Fermentation of kiwifruit juice from two cultivars by probiotic bacteria: Bioactive phenolics, antioxidant activities and flavor volatiles

Impact of ripeness stages on the chemical and sensory profiles of jujube wine: An analysis of physicochemical parameters, antioxidant activity, and volatile compounds

This study demonstrates that the jujube maturity significantly affects the physicochemical properties, antioxidant capacities, and volatile profiles of jujube wine. The semi-red jujube wine exhibited the highest concentrations of total phenolics (1069.73 mg GAE/L) and flavonoids (629.82 mg RE/L), underscoring potential health benefits. These levels decreased with fruit maturation, with notable decreases in catechin, chlorogenic acid, and eugenol concentrations, especially evident between the semi-red and full-red stages. Amino acid concentrations, particularly proline, increased significantly with ripeness, from 5.93 mg/L in semi-red stage to 775.91 mg/L in sweetheart stage, enhancing the wine's flavor complexity. Volatile analysis showed significant changes in the aromatic profile at the sweetheart stage, enriching the wine with fruity and floral esters. These results emphasize that the selection of optimal ripeness depends on balancing the chemical, nutritional, and sensory qualities most desired in jujube wine, providing practical guidelines for wine producers.

Effects of different lactic acid bacteria on the physicochemical properties, functional characteristics and metabolic characteristics of fermented hawthorn juice

Lactic acid bacteria (LAB) fermentation enhances the flavour and functionality of juice substrates; however, research on hawthorn juice is limited. We hypothesize that due to strain specificity, the changes in hawthorn juice after fermentation with different LAB may vary. After selecting LAB strains based on pH and sensory evaluation, the physicochemical properties and anti-inflammatory potential in a lipopolysaccharide-induced RAW 264.7 macrophage model were analysed in vitro. Non-targeted metabolomics revealed fermentation-driven metabolic changes. All strains exhibited increased total acidity and decreased reducing sugar and flavonoid contents. In particular, the Lactobacillus plantarum SC-1.3 and FWDG (strain preservation number) strains suppressed the pro-inflammatory cytokines interleukin-6 and tumour necrosis factor-α, with FWDG exhibiting the strongest effect. Moreover, fermentation resulted in the enrichment of bioactive metabolites, including prunetin and glycitein, which are unique to FWDG. The results provided a basis for the industrialization of hawthorn juice as a dietary product.

Lactic Acid Bacterial Culture Selection for Orange Pomace Fermentation and Its Potential Use in Functional Orange Juice

The main goal of this study is to improve the bioactivity of citrus pomace by subjecting it to solid-state fermentation by Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus plantarum over varying periods of time. The viability of Lactobacillus, as well as the total phenolic content (TPC) and total antioxidant capacity (TAC) values of orange pomace (OP), varied depending on the Lactobacillus species and fermentation period. The incorporation of pomace into orange juice samples at a ratio of 5% considerably enhanced the viability of probiotics. The TPC and TAC of orange juice samples were reduced after fermentation. The addition of orange pomace to orange juice significantly increased prostaglandin H2 and improved antioxidant capacity with more pronounced effects at increased pomace concentrations. After postfermentation with L. plantarum, key bioactive compounds such as corynoxeine and phenolics were upregulated, while picroside III and allocryptopine levels were decreased. On the other hand, metabolomics analysis revealed significant changes after fermentation in amino acid, sphingolipid, and fatty acid metabolism and the synthesis of secondary metabolites improving the nutritional profile and bioactivity of fermented orange juice. These findings highlight the potential of pomace addition and fermentation to improve the health benefits and quality of orange juice products. Therefore, the combined use of fermentation and fortification with OP could be a promising approach to creating new functional foods and promoting the use of edible food waste and byproducts.

Evaluating the effects of a pectinolytic probiotic strain as replacement of enzymatical treatments in melon juice pre-alcohol fermentation

The objective of the current study was to investigate and compare the impact of enzymatic hydrolysis and pre-fermentation with probiotics on the biological activity and metabolic profile of melon juice. We found that fermentation with Lactiplantibacillus plantarum N13, not only decreased the juice pH, total soluble solids and reducing sugar, but also promoted the release of phenolic compounds, increased antioxidant activity and improved juice's aroma profile. Although pectinase and cellulase aided in the release of reducing sugar and total phenols in the juice, the heating process involved in the enzymatic treatment decreased total soluble solids and phenolics in the juice. Altogether, both enzymatic treatment and fermentation with probiotics could aid in the release of bioactive compounds, while fermentation with probiotics demonstrated greater impact on the biological activity and metabolic profile of melon juice. The findings of the current study suggested the use of probiotic cultivars in the pre-alcohol-fermentation process.

Moderate electric field-stimulated brown rice germination: Insights into membrane permeability modulation and antioxidant system activation

This study investigated the effects of moderate electric fields (MEF) on the germination of brown rice (BR) and the underlying mechanisms, focusing on membrane permeability and the antioxidant system. The results revealed a significant increase in germination rate, from 62 % to 84 %, at the 12th hour after exposure to a 100-V MEF. This enhancement was attributed to an increase in cell membrane permeability, a crucial factor in MEF-induced germination. The MEF may induce the formation of reversible electrical pores, thereby increasing cell membrane permeability. Concurrently, MEF treatment triggered the production of reactive oxygen species (ROS), leading to oxidative stress, which has sustained membrane permeability during germination. Furthermore, MEF was found to enhance the antioxidant system, aiding in the elimination of excessive ROS and ensuring normal metabolic activities. These findings underscore the role of MEF in modulating BR germination and highlight its potential for practical applications in agricultural seed technology.

Metabolomic and proteomic profiling reveals the formation mechanism of volatile flavor in egg whites during fermentation by Streptococcus thermophilus

In this study, the flavor of egg whites was significantly improved by lactic acid fermentation, and the metabolic networks of metabolites, volatile compounds, and enzymes were established using gas chromatography-mass spectrometry, metabolomic, and proteomic. Results indicate that among ten types of common lactic acid bacteria, Streptococcus thermophilus endowed egg white with the most pleasant flavor through increasing aldehydes, ketones, alcohols, esters, terpenoids, and aromatic compounds. Amino acid catabolism was the predominant pathway for generating most aldehydes, alcohols, acids, and esters. The changes in the organic acids and derivatives (mainly amino acids, peptides, and analogues) concentration during fermentation are attributed to the hydrolysis of egg white proteins by proteinases and peptidases, and the regulation of enzymes involved in amino acid biosynthesis and other reactions. This study provides a valuable reference for future investigations focusing on regulating the flavor release of egg whites.

Insights into the potential quality markers of Rubus chingii Hu fruit at different growth stages

Rubus chingii Hu fruit (RHF) is a medicinal and edible resource with excellent biological activities. Currently, the existing identification markers can't meet the needs of RHF quality control. This study collected RHF from cultivation fields of three origins [Qiandaohu (QDH), Lishui (LS), and Fuyang (YF)] at green, green to yellow, yellow to orange, and mature stages (G, G to Y, Y to O, M). The physicochemical information of RHF was examined. Water migration and characteristic volatile compounds of RHF at growth stages from different origins were investigated by low field-nuclear magnetic resonance (LF-NMR) technology and gas chromatography-ion mobility spectrometry (GC-IMS) technology. It showed that samples from QDH possessed the highest antioxidant activity at the first three growth stages (e.g.

, DPPH

0.062 ± 0.000, 0.059 ± 0.004 and 0.037 ± 0.002 mmol Trolox/100 g), while FY had the highest at the mature stage (e.g.

, DPPH

0.026 ± 0.001 mmol Trolox/100 g). The total carbohydrates content ranged from 15 % to 43 %. Besides, in the first two stages, the total acidity value was lower (e.g.

, QDH

2.69 ± 0.04 and 2.45 ± 0.04 in g citric acid/L). Furthermore, three origins had the same water migration rule, and finally, 10 compounds, including 5 from the G growth stage, 4 from the G to Y growth stage, and 1 from the Y to O growth stage, were highly correlated with antioxidant activity and can significantly indicate RHF quality from different origins, so they can potentially serve as Q-markers for RHF. Identifying Q-markers provides a research direction for the quality control of RHF, promoting the development of the RHF industry.

Exploring the Multifaceted Health Benefits of Tripolium pannonicum: Antimicrobial, Antioxidant, and Prebiotic Properties With Phytochemical Insights

This study investigates the multifaceted potential of Tripolium pannonicum methanolic extract, focusing on its antimicrobial, antioxidant, and prebiotic properties alongside a comprehensive phytochemical analysis. The antioxidant capacity of the methanolic extract was demonstrated through 2,2-diphenyl-1-picrylhydrazyl radical scavenging and iron ion chelating assays, revealing an IC50 value of 0.073 mg/mL and 5.79 ± 0.04 mg/mL, respectively. Furthermore, the prebiotic activity of T. pannonicum was evaluated, showing enhanced growth of probiotic strains Lactobacillus plantarum and L. fermentum, compared to standard prebiotics, inulin, and fructooligosaccharides. The study also identified 27 bioactive phytochemical compounds in the methanolic extract, including 5-hydroxymethylfurfural and palmitic acid, which were further explored through molecular docking analyses, revealing significant interactions with the human pregnane X receptor. These findings underscore the potential of T. pannonicum as a sustainable health solution in both agricultural and medicinal contexts, warranting further exploration of its therapeutic applications and mechanisms of action.

The impact of different lactobacilli fermentations on secondary metabolites of red raspberry juice and their biotransformation pathways via metabolomics based on UHPLC-MS/MS

Secondary metabolites are a group of invaluable phytochemicals in raspberries. Fermentation process leads to changes in the phytochemical composition of fruits. This study aimed to investigate the influence of Lacticaseibacillus paracasei subsp. paracasei FBKL1.0328 and Lactiplantibacillus plantarum subsp. plantarum FBKL1.0310 on the secondary metabolites of red raspberry juice (CR) and uncover their conversion pathways via metabolomics based on ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). A total of 695 secondary metabolites in the unfermented and fermented samples were identified. There were 90, 83 and 52 differential secondary metabolites identified in LCR (L. paracasei FBKL1.0328 fermented raspberry juice) vs. CR, LPR (L. plantarum FBKL1.0310 fermented raspberry juice) vs. CR, and LCR vs. LPR, respectively. Certain phenolic acids (e.g. 3-phenyllacitc acid), flavonoids (e.g. galangin-7-glucoside), alkaloids (e.g. indole-3-lactic acid), and terpenoids (e.g. glucosyl 7-methyl-3-methyleneoctane-1,2,6,7-tetraol) were selected as the crucial differential metabolites. These two lactobacilli utilized distinct metabolic pathways for processing secondary metabolites. L. paracasei FBKL1.0328 primarily transformed flavonoids through the "Flavone and flavonol biosynthesis" pathway. L. plantarum FBKL1.0310 mainly converted phenolic acids via the "Tyrosine metabolism" pathway and the "Aminobenzoate degradation" pathway. Interestingly, L. plantarum FBKL1.0310 outperformed L. paracasei FBKL1.0328 in upregulating certain valuable bioactive compounds such as indole-3-lactic acid and 3-phenyllacitc acid, underscoring its potential as a promising strain for developing health-beneficial fermented fruit juices. These findings provide insights to how different lactobacilli modify secondary metabolite composition in red raspberry juice and offer valuable information for the industrial application of lactobacilli in fruit processing.

Insight into peroxidase-mediated Morinda citrifolia L. (noni) fruit juice browning and precipitation, and a thermal inactivation strategy

Peroxidase-mediated enzymatic browning during the process of noni fruit juice causes major color deterioration and precipitation, which negatively affects consumer acceptance of the juice. The purpose of this study was to understand the browning and precipitate formation mechanisms in noni fruit juice and improve its quality. Peroxidase was isolated from noni fruit via gel separation purification and characterized for its kinetic properties. The influences of key phenolic compounds on browning and precipitate formation were investigated via a noni-juice-based model system. The results revealed that the major noni peroxidase was a 50.05 kDa dimer subunit, and peroxidase activity was optimal at pH 6.0 and 30 °C, with an activation energy of 159.50 kJ/mol. Additionally, peroxidase activity was significantly inhibited by glutathione, sodium metabisulfite, and ascorbic acid. The active sites contained histidine and arginine residues. All eight phenolic compounds in juice act as specific substrates for peroxidase-mediated browning. Among them, gallic acid made the most significant contribution to both browning and precipitate formation. To effectively deactivate peroxidase activity while minimizing phenolic compound loss, a thermal treatment of 90 °C for 10 min was identified as the optimal approach. This study provides new insights into improving the quality of noni juice and enzyme browning.

Mechanism study on the enhancement of bile acid-binding capacity in corn by-product juice via Lactiplantibacillus plantarum HY127 fermentation

Hyperlipidemia is a common endocrine metabolic disease in humans. Long-term medications often have adverse effects, making the search for safer and more effective treatments crucial. This study aimed to explore the impacts and mechanisms of Lactiplantibacillus plantarum HY127 fermentation on enhancing bile acid-binding capacity (BABC). We fermented corn by-product juice (CBJ) by HY127 and investigated the BABC of HY127 bacterial cells and their metabolites. Our results indicated that HY127 cells (95.25 %) played a major role in enhancing BABC, with metabolites (31.50 %-66.41 %) also contributing. Compared to unfermented CBJ, the contents of phenolics, flavonoids, polysaccharides, and organic acids were significantly higher. Non-targeted metabolomics revealed upregulated amino acids, alkaloids, terpenoids, and other bioactive substances associated with BABC in the supernatant. This study confirmed that HY127 fermentation enhances the BABC of CBJ (increased by 32.02 %-78.76 %), providing a research foundation and technical reference for the development of LAB-fermented corn by-product beverages with hypolipidemic activities.

Changes in Human Colonic Microbiota Promoted by Synbiotic Açai Juice Composed of Gluco-Oligosaccharides, Dextran, and Bifidobacterium breve NRRL B-41408

The present study evaluates the effects of açai juice containing gluco-oligosaccharides and dextran, fermented by Bifidobacterium breve NRRL B-41408 (synbiotic juice), on the human fecal microbiota. The juice is subjected to simulated digestion and fecal fermentation after production and 42 days of refrigerated storage. High throughput 16S rRNA sequencing and HPLC are used to identify the bacterial cells and metabolites. The results show that the viability of B. breve is stable during the refrigerated storage, indicating that the metabolism is maintained even under low temperatures and pH. Furthermore, gluco-oligosaccharides and dextran prove to be resistant to gastrointestinal conditions and are quickly consumed during fecal fermentation. The synbiotic açai juice enhances the microbial diversity and stimulates the production of short-chain fatty acids (SCFA), including acetate, propionate, and isobutyrate. Elevated propionate levels are directly associated with an increased abundance of Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides xylanisolvens, Bacteroides dorei, Bacteroides stercoris, and Bacteroides massiliensis after 48 h of fermentation. This highlights the potential of synbiotic açai juice as a functional beverage, supported by the significant increase in microbial diversity reflected in the Shannon and Simpson's diversity indexes (Shannon = 116.6%, 117.2%, 125.15%, and 116.02%; Simpson's = 151.86%, 177.22%, 152.5%, and 163.73%).

Effects of Lactic Acid Bacteria Fermentation and In Vitro Simulated Digestion on the Bioactivities of Purple Sweet Potato Juice

The effects of lactic acid bacteria fermentation and in vitro simulated digestion on phenolic bioavailability, phenolic bioavailability, and antioxidant activity of purple sweet potato juice (PSPJ) were investigated. The PSPJ was fermented by Lactobacillus rhamnosus and Streptococcus thermophilus. The viable bacterial count, phenolic components, antioxidant activity, phenolic bioaccessibility, and phenolic bioavailability of PSPJ were analyzed during the simulated digestion process in vitro. The data displayed that lactic acid bacteria fermentation increased total α-glucosidase inhibition, total flavonoid content, and ratephenolic content. The antioxidant activities were improved after in vitro simulated digestion due to the biotransformation of phenolic substances by lactic acid bacteria fermentation. The bioaccessibility and bioavailability of phenols in PSPJ were improved with fermentation of lactic acid bacteria. Furthermore, the viable bacteria count of the two strains was significantly improved (>7 log CFU/mL) after simulated digestion in vitro.

Isolation, identification, and evaluation of lactic acid bacteria with probiotic potential from traditional fermented sour meat

Sour meat is a popular traditional fermented product and is a rich source of novel strains with probiotic potential. In this study, we aimed to assess the probiotic potential of lactic acid bacteria (LAB) strains isolated from fermented sour meat. Firstly, the microbial diversity of sour meat from four different areas in China was analyzed. The results showed that LAB were predominant in all samples. Subsequently, LAB were isolated from sour meat and a series of in vitro probiotic tests were carried out. A total of 130 bacterial strains with dissolved calcium were obtained and 10 strains showed a range of 89-97% survival in an acidic environment and high tolerance to bile salts. The ranges of hydrophobicity and auto-aggregation of 10 strains were 4.85-80.75% and 1.58-84.2%, respectively. Besides, all 10 strains exhibited high antimicrobial activity and antioxidant activity, of which, DZ24 possessed the strongest free radical scavenging (45.1%) and anti-lipid oxidizing ability (90.3%). Furthermore, DZ24 was identified as Lactiplantibacillus plantarum by 16S rRNA gene sequencing. Moreover, the fermentation indexes showed that DZ24 could rapidly reduce the pH to 4.14 and showed high salt and nitrite resistance and antioxidant ability. All the above experimental results indicate that Lactiplantibacillus plantarum DZ24 promise a suitable probiotic candidate for future applications in the fermented functional meats.

A Novel Non-Alcoholic Einkorn-Based Beverage Produced by Lactic Acid Fermentation: Microbiological, Chemical, and Sensory Assessment

Einkorn (Triticum monococcum L. ssp. monococcum) is gaining renewed interest for its high nutritional value and digestibility. Lactic acid fermentation could enhance these properties by improving micronutrient bioavailability, sensory properties, and shelf life. This study aimed to develop a novel non-alcoholic einkorn-based beverage through lactic acid fermentation. A multiple-strain starter was selected based on acidifying properties and inoculated into an einkorn-based substrate to produce a yogurt-like beverage. Prototypes were evaluated through physico-chemical, chemical, and microbiological analyses and compared to uninoculated controls. A sensory analysis was also performed to assess flavor attributes before and after lactic acid fermentation. The inoculated starter culture reached a load of approximately 9 Log CFU g⁻¹ and remained viable throughout storage, leading to an increase in lactic acid concentration and high titratable acidity, corresponding to low pH values. Total polyphenol content increased during fermentation and remained stable during storage, whereas antioxidant activity did not show significant differences over time. An increase in monosaccharides, acids, and ketones was observed during fermentation and storage. The prototypes exhibited a distinctive proximate composition, along with yogurt and fruity aroma notes. These results suggest the feasibility of producing a safe and stable non-alcoholic einkorn-based fermented beverage with appealing sensory characteristics.

Extrusion of decoction residues of Roselle (Hibiscus sabdariffa L.) with different starchy wall materials retaining the polyphenol content after in vitro digestion

Decoction residues (DR) of Roselle are a waste with high polyphenol content. The remaining polyphenols are resistant to thermal treatments and have antioxidant properties. An alternative for the use of the DR is the extrusion with wall material that can preserve the antioxidant capacity of the polyphenols. The present study aimed to produce a functional ingredient with the Roselle DR by extrusion with different commercial starchy wall materials (Capsul, N-Lok, and Globe). The extrudates were analyzed for morphology, bioaccessibility of polyphenols, antioxidant capacity (AC), and starch digestion rate. The confocal microscopy showed the presence of fiber with polyphenols. The extruded with Capsul and Globe showed the highest slowly digestible starch (SDS) and resistant starch (RS) content. The bioaccessibility of polyphenols was higher in the Capsul and Globe extrudates indicating gradual release during the intestinal digestion. Capsul and Globe showed the best results in protecting the polyphenols.

Untargeted metabolomics unravels the effects of ginkgolide B-producing Lactiplantibacillus plantarum and co-induced fermentation of ginkgo kernel juice and their underlying vascular endothelial cell protection activity

The objective of this study was to investigate the fermentation mechanism of ginkgo kernel juice (GKJ) under unfermented (Group A), Ginkgolide B (GB)-producing Lactiplantibacillus plantarum fermented (Group B), and co-induced fermented (Group C) conditions. The conditions were optimized and further evaluated for their vascular endothelial cell protective effects in vitro. The co-induced fermented GKJ group extensively promoted GB and total phenol contents, reaching 109.94 and 599.57 μg/mL, respectively. While pH declined from 5.90 to 3.42 during fermentation, the highest total viable count (8.85 log CFU/mL) was detected at 16 h in the L. plantarum group. The co-induced group recorded the highest total phenol contents (594.05 μg/mL) and markedly induced the survival rate, reactive oxygen species formation, and lactate dehydrogenase assay cytotoxicity of H2O2-induced human umbilical vein endothelial cells. An untargeted metabolomics analysis identified 2633 metabolites in the groups. The principal component and orthogonal partial least squares discriminant score plots showed a clear metabolite distinction among the fermentation groups. From the Kyoto Encyclopedia of Genes and Genomes analysis, 309 differential accumulated metabolites (DAMs) were up-regulated and 604 were down-regulated in the A vs. B group, while 702 downregulated and 304 upregulated DAMs were exhibited in the B vs. C group. These DAMs were primarily lipids and lipid-like molecules, organic acids and their derivatives, organoheterocyclic compounds, organic oxygen compounds, benzenoids, phenylpropanoids and polyketides, and unclassified compounds at the superclass level. Overall, the results indicated that L. plantarum and co-induced fermentation improved the cell protection efficacy of GKJ, showing excellent potential for drug delivery applications.

Effect of sequential fermentation with indigenous non-Saccharomyces cerevisiae combinations and Saccharomyces cerevisiae on the chemical composition and aroma compounds evolution of kiwifruit wine

To unlock the potential of indigenous non-Saccharomyces cerevisiae and develop novel starters to enhance the aromatic complexity of kiwifruit wine, Zygosaccharomyces rouxii, Pichia kudriavzevii and Meyerozyma guilliermondii were pairwise combined and then used in sequential fermentation with Saccharomyces cerevisiae. The impact of different starter cultures on the chemical composition and flavor profile of the kiwifruit wines was comprehensively analyzed, and the aroma evolution during alcoholic fermentation was investigated by examining the changes in key volatiles and their loss rates. Compared with Saccharomyces cerevisiae, mixed starter cultures not only improve antioxidant capacity but also increase esters and alcohols yields, presenting intense floral and fruity aromas with high sensory acceptability. The results indicated that sequential inoculation of non-Saccharomyces cerevisiae combination and Saccharomyces cerevisiae promoted the development of volatiles while maintaining the stability of key aroma compounds in the winemaking environment and reducing the aroma loss rates during alcoholic fermentation.

Design of experiment approach to boost volatile production from kiwi byproducts

Design of Experiments (DoE), is a tool to explore relationships between factors and responses of a system. DoE and response surface methodology are increasingly used in different fields, but their application are limited in the valorization of residual biomass and agro-industrial by-products. Agro-industrial biomass residues can be eco-friendly converted into high-value compounds through bioprocesses. This approach identified key factors and predicted optimal conditions for enhancing microbial growth and the production of specific compounds or volatile classes. Lactiplantibacillus plantarum 4193 and Lacticaseibacillus paracasei 2243, were identified as the best starters while the production of methyl heptenone is influenced by fermentation time and pH. This out-turn in the generation of aromatically rich biomass, which can be utilised as a food ingredient or for the extraction of specific volatile compounds, and employed as flavouring agents. This study underlines the potential of fermentation in maximizing the value of unripe kiwi biomass.

Novel approach for ameliorating high-fat diet-induced syndromes via probiotic-fermented oyster mushroom: from metabolites and microbiota to regulation mechanisms

The potential effects of probiotics on lowering lipid accumulation and alleviating gut microbiota perturbation have been extensively substantiated, but whether Lactobacillus rhamnoses-fermented oyster mushroom (FOM) could more pronouncedly attenuate obesity remains unclear. In this study, the anti-obesity effect of FOM was estimated based on the gut microbiota profile and analysis of hepatic lipid metabolic characteristics. The results revealed that FOM intervention dramatically improved hepatic lipid accumulation, characterized by reduction in fat-related factor metabolism levels and liver lesion enzymatic activities and down-regulation of the expression of genes associated with glycolipid metabolism (Foxo1, Gck, G6pd, Il6r and IL-β). Metabolomics analysis indicated HFD-induced dysglycaemia and disturbed amino acid metabolism, characterized by significant enrichment of pathways (butanoate metabolism, arginine biosynthesis, etc.) and elevated levels of D-mannose, succinate and β-D-fructose, followed by a decreased galactitol content. Furthermore, FOM intervention showed significant enrichment of specific pathways, particularly transcriptional misregulation in cancer and FoxO signaling pathways, while the MAPK signaling pathway demonstrated consistent enrichment across all experimental groups. FOM intervention reshaped the gut microbiota structure by facilitating the proliferation of SCFA producers (Romboutsia, Ruminococcaceae and Allobaculum), together with the depletion of Lachnospiraceae population. The current study strengthened our understanding of FOM prebiotic activities and obesity alleviation mechanisms.

Effects of different lactic acid bacteria on phenolic profiles, antioxidant capacities, and volatile compounds in purple sweet potato juice

The effects of three strains of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus rhamnosus, and Streptococcus thermophilus) on viable counts, physicochemical indicators, phenolic profiles, antioxidant capacities, and volatile compounds in purple sweet potato juice were investigated during fermentation. The results showed the viable count of three bacteria increased and exceeded 11 log CFU/mL after fermentation. At the end of fermentation, the purple sweet potato juice exhibited an increase in total phenolic and flavonoid content. In addition, lactic acid bacteria fermentation changed the phenolic profiles and enhanced antioxidant capacities. Moreover, Pearson's correlation analysis showed that DPPH, ABTS, and hydroxyl radical scavenging capacities were positively correlated with caffeic acid and vanillic acid content (p < 0.05). Furthermore, lactic acid bacteria fermentation improved the aroma complexity and sensory quality of purple sweet potato juice. In conclusion, this study provided useful information for the development of purple sweet potato juice fermented by lactic acid bacteria.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05959-5.

Assessing the Potential Biological Activities of Postbiotics Derived from Saccharomyces cerevisiae: An In Vitro Study

A new biotherapeutic strategy involves the use of microbial bioactive substances (postbiotics) that exhibit optimum compatibility and intimate contact with the immune system of the host. This study was aimed at investigating the potential biological activities of postbiotics derived from Saccharomyces cerevisiae (PTCC 5269) (PSC) under in vitro circumstances. Based on the outcomes, the synthesized PSC possessing a high level of phenolic (102.46 ± 0.25 mg GAE/g) and flavonoid (19.87 ± 75.32 mg QE/g) content demonstrated significant radical scavenging activity (87.34 ± 0.56%); antibacterial action towards Listeria monocytogenes, Streptococcus mutans, Salmonella typhi, and Escherichia coli (in order of effectiveness) in both in vitro and food models (whole milk and ground meat); probiotics' growth-promoting activity in the fermentation medium; α-glucosidase enzyme-inhibiting and cholesterol-lowering properties in a concentration- and pH-dependent manner; reduction in the cell viability (with the significant IC50 values of 34.27 and 23.58 μg/mL after 24 and 48 h, respectively); suppressed the initial (G0/G1) phase of the cell's division; induced apoptosis; and increased the expression of PTEN gene, while the IkB, RelA, and Bcl-XL genes indicated diminished expression in treated SW480 cancer cells. These multiple health-promoting functions of PSC can be extended to medical, biomedical, and food scopes, as novel biotherapeutic approaches, in order to design efficient and optimized functional food formulations or/and supplementary medications to use as adjuvant agents for preventing or/and treating chronic/acute disorders.

Untargeted metabolomics analysis of probiotic jujube juice and its anti-obesity effects on high-fat-diet-induced obese mice

BACKGROUND

Dietary intervention, including polyphenol consumption, is recognized as an effective strategy to prevent obesity. Although fermented jujube juice (FJJ) with lactic acid bacteria has been shown to be rich in polyphenols and have strong antioxidant properties, little is known about its anti-obesity properties.

RESULTS

Untargeted metabolomics was employed to identify and analyze the differential metabolites between FJJ and raw jujube juice. A total of 431 metabolites belonging to diverse classes and with various functional active ingredients were quantitatively identified. The animal experiments results showed that FJJ administration for 13 weeks significantly inhibited high-fat-diet-induced body and epididymal adipose weight gain, and improved the serum lipid parameters in obese mice. Additionally, DNA-sequencing results revealed that FJJ treatment increased Akkermansia abundance in the gut and changed the composition of fecal microbiota by decreasing the Firmicutes/Bacteroidota ratio and Helicobacter pylori abundance.

CONCLUSION

These findings suggest that FJJ contributes to regulating lipid accumulation and gut microbiota composition in high-fat-diet-induced obese mice, which helps to prevent obesity. Hence, FJJ has the potential to be a beneficial beverage for controlling obesity. © 2024 Society of Chemical Industry.

Recent advances of fermented fruits: A review on strains, fermentation strategies, and functional activities

Fruits are recognized as healthy foods with abundant nutritional content. However, due to their high content of sugar and water, they are easily contaminated by microorganisms leading to spoilage. Probiotic fermentation is an effective method to prevent fruit spoilage. In addition, during fermentation, the probiotics can react with the nutrients in fruits to produce new derived compounds, giving the fruit specific flavor, enhanced color, active ingredients, and nutritional values. Noteworthy, the choice of fermentation strains and strategies has a significant impact on the quality of fermented fruits. Thus, this review provides comprehensive information on the fermentation strains (especially yeast, lactic acid bacteria, and acetic acid bacteria), fermentation strategies (natural or inoculation fermentation, mono- or mixed-strain inoculation fermentation, and liquid- or solid-state fermentation), and the effect of fermentation on the shelf life, flavor, color, functional components, and physiological activities of fruits. This review will provide a theoretical guidance for the production of fermented fruits.

Exploring the Biogenic Transformation Mechanism of Polyphenols by Lactobacillus plantarum NCU137 Fermentation and Its Enhancement of Antioxidant Properties in Wolfberry Juice

This study investigated the transformation of polyphenols, including free and bound polyphenols during the fermentation of wolfberry juice by Lactobacillus plantarum NCU137. Results indicated that fermentation significantly increased the free polyphenols content and released bound polyphenols, enhancing the antioxidant activity. Analysis showed that there were 19 free polyphenols, mainly scopoletin, pyrogallol, and dihydroferulic acid, and 16 bound polyphenols, especially p-coumaric acid, feruloyl hexoside, and caffeic acid. A significant correlation was observed between the generation and degradation of polyphenols, and specific bound polyphenols peaked during the 24-48 h fermentation. Furthermore, reduced surface roughness and galacturonic acid content in wolfberry residue, along with increased pectinase activity, suggested substantial pectin degradation in the cell wall, which may be associated with the release of polyphenols, due to pectin serving as carriers for bound polyphenols. The fermentation also increased polyphenol oxidase and peroxidase activity, contributing to polyphenol breakdown. These findings provide insights for improving wolfberry juice production.

Widely targeted metabolomics-based analysis of the impact of L. plantarum and L. paracasei fermentation on rosa roxburghii Tratt juice

Rosa roxburghii Tratt fruits (RRT) exhibit extremely high nutritional and medicinal properties due to its unique phytochemical composition. Probiotic fermentation is a common method of processing fruits. Variations in the non-volatile metabolites and bioactivities of RRT juice caused by different lactobacilli are not well understood. Therefore, we aimed to profile the non-volatile components and investigate the impact of L. plantarum fermentation (LP) and L. paracasei fermentation (LC) on RRT juice (the control, CG). There were both similarities and differences in the effects of LP and LC on RRT juice. Both of the two strains significantly increased the content of total phenolic, total flavonoid, and some bioactive compounds such as 2-hydroxyisocaproic acid, hydroxytyrosol and indole-3-lactic acid in RRT juice. Interestingly, compared with L. paracasei, L. plantarum showed better ability to increase the content of total phenolic and these valuable compounds, as well as certain bioactivities. The antioxidant capacity and α-glucosidase inhibitory activity of RRT juice were notably enhanced after the fermentations, whereas its cholesterol esterase inhibitory activity was reduced significantly. Moreover, a total of 1466 metabolites were identified in the unfermented and fermented RRT juices. There were 278, 251 and 134 differential metabolites in LP vs CG, LC vs CG, LC vs LP, respectively, most of which were upregulated. The key differential metabolites were classified into amino acids and their derivatives, organic acids, nucleotides and their analogues, phenolic acids and alkaloids, which can serve as potential markers for authentication and discrimination between the unfermented and lactobacilli fermented RRT juice samples. The KEGG enrichment analysis uncovered that metabolic pathways, purine metabolism, nucleotide metabolism and ABC transporters contributed mainly to the formation of unique composition of fermented RRT juice. These results provide good coverage of the metabolome of RRT juice in both unfermented and fermented forms and also provide a reference for future research on the processing of RRT or other fruits.

Probiotic-fermented tomato with hepatic lipid metabolism modulation effects: analysis of physicochemical properties, bioactivities, and potential bioactive compounds

Lactiplantibacillus plantarum NCUH001046 (LP)-fermented tomatoes exhibited the potential to alleviate obesity in our previous study. This subsequent study further delves deeper into the effects of LP fermentation on the physicochemical properties, bioactivities, and hepatic lipid metabolism modulation of tomatoes, as well as the analysis of potential bioactive compounds exerting obesity-alleviating effects. Results showed that after LP fermentation, viable bacterial counts peaked at 9.11 log CFU mL-1 and sugar decreased, while organic acids, umami amino acids, total phenols, and total flavonoids increased. LP fermentation also improved the inhibition capacities of three digestive enzyme activities and Enterobacter cloacae growth, as well as antioxidant activities. Western blot results indicated that fermented tomatoes, especially live probiotic-fermented tomatoes (LFT), showed improved effects compared to unfermented tomatoes in reducing hepatic lipid accumulation by activating the AMPK signal pathway. UHPLC-Q-TOF/MS-based untargeted metabolomics analysis showed that chlorogenic acid, capsiate, tiliroside, irisflorentin, and homoeriodictyol levels increased after fermentation. Subsequent cell culture assays demonstrated that irisflorentin and homoeriodictyol reduced lipid accumulation via enhancing AMPK expression in oleic acid-induced hyperlipidemic HepG2 cells. Furthermore, Spearman's correlation analysis indicated that the five phenols were positively associated with hepatic AMPK pathway activation. Consequently, it could be inferred that the five phenols may be potential bioactive compounds in LFT to alleviate obesity and lipid metabolism disorders. In summary, these findings underscored the transformative potential of LP fermentation in enhancing the bioactive profile of tomatoes and augmenting its capacity to alleviate obesity and lipid metabolism disorders. This study furnished theoretical underpinnings for the functional investigation of probiotic-fermented plant-based foods.

Polygonatum kingianum Polysaccharides Enhance the Preventive Efficacy of Heat-Inactivated Limosilactobacillus reuteri WX-94 against High-Fat-High-Sucrose-Induced Liver Injury and Gut Dysbacteriosis

Limosilactobacillus reuteri (L. reuteri) is an efficacious probiotic that could reduce inflammation and prevent metabolic disorders. Here, we innovatively found that Polygonatum kingianum polysaccharides (PKP) promoted proliferation and increased stability of L. reuteri WX-94 (a probiotic strain showing anti-inflammation potentials) in simulated digestive fluids in vitro. PKP was composed of galactose, glucose, mannose, and arabinose. The cell-free supernatant extracted from L. reuteri cultured with PKP increased ABTS•+, DPPH•, and FRAP scavenging capacities compared with the supernatant of the medium without PKP and increased metabolites with health-promoting activities, e.g., 3-phenyllactic acid, indole-3-lactic acid, indole-3-carbinol, and propionic acid. Moreover, PKP enhanced alleviating effects of heat-inactivated L. reuteri on high-fat-high-sucrose-induced liver injury in rats via reducing inflammation and regulating expressions of protein and genes involved in fatty acid metabolism (such as HIF1-α, FAβO, CPT1, and AMPK) and fatty acid profiles in liver. Such benefits correlated with its prominent effects on enriching Lactobacillus and short-chain fatty acids while reducing Dubosiella, Fusicatenilacter, Helicobacter, and Oscillospira. Our work provides novel insights into the probiotic property of PKP and emphasizes the great potential of the inactivated L. reuteri cultured with PKP in contracting unhealthy diet-induced liver dysfunctions and gut dysbacteriosis.

Combining thermosonication microstress and pineapple peel extract addition to achieve quality and post-acidification control in yogurt fermentation

This work investigated the effects of the combined use of thermosonication-preconditioned lactic acid bacteria (LAB) with the addition of ultrasound-assisted pineapple peel extracts (UU group) on the post-acidification potential, physicochemical and functional qualities of yogurt products, aimed at achieving prolonged preservation and enhancing functional attributes. Accordingly, the physical-chemical features, adhesion properties, and sensory profiles, acidification kinetics, the contents of major organic acids, and antioxidant activities of the differentially processed yogurts during refrigeration were characterized. Following a 14-day chilled storage process, UU group exhibited acidity levels of 0.5-2 oT lower than the control group and a higher lactose content of 0.07 mg/ml as well as unmodified adhesion potential, indicating that the proposed combination method efficiently inhibited post-acidification and delayed lactose metabolism without leading to significant impairment of the probiotic properties. The results of physicochemical analysis showed no significant changes in viscosity, hardness, and color of yogurt. Furthermore, the total phenolic content of UU-treated samples was 98 μg/mL, 1.78 times higher than that of the control, corresponding with the significantly lower IC50 values of DPPH and ABTS radical scavenging activities of the UU group than those of the control group. Observations by fluorescence inverted microscopy demonstrated the obvious adhesion phenomenon with no significant difference found among differentially prepared yogurts. The results of targeted metabolomics indicated the proposed combination strategy significantly modified the microbial metabolism, leading to the delayed utilization of lactose and the inhibited conversion into glucose during post-fermentation, as well as the decreased lactic acid production and a notable shift towards the formation of relatively weak acids such as succinic acid and citric acid. This study confirmed the feasibility of thermosonication-preconditioned LAB inocula, in combination with the use of natural active components from fruit processing byproducts, to alleviate post-acidification in yogurt and to enhance its antioxidant activities as well as simultaneously maintaining sensory features.

Chemical Profile Characterization of Fruit and Vegetable Juices after Fermentation with Probiotic Strains

Lactic acid bacteria (LAB) are widely applied for fermentation purposes in dairy and non-dairy food matrices with beneficial technological and health-promoting properties. This study describes the effect of two lactic acid bacteria, namely, Lactiplantibacillus paracasei SP5 and Pediococcus pentosaceus SP2, on the phenolic profiles, antioxidant activities, total phenolic content (TPC), carotenoid content, and sensorial profile of two different mixed fruit juices. After 48 h of fermentation, both LABs retained viability over 9 Log CFU/mL in both juices. The TPC, zeaxanthin + lutein, β-carotene content, and antioxidant activity (AA) were elevated for both LABs and mixed juices after 48 h of fermentation compared to control samples. Regarding the phenolic profile, both juices exhibited a significant decrease in chlorogenic acid levels, while quinic acid and tyrosol concentrations showed notable increases.

Effect of mixed fermentation of Lactiplantibacillus plantarum and Lactiplantibacillus pentosus on phytochemical and flavor characteristics of Wallace melon juice

BACKGROUND

Melons (Cucumis melo L.) are among the most commonly consumed fruits but they are highly susceptible to mechanical damage and rot during storage and transportation. New processed products are needed to avoid postharvest fruit loss and to increase health benefits. Fermentation is an effective means of utilizing the nutrients and improving flavor.

RESULTS

Fermented melon juice (MJ) was prepared using three potential probiotics Lactiplantibacillus plantarum CICC21824 (LP), Lactiplantibacillus plantarum GB3-2 (LG), and Lactiplantibacillus pentosus XZ-34 (LX). The nutrition, flavor characteristics, and digestive properties of different fermented MJs were compared. The results demonstrated that, in comparison with mono-fermentation, mixed fermentation by LG and LX could increase the level of organic acids and phenolic acids. Correspondingly, antioxidant capacity was improved significantly and positively correlated with p-coumaric acid and cinnamic acid content. The production of alcohols and acids was more strongly enhanced by mixed culture fermentation, whereas mono-fermentation reduced the content of esters, especially ethyl acetate and isopropyl acetate. Aldehydes and ketones increased significantly in fermented MJ, and damascenone and heptanal could be the characteristic aroma compounds.

CONCLUSION

Mixed fermented MJ provides more beneficial phytochemicals, better flavor, and stronger antioxidant properties than mono-fermentation. © 2024 Society of Chemical Industry.

Succession of microbiota and its influence on the dynamics of volatile compounds in the semi-artificial inoculation fermentation of mulberry wine

To improve the delightful flavor of mulberry wine through semi-artificial inoculation fermentation with Saccharomyces cerevisiae, we studied the dynamics change of microbiota, along with the physicochemical properties and metabolite profiles and their interaction relationship during the fermentation process. The abundance of lactic acid bacteria (Weissella, Lactobacillus, Fructobacillus, and Pediococcus) increased significantly during fermentation, while yeasts gradually established dominance. The inter-kingdom network of the dominant genera analysis further identified the following as core microbiota: Alternaria, Botrytis, Kazachstania, Acremonium, Mycosphaerella, Pediococcus, Gardnerella, and Schizothecium. Additionally, pH, alcohol, and total acid were significantly affected by microbiota variation. Fourteen of all identified volatile compounds with key different aromas were screened using PCA, OPLS-DA, and rOAV. The network of interconnected core microbiota with key different aromas revealed that Kazachstania and Pediococcus had stronger correlations with 1-butanol, 3-methyl-, propanoic acid, and 2-methyl-ethyl ester.

The effect of adding pomace on the bioactive composition and flavor volatiles in fermented orange juice with Lactobacillus

BACKGROUND

The consumption of oranges generates huge amounts of pomaces, which are the potential raw materials to increase the nutritional value of the products.

RESULTS

In this study, the bioactive composition and flavor volatiles in Lactobacillus fermented orange juice with added pomaces were researched. Results showed that the orange juices blended with pomaces were favorable substrates for Lactobacillus growth and the colony counts reached above 9.0 log CFU mL-1 , total phenolics, total flavonoids, and the antioxidant activity in orange juices were increased significantly after adding pomaces. Some amino acids, such as threonine (P < 0.0001), isoleucine (P < 0.01), and glycine (P < 0.01) were markedly higher in fermented orange juices with pomaces. The flavonoid diversity was more abundant by adding pomace fermentation and most flavonoids showed higher levels in fermented juices with the pomace, Lactobacillus fermentum 252 may transform some flavonoids through deglycosylation and reduction reaction. Furthermore, orange pomace mainly improved the flavor volatiles by increasing terpenoids and alcohol, such as d-limonene and benzyl alcohol, and decreasing volatile acids.

CONCLUSION

This study presented a novelty in elevating the nutritional value of juice by the utilization of pomaces, its findings can provide a new way to mine the bioactive ingredient from Citrus by Lactobacillus, and can be used as a guide for the development of new Citrus processing technologies and functional foods. © 2023 Society of Chemical Industry.

Characterization of fermented pomegranate juice: ACE inhibitory activity under in vitro digestion, antioxidant capacity, phenolics composition, chemical properties and sensory evaluation

Consuming pomegranate juice (PJ) is beneficial for hypertensive regulation because of the phenolic compounds in PJ and their inhibitory activity on angiotensin-I-converting enzyme (ACE). To better utilize bioactive function of food, microorganism fermentation has been adopted to alter phenolic metabolism. This study confirms that even under in vitro digestion, fermented PJ (FPJ) maintains higher ACE inhibitory activity than that of PJ. The main phenolic compounds in PJ were compared either under fermentation or in vitro digestion. This study finds that fermentation promotes antioxidant capacity of PJ. The chemical properties of FPJ are evaluated and the corresponding relationship with bioactivities is analyzed. A sensory evaluation comparison is conducted between FPJ and PJ, furnishing interesting information for consumers. This study highlights the relationship between ACE inhibitory activity of PJ and phenolic composition under fermentation and in vitro digestion, providing novel insights for diet regulation of phenolic-rich FPJ in ACE inhibition therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01388-w.

Influence of lactic acid fermentation on the phenolic profile, antioxidant activities, and volatile compounds of black chokeberry (Aronia melanocarpa) juice

Lactic acid fermentation is an effective method for improving the quality of black chokeberry. This study aimed to investigate the influence of lactic acid bacteria on the phenolic profile, antioxidant activities, and volatiles of black chokeberry juice. Initially, 107  cfu/mL of Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Lacticaseibacillus rhamnosus were inoculated into pasteurized black chokeberry juice and fermented for 48 h at 37°C. All these strains enhanced the total phenolic and total flavonoid contents, with La. acidophilus showing the highest total phenolic (1683.64 mg/L) and total flavonoid (659.27 mg/L) contents. Phenolic acids, flavonoids, and anthocyanins were identified using ultrahigh-performance liquid chromatography-tandem mass spectrometry. The prevalent phenolic acid, flavonoid, and anthocyanin in the lactic-acid-fermented black chokeberry juice were cinnamic acid, rutin, and cyanidin-3-O-rutinoside, respectively. Furthermore, following fermentation, the DPPH and ABTS scavenging capacity, as well as the reducing power capacity, increased from 59.98% to 92.70%, 83.06% to 94.95%, and 1.24 to 1.82, respectively. Pearson's correlation analysis revealed that the transformation of phenolic acids, flavonoids, and anthocyanins probably contributed to enhancing antioxidant activities and color conversation in black chokeberry juice. A total of 40 volatiles were detected in the fermented black chokeberry juice by gas chromatography-ion mobility spectrometry. The off-flavor odors, such as 1-penten-3-one and propanal in the black chokeberry juice, were weakened after fermentation. The content of 2-pentanone significantly increased in all fermented juice, imparting an ethereal flavor. Hence, lactic acid fermentation can effectively enhance black chokeberry products' flavor and prebiotic value, offering valuable insights into their production. PRACTICAL APPLICATION: The application of lactic acid bacteria in black chokeberry juice not only enhances its flavor but also improves its health benefits. This study has expanded the range of black chokeberry products and offers a new perspective for the development of the black chokeberry industry.

Application of Cyclocarya paliurus-Kiwifruit Composite Fermented to Enhance Antioxidant Capacity, Flavor, and Sensory Characteristics of Kiwi Wine

A new fermentation method for kiwi wine was explored by developing the well-known medicinal and edible plant Cyclocarya paliurus (C. paliurus) to create more value with undersized kiwifruits. In this study, the changes in bioactive substances during the C. paliurus-kiwi winemaking process were analyzed on the basis of response surface optimization results, and the antioxidant capacity, aromatic compounds, and sensory quality of the C. paliurus-kiwi composite wine with kiwi wine and two commercial kiwi wines were compared. The results showed that DPPH radical, OH- radical, and ABTS+ scavenging rates remained at over 60.0%, 90.0%, and 70.0% in C. paliurus-kiwi wine, respectively. The total flavonoid content (TFC) and total polyphenol content (TPC) of C. paliurus-kiwi wine were significantly higher than those of the other three kiwi wines. C. paliurus-kiwi wine received the highest score and detected 43 volatile compounds. Ethyl hexanoate, which showed stronger fruity and sweet aromas, was one of the main aroma components of C. paliurus-kiwi wine and different from commercial wines. This wine has a good flavor with a natural and quality feeling of C. paliurus-kiwifruit extract, low-cost processing, and great market potential.

Effects of Fermentation with Tetragenococcus halophilus and Zygosaccharomyces rouxii on the Volatile Profiles of Soybean Protein Hydrolysates

The effects of fermentation with lactic acid bacteria (LAB) and yeast on the aroma of samples were analyzed in this work. The volatile features of different soybean hydrolysates were investigated using both GC-MS and GC-IMS. Only 47 volatile flavor compounds (VFCs) were detected when using GC-IMS, while a combination of GC-MS and GC-IMS resulted in the identification of 150 compounds. LAB-yeast fermentation could significantly increase the diversity and concentrations of VFCs (p < 0.05), including alcohols, acids, esters, and sulfurs, while reduce the contents of aldehydes and ketones. Hierarchical clustering and orthogonal partial least squares analyses confirmed the impact of fermentation on the VFCs of the hydrolysates. Seven compounds were identified as significant compounds distinguishing the aromas of different groups. The partial least squares regression analysis of the 25 key VFCs (ROAV > 1) and sensory results revealed that the treatment groups positively correlated with aromatic, caramel, sour, overall aroma, and most of the key VFCs. In summary, fermentation effectively reduced the fatty and bean-like flavors of soybean hydrolysates, enhancing the overall flavor quality, with sequential inoculation proving to be more effective than simultaneous inoculation. These findings provided a theoretical basis for improving and assessing the flavor of soybean protein hydrolysates.

Effect of lactic acid bacteria co-fermentation on antioxidant activity and metabolomic profiles of a juice made from wolfberry and longan

Lactic acid bacteria (LAB) fermentation is frequently employed to improve the nutritional, functional, and sensory characteristics of foods. Our study explored the effects of co-fermentation with Lacticaseibacillus paracasei ZH8 and Lactococcus lactis subsp. lactis YM313 on the physicochemical properties, antioxidant activity, and metabolomic profiles of wolfberry-longan juice (WLJ). Fermentation was carried out at 35 °C for 15 h. The results suggest that WLJ is a favorable substrate for LAB growth, reaching a total viable count exceeding 8 log CFU/mL after fermentation. LAB fermentation increased acidity, reduced the sugar content, and significantly impacted the juice color. The total phenolic and flavonoid contents of the WLJ and the antioxidant capacities based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS radical scavenging abilities and FRAP were significantly improved by LAB fermentation. Nontargeted metabolomics analysis suggested that the contents of small molecule substances in WLJ were considerably affected by LAB fermentation. A total of 374 differential metabolites were identified in the juice before and after fermentation, with 193 significantly upregulated metabolites and 181 siginificantly downregulated metabolites. The regulation of metabolites is important for improving the flavor and functions of juices, such as L-eucylproline, Isovitexin, Netivudine, 3-Phenyllactic acid, vanillin, and ethyl maltol, ect. This study provides a theoretical foundation for developing plant-based foods fermented with LAB.

Butyrogenic, bifidogenic and slight anti-inflammatory effects of a green kiwifruit powder (Kiwi FFG®) in a human gastrointestinal model simulating mild constipation

Green kiwi (Actinidia deliciosa var. Hayward) is a fruit with important nutritional attributes and traditional use as a laxative. In this work, we studied in vitro the colonic fermentation of a standardized green kiwifruit powder (Kiwi FFG®) using representative intestinal microbial content of mildly constipated women. Static (batch) and dynamic configurations of the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) were used to estimate the impact of Kiwi FFG® in the human gut. Analysis of metabolites revealed a significant butyrogenic effect of the kiwifruit powder and, consistently, butyrate-producing bacterial populations (i.e., Faecalibacterium prausnitzii, Cluster IV, Roseburia spp.) were greatly increased in the dynamic gastrointestinal model. Bifidobacterium spp. was also found boosted in the microflora of ascending and transverse colon sections, and a significant rise of Akkermansia muciniphila was identified in the transverse colon. Reporter gene assays using human intestinal cells (HT-29) showed that kiwifruit fermentation metabolites activate the aryl hydrocarbon receptor (AhR) transcriptional pathway, which is an important regulator of intestinal homeostasis and immunity. Moreover, modulation in the production of human interleukins (IL-6 and IL-10) in Caco-2 cells suggested a potential mild anti-inflammatory effect of the kiwifruit powder and its gut microbiota-derived metabolites. Our results suggested a potential health benefit of Kiwi FFG® in the gut microbiota, particularly in the context of constipated people.

Comparative study on Angelica sinensis after different processing with yellow rice wine in color, aromas, chemical components, and antioxidant activities

This study aimed to explore the differences in raw Angelica Sinensis (RAS), wine washing AS (WAS), and wine stir-frying AS (WSAS). The results showed there were differences among the three AS in color and aroma, and 34 aroma compounds were identified. The content determination results revealed the ferulic acid and Z-ligustilide levels of RAS decreased after processing, and those in WAS were higher than in WSAS. Furthermore, 85 representative common components and 37 unique components were tentatively identified in three AS. Finally, the free radical scavenging assay results indicated the antioxidant capacity of RAS was reduced after processing, and the antioxidant capacity of WAS was better than WSAS. Collectively, the RAS undergoes significant changes in color, aromas, components, and antioxidant ability after processing, and the different processing methods also result in significant differences between WAS and WSAS.

GABA and fermented litchi juice enriched with GABA promote the beneficial effects in ameliorating obesity by regulating the gut microbiota in HFD-induced mice

Gamma-aminobutyric acid (GABA) dietary intervention is considered to have therapeutic potential against obesity. Microbial enrichment is an effective strategy to naturally and safely enhance GABA production in food. As litchi is "the king of GABA" in fruits, the retention or enrichment of its content during processing has been a key issue in the litchi industry. This study aimed to investigate the potential of GABA and fermented litchi juice enriched with GABA (FLJ) to protect against obesity in a high-fat diet (HFD) mouse model. Supplementation of GABA and FLJ displayed an anti-obesogenic effect by attenuating body weight gain, fat accumulation, and oxidative damage, and improving the serum lipid profile and hepatic function. Sequencing (16S rRNA) of fecal samples indicated that GABA and FLJ intervention displayed different regulatory effects on HFD-induced gut microbiota dysbiosis at different taxonomic levels. The microbial diversity, the relative abundance of Firmicutes and Bacteroidetes as well as the F/B ratio of GABA and FLJ groups were reversed compared to those of the HFD-induced mice. Our finding broadens the potential mechanisms by which GABA regulates gut flora in the amelioration of obesity and provides guidance for developing FLJ as a functional food to prevent obesity.

Dipicolinic acid enhances kiwifruit resistance to Botrytis cinerea by promoting phenolics accumulation

BACKGROUND

Kiwifruit is highly susceptible to fungal pathogens, such as Botrytis cinerea, which reduce crop production and quality. In this study, dipicolinic acid (DPA), which is one of the main components of Bacillus spores, was evaluated as a new elicitor to enhance kiwifruit resistance to B. cinerea.

RESULTS

DPA enhances antioxidant capacity and induces the accumulation of phenolics in B. cinerea-infected 'Xuxiang' kiwifruit. The contents of the main antifungal phenolics in kiwifruit, including caffeic acid, chlorogenic acid and isoferulic acid, increased after DPA treatment. DPA enhanced H2 O2 levels after 0 and 1 days, which promoted catalase (CAT) and superoxide dismutase (SOD) activities, reducing long-term H2 O2 levels. DPA promoted the up-regulation of several kiwifruit defense genes, including CERK1, MPK3, PR1-1, PR1-2, PR5-1 and PR5-2. Furthermore, DPA at 5 mM inhibited B. cinerea symptoms in kiwifruit (95.1% lesion length inhibition) more effectively than the commercial fungicides carbendazim, difenoconazole, prochloraz and thiram.

CONCLUSIONS

The antioxidant properties of DPA and the main antifungal phenolics of kiwifruit were examined for the first time. This study uncovers new insights regarding the potential mechanisms used by Bacillus species to induce disease resistance. © 2023 Society of Chemical Industry.

An edible coating utilizing Malva sylvestris seed polysaccharide mucilage and postbiotic from Saccharomyces cerevisiae var. boulardii for the preservation of lamb meat

Currently, microbial bioactive substances (postbiotics) are considered a promising tool for achieving customer demand for natural preservatives. This study aimed to investigate the effectiveness of an edible coating developed by Malva sylvestris seed polysaccharide mucilage (MSM) and postbiotics from Saccharomyces cerevisiae var. boulardii ATCC MYA-796 (PSB) for the preservation of lamb meat. PSB were synthesized, and a gas chromatograph connected to a mass spectrometer and a Fourier transform infrared spectrometer were used to determine their chemical components and main functional groups, respectively. The Folin-Ciocalteu and aluminium chloride techniques were utilized to assess the total flavonoid and phenolic levels of PSB. Following that, PSB has been incorporated into the coating mixture, which contains MSM, and its potential radical scavenging and antibacterial activities on lamb meat samples were determined after 10 days of 4 °C storage. PSB contains 2-Methyldecane, 2-Methylpiperidine, phenol, 2,4-bis (1,1-dimethyl ethyl), 5,10-Diethoxy-2,3,7,8- tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d] pyrazine, and Ergotaman-3',6',18-trione, 12'-hydroxy-2'-methyl-5'-(phenylmethyl)-, (5'alpha) as well as various organic acids with significant radical scavenging activity (84.60 ± 0.62 %) and antibacterial action toward Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus, and Listeria innocua as foodborne pathogens. The edible PSB-MSM coating effectively reduced microbial growth and increased meat shelf life (> 10 days). When PSB solutions were added to the edible coating, the moisture content, pH value, and hardness of the samples were also more successfully maintained (P < 0.05). The PSB-MSM coating inhibited lipid oxidation in meat samples considerably and diminished the formation of primary as well as secondary oxidation intermediates (P < 0.05). Additionally, when MSM + 10 % PSB edible coating was utilized, the sensory properties of the samples were maintained more well during preservation. As a significance, the use of edible coatings based on PSB and MSM is efficient in decreasing microbiological and chemical degradation in lamb meat during preservation.

Comparative study of three cultivars of jaboticaba berry: nutrient, antioxidant and volatile compounds

Jaboticaba is a tropical plant and its fruit rich in nutrients, volatile compounds, and biological activities, which considered to be an edible health benefits plant. Despite its popularity for fresh consumption, jaboticaba is rarely used in intensive processing in China. The content of nutrients and antioxidant in jaboticaba greatly impacts how it is processed healthy food. In this study, we evaluated the nutrients, antioxidant capacity, and volatile compounds of three jaboticaba cultivars including Sabara, Argentina, and Fukuoka, respectively. Our results revealed each variety has its merits. Sabara had an abundance of volatile compounds, a suitable acid-sugar ratio, and a slightly lower antioxidant capacity, making it suitable for fresh consumption. Argentina is the richest in volatile compounds in ripe fruit, but slightly lighter in taste and acid-sugar ratio, making it suitable for dry products. The large size, juicy flesh, low acid-sugar ratio, and less volatile compounds content of Fukuoka also make it suitable for juice processing. Three cultivars of jaboticaba berry exhibited different characteristics, providing reference evidence for the manufacturing and processing of jaboticaba health food.

Optimization of Fermentation Conditions and Metabolite Profiling of Grape Juice Fermented with Lactic Acid Bacteria for Improved Flavor and Bioactivity

To enrich the flavor compounds and retain the content of polyphenolics in grape juice (GJ) under long-term storage, Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lacticaseibacillus casei, and Lacticaseibacillus paracasei, were screened and the optimal fermentation conditions were determined as fermentation temperature of 41.2 °C for 24 h with an initial LAB density of 8.5 × 10⁶ CFU/mL. Surprisingly, the retention rates of TPC still remained at 50% after storage for 45 days at 4 °C. Moreover, 251 different metabolites were identified, include 23 polyphenolics, 11 saccharides, and 9 organic acids. Most importantly, the total content of polyphenolics reserved was 92.65% at the end of fermentation. Among them, ephedrannin A content significantly decreased; however, 2',6'-Di-O-acetylononin gradually increased with the fermentation time, which resulted in FGJ maintaining excellent bioactivity. Meanwhile, organic acid content (palmitoylethanolamide, tetraacetylethylenediamine) increased with saccharides (linamarin) decreasing, which leads to FGJ having a unique taste. Furthermore, a total of 85 Volatile organic compounds (VOCs) were identified, mainly including esters, aldehydes, and alcohols. Interestingly, key VOCs could be formed by carboxylic acids and derivatives, and fatty acyls via complex metabolic pathways.

Valorisation of fresh waste grape through fermentation with different exogenous probiotic inoculants

The disposal of fresh waste grape berries restraining the sustainable development of vineyards. The aims of this study were to evaluate the effects of different exogenous probiotic inoculants on the fermentation of fresh waste grape berries. In the fermentation process, the variations of pH and EC value, chemical characteristics of the fermentation products, as well as the microbial communities' composition were simultaneously observed. In addition, the feasibility of using the fermentation products as chemical fertilizer substitute in agricultural production also has been verified in this study. The results indicated that the different probiotic inoculants has shown clear impacts on the variation trends of pH and EC value in the grape waste fermentation. Lactobacillus casei and Zygosaccharomyces rouxii are ideal probiotics for the fermentation of waste grape, which enhanced the contents of free Aa and other nutrients in fermentation products. Compared with Fn treatment (without exogenous inoculants), the total free Aa contents in Fs (inoculation with Z. rouxii) and Fm (inoculation with L. casei and Z. rouxii mixture) treatments have improved by 199.1% and 325.5%, respectively. The microbial communities' composition during the fermentation process also been greatly influenced by the different inoculants. At the genus level, Lactobacillus and Pseudomonas were the dominant bacteria, while Saccharomyces and Candida were the dominant fungi in the fermentation. Using the fermentation products as chemical fertilizer substitute has enhanced the quality of Kyoho grape. Compared with traditional chemical fertilization treatment (T1), application with fermented grape waste (T2) has significantly improved VC and soluble solid contents in grape berries by 16.89% and 20.12%, respectively. In conclusion, fermentation with suitable probiotics was an efficient approach for the disposal and recycling of fresh waste grape in vineyards.

Flavour Volatiles of Fermented Vegetable and Fruit Substrates: A Review

Health, environmental and ethical concerns have resulted in a dramatic increase in demand for plant-based dairy analogues. While the volatile organic compounds (VOCs) responsible for the characteristic flavours of dairy-based products have been extensively studied, little is known about how to reproduce such flavours using only plant-based substrates. As a first step in their development, this review provides an overview of the VOCs associated with fermented (bacteria and/or fungi/yeast) vegetable and fruit substrates. Following PRISMA guidelines and using two English databases (Web of Science and Scopus), thirty-five suitable research papers were identified. The number of fermentation-derived VOCs detected ranged from 32 to 118 (across 30 papers), while 5 papers detected fewer (10 to 25). Bacteria, including lactic acid bacteria (LAB), fungi, and yeast were the micro-organisms used, with LAB being the most commonly reported. Ten studies used a single species, 21 studies used a single type (bacteria, fungi or yeast) of micro-organisms and four studies used mixed fermentation. The nature of the fermentation-derived VOCs detected (alcohols, aldehydes, esters, ketones, acids, terpenes and norisoprenoids, phenols, furans, sulphur compounds, alkenes, alkanes, and benzene derivatives) was dependent on the composition of the vegetable/fruit matrix, the micro-organisms involved, and the fermentation conditions.

Lactobacillus acidophilus Fermented Dandelion Improves Hyperuricemia and Regulates Gut Microbiota

Foodborne prevention and treatment of hyperuricemia (HUA) has received widespread attention. Lactic acid bacteria (LAB) can improve intestinal function, while traditional medicine dandelion has the functions of detoxification and detumescence. Whether LAB fermented dandelion has any effects on HUA and the underlying mechanism is not clear. To address these questions, Lactobacillus acidophilus was selected or maximal xanthine oxidase activity. The effect of Lactobacillus acidophilus fermented dandelion (LAFD) on uric acid metabolism was evaluated by the HUA mouse model. Expression levels of UA, BUN, CRE, XOD, and inflammatory factors in serum were detected. Paraffin sections and staining were used to observe the kidney and small intestine, and mRNA expression of GLUT9, URAT1, OAT1, and ABCG2 related to uric acid metabolism were investigated. Furthermore, the intestinal flora was studied by contents of the cecum and high throughput 16S rRNA sequencing. The results showed that LAFD had a significant inhibitory effect on XOD in vitro (p < 0.01). LAFD could reduce the levels of UA, BUN, CRE, XOD, IL-1 β, IL-6, and TNF- α in serum (p < 0.05), thus inhibiting inflammatory reaction, and reducing UA by decreasing the mRNA expression of GLUT9, URAT1 in kidney and increasing the mRNA expression of OAT1 and ABCG2 in kidney and small intestine (p < 0.05). In addition, the 16S rRNA gene sequencing analysis demonstrated that LAFD treatment can help restore the imbalance of the intestinal microbial ecosystem and reverse the changes in Bacterodietes/Firmicutes, Muribaculaceae, Lachnospiraceae in mice with HUA. It is suggested that the mechanism of LAFD in treating HUA may be related to the regulation of the mRNA expressions of GLUT9, URAT1, OAT1, and ABCG2 in the kidney and small intestine, as well as the regulation of intestinal flora, which provides the experimental basis for the development of new plant fermented products.