New technology to overcome defects in production of fermented plant products- a review

Microbial succession and organic acid metabolism during spontaneous calamondin fermentation: The vital role of Pichia

Calamondin (Citrus microcarpa) is rich in bioactive components, indicating potential for fermented calamondin fruit (FCF) development with improved flavor and bioactivity. However, reports on this are limited. This study systematically analyzed changes in physicochemical properties, phenolic/flavor compounds, enzyme inhibition rates, and microbial community structure during FCF spontaneous fermentation. Results indicated significant changes in organic acid profiles during FCF spontaneous fermentation. The inhibition rate of digestion-related enzymes increased, correlating with phenolic compound composition changes. Additionally, the fermentation improved the flavor profile of FCF, including isoamyl acetate and ethyl acetate formation. The microbial community revealed succession patterns with Acetobacter and Pichia as core genera. Variations in organic acids influenced fungal community succession, particularly Pichia. Additionally, a Pichia terricola strain (QJJY1) was isolated; genomic analysis linked it to carbohydrate and amino acid metabolism. Simulated fermentation demonstrated P. terricola QJJY1's role in regulating organic acid profiles, shedding light on its impact on microbial and metabolite profiles during FCF fermentation. This study offers insights into the high-value utilization of calamondin resources and development of new fermented products.

Analysis of the quality and bacterial composition of spicy cabbage between Liaoning and Yanbian in northeastern China based on flavoromics and amplicon sequencing

BACKGROUND

Chinese spicy cabbage (CSC) is a famous traditional fermented vegetable widely consumed in northeast China. However, the differences in characteristics between Liaoning spicy cabbage (LNSC) and Yanbian spicy cabbage (YBSC), as well as the correlation between flavor attributes and microbiota remain unclear. This study clearly delineated the characteristics and correlations of ingredients, aroma characteristics and microbial communities between LNSC and YBSC.

RESULTS

Metabolomic analysis revealed distinct compositional differences in both volatile and non-volatile metabolites between LNSC and YBSC. Through relative odor activity value analysis, 17 and 14 key flavor compounds were identified as characteristic components in LNSC and YBSC, respectively. Amplicon sequencing demonstrated significant regional variations in the bacterial community structure of CSC. Spearman correlation analysis demonstrated strong correlations between 20 bacteria and 11 free amino acids, 22 volatile flavor compounds.

CONCLUSION

This study systematically compared the quality characteristics between LNSC and YBSC, providing fundamental data for the evaluation of spicy cabbage and fermented food products. © 2025 Society of Chemical Industry.

Screening of strains from pickles and evaluation of characteristics of different methods of fast and low salt fermented mustard leaves (Brassica juncea var. multiceps)

The aim of this study was to isolate strains with excellent fermentation performance from pickles, thus enhancing the quality of rapid, low-salt fermented mustard leaves (Brassica juncea var. multiceps) through process optimization and inoculation fermentation. A high-throughput screening method for acid-producing strains was developed, significantly improving screening efficiency. Lactiplantibacillus plantarum CS8 and Saccharomyces cerevisiae CX1, were selected for their superior fermentation performance and used in subsequent fermentation. Four fermentation methods (spontaneous fermentation, optimized spontaneous fermentation, co-fermentation, and two-phase fermentation) were compared for fermenting fresh mustard leaves at 30 °C for 5 days. Compared to spontaneous fermentation, the other methods resulted in lower pH, higher acid production, and reduced nitrite content, thereby enhancing food safety. Significant variations in metabolites (volatiles, organic acids, and free amino acids) were observed among the groups, with the two-phase fermentation method showing the most favorable changes. Sensory evaluation and microbial community analysis further indicated that the two-phase fermentation achieved higher scores for flavor, taste and overall acceptability, while also shortening the fermentation period and improving both flavor and safety. Therefore, inoculation with these two strains using the two-phase fermentation method can efficiently produce high-quality pickle products in a short time. This research contributes to the industrial production of fermented vegetables, enhancing both pickle quality and economic benefits.

Toxicity of formaldehyde, and its role in the formation of harmful and aromatic compounds during food processing

Formaldehyde is a highly reactive compound known to pose several health risks, including carcinogenic, neurotoxic, reproductive, allergic, immunological, genetic, and respiratory toxicity. While its free concentration in processed foods is typically low even it can be formed through various biochemical and chemical pathways in foods. This study aims to investigate the fate of formaldehyde in food processing from two key perspectives: (1) its role in the formation of other harmful compounds, such as heterocyclic aromatic amines, methylimidazole, advanced glycation end-products, and N-nitrosamines, and (2) its potential to contribute to the generation of aromatic compounds, including oxygen-, sulfur-, and nitrogen-containing heterocyclic aromas. This review provides insights that may help food scientists develop strategies to mitigate formaldehyde's harmful effects while potentially harnessing its role in producing beneficial aromatic compounds.

Innovative enhancement of flavor profiles and functional metabolites composition in Pandanus amaryllifolius through lactic acid bacteria fermentation

Pandanus amaryllifolius, known as Pandan, serves as a coloring agent and spice in food. The effects of lactic acid bacteria (LAB) on Pandan are underexplored. This study aimed to investigate changes in physicochemical properties, antioxidant activity, volatile compounds and metabolites of Pandan fermented with Lactobacillus acidophilus, Levilactobacillus brevis and Lacticaseibacillus rhamnosus. Fermented Pandan showed increased total phenol (13 %-21 %) and flavonoid (33 %-53 %) content. Pandan fermented with L. rhamnosus exhibited significantly higher antioxidant activity, followed by those fermented with L. brevis and L. acidophilus. Key components like naringenin and volatile compounds such as α-ionone significantly increased after fermentation, with the production of new compounds, including damascenone and linalool. These compounds enhance the flavor and functional properties of fermented Pandan. This research lays a foundation for developing novel LAB-fermented Pandan products.

Chloroform Extract from Fermented Viola mandshurica Regulates LPS-Induced Inflammation Response in RAW 264.7 Cells by Inhibiting iNOS and COX-2

Inflammatory is a crucial part of the immune system of body protect it from harmful invaders, such as bacteria, viruses, and other foreign substances. In this study, the effects of chloroform extract of fermented Viola mandshurica (CEFV) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages were investigated. The CEFV significantly inhibited NO production and reduced the expression of inducible nitric oxide synthase (iNOS) at both protein and mRNA levels in a dose-dependent manner. Also, CEFV decreased PGE2 production, suppressed COX-2 expression, and inhibited the activation of the ERK and JNK pathways but not the p38 pathway. Taken together, CEFV suppressed NF-κB activation, which is a key regulator in the inflammatory response. The main phenolic compounds identified in CEFV were tectoridin, luteolin, resveratrol, and hesperetin. Therefore, in this study, CEFC exhibits potent anti-inflammatory effects by downregulating the production of pro-inflammatory mediators and inhibiting key inflammatory pathway in RAW264.7 cells.

Organic acids drove the microbiota succession and consequently altered the flavor quality of Laotan Suancai across fermentation rounds: Insights from the microbiome and metabolome

Laotan Suancai, a popular traditional Chinese fermented vegetable, is manufactured in the industry via four fermentation rounds. However, the differences in flavor quality of Laotan Suancai from the four fermentation rounds and the causes of this variation remain unclear. Metabolome analysis indicated that the different content of five taste compounds and 31 aroma compounds caused the differences in flavor quality among the variated fermentation rounds of Laotan Suancai. Amplicon sequencing indicated that the microbial succession exhibited a certain pattern during four fermentation rounds and further analysis unveiled that organic acids drove the microbiota shift to more acid-resistant populations. Spearman correlation analysis highlighted that seven core microbes may be involved in the formation of differential flavor and the corresponding metabolic pathways were reconstructed by function prediction. Our findings offer a novel perspective on comprehending the deterioration of flavor quality across the fermentation rounds of Laotan Suancai.

Effects of fermented jujube powder on growth performance, rumen fermentation, and antioxidant properties of simmental bulls

Introduction

Fermented jujube powder (FJP) promotes a balance between the intestinal microflora and immune factors in animals. In this study, we aimed to investigate the effects of FJP on the production performance, nutrient digestion, rumen fermentation, and antioxidant properties of bulls.

Methods

Forty Simmental bulls were randomly divided into four groups based on body weight and fed a basal diet with [5, 7.5, or 10% dry matter (DM)] or without FJP. The experimental period was 20 d for adaptation and 60 d for the feeding trial.

Results

Dietary FJP supplementation did not affect DM intake (P > 0.05) but increased the average daily gain quadratically (P = 0.049) and decreased the feed conversion ratio linearly (P = 0.042). FJP quadratically enhanced DM and crude protein digestibility (P = 0.026 and P = 0.041, respectively) and linearly enhanced acid detergent fiber digestibility (P = 0.048). It also increased the total volatile fatty acid concentration quadratically (P = 0.037), acetate molar percentage, and acetate-to-propionate ratio linearly (P = 0.002 and 0.001), and reduced the ammonia nitrogen concentration linearly (P = 0.003). Additionally, xylanase and protease activities and Ruminococcus flavefaciens abundance increased linearly (P = 0.006, 0.018, and 0.009, respectively), and total bacteria, Ruminococcus albus, and Ruminobacter amylophilus abundance increased quadratically (P = 0.047, 0.011, and 0.021, respectively). FJP linearly increased serum total protein concentration and antioxidant capacity (P = 0.003 and 0.018, respectively) and decreased malonaldehyde content (P = 0.006).

Discussion

FJP supplementation (7.5%) enhanced production performance, nutrient digestion, rumen fermentation, and serum antioxidant capacity in bulls. The improved nutrient digestion may be due to an increase in ruminal microorganisms and total volatile fatty acids from the FJP. High blood antioxidant levels indicate that FJP may preserve proteins, thereby boosting the production performance of bulls.

A concise review of the nutritional profiles, microbial dynamics, and health impacts of fermented mushrooms

Mushrooms have garnered significant attention for their nutritional composition and potential health benefits, including antioxidant, antihypertensive, and cholesterol-lowering properties. This review explores the nutritional composition of edible mushrooms, including their high protein content, essential amino acids, low fat, cholesterol levels, and bioactive compounds with medicinal value. Moreover, the study analyzes the microbiology of mushroom fermentation, focusing on the diverse microbial ecosystem involved in the transformation of raw mushrooms and the preservation methods employed to extend their shelf life. Special emphasis is placed on lactic acid fermentation as a cost-effective and efficient preservation technique. It involves controlling the growth of lactic acid bacteria to enhance the microbial stability and nutritional quality of mushrooms. Furthermore, the bioactivities of fermented mushrooms are elucidated, which are antioxidant, antimicrobial, anticancer, anti-glycemic, immune modulatory, and other biological activities. The mechanisms underlying these bioactivities are explored, emphasizing the role of fermented mushrooms in suppressing free radicals, enhancing antioxidant defenses, and modulating immune responses. Overall, this review provides comprehensive insights into the nutritional composition, microbiology, bioactivities, and underlying mechanisms of fermented mushrooms, highlighting their potential as functional foods with significant health-promoting properties.

Palm Kernel Cake Extracts Obtained from the Combination of Bacterial Fermentation and Enzymic Hydrolysis Promote Swine Small Intestine IPEC-J2 Cell Proliferation and Alleviate LPS-Induced Inflammation In Vitro

Co-fermentation with bacteria and enzymes can reduce sugar content in palm kernel cake (PKC); however, the chemical changes and their effects on cell functionality are unclear. This study investigated the active components in pre-treated PKC extracts and their effects on pig small intestine IPEC-J2 cell proliferation and LPS-induced inflammation. The extracts contained 60.75% sugar, 36.80% mannose, 1.75% polyphenols and 0.59% flavone, as determined by chemical analyses, suggesting that the extracts were palm kernel cake oligosaccharides (PKCOS). Then, we found that 1000 µg/mL PKCOS counteracted the decrease in cell viability (CCK8 kit) caused by LPS induction by 5 µg/mL LPS (p < 0.05). Mechanistic studies conducted by RNA-seq and qPCR analyses suggested PKCOS promoted cell proliferation through the upregulation of TNF-α, PI3KAP1, MAP3K5 and Fos in the PI3K/MAPK signalling pathway; alleviated inflammation caused by LPS via the downregulation of the target genes Casp3 and TNF-α in association with apoptosis; and regulated the expression of the antioxidant genes SOD1, SOD2 and GPX4 to exert positive antioxidant effects (p < 0.05). Furthermore, PKCOS upregulated SLC5A1 (encoding SLGT1), HK and MPI in the glycolytic pathway (p < 0.05), suggesting cell survival. In summary, PKCOS has positive effects on promoting swine intestine cell proliferation against inflammation.

Integrated metatranscriptomics and metabolomics reveal microbial succession and flavor formation mechanisms during the spontaneous fermentation of Laotan Suancai

Laotan Suancai, a Chinese traditional fermented vegetable, possesses a unique flavor that depends on the fermentative microbiota. However, the drivers of microbial succession and the correlation between flavor and active microbiota remain unclear. A total of 21 characteristic flavor metabolites were identified in Laotan Suancai by metabolomics, including 8 sulfides, 6 terpenes, 3 organic acids, 2 isothiocyanates, 1 ester, and 1 pyrazine. Metatranscriptome analysis revealed variations in the active microbiota at different stages of fermentation, and further analysis indicated that organic acids were the primary drivers of microbial succession. Additionally, we reconstructed the metabolic network responsible for the formation of characteristic flavor compounds and identified Companilactobacillus alimentarius, Weissella cibaria, Lactiplantibacillus plantarum, and Loigolactobacillus coryniformis as the core functional microbes involved in flavor development. This study contributed to profoundly understanding the relationship between the active microbiota and flavor quality formation, as well as the targeted selection of starters with flavor regulation abilities.

Biological Activity of Fermented Plant Extracts for Potential Dermal Applications

Fermented plant extracts (FPEs) are functional liquids formed as a result of the fermentation of fresh plants by microorganisms, mainly bacteria and fungi. The appropriate selection of plants, microorganism strains, and conditions under which the fermentation process is carried out is very important in terms of obtaining a suitable matrix of biologically active compounds with different biological properties. The purpose of this review is to provide verified data on the current knowledge acquired regarding the biological activity of FPEs for cosmetic use and dermal applications. The antioxidant, antimicrobial, anti-inflammatory, anti-melanogenic, and wound-healing activity of FPEs, as well as their potential dermal applications, will be described.

Valorization of agro-industrial wastes into animal feed through microbial fermentation: A review of the global and Ghanaian case

Agricultural and industrial activities around the world lead to the production of large quantities of agro-industrial wastes (e.g., peels of cassava, pineapple, plantain, banana, and yam, as well as rice husks, rice bran , corn husks, corn cobs, palm kernel cake, soybean meal, wheat bran, etc.). These agro-industrial wastes are discarded indiscriminately, thereby polluting the environment and becoming hazardous to human and animal health. Solid-state fermentation (SSF), a microbial fermentation process, is a viable, efficient approach that transforms discarded agro-industrial wastes into a plethora of useful value-added bioproducts. There is growing interest in the application of SSF in valorizing agro-industrial wastes for the production of fermented, protein-rich animal feed within the livestock industry. SSF reduces anti-nutritional factors whose presence hinders the digestibility and bioavailability of nutrients in agro-industrial wastes. Thus, the application of SSF improves the nutrient contents and quality of valorized agro-industrial wastes as animal feed. Fermented animal feed production may be safer, cheaper and enhance the overall growth performance and health of animals. SSF, therefore, as a strategic approach in a circular bioeconomy, presents economic and practical advantages that guarantee efficient recycling and valorization of agro-industrial wastes that ameliorate environmental pollution. This paper reviews the status of global and local Ghanaian biotransformation and valorization of agro-industrial wastes through SSF for the production of nutrient-rich animal feed.

The Antioxidant Activity and Protection of Probiotic Bacteria in the In Vitro Gastrointestinal Digestion of a Blueberry Juice and Whey Protein Fermentation System

Blueberries have received great attention due to the health effects of their bioactive compounds, such as antioxidant, antitumor, and anti-obesity properties. Probiotics also have these health-promoting benefits. However, these biological activities may be affected by the processs of gastrointestinal digestion, which decreases their functionality. This study aimed to use a more convenient method to improve the blueberries’ antioxidant activity and protective effects on probiotic cells by fermentation with whey protein, and to explore the possible mechanisms underlying these effects. This result showed that the total phenolic content, anthocyanin content, reducing power, DPPH radical scavenging capacity, and probiotic cells’ survival in a blueberry juice and whey protein fermentation system were enhanced in a model of in vitro gastrointestinal digestion. The bioactive compounds in blueberry juice interacted with whey protein, as shown through FTIR. The stability of phenolic compounds was enhanced, and the release of functional compounds in the mixture fermentation system was delayed through CLSM. Interactions between bioactive compounds in blueberries, whey protein, and bacterial surface proteins, glycoproteins or polysaccharides during fermentation were studied by SDS-PAGE. Thus, the stability of bioactive activities in the mixed system after fermentation was strengthened by the interaction. The mixed fermentation system has promising potential for improving antioxidant activity and protecting probiotic cells.

Advances in the Role and Mechanisms of Essential Oils and Plant Extracts as Natural Preservatives to Extend the Postharvest Shelf Life of Edible Mushrooms

China has a large variety of edible mushrooms and ranks first in the world in terms of production and variety. Nevertheless, due to their high moisture content and rapid respiration rate, they experience constant quality deterioration, browning of color, loss of moisture, changes in texture, increases in microbial populations, and loss of nutrition and flavor during postharvest storage. Therefore, this paper reviews the effects of essential oils and plant extracts on the preservation of edible mushrooms and summarizes their mechanisms of action to better understand their effects during the storage of mushrooms. The quality degradation process of edible mushrooms is complex and influenced by internal and external factors. Essential oils and plant extracts are considered environmentally friendly preservation methods for better postharvest quality. This review aims to provide a reference for the development of new green and safe preservation and provides research directions for the postharvest processing and product development of edible mushrooms.

Optimizing Conditions in the Acid Tolerance Test for Potential Probiotics Using Response Surface Methodology

Acid tolerance is an important feature of probiotic development. It is one of the factors underlying the beneficial effects of probiotics in the intestine. However, the methods used by different researchers to test acid tolerance vary, causing confusion in the interpretation of the results. Therefore, in this study, we determine the optimal conditions for the acid tolerance test using response surface methodology. The factors of pH (2.5 to 3.5), exposure time (1 to 2 h), and pepsin (presence or absence) were used as independent variables, and the survival rates of seven strains (Lacticaseibacillus casei KACC 12413, Lactiplantibacillus plantarum KACC 15357, Limosilactobacillus fermentum KACC 11441, Lactiplantibacillus plantarum WCFS1, Lacticaseibacillus rhamnosus GG, Lactiplantibacillus plantarum KCTC 21024, and Lactiplantibacillus plantarum WiKim 0112) known to have probiotic properties were used as dependent variables. The results of the analysis of variance (ANOVA) indicated that the pH value and exposure time in acidic environments significantly affected the acid tolerance test model, and their interaction also had an effect (P < 0.05). Using the ANOVA results, the condition of the acid tolerance test was optimized with a target of an 85% survival rate for each strain. The optimized conditions of the acid tolerance test were as follows: pH 2.92, exposure time of 1.73 h, and presence of pepsin and pH 3, exposure time of 1.98 h, and absence of pepsin. These results can optimize strain selection with rigorous acid tolerance without confusion by unifying the conditions for the acid tolerance test. IMPORTANCE The acid tolerance test, which is the first step in selecting probiotics, is not standardized and can often cause confusion in the interpretation of results. Thus, in the present study, we optimized the conditions for the acid tolerance test using response surface methodology. These optimized conditions can be used to screen for strains with acid tolerance.

Legumes and Legume-Based Beverages Fermented with Lactic Acid Bacteria as a Potential Carrier of Probiotics and Prebiotics

Fermentation is widely used in the processing of dairy, meat, and plant products. Due to the growing popularity of plant diets and the health benefits of consuming fermented products, there has been growing interest in the fermentation of plant products and the selection of microorganisms suitable for this process. The review provides a brief overview of lactic acid bacteria (LAB) and their use in fermentation of legumes and legume-based beverages. Its scope also extends to prebiotic ingredients present in legumes and legume-based beverages that can support the growth of LAB. Legumes are a suitable matrix for the production of plant-based beverages, which are the most popular products among dairy alternatives. Legumes and legume-based beverages have been successfully fermented with LAB. Legumes are a natural source of ingredients with prebiotic properties, including oligosaccharides, resistant starch, polyphenols, and isoflavones. These compounds provide a broad range of important physiological benefits, including anti-inflammatory and immune regulation, as well as anti-cancer properties and metabolic regulation. The properties of legumes make it possible to use them to create synbiotic food, which is a source of probiotics and prebiotics.