Development of weaning food with prebiotic effects based on roasted or extruded quinoa and millet flour.

Weaning is the gradual process of introducing solids or semisolid foods into an infant's diet, in order to ensure their healthy growth. This study developed two kinds of formula weaning food based on roasted or extruded quinoa and millet flour, and evaluated their quality. A fructo-oligosaccharide (FOS)/galacto-oligosaccharide (GOS) mix was added to provide the prebiotic potential. The protein contents of the roasted quinoa-millet complementary food (RQMCF) and extruded quinoa-millet complementary food (EQMCF) were 16.7% and 17.74% higher, respectively, than that of commercial millet complementary food (CMCF). Both RQMCF and EQMCF provided sufficient levels of energy and minerals. Extrusion provided the foods with a lower viscosity, and higher solubility and water absorption ability than roasting. In vitro digestion results showed that EQMCF exhibited the highest starch and protein digestibility (89.76% and 88.72%, respectively) followed by RQMCF (87.75% and 86.63%) and CMCF (83.35% and 81.54%). The digestas of RQMCF and EQMCF after in vitro digestion exhibited prebiotic effects by promoting the growth of the probiotics (Lactobacillus plantarum and Lactobacillus delbrueckii). These results will contribute to developing complementary weaning foods for infants. PRACTICAL APPLICATION: This study has shown that extrusion is an efficient and stable processing method for producing infant complementary foods with low density, balanced nutrition, and high levels of starch and protein digestibility. Extruded quinoa-millet prebiotic complementary food can also promote the proliferation of probiotics. This will provide a new direction for developing novel infant formula weaning foods.

Comparative study of thermal processing on the physicochemical properties and prebiotic effects of the oat ß-glucan by in vitro human fecal microbiota fermentation.

This study aimed to compare the prebiotic effects of oat ß-glucan between steaming and microwave processing by high-throughput sequencing. The results showed that microwave-processed oat ß-glucan with lower average molecular weight (Mw) exhibited a more significant effect in promoting Lactobacillus and Bifidobacterium compared with steaming processed oat ß-glucan with higher Mw at the genus level. The overall microbial composition structure results indicated that the relative abundance of Escherichia-Shigella, Lactobacillus, Enterococcus, and Dialister exhibited significant differences between the samples (p < 0.05). Additionally, the short-chain fatty acid in microwave-processed oat ß-glucan fermentation slurries significantly increased (p < 0.05), and more butyrate was produced from microwave-processed oat ß-glucan, which may be attributed to the higher levels of Blautia and Dialister as butyrate-producers. These results suggest that microwave processing contributed to the degradation of oat ß-glucan and enhanced its prebiotic function.

Structural, antioxidant and adsorption properties of dietary fiber from foxtail millet (Setaria italica) bran.

BACKGROUND: Foxtail millet (Setaria italica) bran is a by-product of millet processing, rich in dietary fiber (DF) and has great application value. A comparative study was conducted to explore the differences in structural and functional properties among millet bran DF, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). RESULTS: There was a significant difference in the content of monosaccharides between SDF and IDF, in which xylose, arabinose and glucose were the main compositions. The results of scanning electron microscopy showed that DF and IDF had different forms of network structure, and SDF presented a sign of mutual adhesion. The total phenolic and flavonoid contents were 0.54 and 0.08 g kg-1 in SDF. Antioxidant activity of SDF was higher than that of IDF based on the evaluation of free radical scavenging and iron reducing capacity in vitro. Meanwhile, the glucose dialysis retardation index of IDF and SDF was 12.59% and 9.26% at 30 min, respectively. And, there was no significant difference in the adsorption capacity of glucose among different samples (P > 0.05). Furthermore, SDF had strong α-amylase inhibition (17.92% inhibition rate) and sodium cholate adsorption capacities; the adsorption amount was 16.76 g kg-1 in 2.00 g L-1 sodium cholate solution. CONCLUSION: Foxtail millet bran DF, especially SDF, has good functional properties and would be a suitable ingredient for health-beneficial food production. However, the relevant verification trials in vivo need to be carried out in the next steps. © 2019 Society of Chemical Industry.

Effects of thermal processing on the structural and functional properties of soluble dietary fiber from whole grain oats.

Normal pressure steaming, high pressure steaming, microwave, and frying are widely used to deactivate enzyme in the oats, but these thermal processing methods may affect the structural and functional properties of soluble dietary fiber, which contribute greatly to the health benefits of oat foods. The objective of this study was to evaluate the effects of four different thermal processing methods on the structural and functional properties of soluble dietary fiber from whole grain oats. The results showed that the thermal processing resulted in changes on nutritional components of whole grain oats. Especially dietary fiber components, the total dietary fiber, insoluble dietary fiber, and soluble dietary fiber content of heat-treated oats were significantly increased ( p < 0.05). Moreover, thermal processing can not only result in an increase in molecular weight and particle size, but also cause molecular aggregation and different functional properties of soluble dietary fiber. High pressure steaming-treated oat soluble dietary fiber displayed significantly higher swelling and emulsifying ( p < 0.05), but microwave-treated oat soluble dietary fiber exhibited the highest glucose, cholesterol, and sodium cholate adsorption capacities. These results might provide basic information to help to better understand the functionality of oat soluble dietary fiber and improve the process efficiency of oat foods with high nutritional qualities.

In vitro fermentation of oat ß-glucan and hydrolysates by fecal microbiota and selected probiotic strains.

BACKGROUND: Emerging evidence suggested that the prebiotic ability of ß-glucan was intimately related to its molecular weight (Mw ). However, the effect of oat ß-glucan with differing Mw on gut homeostasis was inconsistent. Importantly, knowledge of the fermentation properties of oat ß-glucan fractions was still limited. The present study aimed to evaluate the prebiotic potential of raw and hydrolyzed oat ß-glucan during in vitro fermentation by fecal microbiota and selected probiotic strains. RESULTS: The results obtained showed that both oat ß-glucan (OG) and hydrolysates (OGH) comparably promoted the growth of fecal Lactobacillus counts (P < 0.05). Importantly, OGH revealed greater fermentability compared to OG as denoted by lower pH value and higher short-chain fatty acid concentration (P < 0.05). Moreover, OGH was found to be more favorable to provide growth substrates for Lactobacillus helveticus R389 (LR389), Lactobacillus rhamnosus GG ATCC 53103 (LGG) and Bifidobacterium longum BB536 (BB536) than OG, and was preferentially utilized by LR389, LGG and BB536 as the sole carbon source. CONCLUSION: The results of the present study indicate that oat ß-glucan hydrolysates could serve as a more promising material for developing novel symbiotic foods. © 2017 Society of Chemical Industry.

Effects of oat ß-glucan and barley ß-glucan on fecal characteristics, intestinal microflora, and intestinal bacterial metabolites in rats.

The primary objective was to determine the beneficial effects of oat ß-glucan (OG) and barley ß-glucan (BG) on gut health. A total of 200 male Sprague-Dawley rats were divided into 5 groups of 40 rats each, control group (CON), low-dose OG-administered group (OGL), high-dose OG-administered group (OGH), low-dose BG-administered group (BGL), and high-dose BG-administered group (BGH). OGL and OGH were administered oat ß-glucan by intragastric gavage at a dose of 0.35 g/kg of body weight (BW) and 0.70 g/kg of BW daily for 6 weeks, and BGL and BGH were administered barley ß-glucan. The CON received normal saline. Intestinal-health-related indexes were analyzed at baseline, week 3, week 6, and week 7. Cereal ß-glucan significantly influenced the fecal water content, pH value, ammonia levels, ß-glucuronidase activity, azoreductase activity, and colonic short-chain fatty acid (SCFA) concentrations (p < 0.05). Moreover, the population of Lactobacillus and Bifidobacterium increased (p < 0.05), whereas the number of Enterobacteriaceae decreased (p < 0.05) in a dose-dependent manner during the period of cereal ß-glucan administration. These results suggested that cereal ß-glucan might exert favorable effects on improving intestinal functions and health but the gut-health-promoting effects of oat ß-glucan were better than those of barley ß-glucan.

Hypoglycemic effects and biochemical mechanisms of oat products on streptozotocin-induced diabetic mice.

Oat products are abundant in ß-glucan, which could lower the glycemic index of products or foods. A low glycemic index is beneficial in the control of postprandial glycemia. The study examined the hypoglycemic effects of oat products that had the same percentage of oat ß-glucan and were added into the diet fed to streptozotocin-induced diabetic mice for 6 weeks, and potential mechanisms are discussed here. Oat products significantly decreased fasting blood glucose and glycosylated serum protein (p < 0.05), but the hypoglycemic effect was not more than that of metformin (p > 0.05). Oat products increased glycogen, hormone, and nuclear receptor levels (p < 0.05), decreased free fatty acid content and succinate dehydrogenase activity (p < 0.05), and inhibited pancreatic apoptosis (p < 0.05). The results showed oat products had hypoglycemic effects. Hypoglycemic effects of oat products might be regulating glucose and fat metabolisms, stimulating hormone secretion, activating the nuclear receptor, and protecting organ function.