Effect of Lactobacillus rhamnosus on Physicochemical Properties of Fermented Plant-Based Raw Materials

Potential Health Benefits of Fermented Vegetables with Additions of Lacticaseibacillus rhamnosus GG and Polyphenol Vitexin Based on Their Antioxidant Properties and Prohealth Profiles

Fermented vegetables are increasingly being recognized as an important dietary component, particularly of plant-based diets, to achieve a sustainable healthy gut because of their microbial diversity and antioxidant properties. However, the functional relevance of fermented vegetables varies based on the raw ingredients used and nutrient supplementation. Therefore, in the present study, we investigated the microbial diversity and antioxidant activity of three formulas of fermented vegetables (standard, supplemented with Lacticaseibacillus rhamnosus GG, and supplemented with polyphenol vitexin) at days 0 and 15. The bacterial community profiles were determined through 16S rRNA sequencing analysis, and antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl and by measuring the oxygen radical absorbance capacity, the ferric reducing ability of plasma, and the total phenolic content. The results confirm microbial diversity in the taxonomic composition of the different formulas of fermented vegetables, with different bacteria predominating, particularly lactic acid bacteria including the genera Weissella, Pedicocccus, Leuconostoc, and Lactobacillus. Spearman's correlation analysis showed significant differences in the specific bacteria present in the different formulas of fermented vegetables that conferred antioxidant capacity. Our findings show that supplementation with L. rhamnosus GG and polyphenol vitexin may effectively enhance the functional relevance of foods by promoting cellular protection against oxidative stress.

A glimpse into plant-based fermented products alternative to animal based products: Formulation, processing, health benefits

Fermented foods and beverages are increasingly being included in the diets of people around the world, as they significantly contribute to flavor and interest in nutrition and food consumption. Plant sources, like cereals and pulses, are employed to produce vegan fermented foods that are either commercially available or the subject of ongoing scientific investigation. In addition, the inclination towards nutritionally healthy, natural, and clean-label products amongst consumers has encouraged the development of vegan fermented products alternative to animal-based products for industrial-scale production. However, as the vegan diet is more restrictive than the vegetarian diet, manufacturing food products for vegans presents a significant problem due to the limited availability of many raw materials. So further research is required on this topic. This paper aims to review the formulation, quality, microbial resources, health benefits, and safety of foods that can be categorised as vegan fermented foods and beverages.

Impact of a Starch Hydrolysate on the Production of Exopolysaccharides in a Fermented Plant-Based Dessert Formulation

Plant-based desserts are becoming increasingly popular with and appreciated by consumers. However, they are limited by the choice of ingredients, which are often expensive and unstable with a random texture. Therefore, the aim of the research is to propose a new product that offers an advantageous texture and flavour in a fermented dessert based on a flour mix supplemented with an enzymatic hydrolysate. This study involved the development of two processes: (i) an enzymatic hydrolysis of oat flour and (ii) a fermentation of a flour mixture (oat, chickpea, and coconut) by lactic acid bacteria (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus). The result of the oat flour hydrolysate shows a significant decrease in starch after 60 min of reaction, followed by an increase in sugar content. During 23 days of storage at 4 °C, the formulations used showed post-acidification, water retention capacity decrease, and hardness increase related to the hydrolysate rate (p < 0.05). All formulations allowed the viability of lactic bacteria (over 5 log10 CFU/mL) and verified their ability to produce exopolysaccharides (0.23-0.73 g/100 g). The prototyping of such a product represents a key step in meeting the growing demand for plant-based alternatives, with qualitative sensory characteristics without additives.

Antioxidative Properties of Fermented Soymilk Using Lactiplantibacillus plantarum LP95

In recent times, there has been a growing consumer interest in replacing animal foods with alternative plant-based products. Starting from this assumption, for its functional properties, soymilk fermented with lactic acid bacteria is gaining an important position in the food industry. In the present study, soymilk was fermented with Lactiplantibacillus plantarum LP95 at 37 °C, without the use of stabilizers as well as thickeners and acidity regulators. We evaluated the antioxidant capacity of fermented soymilk along with its enrichment in aglycone isoflavones. The conversion of isoflavone glucosides to aglycones (genistein, glycitein, and daidzein) was analyzed together with antioxidant activity (ABTS) measurements, lipid peroxidation measurements obtained by a thiobarbituric acid reactive substance (TBARS) assay, and apparent viscosity measurements. From these investigations, soymilk fermentation using Lp. plantarum LP95 as a starter significantly increased isoflavones' transformation to their aglycone forms. The content of daidzein, glycitein, and genistein increased after 24 h of fermentation, reaching levels of 48.45 ± 1.30, 5.10 ± 0.16, and 56.35 ± 1.02 μmol/100 g of dry weight, respectively. Furthermore, the antioxidant activity increased after 6 h with a reduction in MDA (malondialdehyde). The apparent viscosity was found to increase after 24 h of fermentation, while it slightly decreased, starting from 21 days of storage. Based on this evidence, Lp. plantarum LP95 appears to be a promising candidate as a starter for fermented soymilk production.

Applicable Strains, Processing Techniques and Health Benefits of Fermented Oat Beverages: A Review

Based on the high nutrients of oat and the demand of health-conscious consumers for value-added and functional foods, fermented oat beverages have great market prospects. This review summarizes the applicable strains, processing techniques and health benefits of fermented oat beverages. Firstly, the fermentation characteristics and conditions of the applicable strains are systematically described. Secondly, the advantages of pre-treatment processes such as enzymatic hydrolysis, germination, milling and drying are summarized. Furthermore, fermented oat beverages can increase the nutrient content and reduce the content of anti-nutritional factors, thereby reducing some risk factors related to many diseases such as diabetes, high cholesterol and high blood pressure. This paper discusses the current research status of fermented oat beverages, which has academic significance for researchers interested in the application potential of oat. Future studies on fermenting oat beverages can focus on the development of special compound fermentation agents and the richness of their taste.

Deciphering Microbial Diversity and Functional Codes of Traditional Fermented Whole Grain Tianpei from Typical Regions of China

Whole grains are a crucial part of healthy and sustainable diets, attracting great attention. Tianpei is a popular traditional fermented whole grain food and beverage from China. It is suitable for all ages with lots of health benefits. However, its microflora and their functions, relations between microbial taxa and functions with Tianpei properties, were still little informed, limiting the fermentation optimization and quality improvement. In this study, the characteristics and distribution of the microbial flora taxa and their functions of the fermented whole grain Tianpei from typical regions of China were mainly deciphered through metagenomic methods. Phyla Mucoromycota, Firmicutes, Ascomycota, and Proteobacteria were the most abundant. Rhizopus, Limosilactobacillus, and Lactobacillus were the most abundant genera. Microbial COG functions carbohydrate transport and metabolism (mainly including fructose, galactose, glucose, L-arabinose, and mannose) and amino acid transport and metabolism (mainly including arginine, asparagine, glutamine, and glycine) kept a high abundance. PCA (Principal Component Analysis) illustrated that the microbial community and their functions of every Tianpei sample clustered individually based on the analysis, NR, related with the factors of raw material and sources. The microbial taxa, microbial functions, and the Tianpei properties were significantly correlated. Rhizopus, Limosilactobacillus, and Lactobacillus contributed most COG functions in Tianpei samples. Analysis of quorum sensing, pfam, secretion protein, probio, and cytochromes P450 were also annotated and found among Tianpei microbial communities. A sum of 105 probiotics were classified, mainly belonging to Lactobacillus, Leuconostoc, Acetobacter, Bacillus, Bifidobacterium, Pediococcus, etc. Tianpei samples made in the library with the most abundant and functional microbial key taxa strains—Rhizophus oryzae, Lactobacillus plantarum, and Limosilactobacillus fermentum—showed rich nutrient chemicals. The results indicate that microbial taxa and their functions could determine Tianpei properties. Thus, the quality /nutrients, flavor, and industrial production of Tianpei could be further investigated, promoted, and improved in the future based on the characteristics of these microbial taxa and their functions, such as the regulations of the main carbohydrate and AA. The study will also lay a foundation for the fermentative characteristics and condition technology of fermented whole grain food.

Integrated Microbiomic and Metabolomic Dynamics of Fermented Corn and Soybean By-Product Mixed Substrate

Microbes and their metabolites produced in fermented food have been considered as critical contributors to the quality of the final products, but the comprehensive understanding of the microbiomic and metabolomic dynamics in plant-based food during solid-state fermentation remains unclear. Here, the probiotics of Bacillus subtilis and Enterococcus faecalis were inoculated into corn and defatted soybean to achieve the two-stage solid-state fermentation. A 16S sequencing and liquid chromatography–tandem mass spectrometry were applied to investigate the dynamics of microbiota, metabolites, and their integrated correlations during fermentation. The results showed that the predominant bacteria changed from Streptophyta and Rickettsiales at 0 h to Bacillus and Pseudomonas in aerobic stage and then to Bacillus, Enterococcus, and Pseudomonas in anaerobic stage. In total, 229 notably different metabolites were identified at different fermentation times, and protein degradation, amino acid synthesis, and carbohydrate metabolism were the main metabolic pathways during the fermentation. Notably, phenylalanine metabolism was the most important metabolic pathway in the fermentation process. Further analysis of the correlations among the microbiota, metabolites, and physicochemical characteristics indicated that Bacillus spp. was significantly correlated with amino acids and carbohydrate metabolism in aerobic stage, and Enterococcus spp. was remarkably associated with amino acids metabolism and lactic acid production in the anaerobic stage. The present study provides new insights into the dynamic changes in the metabolism underlying the metabolic and microbial profiles at different fermentation stages, and are expected to be useful for future studies on the quality of fermented plant-based food.

Plant and Dairy-Based Yogurts: A Comparison of Consumer Sensory Acceptability Linked to Textural Analysis

Yogurt, readily available in plant and dairy-based formulations, is widely consumed and linked with health benefits. This research is aimed to understand the sensory and textural spectrum of commercially available dairy and plant-based yogurts. In a preliminary study, qualitative focus group discussions (4 groups; n = 32) were used to determine perceptions of 28 dairy and plant-based yogurts, identifying positive consumer perceptions of plant-based yogurts. A smaller subset of five spoonable and one drinkable yogurts—(Reference, Soy, Coconut, Cookies, Berry, and Drinkable) was subsequently selected for rheological and structural measurements, showing wide variations in the microstructure and rheology of selected yogurt samples. A quantitative blind sensory tasting (n = 117) showed varying yogurt acceptability, with Berry being the least-liked and Cookies being the most-liked yogurt, in terms of overall liking. The multi-factor analysis confirmed that compositional and textural elements, including protein content, gel firmness, and consistency coefficient, displayed a positive relationship with overall liking. In contrast, fat, sugar, and calories were negatively correlated to the overall liking. This research showed that texture and other compositional factors are significant determinants of the consumer acceptability of yogurt products and are essential properties to consider in product development.

Development of Probiotic Almond Beverage Using Lacticaseibacillus rhamnosus GR-1 Fortified with Short-Chain and Long-Chain Inulin Fibre

Plant-based beverages are growing in popularity due to the rise of vegetarianism and other health trends. A probiotic almond beverage that combines the properties of almonds, inulin, and Lacticaseibacillusrhamnosus GR-1 may meet the demand for a non-dairy health-promoting food. The purpose of this study was to investigate the viability of L. rhamnosus GR-1 and pH in five fermented almond beverage samples, supplemented with either 2% or 5% (w/v) short-chain or long-chain inulin over 9 h of fermentation and 30 days of refrigerated storage. All almond beverage samples achieved a mean viable count of at least 107 CFU/mL during 9h of fermentation and 30 days of refrigerated storage. The probiotic almond beverage supplemented with 2% (w/v) short-chain inulin had a significantly higher mean microbial count (p = 0.048) and lower pH (p < 0.001) throughout fermentation, while the control and the long-chain inulin treatments had the lowest viable counts and acidity, respectively. This study shows that the addition of short-chain and long-chain inulin had no adverse effects on the viability of L. rhamnosus GR-1. Therefore, the probiotic almond beverage has the potential to be a valid alternative to dairy-based probiotic products.