Fermented soymilk and soy and cow milk mixture, supplemented with orange peel fiber or Tremella flava fermented powder as prebiotics for high exopolysaccharide-producing Lactobacillus pentosus SLC 13

Partial Characterization and Immunomodulatory Effects of Exopolysaccharides from Streptococcus thermophilus SBC8781 during Soy Milk and Cow Milk Fermentation

The immunomodulatory properties of exopolysaccharides (EPSs) produced by Streptococcus thermophilus have not been explored in depth. In addition, there are no comparative studies of the functional properties of EPSs produced by streptococci in different food matrices. In this work, EPSs from S. thermophilus SBC8781 were isolated after soy milk (EPS-s) or cow milk (EPS-m) fermentation, identified, and characterized in their abilities to modulate immunity in porcine intestinal epithelial cells. Fresh soy milk and cow milk were inoculated with S. thermophilus SBC8781 (7 log CFU/mL) and incubated at 37 °C for 24 h. The extraction of EPSs was performed by the ethanol precipitation method. Analytical techniques, including NMR, UV-vis spectroscopy, and chromatography, identified and characterized both biopolymer samples as polysaccharides with high purity levels and similar Mw. EPS-s and EPS-m had heteropolysaccharide structures formed by galactose, glucose, rhamnose, ribose, and mannose, although with different monomer proportions. On the other hand, EPS-s had higher quantities of acidic polymer than EPS-m. The biopolymer production of the SBC8781 strain from the vegetable culture broth was 200-240 mg/L, which was higher than that produced in milk, which reached concentrations of 50-70 mg/L. For immunomodulatory assays, intestinal epithelial cells were stimulated with 100 µg/mL of EPS-s or EPS-m for 48 h and then stimulated with the Toll-like receptor 3 agonist poly(I:C). EPS-s significantly reduced the expression of IL-6, IFN-β, IL-8, and MCP-1 and increased the negative regulator A20 in intestinal epithelial cells. Similarly, EPS-m induced a significant reduction of IL-6 and IL-8 expressions, but its effect was less remarkable than that caused by EPS-s. Results indicate that the structure and the immunomodulatory activity of EPSs produced by the SBC8781 strain vary according to the fermentation substrate. Soy milk fermented with S. thermophilus SBC8781 could be a new immunomodulatory functional food, which should be further evaluated in preclinical trials.

The Quality and Flavor Changes of Different Soymilk and Milk Mixtures Fermented Products during Storage

This study explored the effects of two mixed fermentation methods: one was fermenting a soymilk and milk mixture by a lactic acid bacteria fermenting agent at 0.1 g/kg and 42 °C until the acidity was 70 °T, which was set as the MFSM method, and the other was fermenting milk alone by lactic acid bacteria at 42 °C for 12 h, placing it in a 4 °C refrigerator after acidification for 24 h and then mixing it with soymilk at a 1.5:1 ratio and storing the mixture at 4 °C, which was set as the SMFSM method. The quality and flavor of the soymilk and milk mixture products were investigated on the 0th, 15th and 30th days during storage. The changes in acidity, pH, number of viable bacteria, viscosity, water-holding capacity, texture, rheological properties, sensory quality and volatile flavors were determined. The results showed that compared with the fermented soymilk and milk mixtures under the MFSM method, the samples of fermented soymilk and milk mixtures under the SMFSM method showed a significant slowdown of acidification during storage, so that the sensory quality of the products was almost unaffected by acidity on the 30th day of storage. Furthermore, the number of viable bacteria was greater than 7 log cfu/mL. The water holding capacity did not change significantly until the 30th day. There was also no whey precipitation, indicating good stability. The samples in SMFSM mode had higher aromatic contents and beans during storage than the fermented soymilk and milk mixtures in MFSM mode. The rich variety of volatile flavors and the presence of acetoin, 2-heptanone, and (E,E)-3,5-octadien-2-one throughout the storage period allowed the samples to maintain a good sensory flavor during storage.

Nutritional and in vitro antioxidant activity analyses of formulated soymilk dessert

Soymilk (SM) is nutritionally nearly equal to milk from cows and is free of cholesterol, gluten, and lactose. This study’s objective was to formulate a cholesterol-free soymilk dessert (SOD) and compare it’s to commercial desserts (CODs). Results indicated that the CODs contain substantial amounts of cholesterol while SOD does not. Soymilk dessert has more protein, and vitamin E than CODs, but less fat and calcium. In addition, the result also highlighted that SOD has higher number of amino acids compared to CODs. The total antioxidant, flavonoids and phenolics content of SOD were significantly higher than CODs. Furthermore, the in vitro antioxidant activity of SOD and CODs by DPPH and ABTS methods revealed that the IC₅₀ of SODs significantly (p < 0.001) lower than CODs, and lower IC₅₀ indicated the higher free radical scavenging power of SODs than CODs. These findings indicated that this non-dairy SOD may provide beneficial protein, as well as minerals, and antioxidants to support the body’s various physiological functions.

Recent Advances in the Production of Exopolysaccharide (EPS) from Lactobacillus spp. and Its Application in the Food Industry: A Review

Exopolysaccharide (EPS) show remarkable properties in various food applications. In this review paper, EPS composition, structural characterization, biosynthesis pathways, and recent advancements in the context of application of EPS-producing Lactobacillus spp. in different food industries are discussed. Various chemical and physical properties of Lactobacillus EPS, such as the structural, rheological, and shelf-life enhancement of different food products, are mentioned. Moreover, EPSs play a characteristic role in starter culture techniques, yogurt production, immunomodulation, and potential prebiotics. It has been seen that the wastes of fermented and non-fermented products are used as biological food for EPS extraction. The main capabilities of probiotics are the use of EPS for technological properties such as texture and flavor enhancement, juiciness, and water holding capacities of specific food products. For these reasons, EPSs are used in functional and fermented food products to enhance the healthy activity of the human digestive system as well as for the benefit of the food industry to lower product damage and increase consumer demand. Additionally, some pseudocereals such as amaranth and quinoa that produce EPS also play an important role in improving the organoleptic properties of food-grade products. In conclusion, more attention should be given to sustainable extraction techniques of LAB EPS to enhance structural and functional use in the developmental process of food products to meet consumer preferences.

Microbial Exopolysaccharides in Traditional Mexican Fermented Beverages

Exopolysaccharides (EPS) are biopolymers produced by many microorganisms, including some species of the genus Acetobacter, Bacillus, Fructobacillus, Leuconostoc, Lactobacillus, Lactiplantibacillus, Pediococcus, Pichia, Rhodotorula, Saccharomycodes, Schizosaccharomyces, and Sphingomonas, which have been reported in the microbiota of traditional fermented beverages. Dextran, levan, glucan, gellan, and cellulose, among others, are EPS produced by these genera. Extracellular biopolymers are responsible for contributing to specific characteristics to fermented products, such as modifying their organoleptic properties or contributing to biological activities. However, EPS can be easily found in the dairy industry, where they affect rheological properties in products such as yogurt or cheese, among others. Over the years, LAB has been recognized as good starter strains in spontaneous fermentation, as they can contribute beneficial properties to the final product in conjunction with yeasts. To the best our knowledge, several articles have reported that the EPS produced by LAB and yeasts possess many both biological and technological properties that can be influenced by many factors in which fermentation occurs. Therefore, this review presents traditional Mexican fermented beverages (tavern, tuba, sotol, and aguamiel) and relates them to the microbial EPS, which affect biological and techno-functional activities.

The Inoculation of Probiotics In Vivo Is a Challenge: Strategies to Improve Their Survival, to Avoid Unpleasant Changes, or to Enhance Their Performances in Beverages

The inoculation of probiotics in beverages (probiotication) requires special technologies, as probiotic microorganisms can experience stress during food processing (acid, cold, drying, starvation, oxidative, and osmotic stresses) and gastrointestinal transit. Survival to harsh conditions is an essential prerequisite for probiotic bacteria before reaching the target site where they can exert their health promoting effects, but several probiotics show a poor resistance to technological processes, limiting their use to a restricted number of food products. Therefore, this paper offers a short overview of the ways to improve bacterial resistance: by inducing a phenotypic modification (adaptation) or by surrounding bacteria through a physical protection (microencapsulation). A second topic briefly addressed is genetic manipulation, while the last section addresses the control of metabolism by attenuation through physical treatments to design new kinds of food.

Prebiotic potential of hemp blended drinks fermented by probiotics

Plant-based drinks as substitute for milk consumption are raising striking interest in the food industry. Soy and rice drinks are the most studied and successful milk substitutes. An untapped source is hemp seed, which is a powerhouse of nutrients bearing bioactive compounds, but the production of derived drink is limited. The present work is about introducing new formulations of commercial hemp seed-derived drink to be fermented with probiotics (Lactobacillus fermentum, Lb. plantarum and Bifidobacterium bifidum). In this work for the first time the prebiotic activity of different hemp seed drinks was assessed by cultural and quantitative PCR methods. In addition, to better describe the prebiotic potential, VOCs alkenes and volatile organic acids were characterized by a metabolomic approach via GC-MS SPME. Obtained results showed that the hemp seed drinks had strong prebiotic activity, ability to support probiotics growth and to increase the content of some bioactive compounds. These outputs are in part due to the presence of different terpenes that inhibit the growth of enteropathogens and to high levels of acetate, propionate and butyrate produced during fermentation that support the growth of probiotics. Although the health potential of hemp seed is well known, derived drinks are hitherto scarcely transformed and distributed, thus this work could provide some basics to produce prebiotic and probiotic fermented hemp seed drinks.