Fermentation with mono- and mixed cultures of Lactobacillus plantarum and L. casei enhances the phytochemical content and biological activities of cherry silverberry (Elaeagnus multiflora Thunb.) fruit

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.

Fermentation improves antioxidant capacity and γ-aminobutyric acid content of Ganmai Dazao Decoction by lactic acid bacteria

Introduction

Ganmai Dazao Decoction is a traditional Chinese recipe, and is composed of licorice, floating wheat, and jujube.

Methods

Effects of lactic acid bacteria fermentation on the physicochemical properties, antioxidant activity, and γ-aminobutyric acid of Ganmai Dazao Decoction were studied. The changes of small and medium molecules in Ganmai Dazao Decoction before and after fermentation were determined by LC-MS non-targeted metabolomics.

Results

The results showed that the contents of lactic acid, citric acid, acetic acid, and total phenol content increased significantly, DPPH free radical clearance and hydroxyl free radical clearance were significantly increased. γ-aminobutyric acid content was 12.06% higher after fermentation than before fermentation. A total of 553 differential metabolites were detected and identified from the Ganmai Dazao Decoction before and after fermentation by partial least squares discrimination and VIP analysis.

Discussion

Among the top 30 differential metabolites with VIP values, the content of five functional substances increased significantly. Our results showed that lactic acid bacteria fermentation of Ganmai Dazao Decoction improves its antioxidant effects and that fermentation of Ganmai Dazao Decoction with lactic acid bacteria is an innovative approach that improves the health-promoting ingredients of Ganmai Dazao Decoction.

Conversion of (poly)phenolic compounds in food fermentations by lactic acid bacteria: Novel insights into metabolic pathways and functional metabolites

Lactobacillaceae are among the major fermentation organisms in most food fermentations but the metabolic pathways for conversion of (poly)phenolic compounds by lactobacilli have been elucidated only in the past two decades. Hydroxycinnamic and hydroxybenzoic acids are metabolized by separate enzymes which include multiple esterases, decarboxylases and hydroxycinnamic acid reductases. Glycosides of phenolic compounds including flavonoids are metabolized by glycosidases, some of which are dedicated to glycosides of plant phytochemicals rather than oligosaccharides. Metabolism of phenolic compounds in food fermentations often differs from metabolism in vitro, likely reflecting the diversity of phenolic compounds and the unknown stimuli that induce expression of metabolic genes. Current knowledge will facilitate fermentation strategies to achieve improved food quality by targeted conversion of phenolic compounds.

Probiotic fermentation of polyphenols: potential sources of novel functional foods

Fermented functional food products are among the major segments of food processing industry. Fermentation imparts several characteristic effects on foods including the enhancement of organoleptic characteristics, increased shelf-life, and production of novel health beneficial compounds. However, in addition to macronutrients present in the food, secondary metabolites such as polyphenols are also emerging as suitable fermentable substrates. Despite the traditional antimicrobial view of polyphenols, accumulating research shows that polyphenols exert differential effects on bacterial communities by suppressing the growth of pathogenic microbes while concomitantly promoting the proliferation and survival of probiotic bacteria. Conversely, probiotic bacteria not only survive among polyphenols but also induce their fermentation which often leads to improved bioavailability of polyphenols, production of novel metabolic intermediates, increased polyphenolic content, and thus enhanced functional capacity of the fermented food. In addition, selective fermentation of combinations of polyphenol-rich foods or fortification with polyphenols can result in novel functional foods. The present narrative review specifically explores the potential of polyphenols as fermentable substrates in functional foods. We discuss the emerging bidirectional relationship between polyphenols and probiotic bacteria with an aim at promoting the development of novel functional foods based on the amalgamation of probiotic bacteria and polyphenols.

Graphical abstract

The Bioactive Profile, Nutritional Value, Health Benefits and Agronomic Requirements of Cherry Silverberry (Elaeagnus multiflora Thunb.): A Review

The cherry silverberry (Elaeagnus multiflora Thunb.) is a lesser-known plant species with high nutritional and therapeutic potential. Cherry silverberry contains numerous biologically active compounds. The cherry silverberry is a shrub growing up to 3 m. Its drupe-like fruit is ellipsoidal, up to 1 cm long, and set on stems. It is red in color, juicy, and sour, and its taste resembles that of red currants. According to the literature, cherry silverberry fruit contains carbohydrates, organic acids, and amino acids, as well as vitamin C, in addition to biominerals, polyphenols, flavonoids, carotenoids, chlorophylls, and tocopherols, which contribute to its high nutritional value. New biotypes of cherry silverberry cultivated in Poland can be used for the production of functional foods and direct consumption. In China, the cherry silverberry, known as goumi, has been used as a medicinal plant and a natural remedy for cough, diarrhea, itch, foul sores, and, even, cancer. This review article summarizes the scant research findings on the nutritional and therapeutic benefits of cherry silverberry.

Lactiplantibacillus plantarum CCMA 0743 and Lacticaseibacillus paracasei subsp. paracasei LBC-81 metabolism during the single and mixed fermentation of tropical fruit juices

Fruit juices have shown promising results as new probiotic carriers. This study aimed to evaluate acerola, jelly palm, and passion fruit juices as substrates for fermentation using Lactiplantibacillus plantarum CCMA 0743 and Lacticaseibacillus paracasei LBC-81 in single and mixed cultures. First, the juices were evaluated as substrate and selected based on bacterial growth performance during fermentation. Afterward, the impact of fermentation on sugars, organic acids, and bioactive compounds was also appraised. Phytochemical modification of three different juices fermented by lactic acid bacteria at 37 °C/24 h was evaluated. After 18 h of fermentation, passion fruit juice showed higher cell viable counts of single and mixed L. plantarum CCMA 0743 culture, above 9.00 Log CFU/mL, and pH between 4.07 and 4.10. Sugars consumption and organic acid production were influenced by juice composition and culture used. The mixed culture reduced the total sugars in the passion fruit juice by approximately 53.0% (8.51 g/L). Lactic acid was the main product of the sugars fermentation, with higher concentrations detected in passion fruit juice (8.39-11.23 g/L). Bioactive compounds were analyzed on the selected substrate. The fermentative process reduced antioxidant activity and carotenoid content. However, single L. plantarum CCMA 0743 culture increased the yellow flavonoid content of passion fruit juice by approximately 3.0 µg/mL. L. plantarum CCMA 0743 showed high and suitable cell, viable counts, to claimed probiotic products, increasing bioactive compounds in passion fruit juice. Therefore, this strain and passion fruit substrate showed attractive potential to produce alternative and functional fermented fruit beverages.

Biotransformation of the Brazilian Caatinga fruit-derived phenolics by Lactobacillus acidophilus La-5 and Lacticaseibacillus casei 01 impacts bioaccessibility and antioxidant activity

This study aims to evaluate the effect of fermentation of fruit purees (seriguela, mangaba, mango, and acerola) with Lacticaseibacillus casei 01 and/or Lactobacillus acidophilus LA-05 on the profile and bioaccessibility of phenolics and antioxidant activity. The physicochemical parameters and sugar and organic acid contents were also measured for evaluating the fermentation system. Fruit purees were adequate substrates for the growth of probiotic cultures, presenting high viability in the product and after simulated gastrointestinal conditions (≥7 log CFU/g). The fermentation with probiotic cultures increased the lactic acid (8.45-15.44 mg/mL), acetic acid (0.05-1.05 mg/mL), and phenolic contents and bioaccessibility, while the pH values and glucose and fructose contents were decreased (p < 0.05). L. acidophilus was found in higher counts in seriguela puree (8.00 ± 0.03), resulting in a higher consumption of maltose, fructose, and glucose, increased phenolic compounds content and bioacessibility and higher antioxidant activity (p < 0.05). The co-cultivation of both probiotic strains showed promising results for mango, mangaba and seriguela purees, resulting in an increased content and bioaccessibility of phenolics and higher antioxidant activity (p < 0.05). Our findings demonstrate for the first time that the Brazilian Caatinga fruit-derived phenolics can be biotransformed by Lactobacillus and amended genera probiotics to bioaccesible phenolics with antioxidant activity. The knowledge obtained from this study will provide fundamental concepts of the use of synergistic probiotics for future fermentation of other fruit purees to increase the bioaccesibility and antioxidant activity of biotransformed phenolic compounds.

Protective Effect of Prunus mume Fermented with Mixed Lactic Acid Bacteria in Dextran Sodium Sulfate-Induced Colitis

The fruit of Prunus mume (PM) is widely cultivated in East Asia, and it has been used as a folk medication for gastrointestinal disorders, e.g., diarrhea, stomach ache and ulceration. In this study, the pectinase-treated PM juice (PJ) was fermented with Lactobacillus strains containing fundamental organic acids and free amino acids. The PJ fermented with Lactobacillus plantarum and L. casei (FP) was investigated for its protective effect in dextran sodium sulfate (DSS)-induced colitis mice model. The administration of FP reduced lipid peroxidation and histopathological colitis symptoms, e.g., shortening of the colon length, depletion of mucin, epithelial injury and ulceration, in colonic tissues. The FP-supplemented group showed the alleviation of pro-inflammatory cytokines. Compared with the DSS control group, the supplementation of FP significantly reduced the levels of serum interferon-γ (IFN-γ), interleukin (IL)-1β, IL-6, IL-12 and IL-17 as well as colonic tumor necrosis factor-α, IFN-γ, IL-12 and IL-17. Furthermore, the DSS-induced TUNEL-positive area was significantly reduced by the FP supplementation. These results show that the supplementation of FP fermented with mixed lactic acid bacteria, L. plantarum and L. casei, elucidated the protective effect in DSS-induced colitis mice. Hence, this study suggests that FP can be utilized as a natural therapeutic agent for colitis and intestinal inflammation.