Effects of micronized okara dietary fiber on cecal microbiota, serum cholesterol and lipid levels in BALB/c mice

Postprandial glycemic and circulating SCFA concentrations following okara- and biovalorized okara-containing biscuit consumption in middle-aged and older adults: a crossover randomized controlled trial

Okara is a high-fiber food by-product that can be biotransformed with Rhizopus oligosporus to improve its nutritional value and palatability. This research aims to assess postprandial changes in glycemic-related and lipid-related outcomes in middle-aged and older Singaporeans following okara- and biovalorized okara-containing biscuit consumption. Fifteen participants (58 ± 6 years old, mean ± SD) completed the randomized crossover study. Participants were provided control (C), okara (AOK)-, and biovalorized okara (RO)-containing biscuits in separate 4 h mixed meal tolerance tests. Serum glucose and insulin, insulin indices, serum short-chain fatty acids (SCFA) and lipid-lipoprotein panels, and sensory analysis were assessed. Glucose-stimulated insulin secretion was significantly lower for RO than for C (p: 0.035) while log insulin incremental area under the curve (AUC) was significantly lower for AOK compared to that for C (p: 0.023). The estimated insulin sensitivity index and estimated metabolic clearance rate were significantly higher for AOK compared to that for C (p: 0.025 and 0.016 respectively). Normalized AUC for total SCFA was significantly higher for RO compared to that for C (p: 0.038). Normalized AUC for LDL-cholesterol was significantly higher for AOK than for C (p: 0.010). No significant difference was noted for glucose, total cholesterol, HDL-cholesterol, and triglyceride concentrations. RO had greater flavor and overall liking than AOK (p: 0.007 and 0.017 respectively). Biscuits incorporated with okara or biovalorized okara can attenuate postprandial insulin responses. RO offered a greater SCFA response than C, indicating improved SCFA concentrations upon consumption of okara improved with fermentation. The trial was registered under https://www.clinicaltrials.gov (NCT03978104, 25 May 2019).

Structural and Potential Functional Properties of Alkali-Extracted Dietary Fiber From Antrodia camphorata

Antrodia camphorata is rich in a variety of bioactive ingredients; however, the utilization efficiency of the residue of A. camphorata is low, resulting in serious waste. It is necessary to deeply study the functional components of A. camphorata residues to achieve high-value utilization. In this study, the components, structural characteristics, and functional properties of alkali-extracted dietary fiber extracted from residues of A. camphorata (basswood and dish cultured fruiting body, respectively) were investigated. There were similar components and structural characteristics of ACA-DK (extract from basswood cultured) and ACA-DF (extract from dish cultured). The two alkali-extracted dietary fiber were composed of mainly cellulose and xylan. However, ACA-DK has better adsorption capacities than ACA-DF on lipophilic substances such as oil (12.09 g/g), cholesterol (20.99 mg/g), and bile salts (69.68 mg/g). In vitro immunomodulatory assays stated that ACA-DK had a good effect on promoting the proliferation of RAW 264.7 cells and can activate cell phagocytosis, NO synthesis, and other immune capabilities. The edible fungus A. camphorata is a good source of functional dietary fiber. The alkali-extracted dietary fiber of A. camphorata might be used as a functional ingredient in the medicine and food industry.

Micronized Dietary Okara Fiber: Characterization, Antioxidant, Antihyperglycemic, Antihyperlipidemic, and Pancreato-Protective Effects in High Fat Diet/Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus (DM) is a lifelong devastating and debilitating disease with serious chronic complications. Okara is a byproduct generated from soymilk or tofu production and it has been reported to have antioxidant and lipid-lowering effects. However, the antidiabetic effects and pancreatic β-cells' secretory functions of micronized okara fiber (MOF) have not been reported. Therefore, this study explored the antidiabetic effects and modulatory potentials of MOF on pancreatic β-cells' secretory functions in a high fat/high sugar/streptozotocin rat model of diabetes mellitus. Fiber-rich okara was prepared by removing fat and proteins from freshly obtained okara, followed by micronization. Fiber-rich okara was prepared, micronized, and characterized for hydrophobicity, thermal stability, structure-function relationship, and antioxidant potentials. We then established a rat model of DM and MOF and two doses (100 and 400 mg kg^-1) were administered to see its anti-DM effect. Four weeks of MOF supplementation significantly reduced blood glucose, increased serum insulin level, improved hepatorenal functions, glucose tolerance, and regenerated pancreatic β-cells in the treated DM rats. Furthermore, MOF significantly improved the pancreatic antioxidant defense system by significantly elevating glutathione peroxidase, catalase, and superoxide dismutase activities while depleting the malonaldehyde level in the pancreas of the treated diabetic rats. Our results indicated that MOF ameliorated DM by impeding hyperglycemia, hyperlipidemia, and oxidative stress and enhancing the secretory functions of the beta cells, suggesting that MOF might be used as a protective nutrient in DM.

Dietary emulsifier glycerol monodecanoate affects gut microbiota contributing to regulating lipid metabolism, insulin sensitivity and inflammation

Glycerol monodecanoate (GMD) is a medium-chain monoacylglycerol that possesses emulsifying and antibacterial properties. Common emulsifiers carboxymethylcellulose and polysorbate-80 have been reported to cause intestinal microbiota dysbiosis and metabolic disturbances. While...

Effect of soybean insoluble dietary fiber on prevention of obesity in high-fat diet fed mice via regulation of the gut microbiota

Increasing evidence has shown that the gut microbiota plays an important role in preventing obesity; however, the mechanism by which insoluble dietary fiber (IDF) prevents high-fat diet (HFD)-induced obesity remains unclear. This study aimed to investigate the effect of SIDF on obesity in HFD mice and determine the mechanism by which it prevents obesity through regulating the gut microbiota. Soybean insoluble dietary fiber (SIDF) was used as an intervention in HFD mice for 20 weeks. The results showed that SIDF significantly reduced the body weight (BW), fat index, total cholesterol, triglyceride, and low-density lipoprotein cholesterol while increasing the content of high-density lipoprotein cholesterol in HFD mice. SIDF intervention was also beneficial for the reduction of liver lipid content and fatty droplets in mice. Furthermore, SIDF intervention improved the gut microbiota composition by increasing the relative abundance of potentially beneficial bacteria (such as Lactobacillales [order], Lactobacillus [genus], Lachnospirace_Nk4A136_group [genus]), and reduced the relative abundance of potentially harmful bacteria (such as Lachnospiraceae [family] and Bacteroides_acidifaciens [species]), which correlated with obesity (at least p < 0.05 in all instances). Finally, SIDF was fermented by related beneficial bacteria, which increased the content of the short-chain fatty acids (SCFAs), and promoted the secretion of satiety hormones. In conclusion, SIDF intervention could prevent obesity in HFD mice by modulating the gut microbiota composition. Hence, SIDF may be used as a potential ingredient in functional foods.

Replacing soybean meal with okara meal: Effects on production, milk fatty acid and plasma amino acid profile, and nutrient utilization in dairy cows

Okara meal is a byproduct from the production of soymilk and tofu and can potentially replace soybean meal (SBM) in dairy diets due to its high crude protein (CP) concentration and residual fat. The objective of this study was to investigate the effects of replacing SBM with okara meal on feed intake, yields of milk and milk components, milk fatty acid (FA) profile, nutrient utilization, and plasma AA concentration in lactating dairy cows. Twelve multiparous (65 ± 33 d in milk) and 8 primiparous (100 ± 35 d in milk) organically certified Jersey cows were paired by parity or days in milk, and within pair, randomly assigned to treatments in a crossover design with 21-d periods (14 d for diet adaptation and 7 d for data and sample collection). Diets were fed as total mixed ration formulated to be isonitrogenous and isofibrous and contained (dry matter basis) 50% mixed, mostly grass baleage, 2% sugarcane liquid molasses, 2% minerals-vitamins premix, and either (1) 8.1% SBM, 10% soyhulls, and 27.9% ground corn (CTRL); or (2) 15% okara meal, 8% soyhulls, and 23% ground corn (OKR). Dietary CP, ash-free neutral detergent fiber, and total FA averaged 15.4, 35.3, and 3.08% for CTRL and 15.9%, 36.3%, and 3.74% for OKR, respectively. Substitution of SBM with okara meal did not alter dry matter intake but increased intakes of CP and ash-free neutral detergent fiber. Additionally, no significant differences between treatments were observed for yields of milk and milk components, and concentrations of milk fat, lactose, and total solids. However, milk true protein concentration was lower in cows fed OKR (3.76%) versus CTRL (3.81%). Both milk urea N (8.51 vs. 9.47 mg/dL) and plasma urea N (16.9 vs. 17.8 mg/dL) concentrations decreased with OKR relative to the CTRL diet, respectively. Compared with CTRL, feeding OKR lowered the milk proportions of total odd-chain FA, de novo FA, and mixed FA and increased those of preformed FA, total n-6 FA, and total n-3 FA. The milk proportions of trans-10 18:1, trans-11 18:1, and cis-9,trans-11 18:2 were greater with feeding OKR versus the CTRL diet. The apparent total-tract digestibility of nutrients, urinary excretion of total purine derivatives (uric acid plus allantoin), and total N were not affected by treatments. Except for plasma Leu, which was lower in OKR compared with the CTRL diet, no other significant changes in the plasma concentrations of AA were observed. The plasma concentration of carnosine was lowest in cows receiving the OKR diet. Overall, our results revealed that okara meal can completely replace SBM without negatively affecting production and nutrient digestibility in early- to mid-lactation Jersey cows. Further research is needed to assess the economic feasibility of including okara meal in dairy diets, as well as the amount of okara meal that maximizes yields of milk and milk components in dairy cows in different stages of lactation.

Influence of okara with varying particle sizes on the gelling, rheological, and microstructural properties of glucono-δ-lactone-induced tofu

Influence of lyophilized okara with varying particle sizes (250-380, 150-180, 120-150, and < 75 μm) on the quality of glucono-δ-lactone-induced tofu was investigated. Adding okara significantly (p < 0.05) improved the yield, water-holding capacity, cooking loss, and nutritional value of the conventional tofu. The gel strength and sensory score of the okara-added tofu (OAT) increased with the decreasing of the particle size of okara, and these quality attributes of the OAT were better than those of the conventional tofu, except for the OAT with 250-380 μm okara. The microstructural profile of the OAT with reduced okara particle size was similar to that of the conventional tofu. Theoretically, the addition of okara mainly impacted the interactions among denatured proteins via disulfide bonding and hydrophobic interactions and the sizes of insoluble solid and oil droplet in soymilk, thereby affecting the formation of the gel network and finally the edible quality of tofu. In conclusion, the addition of okara with appropriate particle sizes can remarkably improve the processing quality and nutritional value of tofu, which is beneficial to the reasonable exploration of okara for the producers of soybean products.

Soy, Soy Foods and Their Role in Vegetarian Diets

Soy is a basic food ingredient of traditional Asian cuisine used for thousands of years. In Western countries, soybeans have been introduced about a hundred years ago and recently they are mainly used for surrogate foods production. Soy and soy foods are common nutritional solutions for vegetarians, due to their high protein content and versatility in the production of meat analogues and milk substitutes. However, there are some doubts about the potential effects on health, such as the effectiveness on cardiovascular risk reduction or, conversely, on the possible disruption of thyroid function and sexual hormones. The soy components that have stimulated the most research interest are isoflavones, which are polyphenols with estrogenic properties highly contained in soybeans. In this review, we discuss the characteristics of soy and soy foods, focusing on their nutrient content, including phytoestrogens and other bioactive substances that are noteworthy for vegetarians, the largest soy consumers in the Western countries. The safety of use will also be discussed, given the growing trend in adoption of vegetarian styles and the new soy-based foods availability.

Soy and Gut Microbiota: Interaction and Implication for Human Health

Soy (Glycine max) is a major commodity in the United States, and soy foods are gaining popularity due to their reported health-promoting effects. In the past two decades, soy and soy bioactive components have been studied for their health-promoting/disease-preventing activities and potential mechanisms of action. Recent studies have identified gut microbiota as an important component in the human body ecosystem and possibly a critical modulator of human health. Soy foods' interaction with the gut microbiota may critically influence many aspects of human development, physiology, immunity, and nutrition at different stages of life. This review summarizes current knowledge on the effects of soy foods and soy components on gut microbiota population and composition. It was found, although results vary in different studies, in general, both animal and human studies have shown that consumption of soy foods can increase the levels of bifidobacteria and lactobacilli and alter the ratio between Firmicutes and Bacteroidetes. These changes in microbiota are consistent with reported reductions in pathogenic bacteria populations in the gut, thereby lowering the risk of diseases and leading to beneficial effects on human health.

Tea Dietary Fiber Improves Serum and Hepatic Lipid Profiles in Mice Fed a High Cholesterol Diet

Tea dietary fiber (TDF) was prepared from tea residues and modified to get cellulose-modified TDF (CTDF) by cellulase or micronized TDF (MTDF) by ultrafine grinding. The in vitro lipid-binding capacities of the three fibers and their effects on serum and hepatic lipid profiles in mice fed a high cholesterol diet were evaluated. The results showed that the three fibers had excellent lipid-binding capacities, and the cholesterol- and sodium cholate-binding capacities of CTDF and MTDF were significantly higher than those of TDF. Animal studies showed that, compared to model control, the three fibers significantly decreased mice average daily gain, gain: feed, and liver index, reduced total cholesterol (TC), triglyceride, and low density lipoprotein-cholesterol of serum and liver, increased serum and hepatic high density lipoprotein-cholesterol to TC ratio, and promoted the excretion of fecal lipids, and they also significantly increased the activities of superoxide dismutase and glutathione peroxidase of serum and liver, and decreased lipid peroxidation; moreover, the effects of CTDF and MTDF were better than that of TDF. It was concluded that the three fibers could improve serum and hepatic lipid profiles in mice fed a high cholesterol diet and the mechanism of action might be due to the promotion of fecal excretion of lipids through their lipid-binding ability and the inhibition of lipid peroxidation. These findings suggest that tea dietary fiber has the potential to be used as a functional ingredient to control cardiovascular disease.