-density lipoprotein (56.35 ± 1.05 mg/dL), triglycerides (105.29 ± 1.95 mg/dL), and increased high-density lipoprotein level (48.35 ± 1.35 mg/dL). These findings provide conclusive evidence that the cereal cell wall is beneficial in the treatment of hypercholesterolemia and may potentially provide protection against other acute, recurring, or chronic illnesses.

Resistant starch content of selected Australian foods

A growing body of research has identified interactions between microorganisms and nutrients within the gut, collectively referred to as the ‘gut microbiome’(1). Alongside this, distinct structural characteristics/components of dietary fibre have been recognised to exhibit various physiological effects on the body(1). These inherent physiological properties have the potential to result in diverse health benefits through the consumption of resistant starch, a specific form of dietary fibre(2). It is important to note that the laboratory-based techniques employed to assess resistant starch content from current Australian dietary composition data are antiquated and have not been conducted using updated testing methods(3). Results from updated testing methods may contribute to and inform nutritional recommendations to support and improve health outcomes. To assess the resistant starch content of starch-containing Australian foods using the updated Association of Analytical Chemists (AOAC) 2002.02 testing methods approved by Food Standards Australia New Zealand(3). Standardised kits (K-RSTAR) and control flours were used for assaying. Forty commonly consumed and available Australian foods were tested in duplicate for their resistant starch content. Calculated resistant starch values (in grams) were recorded using calculation tools provided by Megazyme. Means, standard deviations, and coefficient of variations between duplicate samples were recorded in a Microsoft Excel spreadsheet. The resistant starch content of foods varied from 0-13.72g/100g for rice crackers, beetroot, and hi-maize pancakes, respectively. Foods with the highest resistant starch were hi-maize flour pancakes, red kidney beans, Lebanese bread, and Cornflakes cereal, which ranged from 2.30-13.72g/100g. The lowest resistant starch foods included beetroot, rice crackers, All Bran cereal, and Nutri-grain cereal, ranging from 0-0.04g/100g. Changes in the foods’ natural chemical, physical, and enzymatic qualities may have led to slight batch variations and deviations from the literature available. This study is the first known Australian study to investigate the resistant starch content of selected Australian foods using the AOAC 2002.02 assay method. This data can be used to assess resistant starch consumption in the Australian population, inform gut microbiome research, and guide clinical practice recommendations for fibre intake.

A comparative analysis of cutin monomers from cereal brans and fruit peels: Isolation and characterization

Plant cuticles contain mainly lipid polymers (cutin), protecting them against desiccation and environmental stresses. The monomeric composition of the cuticular polymer fractions of three cereal fibers: maize bran, wheat bran and sorghum bran, as well as hemicellulose/cellulose fractions isolated from sorghum bran were investigated and compared with cuticular content isolated from apple and tomato peel samples. Total cuticular contents in apple and tomato peels were the highest, ranging from 54.5 % to 54.8 %, when compared with the total cuticular content of maize, wheat and sorghum brans. Among three cereal samples, the cuticular material content in sorghum bran (7.14%) was higher than the maize bran and wheat bran (3.92% and 5.92% respectively). The hexadecanoic acid (C16), octadecanoic acid (C18), ω-hydroxy fatty acids, with medium chain functional groups such as enoic, epoxy and hydroxyl groups were identified in each cutin sample. The percentage of p-coumaric acid in apple and tomato peel samples were 84.0% and 78.7% respectively of the total phenolic acids present. The ferulic acid content in maize, sorghum and wheat brans were 94.1%, 92.8% and 88.0% respectively, indicating that ferulic acid was the major phenolic compound in these brans.

Pilot Study of Heat-Stabilized Rice Bran Acceptability in Households of Rural Southwest Guatemala and Estimates of Fiber, Protein, and Micro-Nutrient Intakes among Mothers and Children.

Nutrient-dense, acceptable foods are needed in low-resource settings. Rice bran, a global staple byproduct of white rice processing, is rich in amino acids, fibers, and vitamins, when compared to other cereal brans. This pilot study examines the nutritional contribution of rice bran to the daily diets of mother-child pairs in rural southwest Guatemala. Thirty households were screened. Mothers (≥18 years) and children (6 to 24 months) completed 24 h dietary recalls at baseline and after 12 weeks (endline) for diet intake and diversity analyses. During biweekly visits for 12 weeks, households with <5 members received 14 packets containing 60 g of heat-stabilized rice bran, and those with ≥5 members received 28 packets. The macro- and micro-nutrient contributions of rice bran and whole, cooked black beans were included in dietary simulation models with average intakes established between the recalls and for comparison with dietary reference intakes (DRIs). A baseline child food frequency questionnaire was administered. The 27 mothers and 23 children with complete recalls were included in analyses. Daily maternal consumption of 10 g/d of rice bran plus 100 g/d of black beans resulted in all achieving at least 50% of the fiber, protein, magnesium, niacin, potassium, and thiamin DRIs. Daily child consumption of 3 g/d of rice bran plus 10 g/d of black beans resulted in all achieving at least 50% of the magnesium, niacin, phosphorous, and thiamine DRIs. For 15/17 food categories, male children had a higher intake frequency, notably for animal-source foods and coffee. Dietary rice bran coupled with black beans could improve nutritional adequacy, especially for fiber and key micro-nutrients, with broader implications for addressing maternal and child malnutrition in low-resource settings.

Comparative study on chemical composition, functional properties of dietary fibers prepared from four China cereal brans

Comparison of chemical composition and functional properties of insoluble and soluble dietary fiber (IDF, SDF) obtained from four China cereal brans was investigated. With findings, IDFs and SDFs for rice bran (RB), wheat bran (WB), highland barely bran (HBB) and tartary buckwheat bran (TBB) contained several monosaccharides such as arabinose, galactose, glucose, xylose, and galacturonic acid. The RBIDF was shrinking and formed a rugged microscopic structure, while the structure of WBIDF was dense and flat. HBBIDF and TBBIDF showed fold and flake structure. The glucose adsorption capacity of the HBBIDF was highest among all samples, which was 3.2 mmol/g. TBBIDF exhibited the highest value of cholesterol adsorption capacity (10.5 mg/g) at pH 7.0 and maximum binding capacity (BCmax, 365.2 μmol/g) for cadmium at pH 7.0 among all samples, respectively. As a result, HBBIDF and TBBIDF are potential fiber-rich ingredients in functional foods.

Stabilization of Vitamin A by Cereal Bran: The Importance of the Balance between Antioxidants, Pro-oxidants, and Oxidation-Sensitive Components.

This study investigated the contribution of bran antioxidants and lipids to the stabilizing effect of cereal bran on vitamin A during accelerated storage. Hereto, wheat and rice bran samples subjected to a sequential extraction process were used. Vitamin A stabilization was more pronounced for wheat compared to rice bran. This was attributed to the higher antioxidant capacity and lower degree of lipid oxidation of wheat compared to rice bran. Removal of the chloroform/methanol-extractable fraction resulted in a substantial decrease in vitamin A retention from 78 to 26% for wheat bran and from 30 to 0% for rice bran after 2 weeks of accelerated storage. However, the vitamin A-stabilizing effect could not be attributed to specific components. The ability of cereal bran to stabilize vitamin A is therefore believed to be determined by the balance of antioxidants, pro-oxidants, and oxidation-sensitive components in the system.