Advancing Insights into Probiotics during Vegetable Fermentation

Progress in Probiotic Science: Prospects of Functional Probiotic-Based Foods and Beverages

This comprehensive review explores the evolving role of probiotic-based foods and beverages, highlighting their potential as functional and "future foods" that could significantly enhance nutrition, health, and overall well-being. These products are gaining prominence for their benefits in gut health, immune support, and holistic wellness. However, their future success depends on addressing critical safety concerns and navigating administrative complexities. Ensuring that these products "do more good than harm" involves rigorous evaluations of probiotic strains, particularly those sourced from the human gastrointestinal tract. Lactic acid bacteria (LABs) serve as versatile and effective functional starter cultures for the development of probiotic foods and beverages. The review emphasizes the role of LABs as functional starter cultures and the development of precision probiotics in advancing these products. Establishing standardized guidelines and transparent practices is essential, requiring collaboration among regulatory bodies, industry stakeholders, and the scientific community. The review underscores the importance of innovation in developing "friendly bacteria," "super probiotics," precision fermentation, and effective safety assessments. The prospects of functional probiotic-based foods and beverages rely on refining these elements and adapting to emerging scientific advancements. Ultimately, empowering consumers with accurate information, fostering innovation, and maintaining stringent safety standards will shape the future of these products as trusted and beneficial components of a health-conscious society. Probiotic-based foods and beverages, often infused with LABs, a "friendly bacteria," are emerging as "super probiotics" and "future foods" designed to "do more good than harm" for overall health.

Effect of Glycosidase Production by Rhodotorula mucilaginosa on the Release of Flavor Compounds in Fermented White Radish

Fermented vegetables are highly valued by consumers for their distinct flavors and rich nutritional content. Microbial fermentation imparts distinct flavors to these vegetables, with red yeast being a common microorganism involved in the fermentation process. However, studies on the impact of red yeast on flavor development in fermented vegetables remain scarce. This study employed multi-omics to analyze the effect of glycosidase produced by Rhodotorula mucilaginosa on the release of bound flavor compounds in vegetables. The results indicate that the yeast possesses multiple glycosidase-encoding genes, with the activities of α-galactosidase, β-glucosidase, and α-mannosidase being detected. Following the inoculation of yeast into fermented vegetable juice, a significant increase was observed in the expression of the β-glucosidase gene (bglX) and the α-glucosidase maltase gene (malL), alongside an increase in the content of flavor compounds correlated with the enzymatic activity detected. The application of commercial glycosidase to vegetable juice resulted in increased levels of cis-2-pentenol, hyacinthin, geranylacetone, and 1-dodecanol, consistent with findings from yeast-fermented vegetable juice. Thus, Rhodotorula mucilaginosa can secrete glycosidases that hydrolyze and release endogenous bound flavor compounds in vegetables, thereby enhancing the flavor quality of the final product.

Integrating metabolite profiles and macrotranscriptomics to explore the flavor improvement mechanisms of fermented oyster hydrolysates with endogenous microbe (Lactobacillus pentosus) inoculation

The study investigates the impacts of indigenous bacterial strains inoculation specifically L. pentosus, on the flavor characteristics, microbial composition, and metabolite profiles of fermented oyster hydrolysates. This research aimed to elucidate potential mechanisms underlying the reduction of off-flavors in fermented hydrolysates. A total of 46 and 57 volatile compounds were detected by GC-MS and GC-IMS in hydrolysates inoculated with different core microbes, respectively. The 9 key volatile compounds detected by GC-MS analysis. (E, E)-2,4-heptadienal, heptanal, octanal, pentanal, and (E)-2-octenal reduced the off-flavor of the fermented oyster hydrolysate. Meanwhile 1-octen-3-ol, 3-octanone, 4-octanone, and (E, Z)-2,6-nonadienal enhanced the direct contribution of desirable flavors. Variation in 16 amino acids, 10 organic acids and 3 nucleotides were monitored to further understand the metabolic changes affecting flavor quality. Moreover, pyruvate decarboxylase [EC 4.1.1.1], phosphomannanase [EC 3.2.1.109], lipoyl-CoA synthetase [EC 6.3.2.4], and arginine kinase [EC 2.7.3.3] were the main microbiologically active enzymes. An increase in the content of aromatic compounds and a decrease in the content of C6-C9 unsaturated aldehydes through Lys, Phe, Asp, Glu, phosphoenolpyruvate, oleic acid, and linoleic acid metabolism pathways improved the flavor of oyster hydrolysates fermented by L. pentosus. This research provides a theoretical basis for leveraging autochthonous microbial fermentation to systematically improve flavor characteristics in fermented products.

Isolation and Evaluation of Rhizopus arrhizus Strains from Traditional Rice Wine Starters (Jiuqu): Enzyme Activities, Antioxidant Capacity, and Flavour Compounds

Seventy-eight autochthonous strains of Rhizopus arrhizus were isolated from rice wine starter samples across twenty-nine regions in China to evaluate their potential in traditional rice wine fermentation. Strains were assessed for enzyme activity, antioxidant properties, amino acid production, and volatile flavour compounds. Significant variation in enzyme activities was observed, with acidic protease activity ranging from 280 to 1023 U/g, amylase from 557 to 1681 U/g, and esterase from 370 to 2949 U/g. Strains W17 and W42 exhibited the highest enzyme activities and antioxidant capacities, with a total phenolic content of 828 mg/L, total flavonoids of 215 μg/L, and an ABTS scavenging rate of 96.3%. They also produced high levels of glutamic acid (up to 3083 mg/L), enhancing the flavour profile. Histamine levels were low, ranging from 8 to 205 μg/L, ensuring product safety. Analysis of volatile compounds identified 80 substances, including 16 key aroma-active compounds, contributing to a complex flavour profile. These results provide a basis for selecting R. arrhizus strains to optimise rice wine fermentation, addressing market demand for diverse and functional products.

Multifunctional Applications of Lactic Acid Bacteria: Enhancing Safety, Quality, and Nutritional Value in Foods and Fermented Beverages

Lactic Acid Bacteria (LAB) have garnered significant attention in the food and beverage industry for their significant roles in enhancing safety, quality, and nutritional value. As starter cultures, probiotics, and bacteriocin producers, LAB contributes to the production of high-quality foods and beverages that meet the growing consumer demand for minimally processed functional and health-promoting food products. Industrial food processing, especially in the fresh produce and beverage sector, is shifting to the use of more natural bioproducts in food production, prioritizing not only preservation but also the enhancement of functional characteristics in the final product. Starter cultures, essential to this approach, are carefully selected for their robust adaptation to the food environment. These cultures, often combined with probiotics, contribute beyond their basic fermentation roles by improving the safety, nutritional value, and health-promoting properties of foods. Thus, their selection is critical in preserving the integrity, quality, and nutrition of foods, especially in fresh produce and fruits and vegetable beverages, which have a dynamic microbiome. In addition to reducing the risk of foodborne illnesses and spoilage through the metabolites, including bacteriocins they produce, the use of LAB in these products can contribute essential amino acids, lactic acids, and other bioproducts that directly impact food quality. As a result, LAB can significantly alter the organoleptic and nutritional quality of foods while extending their shelf life. This review is aimed at highlighting the diverse applications of LAB in enhancing safety, quality, and nutritional value across a range of food products and fermented beverages, with a specific focus on essential metabolites in fruit and vegetable beverages and their critical contributions as starter cultures, probiotics, and bacteriocin producers.

Physicochemical, Nutritional, and Antioxidant Properties of Traditionally Fermented Thai Vegetables: A Promising Functional Plant-Based Food

Fermented plant-based products were gathered from various regions in Thailand and categorized into 10 types of traditional commercial vegetables. Different vegetable materials and natural fermentation methods influence the diverse physical, chemical, nutritional, and functional attributes of the products. All the traditionally fermented Thai vegetable samples collected showed physicochemical properties associated with the fermentation process, contributing to the nutritional and functional quality of the final products. Achieving consistent research results is challenging due to the intricate nature of food matrices and biochemical processes during fermentation. The roles of microorganisms, especially probiotics, are crucial in delivering health benefits through fermented foods. Traditionally fermented Thai vegetable foods contain high levels of total soluble solids, titratable acidity, and salinity in pickled shallot and ginger as a result of the natural fermentation process and the ingredients used. The research findings were confirmed using a hierarchical cluster analysis (HCA)-derived dendrogram pattern. The nutritional compositions, total phenolic contents, and antioxidant activities varied among the different types of vegetables. The correlations among lipid, protein, fiber, total soluble solid (TSSs), total titratable acidity (TTA), and salinity as potential biomarkers in fermented vegetable products were examined. The results suggest that traditionally fermented Thai vegetable products significantly impacted food research by enhancing the quality and preserving the authenticity of traditionally fermented Thai vegetables.

Effects and mechanisms of sciadonic acid on colonic transit function through regulating 5-HT4/cAMP/PKA/AQP4 signaling pathway in STC model mice

Torreya grandis (T. grandis) oil has been reported to alleviate symptoms of slow transit constipation (STC). However, the impact of sciadonic acid (SA), a distinctive fatty acid found in T. grandis oil, on the pathological progression of STC remains unclear. This study aimed to evaluate the effect of SA on STC and uncover the underlying mechanisms. The STC model was established by feeding Balb/c mice with loperamide. After 2 weeks of intervention, SA significantly improved weight loss and intestinal motility decline induced by STC, along with enhancing plasma indices and reducing colon pathological damage. SA effectively reversed the STC-induced decrease in the 5-HT4/cAMP/PKA/AQP4 signaling pathway genes and expression. Furthermore, 16S rRNA analysis demonstrated that SA mitigated the imbalance of the intestinal microbiota induced by STC, by reducing the ratio of Firmicutes to Bacteroidetes (F/B) and increasing the abundance of beneficial bacteria such as Akkermansia. In conclusion, SA intervention alleviated colonic dysfunction in STC mice. The activation of the SA-mediated 5-HT4/cAMP/PKA/AQP4 signaling pathway may serve as a potential target for STC treatment. These findings suggest that SA holds promise as a treatment option for STC and could potentially be extended to other related gut diseases for further investigation.

Advancements in the impact of human microbiota and probiotics on leukemia

The human gut microbiota is a complex ecosystem that plays a crucial role in promoting the interaction between the body and its environment. It has been increasingly recognized that the gut microbiota has diverse physiological functions. Recent studies have shown a close association between the gut microbiota and the development of certain tumors, including leukemia. Leukemia is a malignant clonal disease characterized by the uncontrolled growth of one or more types of blood cells, which is the most common cancer in children. The imbalance of gut microbiota is linked to the pathological mechanisms of leukemia. Probiotics, which are beneficial microorganisms that help maintain the balance of the host microbiome, play a role in regulating gut microbiota. Probiotics have the potential to assist in the treatment of leukemia and improve the clinical prognosis of leukemia patients. This study reviews the relationship between gut microbiota, probiotics, and the progression of leukemia based on current research. In addition, utilizing zebrafish leukemia models in future studies might reveal the specific mechanisms of their interactions, thereby providing new insights into the clinical treatment of leukemia. In conclusion, further investigation is still needed to fully understand the accurate role of microbes in leukemia.

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.

The Influence of Diet and Its Components on the Development and Prevention of Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is diagnosed annually in nearly a million people worldwide, with approximately half of them being diagnosed at an advanced stage of the disease. Non-infectious risk factors for the development of HCC include an unbalanced lifestyle, including poor dietary choices characterized by a low intake of antioxidants, such as vitamins E and C, selenium, and polyphenols, as well as an excessive consumption of energy and harmful substances. Repeated bad dietary choices that contribute to an unbalanced lifestyle lead to the accumulation of fatty substances in the liver and to it entering an inflammatory state, which, without intervention, results in cirrhosis, the main cause of HCC. This review of the English language literature aims to present the food components that, when included in the daily diet, reduce the risk of developing HCC, as well as identifying foods that may have a carcinogenic effect on liver cells.