Effect of Controlled Microbial Fermentation on Nutritional and Functional Characteristics of Cowpea Bean Flours

Fermentation with Lactic Acid Bacteria for Bean Flour Improvement: Experimental Study and Molecular Modeling as Complementary Tools

Pulses are considered superfoods for the future world due to their properties, but they require processing to reduce antinutritional factors (ANFs) and increase bioactivity. In this study, bean flour (Phaseolus vulgaris L.) was fermented under different conditions (addition of Lactiplantibacillus plantarum CRL 2211 and/or Weissella paramesenteroides CRL 2182, temperature, time and dough yield) to improve its nutri-functional quality. Fermentation for 24 h at 37 °C with the mixed starter increased the lactic acid bacteria (LAB) population, acidity, polyphenol content (TPC) and ANF removal more than spontaneous fermentation. Statistical and rep-PCR analysis showed that fermentation was mainly conducted by Lp. plantarum CRL 2211. Metabolic modeling revealed potential cross-feeding between Lp. plantarum and W. paramesenteroides, while the molecular docking and dynamic simulation of LAB tannases and proteinases involved in ANF removal revealed their chemical affinity to gallocatechin and trypsin inhibitors. Fermentation was better than soaking, germination and cooking for enhancing bean flour properties: it increased the free amino acids content by 50% by releasing glutamine, glutamic acid, arginine, leucine and lysine and modified TPC by increasing gallic acid and decreasing caffeic, ferulic and vanillic acids and quercetin-3-glucoside. The combination of experimental and simulation data may help us to understand fermentation processes and to design products with desirable features.

Fermented Grapevine Leaves: Potential Preserving Agent in Yogurt

In this study, we monitored the fermentative process of Vitis vinifera L. leaves (grapevine), spontaneously or promoted by Saccharomyces cerevisiae, in both solid and liquid media. We also aimed to evaluate the effect on the bioactivity and shelf life of yogurt incorporating fermented and non-fermented grapevine leaves compared to yogurt produced with the preservative potassium sorbate. The results revealed that fermented grapevine leaf extracts increased their bioactive compounds and antioxidant activity, particularly in fermentations in a solid medium. In yogurt samples with incorporation extract from solid spontaneous fermentation and extract from solid yeast fermentation, even in small quantities, they exhibited higher levels of total phenols (1.94 and 2.16 mg GAE/g of yogurt, respectively) and antioxidant activity (5.30 and 5.77 mg TroloxE/g of yogurt; and 1.33 and 1.34 mg Fe(II)E/g of yogurt, respectively) compared to control yogurt (1.44 mg GAE/g of yogurt, 4.00 mg TroloxE/g of yogurt, and 1.01 mg Fe(II)E/g of yogurt). Additionally, yogurts supplemented with fermented grapevine leaves demonstrated the potential to inhibit microbial growth without impairing the multiplication of lactic acid bacteria.

Complementary nutritional and health promoting constituents in germinated and probiotic fermented flours from cowpea, sorghum and orange fleshed sweet potato

Germination and fermentation are age-long food processes that beneficially improve food composition. Biological modulation by germination and probiotic fermentation of cowpea, sorghum, and orange-fleshed sweet potato (OFSP) and subsequent effects on the physicochemical (pH and total titratable acidity), nutritional, antinutritional factors and health-promoting constituents/properties (insoluble dietary fibres, total flavonoid and phenolic contents (TFC and TPC) and antioxidant capacity) of the derived flours were investigated in this study. The quantification of targeted compounds (organic acids and phenolic compounds) on an ultra-high performance liquid chromatography (UHPLC) system was also done. The whole cowpea and sorghum were germinated at 35 °C for 48 h. On the other hand, the milled whole grains and beans and OFSP were fermented using probiotic mesophilic culture at 35 °C for 48 h. Among the resultant bioprocessed flours, fermented sorghum and sweet potato (FSF and FSP) showed mild acidity, increased TPC, and improved ferric ion-reducing antioxidant power. While FSF had better slowly digestible and resistant starches and the lowest oxalate content, FSP indicated better hemicellulose, lowest fat, highest luteolin, caffeic and vanillic acids. Germinated cowpea flour exhibited reduced tannin, better lactic acid, the highest crude fibre, cellulose, lignin, protein, fumaric, L-ascorbic, trans-ferulic and sinapic acids. The comparable and complementary variations suggest the considerable influence of the substrate types, followed by the specific processing-based hydrolysis and biochemical transitions. Thus, compositing the bioprocessed flours based on the unique constituent features for developing functional products from climate-smart edibles may partly be the driver to ameliorating linked risk factors of cardiometabolic diseases.

Steamed Multigrain Bread Prepared from Dough Fermented with Lactic Acid Bacteria and Its Effect on Type 2 Diabetes

Multigrain products can prevent the occurrence of chronic noninfectious diseases such as hyperglycemia and hyperlipidemia. In this study, multigrain dough fermented by lactic acid bacteria (LAB) was used for the preparation of good-quality steamed multigrain bread, and its effects on type 2 diabetes were investigated. The results showed that the multigrain dough fermented with LAB significantly enhanced the specific volume, texture, and nutritional value of the steamed bread. The steamed multigrain bread had a low glycemic index and was found to increase liver glycogen and reduce triglyceride and insulin levels, while improving oral glucose tolerance and blood lipid levels in diabetic mice. The steamed multigrain bread made from dough fermented with LAB had comparable effects on type 2 diabetes to steamed multigrain bread prepared from dough fermented without LAB. In conclusion, multigrain dough fermentation with LAB improved the quality of the steamed bread while preserving its original efficacy. These findings provide a novel approach to the production of functional commercial foods.

Comparison of the Chemical Properties of Vinegar Obtained via One-Step Fermentation and Sequential Fermentation from Dragon Fruit and Pineapple

Dragon fruit has many potential health benefits. It is inexpensive and widely cultivated in Thailand. The addition of dragon fruit to pineapple vinegar may help enhance the total phenolic compounds and antioxidant activity. This study aimed to study and compare the chemical characteristics of vinegar produced via one-step fermentation of a mixture of pineapple and dragon fruit juice from Krok Phra District of Thailand using Saccharomyces cerevisiae var. burgundy with that obtained using sequential fermentation using Saccharomyces cerevisiae var. burgundy and Acetobacter aceti. When the two fermentation methods were compared on day 20, the maximum acetic acid concentration obtained from sequential fermentation was 5.79 ± 0.25%, which was higher than that obtained in one-step fermentation (1.93%). The total phenolic compound content in the mixed fruit vinegar obtained from sequential fermentation and one-step fermentation was 228.01 and 242.2 mg/L gallic acid equivalents, respectively. The antioxidant content of the products obtained in sequential and one-step fermentations was 187.91 mg/L GAE and 209.33 µg/g of Trolox equivalents, respectively, which was consistent with the total phenolic compound content. This indicated that the acetic acid content in the mixed pineapple and dragon fruit juice vinegar obtained using sequential fermentation was higher than that obtained using one-step fermentation although its total phenolic content and the antioxidant activities were slightly lower. These observations will be useful for improving vinegar fermentation in the area.

Fermented Biomass of Arthrospira platensis as a Potential Food Ingredient

Lactic acid fermentation (LAF) is known to improve nutritional properties and functionality and to extend the shelf life of foods. We studied the LAF of Arthrospira platensis as the sole substrate using Lactobacillus plantarum as the starter culture. Fermented (FB) and non-fermented broth (NFB) were analysed by means of pH, lactic acid bacteria (LAB) count, lactic acid concentration, microbiological safety, and nutritional composition. Additionally, water and ethanol extracts were prepared on which total phenolic content, DPPH radical scavenging activity, and cellular antioxidant activity were determined. The maximum increase in LAB count and lactic acid concentration and drop in pH was observed in the first 24 h of fermentation. Total phenolic content and DPPH radical scavinging activity of ethanol extracts increased after fermentation compared with NFB. Ethanol extracts of FB have been shown as a potential source of antioxidants, which efficiently lowered oxidation level in the cells of yeast Saccharomyces cerevisiae, as well as the oxidative damage of lipids. Additionally, the level of non-protein nitrogen increased, indicating higher protein bioavailability, and fat content decreased in comparison with NFB. No presence of pathogenic bacteria and low pH indicate enhancement of FB microbiological stability. Therefore, inclusion of fermented A. platensis into food products could lead to added-value foods based on microalgae.

Development and Optimization of Djulis Sourdough Bread Fermented by Lactic Acid Bacteria for Antioxidant Capacity

This study developed a nutritionally valuable product with bioactive activity that improves the quality of bread. Djulis (Chenopodium formosanum), a native plant of Taiwan, was fermented using 23 different lactic acid bacteria strains. Lactobacillus casei BCRC10697 was identified as the ideal strain for fermentation, as it lowered the pH value of samples to 4.6 and demonstrated proteolysis ability 1.88 times higher than controls after 24 h of fermentation. Response surface methodology was adopted to optimize the djulis fermentation conditions for trolox equivalent antioxidant capacity (TEAC). The optimal conditions were a temperature of 33.5 °C, fructose content of 7.7%, and dough yield of 332.8, which yielded a TEAC at 6.82 mmol/kg. A 63% increase in TEAC and 20% increase in DPPH were observed when compared with unfermented djulis. Subsequently, the fermented djulis was used in different proportions as a substitute for wheat flour to make bread. The total phenolic and flavonoid compounds were 4.23 mg GAE/g and 3.46 mg QE/g, marking respective increases of 18% and 40% when the djulis was added. Texture analysis revealed that adding djulis increased the hardness and chewiness of sourdough breads. It also extended their shelf life by approximately 2 days. Thus, adding djulis to sourdough can enhance the functionality of breads and may provide a potential basis for developing djulis-based functional food.

Effect of Auricularia auricula fermentation broth on the liver and stomach of mice with acute alcoholism

In this paper, the protective effect of Auricularia auricula (A. auricula) fermentation broth on the liver and stomach of mice with acute alcoholism was studied. The A. auricula fermentation broth was prepared by adding Bacillus subtilis, lactic acid bacteria, and Saccharomyces cerevisiae to A. auricula solution. The changes of physical and chemical indexes during the fermentation of A. auricula were monitored, and the results showed the content of polysaccharides and protein in the two kinds of fermentation broth after the fermentation was completed. Furthermore, the characteristic structures of active substances such as proteins, polysaccharides and phenolics were found in the A. auricula fermentation by structural analysis. Antioxidant activity test results showed that the A. auricula fermentation broth had a strong ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals. Cell experiments showed that the fermentation broth of A. auricula could significantly enhance the activity of NRK cells and protect NRK cells from H₂O₂ damage. Animal experiments showed that the A. auricula fermentation broth had protective effects on the liver and stomach of mice with acute alcoholism, and significantly reduced the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC) and triglycerides (TG) in serum. These results indicated that the A. auricula fermentation broth had protective effects on the liver and stomach of mice with acute alcoholism, and could be used as a potential functional food to prevent liver and stomach damage caused by acute alcoholism.