Effect of Dephytinization by Fermentation and Hydrothermal Autoclaving Treatments on the Antioxidant Activity, Dietary Fiber, and Phenolic Content of Oat Bran

Deciphering the structure-function-quality improvement role of starch gels by wheat bran insoluble dietary fibers obtained from different fermentation patterns and its potential mechanisms

Insoluble dietary fiber (IDF) isolated through co-fermented bran from probiotics may improve starch gel-based foods. This work aimed to elucidate the comprehensive impact of different IDF samples (CK, unfermented; NF, natively fermented; YF, yeast fermented; LF, Lactobacillus plantarum fermented; and MF, mix-fermented) and their addition ratios (0.3-0.9%) on gel structure-property function. Results indicated that IDF introduction altered the starch pasting behavior (decreased the viscosity and advanced the pasting time). Also, YF, LF, and MF showed less effect on gel multiscale morphology (SEM and CLSM); however, their excessively high ratio resulted in network structure deterioration. Moreover, FT-IR, XRD, and Raman characterization identified the composite gels interaction mechanisms mainly by hydrogen bonding forces, van der Waals forces, water competition, and physical entanglement. This modulation improved the composite gel water distribution, rheological/stress-strain behavior, textural properties, color, stability, and digestive characteristics. The obtained findings may shed light on the construction and development of whole-grain gel-based food products with new perspectives.

Cereal bran proteins: recent advances in extraction, properties, and applications

The projected global population is expected to reach around 9.7 billion by 2050, indicating a greater demand for proteins in the human diet. Cereal bran proteins (CBPs) have been identified as high-quality proteins, with potential applications in both the food and pharmaceutical industries. In 2020, global cereal grain production was 2.1 billion metric tonnes, including wheat, rice, corn, millet, barley, and oats. Cereal bran, obtained through milling, made up 10-20% of total cereal grain production, varying by grain type and milling degree. In this article, the molecular composition and nutritional value of CBPs are summarized, and recent advances in their extraction and purification are discussed. The functional properties of CBPs are then reviewed, including their solubility, binding, emulsifying, foaming, gelling, and thermal properties. Finally, current challenges to the application of CBPs in foods are highlighted, such as the presence of antinutritional factors, low digestibility, and allergenicity, as well as potential strategies to improve the nutritional and functional properties by overcoming these challenges. CBPs exhibit nutritional and functional attributes that are similar to those of other widely used plant-based protein sources. Thus, CBPs have considerable potential for use as ingredients in food, pharmaceutical, and other products.

Dephytinized flaxseed flours by phytase enzyme and fermentation: functional ingredients to enhance the nutritional quality of noodles

BACKGROUND

Phytic acid is an antinutritional compound that reduces the bioavailability of minerals and proteins. Flaxseed is a rich source of unsaturated fatty acids and antioxidants. In this study, flaxseed flour was dephytinized by phytase enzyme and fermentation. Untreated and dephytinized flaxseed flours were used in noodle production at 0%, 10%, 20% and 30% levels to improve nutritional quality.

RESULTS

The addition of flaxseed flours did not show an adverse effect on the cooking loss values of noodles (4.22-4.85%). Firmness values of noodles containing 10% flaxseed flour were close to the control (0% flaxseed flour). The ash, protein and fat levels of noodles were enhanced with the addition of flaxseed flours. The use of 30% phytase-treated flaxseed flour in noodles elicited lower phytic acid concentration (1.35 g kg^-1 ) than the control (1.52 g kg^-1 ). The greatest total phenolic contents in noodles were obtained with the inclusion of fermented flour. Besides that, noodles made from flaxseed flours exhibited stronger antioxidant activity than the control. The overall acceptability scores of noodles containing 10% and 20% dephytinized flours were close to the control.

CONCLUSION

The findings demonstrated that the inclusion of dephytinized flaxseed flours up to 20% can allow the production of functional noodles with acceptable quality. Moreover, phytase enzyme treatment method revealed lower phytic acid content than fermentation method in noodles and better antioxidant properties than untreated noodles. © 2022 Society of Chemical Industry.

Dephytinization of wheat and rice bran by cross-linked enzyme aggregates of Mucor indicus phytase: a viable prospect for food and feed industries

BACKGROUND

Novel feeds for improved feed intake and for enhanced nutrient bioavailability have recently attracted attention. Insoluble dietary fibers, especially rice and wheat bran, have generated much interest due to their nutritional value. Incorporating insoluble dietary fiber into diets could be a viable way to maximize the feed conversion ratio.

RESULTS

Cross-linked phytase aggregates (CLPA) were synthesized by precipitating enzymes followed by cross-linking with 5 mmol L^-1 glutaraldehyde, yielding 88.24 (U g^-1 ) of enzyme load without the assistance of a proteic feeder. The epitome of the study is the dephosphorylation of wheat bran and rice bran by varying pH, enzyme concentration, and temperature. The highest inorganic phosphorus liberation by 150 U L-^-1 of free phytase was 23.72 (wheat bran) and 48.08 mg g^-1 (rice bran) after 12 h of incubation.  Furthermore, 150 U L^-1 of CLPA liberated 28.72 (wheat bran) and 52.08 mg g^-1 (rice bran) of inorganic phosphorus with an incubation time of 12 h.

CONCLUSION

Thermostable free phytase was insolubilized to dephosphorylate the agro-residue, namely, wheat bran and rice bran, to reduce the anti-nutritional factor (the phytate content) of these insoluble dietary fibers. © 2022 Society of Chemical Industry.

Improving the adsorption characteristics and antioxidant activity of oat bran by superfine grinding

Oat bran (OB) is a by-product of oat, which is rich in β-glucan. As a new food processing technology, ultrafine powder can improve the surface properties of samples. OB with different grinding times was prepared, and its functional components, physical properties, adsorption properties, and antioxidant properties were evaluated. Results showed that with increased grinding times, the average particle size of OB decreased significantly (p < .05). And the water-holding capacity, swelling capacity, and water solubility index of OB increased significantly (p < .05), whereas the animal and vegetable oil-holding capacities decreased. Oat bran could adsorb cholic acid and glucose, which was related to the time of superfine grinding. In addition, the antioxidant capacity of OB was improved after superfine grinding. Related analysis shows that there was significant positive relationship between β-glucan, polyphenols and soluble dietary fibers and antioxidant indicators (p < .05). The Fourier transform infrared (FTIR) results showed that the FTIR spectra of OB powder with different crushing times were similar. On the basis of the above analyses, it is suggested that OB prepared by superfine grinding for 5 min had good physical and chemical properties and antioxidant properties and is widely used in food.

Comparative Study of Raw and Fermented Oat Bran: Nutritional Composition with Special Reference to Their Structural and Antioxidant Profile

Oat bran has gained significant attention among cereal brans owing to its comparatively higher presence of dietary fibers and phytochemicals. The objective of the current research is to personify the nutritional and functional aspects of oat bran after yeast-induced (Saccharomyces cerevisiae) fermentation. For this purpose, a comparative study of raw and fermented oat bran was conducted to investigate the nutritional profile, antioxidant activity and functional characteristics of oat bran. Furthermore, pre- and post-structural variations on fermented bran were determined through scanning electron microscopy (SEM). The results show that crude fat, protein and total dietary fiber (soluble and insoluble) contents were significantly improved after fermentation. Moreover, the post-fermentation value of soluble dietary fiber was increased from 5.01 ± 0.21 to 7.2 ± 0.1%. Antioxidant activity, DPPH-RSA and ferric reducing antioxidant power values of bran samples were also enhanced through fermentation and the anti-nutritional factor, i.e., phytate, was significantly reduced from 1113.3 ± 8.5 to 283.4 ± 3.5 mg/100 g in bran samples after fermentation. Furthermore, the surface morphology of fermented oat bran shows scattering and pores, while raw oat bran shows visible aggregation in SEM micrographs. Water-holding capacity was also enhanced up to 2.11 (5.68%) after fermentation. In conclusion, the post-fermentation results revealed that yeast-induced fermentation enhanced the physicochemical, structural and antioxidant characteristics of oat bran.

Screen of high efficiency cellulose degrading strains and effects on tea residues dietary fiber modification: Structural properties and adsorption capacities

In our study, two high efficiency cellulose degrading strains were screened, isolated and identified as Cochliobolus kusanoi and Aspergillus puulaauensis by 18S rDNA gene sequencing. In addition, the composite microbial system was constructed to develop the synergistic effect among different strains. Under the optimum conditions, the yield of soluble dietary fiber from tea residues by mixed fermentation method (MF-SDF) dramatically increased compared to single strain fermentation. The structural analysis demonstrated that all samples possessed the representative infrared absorption peaks of polysaccharides, whereas MF-SDF revealed more loose structure, lower crystallinity and smaller molecular size. For the adsorption capacities indexes, MF-SDF also owned the highest adsorbing capacity for the water molecule, oil molecule, cholesterol molecule and nitrite ion. Overall, our data showed that mixed fermentation method could be better choices to improve the functional properties of dietary fiber, and screening of cellulose degrading strains could provide new thinkings for the study of dietary fiber modification and realize high-quality utilization of crop residues.

Biotechnological Processes Simulating the Natural Fermentation Process of Bee Bread and Therapeutic Properties-An Overview

Recent signs of progress in functional foods and nutraceuticals highlighted the favorable impact of bioactive molecules on human health and longevity. As an outcome of the fermentation process, an increasing interest is developed in bee products. Bee bread (BB) is a different product intended for humans and bees, resulting from bee pollen's lactic fermentation in the honeycombs, abundant in polyphenols, nutrients (vitamins and proteins), fatty acids, and minerals. BB conservation is correlated to bacteria metabolites, mainly created by Pseudomonas spp., Lactobacillus spp., and Saccharomyces spp., which give lactic acid bacteria the ability to outperform other microbial groups. Because of enzymatic transformations, the fermentation process increases the content of new compounds. After the fermentation process is finalized, the meaningful content of lactic acid and several metabolites prevent the damage caused by various pathogens that could influence the quality of BB. Over the last few years, there has been an increase in bee pollen fermentation processes to unconventional dietary and functional supplements. The use of the chosen starters improves the bioavailability and digestibility of bioactive substances naturally found in bee pollen. As a consequence of enzymatic changes, the fermentation process enhances BB components and preserves them against loss of characteristics. In this aspect, the present review describes the current biotechnological advancements in the development of BB rich in beneficial components derived from bee pollen fermentation and its use as a food supplement and probiotic product with increased shelf life and multiple health benefits.

Dietary fiber in bakery products: Source, processing, and function

Bakery products are prevalently consumed foods in the world, and they have been regarded as convenient dietary vehicles for delivering nutritive ingredients into people's diet, of which, dietary fiber (DF) is one of the most popular items. The food industry attempts to produce fiber-enriched bakery products with both increasing nutritional value and appealing palatability. As many new sources of DFs become available, and consumers are moving towards healthier diets, studies of using these DFs as functional ingredients in baked goods are becoming vast. Besides, the nutrition value of DF is commonly accepted, and many investigations have also revealed the health benefits of fiber-enriched bakery products. Thus, this chapter presents an overview of (1) trends in supplementation of DF from various sources, (2) impact of DF on dough processing, quality and physiological functionality of bakery products, and (3) technologies used to improve the compatibility of DF in bakery products.

Food Processing Technologies to Develop Functional Foods With Enriched Bioactive Phenolic Compounds in Cereals

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.

Review of the beneficial and anti-nutritional qualities of phytic acid, and procedures for removing it from food products

Phytic acid (PA) is the primary phosphorus reserve in cereals and legumes which serves the biosynthesis needs of growing tissues during germination. It is generally considered to be an anti-nutritional factor found in grains because it can bind to minerals, proteins, and starch, limiting their bioavailability. However, this same mineral binding property can also confer a number of health benefits such as reducing the risk of certain cancers, supporting heart health, and managing renal stones. In addition, the ability of PA to bind minerals allows it to be used in certain food quality applications such as stabilizing the green color of vegetables, preventing lipid peroxidation, and reducing enzymatic browning in fruits/vegetables. These beneficial properties create a potential for added-value applications in the utilization of PA in many new areas. Many possible processing techniques for the preparation of raw materials in the food industry can be used to reduce the concentration of PA in foods to mitigate its anti-nutritional effects. In turn, the recovered PA by-products could be available for novel uses. In this review, a general overview of the beneficial and anti-nutritional effects of PA will be discussed and then dephytinization methods will be explained.

Application of Autoclave Treatment for Development of a Natural Wheat Bran Antioxidant Ingredient

The study evaluated the effect of autoclaving as a hydrothermal treatment on the quality and bioactivity of wheat bran (WB) with the objective of producing a natural ingredient with enhanced healthy properties. Nutritional, antioxidant, techno-functional and sensorial parameters were studied, and temperatures of 100, 115 and 130 °C were explored. Of these, 130 °C was found to be the best treatment, resulting in an ingredient with high storage stability, antioxidant properties, a four-fold increase in the concentration of free ferulic acid (compared with non-treated WB), and increased content of apigenin-6-C-arabinoside-8-C-hexoside, a flavonoid with reported antioxidant and antifungal properties. On the other hand, the autoclave treatment enhanced water absorption capacity and reduced WB pasting viscosity, mainly at higher temperature (130 °C), which would allow incorporation of the treated WB in liquid matrices such as juices, soups or milkshakes, among others. Although the glycemic index (GI) of the autoclaved samples increased, the use of intermediate particle size of 106 to 300 µm could contribute to the reduction of the glycemic load.

Harnessing Microbes for Sustainable Development: Food Fermentation as a Tool for Improving the Nutritional Quality of Alternative Protein Sources

In order to support the multiple levels of sustainable development, the nutritional quality of plant-based protein sources needs to be improved by food technological means. Microbial fermentation is an ancient food technology, utilizing dynamic populations of microorganisms and possessing a high potential to modify chemical composition and cell structures of plants and thus to remove undesirable compounds and to increase bioavailability of nutrients. In addition, fermentation can be used to improve food safety. In this review, the effects of fermentation on the protein digestibility and micronutrient availability in plant-derived raw materials are surveyed. The main focus is on the most important legume, cereal, and pseudocereal species (Cicer arietinum, Phaseolus vulgaris, Vicia faba, Lupinus angustifolius, Pisum sativum, Glycine max; Avena sativa, Secale cereale, Triticum aestivum, Triticum durum, Sorghum bicolor; and Chenopodium quinoa, respectively) of the agrifood sector. Furthermore, the current knowledge regarding the in vivo health effects of fermented foods is examined, and the critical points of fermentation technology from the health and food safety point of view are discussed.

The Dual Role of Oat Bran Water Extract in Bone Homeostasis Through the Regulation of Osteoclastogenesis and Osteoblast Differentiation

The number of patients with bone metabolic disorders including osteoporosis is increasing worldwide. These disorders often facilitate bone fractures, which seriously impact the patient's quality of life and could lead to further health complications. Bone homeostasis is tightly regulated to balance bone resorption and formation. However, many anti-osteoporotic agents are broadly categorized as either bone forming or anti-resorptive, and their therapeutic use is often limited due to unwanted side effects. Therefore, safe and effective therapeutic agents are needed for osteoporosis. This study aims to clarify the bone protecting effects of oat bran water extract (OBWE) and its mode of action. OBWE inhibited RANKL (receptor activator of nuclear factor-κB ligand)-induced osteoclast differentiation by blocking c-Fos/NFATc1 through the alteration of I-κB. Furthermore, we found that OBWE enhanced BMP-2-stimulated osteoblast differentiation by the induction of Runx2 via Smad signaling molecules. In addition, the anti-osteoporotic activity of OBWE was also evaluated using an in vivo model. OBWE significantly restored ovariectomy-induced bone loss. These in vitro and in vivo results showed that OBWE has the potential to prevent and treat bone metabolic disorders including osteoporosis.