Aspergillus oryzae Fermented Rice Bran: A Byproduct with Enhanced Bioactive Compounds and Antioxidant Potential

Cereal dietary fiber regulates the quality of whole grain products: Interaction between composition, modification and processing adaptability

The coarse texture and difficulty in processing dietary fiber (DF) in cereal bran have become limiting factors for the development of the whole cereal grain (WCG) food industry. To promote the development of the WCG industry, this review comprehensively summarizes the various forms and structures of cereal DF, including key features such as molecular weight, chain structure, and substitution groups. Different modification methods for changing the chemical structure of DF and their effects on the modification methods on physicochemical properties and biological activities of DF are discussed systematically. Furthermore, the review focusses on exploring the interactions between DF and dough components and discusses the effects on the gluten network structure, starch gelatinization and retrogradation, fermentation, glass transition, gelation, and rheological and crystalline characteristics of dough. Additionally, opportunities and challenges regarding the further development of DF for the flour products are also reviewed. The objective of this review is to establish a comprehensive foundation for the precise modification of cereal DF, particularly focusing on its application in dough-related products, and to advance the development and production of WCG products.

Antioxidative Potential and Ameliorative Effects of Rice Bran Fermented with Lactobacillus against High-Fat Diet-Induced Oxidative Stress in Mice

Rice bran is an important byproduct of the rice polishing process, rich in nutrients, but it is underutilized and often used as feed or discarded, resulting in a huge amount of waste. In this study, rice bran was fermented by Lactobacillus fermentum MF423 to obtain a product with high antioxidant activity. First, a reliable and efficient method for assessing the antioxidant capacity of the fermentation products was established using high-performance liquid chromatography (HPLC), which ensured the consistency of the batch fermentation. The fermented rice bran product (FLRB) exhibited significant antioxidant activity in cells, C. elegans, and hyperlipidemic mice. Transcriptome analysis of mouse livers showed that the expression of plin5 was upregulated in diabetic mice administered FLRB, thereby preventing the excessive production of free fatty acids (FFAs) and the subsequent generation of large amounts of reactive oxygen species (ROS). These studies lay the foundation for the application of rice bran fermentation products.

Chicken viscera meal as substrate for the simultaneous production of antioxidant compounds and proteases by Aspergillus oryzae

The use of chicken waste can contribute to the development of new processes and obtaining molecules with high added value. An experimental design was applied to evaluate the effect of moisture, temperature, and inoculum size on the production of antioxidant peptides and proteases by A. oryzae IOC3999 through solid-state fermentation (SSF) of chicken viscera meal. As a result, the process conditions strongly influenced protease production and antioxidant activity of the fermented products. A global analysis of the results indicated that the most adequate conditions for SSF were (assay 9): 40% initial moisture, 30 °C as the incubation temperature, 5.05 × 106 spores/g as the inoculum size, and 48-h fermentation as the fermentation time. Under this condition, the antioxidant activities for the ABTS- and DPPH-radicals inhibition and ferric reducing antioxidant power (FRAP) methods were 376.16, 153.29, and 300.47 (µmol TE/g), respectively, and the protease production reached 428.22 U/g. Ultrafiltration of the crude extract obtained under optimized fermentation conditions was performed, and the fraction containing peptides with molecular mass lower than 3 kDa showed the highest antioxidant activity. The proteases were biochemically characterized and showed maximal activity at pH values ranging from 5.0 to 6.0 and a temperature of 50 °C. The thermodynamic parameters indicated that the process of thermal protease inactivation is not spontaneous (ΔG*d > 88.78 kJ/mol), increasing with temperature (ΔH*d 27.01-26.88 kJ/mol), and with reduced disorder in the system (ΔS*d <  - 197.74 kJ/mol) probably caused by agglomeration of partially denatured enzymes.

Consortia of lactic acid bacteria strains increase the antioxidant activity and bioactive compounds of quinoa sourdough - based biscuits

The aim of this work was to use consortia (two or three strains) of lactic acid bacteria (LAB) [Lactiplantibacillus plantarum CRL 1964 and CRL 1973, and Leuconostoc mesenteroides subsp. mesenteroides CRL 2131] to obtain quinoa sourdoughs (QS) for further manufacturing of quinoa sourdough-based biscuits (QB). Microbial grow and acidification were evaluated in QS while antioxidant activity (AOA), total phenolic compounds (TPC) and total flavonoid compounds (TFC) were determined in QS and QB. QS inoculated with LAB consortia respect to monocultures showed higher growth and acidification, AOA (7.9?42.6%), TPC (19.9?35.0%) and TFC (6.1?31.6%). QB prepared with QS inoculated by LAB consortia showed higher AOA (5.0-81.1%), TPC (22.5?57.5%) and TFC (14.0-79.9%) than biscuits inoculated by monocultures sourdoughs. These results were attributed to a synergic effect from LAB consortia. Principal component analysis showed the highest scores of the evaluated characteristics for biscuits made with consortia sourdough of two (CRL1964?+?CRL2131) and three (CRL1964?+?CRL1973?+?CRL2131) strains.

From bitter to delicious: properties and uses of microbial aminopeptidases

Protein hydrolysates are easily digested and utilized by humans and animals, and are less likely to cause allergies. Protein hydrolysis caused by endopeptidases often leads to the exposure of hydrophobic amino acids at the ends of peptides, which consequently causes bitter taste. Microbial aminopeptidases remove the exposed hydrophobic amino acids at the ends of aminopeptides, which improves taste, allowing for easier production. This processe is attacking significant attention from industry and laboratories. Aminopeptidases selectively hydrolyze peptide bonds from the N-terminal of proteins or peptides to produce free amino acids. Aminopeptidases can be classified into leucine, lysine, methionine and proline aminopeptidases by hydrolyzed N-terminal residues; metallo-, serine- and cysteine- aminopeptidases by the reaction mechanisms; dipeptide and triphoptide enzymes by the released number of amino acid residues at the end of hydrolyzed peptides; or acidic, neutral and basic aminopeptidases by their optimal hydrolysis pH. Commercial aminopeptidases are generally produced by microbial fermentation, and are mainly applied in the debittering of protein hydrolysates, the deep hydrolysis of protein, and the production of condiments, cheese, and bioactive peptides, as well as for disease detection in the medical industry.

Effect of fermented heat-treated rice bran on performance and possible role of intestinal microbiota in laying hens

Rice bran is a high-quality and renewable livestock feed material rich in nutrients and bioactive substances. To investigate the effects of dietary supplementation with fermented heat-treated rice bran on the performance, apparent digestibility of nutrients, cecal microbiota and metabolites in laying hens, a total of 128 18-week-old Hy-Line brown layers were randomly assigned to four treatment groups: 2.5% HRB (basal diet contained 2.5% heat-treated rice bran), 5.0% HRB (5.0% heat-treated rice bran), 2.5% FHRB (2.5% fermented heat-treated rice bran), 5.0% FHRB (5.0% fermented heat-treated rice bran). Results showed that FHRB supplementation significantly increased the average daily feed intake (ADFI) during 25-28 weeks, and improved apparent digestibility of dry matter (DM), crude protein (CP), ether extract (EE) and crude fiber (CF) in laying hens. Moreover, feeding 5.0% of HRB and FHRB resulted higher egg production (EP) and average egg weight (AEW) during the feeding period, and decreased the feed conversion ratio (FCR) during 21 to 28 weeks. The alpha and beta diversity indices indicated that FHRB altered the cecal microbiota. In particular, dietary supplementation with FHRB significantly increased the relative abundances of Lachnospira and Clostridium. Compared with the 2.5% level of supplementation, supplementing 5.0% HRB and 5.0% FHRB increased the relative abundances of Firmicutes, Ruminococcus and Peptococcus, and lowered the relative abundance of Actinobacteria. Furthermore, dietary FHRB supplementation significantly increased the concentration of short-chain fatty acids in cecum and changed the overall metabolome. The results of correlation analysis showed a close interaction between cecal microbiota, metabolites and apparent digestibility of nutrients. Taken together, we revealed that FHRB supplementation can induce characteristic structural and metabolic changes in the cecal microbiome, which could potentially promote nutrient digestion and absorption, and improve the production performance of laying hens.

Impact of Lactobacillus apis on the antioxidant activity, phytic acid degradation, nutraceutical value and flavor properties of fermented wheat bran, compared to Saccharomyces cerevisiae and Lactobacillus plantarum

This study aimed to use a novel Lactobacillus strain (L. apis) isolated from the bee gut to develop a wheat bran (WB) deep-processing technology. Compared to the most popular strains (S. cerevisiae and L. plantarum), we found that L. apis had a greater ability to enhance the fermented WB antioxidant activity through hydroxyl radical scavenging, metal chelating ability, reducing power, and ferric reducing antioxidant power. While L. apis and L. plantarum had similar effects on DPPH^• and ABTS^•+ scavenging activities. This improvement in antioxidant activity has been associated with some metabolic compounds, such as sinapic acid, hydroferulic acid, pyruvic acid, neocostose, oxalic acid, salicylic acid, and schaftoside. Furthermore, L. apis degraded 48.33% of the phytic acid in WB, higher than S. cerevisiae (26.73%) and L. plantarum (35.89%). All strains improved the volatile profile of WB, and the fermented WB by each strain displayed a unique volatile composition. L. apis increased the level of conditional amino acids and branched-chain amino acids significantly. S. cerevisiae increased γ-aminobutyric acid the most, from 230.8 mg/L in unfermented samples to 609.8 mg/L in the fermented WB. While L. apis and L. plantarum also increased the level of γ-aminobutyric acid to 384.5 mg/L and 295.04 mg/L, respectively. Finally, we found that L. apis remarkably increased the content of organic acids and water-soluble vitamins in wheat bran.

Enhancement Methods of Antioxidant Capacity in Rice Bran: A Review

Rice (Oryza sativa L.) is a primary food that is widely consumed throughout the world, especially in Asian countries. The two main subspecies of rice are japonica and indica which are different in physical characteristics. In general, both indica and japonica rice consist of three types of grain colors, namely white, red, and black. Furthermore, rice and rice by-products contain secondary metabolites such as phenolic compounds, flavonoids, and tocopherols that have bioactivities such as antioxidants, antimicrobial, cancer chemopreventive, antidiabetic, and hypolipidemic agents. The existence of health benefits in rice bran, especially as antioxidants, gives rice bran the opportunity to be used as a functional food. Most of the bioactive compounds in plants are found in bound form with cell wall components such as cellulose and lignin. The process of releasing bonds between bioactive components and cell wall components in rice bran can increase the antioxidant capacity. Fermentation and treatment with enzymes were able to increase the total phenolic content, total flavonoids, tocotrienols, tocopherols, and γ-oryzanol in rice bran.

Impact of a novel probiotic Lactobacillus strain isolated from the bee gut on GABA content, antioxidant activity, and potential cytotoxic activity against HT-29 cell line of rice bran

Rice bran was fermented with Lactobacillus apis, isolated from the bee gut as a novel probiotic strain, and Saccharomyces cerevisiae to investigate the relationship between its metabolites and antioxidant activity, nutraceutical value, and cytotoxic activity against the HT-29 cell line. The findings showed that L. apis improved the antioxidant activity (DPPH of 37.73%) and antioxidant capacity (ABTS of 37.62 mg Trolox/g,), as well as, hydroxyl radical-scavenging activity (91.55%) of rice bran compared to S. cerevisiae. The metabolic analysis of volatile compounds revealed an increase of alcohols and lactones in the samples fermented with S. cerevisiae. While the samples fermented with L. apis displayed an increase of ketones, esters, and thiazoles. On the other hand, L. apis and S. cerevisiae exhibited a significant ability to increase γ-aminobutyric acid during different fermentation times. Compared with non-fermented samples (18.54%), L. apis increased the cytotoxic activity of rice bran against the HT-29 cell line to 34.17%, and S. cerevisiae to 31.34%. These results suggest that the fermentation of rice bran with S. cerevisiae and L. apis provides a promising strategy to improve the antioxidant activity and nutraceuticals of rice bran, and a potential source for plant-based pharmaceutical products.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-022-05512-2.

Recent Developments in Fermented Cereals on Nutritional Constituents and Potential Health Benefits

Fermentation is one of the most economical and safe methods to improve the nutritional value, sensory quality and functional characteristics of raw materials, and it is also an important method for cereal processing. This paper reviews the effects of microbial fermentation on cereals, focusing on their nutritional value and health benefits, including the effects of fermentation on the protein, starch, phenolic compounds contents, and other nutrient components of cereals. The bioactive compounds produced by fermented cereals have positive effects on health regulation. Finally, the future market development of fermented cereal products is summarized and prospected.

The Acute Effect of a Novel Miso-Type Sauce, Enhanced with a Carotenoid-Rich Extract from Fruit By-Products, on Postprandial Biomarkers of Oxidative Stress and Inflammation

Several fruit by-products may exert a beneficial role on oxidative stress and inflammation modulation, providing essential bioactive components, such as polyphenols and carotenoids. Recently, the potential bioactivity of miso has been reported. The aim of this dietary intervention−clinical study was to evaluate the acute effect of a novel, functional miso-type sauce based on legumes, on postprandial biomarkers of oxidative stress and inflammation. In this randomized, cross-over design, intervention−clinical trial, 14 healthy volunteers, aged 20−30 years old, consumed a rice meal rich in fat and carbohydrates (258 g), containing a legume-based sauce. After a 1-week washout period, the same subjects consumed the same meal, containing the novel fermented miso-type sauce, enhanced with 50% carotenoid-rich, fruit peel extract. Differences in postprandial total plasma antioxidant capacity according to the FRAP method, serum lipids, glucose, uric acid levels, and antithrombotic activity in platelet-rich plasma were evaluated before, 30 min, 1.5 h, and 3 h after consumption. The results showed that, in comparison to the control group, consumption of the novel sauce resulted in a significantly increased total plasma antioxidant capacity 3 h after consumption (p < 0.05). In addition, we observed a significant attenuation of triglycerides concentration increase in the last 1.5 h in the functional group (p < 0.05). A significant decrease in serum aggregation was found at 30 min and 3 h after functional sauce intake in comparison with the baseline (p < 0.05). Finally, LDL-cholesterol concentrations were significantly reduced 3 h after the functional meal consumption, in comparison with baseline values (p < 0.05). The remaining biomarkers did not show statistically significant differences (p > 0.05). Further investigation is needed in order to validate the current results.

Antidiabetic Function of Lactobacillus fermentum MF423-Fermented Rice Bran and Its Effect on Gut Microbiota Structure in Type 2 Diabetic Mice

Rice bran is an industrial byproduct that exerts several bioactivities despite its limited bioavailability. In this study, rice bran fermented with Lactobacillus fermentum MF423 (FLRB) had enhanced antidiabetic effects both in vitro and in vivo. FLRB could increase glucose consumption and decrease lipid accumulation in insulin resistant HepG2 cells. Eight weeks of FLRB treatment significantly reduced the levels of blood glucose and lipids and elevated antioxidant activity in type 2 diabetic mellitus (T2DM) mice. H&E staining revealed alleviation of overt lesions in the livers of FLRB-treated mice. Moreover, high-throughput sequencing showed notable variation in the composition of gut microbiota in FLRB-treated mice, especially for short-chain fatty acids (SCFAs)-producing bacteria such as Dubosiella and Lactobacillus. In conclusion, our results suggested that rice bran fermentation products can modulate the intestinal microbiota and improve T2DM-related biochemical abnormalities, so they can be applied as potential probiotics or dietary supplements.

Calligonum polygonoides L. as Novel Source of Bioactive Compounds in Hot Arid Regions: Evaluation of Phytochemical Composition and Antioxidant Activity

Calligonum polygonoides L. (Phog) is an endemic perennial herb that is highly resistant to all type of abiotic stresses and dominant biomass as well as phytochemicals producer in its natural habitat of the “Thar Desert” of Rajasthan, India. The present study was conducted to evaluate the effect of extreme environmental conditions on the phenolic, flavonoids, tannin content, and total antioxidant activities of C. polygonoides foliage harvested during different months. It exhibited a significant variation in the content of phenolic compounds, flavonoids, tannins, and antioxidant activity with harvesting time and all parameters are positively correlated to each other. The highest phenolic compounds and antioxidant activity was observed during severe winter and summer months, when monthly average environmental temperature was lowest and highest of the year, respectively. On the basis of the results, two harvests of C. polygonoides foliage during June and December are advised to maximize the phenolic compound production with highest antioxidant activity. These results demonstrate C. polygonoides, which is a dominant biomass producer under the harsh climatic conditions, can be an important source for the development of the functional foods rich in antioxidants in hot arid regions.

Custard Apple (Annona squamosa L.) Leaves: Nutritional Composition, Phytochemical Profile, and Health-Promoting Biological Activities

Annona squamosa L. (custard apple) belongs to the family Annonaceae and is an important tropical fruit cultivated in the West Indies, South and Central America, Ecuador, Peru, Brazil, India, Mexico, the Bahamas, Bermuda, and Egypt. Leaves of custard apple plants have been studied for their health benefits, which are attributed to a considerable diversity of phytochemicals. These compounds include phenol-based compounds, e.g., proanthocyanidins, comprising 18 different phenolic compounds, mainly alkaloids and flavonoids. Extracts from Annona squamosa leaves (ASLs) have been studied for their biological activities, including anticancer, antidiabetic, antioxidant, antimicrobial, antiobesity, lipid-lowering, and hepatoprotective functions. In the current article, we discussed the nutritional and phytochemical diversity of ASLs. Additionally, ASL extracts were discussed with respect to their biological activities, which were established by in vivo and in vitro experiments. A survey of the literature based on the phytochemical profile and health-promoting effects of ASLs showed that they can be used as potential ingredients for the development of pharmaceutical drugs and functional foods. Although there are sufficient findings available from in vitro and in vivo investigations, clinical trials are still needed to determine the exact effects of ASL extracts on human health.

Guava (Psidium guajava L.) Leaves: Nutritional Composition, Phytochemical Profile, and Health-Promoting Bioactivities

Psidium guajava (L.) belongs to the Myrtaceae family and it is an important fruit in tropical areas like India, Indonesia, Pakistan, Bangladesh, and South America. The leaves of the guava plant have been studied for their health benefits which are attributed to their plethora of phytochemicals, such as quercetin, avicularin, apigenin, guaijaverin, kaempferol, hyperin, myricetin, gallic acid, catechin, epicatechin, chlorogenic acid, epigallocatechin gallate, and caffeic acid. Extracts from guava leaves (GLs) have been studied for their biological activities, including anticancer, antidiabetic, antioxidant, antidiarrheal, antimicrobial, lipid-lowering, and hepatoprotection activities. In the present review, we comprehensively present the nutritional profile and phytochemical profile of GLs. Further, various bioactivities of the GL extracts are also discussed critically. Considering the phytochemical profile and beneficial effects of GLs, they can potentially be used as an ingredient in the development of functional foods and pharmaceuticals. More detailed clinical trials need to be conducted to establish the efficacy of the GL extracts.