Effect of lactobacillus strains on phenolic profile, color attributes and antioxidant activities of lactic-acid-fermented mulberry juice

Evaluation of a strawberry fermented beverage with potential health benefits

Background

Functional fermented beverages are popular worldwide due to their potential to promote health. Starter culture is the main determinant of the final quality and flavor of fermented beverages. The co-cultivation of lactic acid bacteria (LAB) and yeast makes a significant contribution to the safe flavor of fermented beverages. However, the research on the potential of antioxidant, antimicrobial, and anti-biofilm formation of strawberry fermented beverage obtained by combining the LAB and yeast as starter cultures has not been well explored.

Methods

In this study, LAB and yeast were combined as starter culture to obtain strawberry fermented beverage. Fourier transform infrared (FTIR ) spectroscopy was used for the qualitative analysis of the fresh strawberry juice and fermented beverage. From the changes in antioxidant content, free radical scavenging ability, total superoxide dismutase (T-SOD) activity and total antioxidant capacity (T-AOC) to evaluate the antioxidant capacity of fermented beverage in vitro. The antibacterial ability was tested by the Oxford cup method. The biofilms of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538 under fermented beverages treatment was observed by Fluorescence microscope. In addition, sensory analysis was conducted in this study.

Results

In this study, the absorption peaks of Fourier transform infrared between 1,542 cm^-1 and 976 cm^-1, suggest the existence of organic acids, sugars and ethanol. The total phenols and total flavonoids content decreased by 91.1% and 97.5%, respectively. T-SOD activity increased by 33.33%.The scavenging ability of fermented beverage on superoxide anion free radicals was enhanced, and the scavenging ability on DPPH free radicals, hydroxyl free radicals, and ABTS free radicals was weakened. However, the T-AOC increased from 4.15 ± 0.81 to 8.43 ± 0.27 U/mL. Fermented beverage shows antibacterial activity against four pathogens. The minimum inhibitory concentration (MIC) values of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538 were 0.05 mL/mL and 0.025 mL/mL, respectively, and the minimum bactericidal concentration (MBC) were both 0.2 mL/mL. It was observed by fluorescence microscope that the green fluorescence area of the two biofilms is greatly reduced after being treated with fermented beverage. Sensory analysis results show that the average scores of fermented beverage in color, appearance and taste were increased. The overall impression and flavor were decreased.

Conclusion

These results demonstrated that strawberry fermented beverage has potential benefits such as an antioxidant, antibacterial, and anti-biofilm formation, providing the potential for the fermented beverage to become promising candidates for natural antioxidants, antibacterial agents and anti-biofilm agents.

Probiotics-fermented blueberry juices as potential antidiabetic product: antioxidant, antimicrobial and antidiabetic potentials

BACKGROUND

Fermentation is a traditional food-preserving technique. It is an effective process, widely used to enrich the nutrients diversity and bioactivity of the fermented foods since ancient times. This study aimed at investigating the effects of various fermentation starters on the physicochemical, antioxidant, antimicrobial, and antidiabetic properties of blueberry juices. The blueberry juices were fermented by natural fermentation (NFBJ), self-made starters fermentation (SFBJ), and commercial starters fermentation (CFBJ); fresh blueberry juice (BBJ) was processed without fermentation for comparison.

RESULTS

Probiotics-fermented blueberry juices (SFBJ and CFBJ) showed less total and reducing sugars, higher titratable acidity, and a wider variety and higher amounts of organic acids than non-fermented blueberry juice (BBJ) did. All the fermented blueberry juices (NFBJ, SFBJ, and CFBJ) showed significantly (P < 0.05) higher antioxidant potentials than that of BBJ measured by 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid, cupric-reducing antioxidant capacity, and ferric-reducing ability power assays. The SFBJ exhibited the highest antibacterial activities against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium, with inhibition zone diameters of 38.84 ± 1.74 mm, 34.91 ± 1.53 mm, and 36.18 ± 3.16 mm respectively. Compared with BBJ, the α-glucosidase inhibitory activity of the SFBJ and CFBJ increased by two-to threefold. The α-amylase inhibitory activity of the SFBJ and CFBJ increased by 600%, whereas the spontaneous fermentation showed no improvement. The SFBJ and CFBJ promoted glucose consumption of HepG2 cell lines, indicating the promising potential for a higher glucose bio-utilization.

CONCLUSIONS

The SFBJ and CFBJ showed remarkable improvements in the antioxidant, antimicrobial, and antidiabetic activities compared with non-fermented and spontaneous fermented juices, indicating their promising potentials as an antihyperglycemic agent. © 2021 Society of Chemical Industry.

Thermosonication Combined with Natural Antimicrobial Nisin: A Potential Technique Ensuring Microbiological Safety and Improving the Quality Parameters of Orange Juice

Currently, thermal pasteurisation (TP) remains the most widely applied technique for commercial orange juice preservation; however, a high temperature causes adverse effects on the quality attributes of orange juice. In order to explore a novel non-thermal sterilization method for orange juice, the impacts of thermosonication combined with nisin (TSN) and TP treatments on the quality attributes including microbial and enzyme inactivation and the physicochemical, nutritional, functional, and sensory qualities of orange juice were studied. Both TP and TSN treatments achieved desirable bactericidal and enzyme inactivation effects, and nisin had a significant synergistic lethal effect on aerobic bacteria in orange juice (p < 0.05). Additionally, TSN treatment significantly improved the color attributes of orange juice and well maintained its physicochemical properties and sensory quality. More importantly, TSN treatment significantly increased the total polyphenols content (TPC) and total carotenoids (TC) by 10.03% and 20.10%, increased the ORAC and DPPH by 51.10% and 10.58%, and the contents of total flavonoids and ascorbic acid were largely retained. Correlation analysis of antioxidant activity showed that the ORAC and scavenging ability of DPPH radicals of orange juice are mainly attributed to TC and TPC. These findings indicate that TSN shows great potential application value, which could guarantee the microbiological safety and improve the quality attributes of orange juice.

Fermentation of blueberry juices using autochthonous lactic acid bacteria isolated from fruit environment: Fermentation characteristics and evolution of phenolic profiles

In this study, 4 Lactobacillus plantarum strains and 5 Lactobacillus fermentum strains adapting well to the unfavorable fruit system were isolated under different fruit environments. The fermentation ability of these autochthonous lactic acid bacteria (LAB) strains in blueberry juice, and the influence of microbial metabolism on juice composition were explored. After 48 h of fermentation, the viable cell counts exceeded 10.0 log CFU/mL, malic acid content decreased from 511.47 ± 10.50 mg/L to below 146.38 ± 3.79 mg/L, and lactic acid content increased from 0 mg/L to above 2184.90 ± 335.80 mg/L. Moreover, the metabolism of these strains exerted a profound influence on the phenolic composition of juice. Total phenolic content in blueberry juice increased by 6.1-81.2% under lactic acid fermentation, and the antioxidant capacity in vitro enhanced by at least 34.0%. Anthocyanin content showed a declining trend, while the profile of non-anthocyaninic phenolics exhibited complex changes. The increments of rutin, myricetin and gallic acid contents through 48 h lactic acid fermentation exceeded 136%, 71% and 38%, respectively. Instead, the contents of p-hydroxybenzoic acid and caffeic acid decreased with fermentation. Overall, Lactobacillus plantarum LSJ-TY-HYB-T9 and LSJ-TY-HYB-T7, and Lactobacillus fermentum LSJ-TY-HYB-C22 and LSJ-TY-HYB-L16 could be the suitable strains to produce fermented fruit juices, including blueberry in practical applications.

Evaluation of Probiotic Properties of Pediococcus acidilactici M76 Producing Functional Exopolysaccharides and Its Lactic Acid Fermentation of Black Raspberry Extract

This study aimed to determine the probiotic potential of Pediococcus acidilactici M76 (PA-M76) for lactic acid fermentation of black raspberry extract (BRE). PA-M76 showed outstanding probiotic properties with high tolerance in acidic GIT environments, broad antimicrobial activity, and high adhesion capability in the intestinal tract of Caenorhabditis elegans. PA-M76 treatment resulted in significant increases of pro-inflammatory cytokine mRNA expression in macrophages, indicating that PA-M76 elicits an effective immune response. When PA-M76 was used for lactic acid fermentation of BRE, an EPS yield of 1.62 g/L was obtained under optimal conditions. Lactic acid fermentation of BRE by PA-M76 did not significantly affect the total anthocyanin and flavonoid content, except for a significant increase in total polyphenol content compared to non-fermented BRE (NfBRE). However, fBRE exhibited increased DPPH radical scavenging activity, linoleic acid peroxidation inhibition rate, and ABTS scavenging activity of fBRE compared to NfBRE. Among the 28 compounds identified in the GC-MS analysis, esters were present as the major groups. The total concentration of volatile compounds was higher in fBRE than that in NfBRE. However, the undesirable flavor of terpenes decreased. PA-M76 might be useful for preparing functionally enhanced fermented beverages with a higher antioxidant activity of EPS and enhanced flavors.

Biotransformation of Polyphenols in Apple Pomace Fermented by β-Glucosidase-Producing Lactobacillus rhamnosus L08

Apple pomace, the main by-product in apple processing, is a cheap source of bioactive compounds that could be used in the food industry. However, the value of this by-product is still far from being fully realized. In this study, 11 strains of Lactobacillus strains were assayed for β-glucosidase activity, and only Lactobacillus rhamnosus L08 (L. rhamnosus L08) showed high cell-membrane associated β-glucosidase activity. We then evaluated the effects of fermentation of apple pomace using the selected strain, focusing on the biotransformation of polyphenols and antioxidant capacity. We found that L. rhamnosus L08 fermentation significantly reduced the contents of quercitrin and phlorizin in apple pomace, while increasing the contents of quercetin and phloretin. The contents of gallic acid, epicatechin acid, caffeic acid, and ferulic acid were also increased in apple pomace after fermentation. In addition, the antioxidant activities of apple pomace were enhanced during fermentation, based on the bioconversion of phenolic profiles. Our results demonstrate that lactic acid bacteria fermentation is a promising approach to enhance the bioactivity of phenolic compounds in apple pomace. Moreover, this study demonstrates that, as a valuable processing by-product with bioactive components, apple pomace can be used in the food industry to provide economic benefits.

Antioxidant Effect of Soymilk Fermented by Lactobacillus plantarum HFY01 on D-Galactose-Induced Premature Aging Mouse Model

The antioxidant effect of soymilk fermented by Lactobacillus plantarum HFY01 (screened from yak yogurt) was investigated on mice with premature aging induced by D-galactose. In vitro antioxidant results showed that L. plantarum HFY01-fermented soymilk (LP-HFY01-DR) had better ability to scavenge the free radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) than unfermented soymilk and Lactobacillus bulgaricus-fermented soymilk. Histopathological observation showed that LP-HFY01-DR could protect the skin, spleen and liver, reduce oxidative damage and inflammation. Biochemical results showed that LP-HFY01-DR could effectively upregulate glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels and decrease malondialdehyde (MDA) content in the liver, brain, and serum. Real-time quantitative reverse transcription polymerase chain reaction further showed that LP-HFY01-DR could promote the relative expression levels of the genes encoding for cuprozinc superoxide dismutase (Cu/Zn-SOD, SOD1), manganese superoxide dismutase (Mn-SOD, SOD2), CAT, GSH, and GSH-Px in the liver, spleen, and skin. High-performance liquid chromatography results revealed daidzin, glycitin, genistin, daidzein, glycitein, and genistein in LP-HFY01-DR. In conclusion, LP-HFY01-DR could improve the antioxidant capacity in mice with premature aging induced by D-galactose.

Fermentation of Jamaican Cherries Juice Using Lactobacillus plantarum Elevates Antioxidant Potential and Inhibitory Activity against Type II Diabetes-Related Enzymes

Jamaican cherry (Muntinga calabura Linn.) is tropical tree that is known to produce edible fruit with high nutritional and antioxidant properties. However, its use as functional food is still limited. Previous studies suggest that fermentation with probiotic bacteria could enhance the functional properties of non-dairy products, such as juices. In this study, we analyze the metabolite composition and activity of Jamaican cherry juice following fermentation with Lactobacillus plantarum FNCC 0027 in various substrate compositions. The metabolite profile after fermentation was analyzed using UPLC-HRMS-MS and several bioactive compounds were detected in the substrate following fermentation, including gallic acid, dihydrokaempferol, and 5,7-dihydroxyflavone. We also found that total phenolic content, antioxidant activities, and inhibition of diabetic-related enzymes were enhanced after fermentation using L. plantarum. The significance of its elevation depends on the substrate composition. Overall, our findings suggest that fermentation with L. plantarum FNCC 0027 can improve the functional activities of Jamaican cherry juice.

Application of ultrasonication at different microbial growth stages during apple juice fermentation by Lactobacillus plantarum: Investigation on the metabolic response

In this work, low-intensity ultrasonication (58.3 and 93.6 W/L) was performed at lag, logarithmic and stationary growth phases of Lactobacillus plantarum in apple juice fermentation, separately. Microbial responses to sonication, including microbial growth, profiles of organic acids profile, amino acids, phenolics, and antioxidant capacity, were examined. The results revealed that obvious responses were made by Lactobacillus plantarum to ultrasonication at lag and logarithmic phases, whereas sonication at stationary phase had a negligible impact. Sonication at lag and logarithmic phases promoted microbial growth and intensified biotransformation of malic acid to lactic acid. For example, after sonication at lag phase for 0.5 h, microbial count and lactic acid content in the ultrasound-treated samples at 58.3 W/L reached 7.91 ± 0.01 Log CFU/mL and 133.70 ± 7.39 mg/L, which were significantly higher than that in the non-sonicated samples. However, the ultrasonic effect on microbial growth and metabolism of organic acids attenuated with fermentation. Moreover, ultrasonication at lag and logarithmic phases had complex influences on the metabolism of apple phenolics such as chlorogenic acid, caffeic acid, procyanidin B2, catechin and gallic acid. Ultrasound could positively affect the hydrolysis of chlorogenic acid to caffeic acid, the transformation of procyanidin B2 and decarboxylation of gallic acid. The metabolism of organic acids and free amino acids in the sonicated samples was statistically correlated with phenolic metabolism, implying that ultrasound may benefit phenolic derivation by improving the microbial metabolism of organic acids and amino acids.

Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

In vitro growth performance, antioxidant activity and cell surface physiological characteristics of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6 stressed at different NaCl concentrations

This study investigated the impact of NaCl concentrations on the growth performance, antioxidant activity, and cell surface physiological characteristics of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6. The growth of the two strains was significantly inhibited by 4 and 6% NaCl and stagnated at 8% NaCl (P < 0.05). Compared with the control, both strains showed higher acid-producing activity, antioxidant activity and autoaggregation ability at 2 or 4% NaCl. A lower cell surface hydrophobicity of the two strains was observed with increased NaCl concentrations. High NaCl concentrations resulted in cell surface damage and deformation and even slowed the proliferation of the strains, and led to significant shifts in amide A and amide III groups in proteins and the C-H stretching of >CH2 in fatty acids (P < 0.05). In summary, appropriate NaCl concentrations (2 and 4%) improved the antioxidant activity of the two strains, while the higher NaCl concentrations (6%) decreased their antioxidant activity, which may be due to the associated changes in the cell surface structural properties of the two strains.

Microbiological and Chemical Properties of Chokeberry Juice Fermented by Novel Lactic Acid Bacteria with Potential Probiotic Properties during Fermentation at 4 °C for 4 Weeks

On the frame of this research survey, a novel potentially probiotic strain (Lactobacillus paracasei SP5) recently isolated from kefir grains was evaluated for chokeberry juice fermentation. Chokeberry juice was retrieved from the variety Aronia melanocarpa, a plant known to provide small, dark berries and to be one of the richest sources of antioxidants. The juice was subsequently fermented inoculating L. paracasei SP5 for 48 h at 30 °C. The fermented juices were left at 4 °C and tested regarding microbiological and physicochemical characteristics for 4 weeks. The potentially probiotic strain was proved capable of performing lactic acid fermentation at 30 °C. Cell viability of L. paracasei was detected in high levels during fermentation and the whole storage period, while the fermented juice showed higher levels of viability in juice with 40.3 g/L of initial sugar concentration. No ethanol was detected in the final fermented juice. Fermented chokeberry juice was characterized by aromatic desirable volatiles, which were retained in adequate levels for the whole storage period. Specifically, the occurrence of organic esters detected in fermented juices is considered as positive evidence of the provision of fruity and floral notes to the final product. During storage, total phenolics content and antioxidant activity were observed in higher levels in fermented chokeberry juice compared with non-fermented juice. Subsequently, fermentation of chokeberry juice by potentially probiotic lactic acid bacteria could provide high industrialization potential, providing the market with a nutritional beverage of good volatile quality with an enhanced shelf-life compared with an unfermented fresh juice.

Effect of Blueberry Anthocyanin-Rich Extracts on Peripheral and Hippocampal Antioxidant Defensiveness: The Analysis of the Serum Fatty Acid Species and Gut Microbiota Profile

The current study investigated the positive effects of blueberry anthocyanin-rich extracts (BAE) on either peripheral or hippocampal antioxidant defensiveness and established the connection of the improved antioxidant status with the altered fatty acid species and gut microbiota profile. High-fat diet-induced oxidative stress in C57BL/6 mice was attenuated by BAE administration, which was reflected by strengthened antioxidant enzymes, alleviated hepatic steatosis, and improved hippocampal neuronal status. Serum lipidomics analysis indicated that the fatty acid species were altered toward the elevated unsaturated/saturated ratio, along with phospholipid species toward enriched n-3 polyunsaturated fatty acid compositions. The modulated antioxidant pattern could be attributed to the increased bacteria diversity, stimulated probiotics (Bifidobacterium and Lactobacillus) and short-chain fatty acid (SCFA) producers (Roseburia, Faecalibaculum, and Parabacteroides) improved by anthocyanins and their metabolites, which improved the colon environment, characterized by promoted SCFAs, restored colonic mucosa, and reorganized microbial structure. Thus, anthocyanin-rich dietary intervention is a promising approach for the defensiveness in human oxidative damage and neurodegeneration.

Impact of malolactic fermentation with Lactobacillus plantarum on volatile compounds of sea buckthorn juice

Malolactic fermentation using sea buckthorn (Hippophaë rhamnoides) juice as raw material was performed with six different strains of Lactobacillus plantarum. Increasing juice pH from 2.7 to 3.5 or adapting cells to low pH (i.e., acclimation) prior to inoculation allowed malolactic fermentation with all tested strains. Moreover, reducing pH of the growth medium from 6 to 4.5 with l-malate had little or no impact on biomass production. Volatile profile of sea buckthorn juice was analyzed with HS-SPME–GC–MS before and after fermentation. A total of 92 volatiles were tentatively identified and semi-quantified from sea buckthorn juice, majority of which were esters with fruity odor descriptors. Esters and terpenes were decreased in both inoculated and control juices during incubation. Microbial activity increased the levels of acetic acid (vinegar like), free fatty acids (cheese like), ketones (buttery like), and alcohols with fruity descriptors. Conversely, aldehydes associated with “green” aroma were decreased as a result of fermentation. Juices fermented with DSM 1055 had the highest acid and alcohol content, while fermentation with DSM 13273 resulted in the highest content of ketones. Compared to inoculation with other strains, fermentation with strains DSM 16365 and DSM 100813 resulted in rapid malolactic fermentation, less production of volatile acids, and lower loss of esters and terpenes important for natural sea buckthorn flavor.

Synbiotic açaí juice (Euterpe oleracea) containing sucralose as noncaloric sweetener: Processing optimization, bioactive compounds, and acceptance during storage

This study aimed to evaluate the fermentation process of Lacticaseibacillus casei in the açaí juice, and to evaluate the addition of fructooligosaccharides and sucrose. The organic acids, anthocyanins, polyphenolic compounds, and antioxidant activity were also investigated during fermentation. Moreover, the impact of sucrose and sucralose on microbial viability and sensory acceptance of synbiotic products was evaluated during 42 days storage at refrigerated conditions. The conditions for synbiotic juice production were the initial pH of 6.1 and fermentation undertaken at 28 °C for 22 hr. During fermentation, the higher viability was obtained when a combination of 40 g/L of FOS+10 g/L of sucrose was used (9.70 ± 0.01 log CFU/mL). The lactic acid increased from 0.82 to 1.29 g/L during the fermentation while citric acid decreased from 1.05 to 0.75 g/L. The cyanidin-3-O-rutinoside, polyphenolic compounds, and antioxidant activity increased. Thus, fermentation improved the functional value of the beverage. The L. casei viability reduced from 9.71 ± 0.04 to 8.90 ± 0.06 log CFU/ mL in the juice with sucrose, and from 9.71 ± 0.04 to 8.71 ± 0.14 log CFU/ mL in the juice with sucralose. Thus, the açaí juice is a viable matrix for the synbiotic food, which allows the viability maintenance during the storage. Regarding sensory acceptance, the internal preference mapping indicated an increase in the color preference with the storage of synbiotic juices. However, the flavor and overall acceptance reduced with storage. Nevertheless, the flavor and overall acceptance of juice with sucralose were better than the juice with sucrose. After 42 days of storage, penalty analysis revealed that beverage with sucrose showed a lack of sweet taste and excess of sour taste. Thus, a high-quality açaí product with viable probiotic microorganism, high anthocyanins, and polyphenolic compounds contents could be obtained, which can be exploited for commercial use. PRACTICAL APPLICATION: Synbiotic açaí juice is a healthier alternative to consuming products containing this fruit. The inclusion of probiotic microorganisms and prebiotic fructooligosaccharides increased bioactive compounds contents during the shelf life of the juice. The sensory evaluation using the internal preference mapping revealed that the juice flavor with sucralose was better accepted than the juice formulated with addition of sucrose.

Influence of sea buckthorn juice addition on the growth of microbial food cultures

The aim of the article was to investigate the effect of sea buckthorn juice addition on the growth of microbial cultures in growth medium and juice mixtures. Pure sea buckthorn juice was found to inhibit the growth of all 11 monitored microbial cultures. Lactobacillus plantarum CCM 7039, Lactobacillus plantarum K816, Lactobacillus brevis CCM 1815 and, to a lesser extent, the probiotic strain Lactobacillus rhamnosus GG, grew in a growth medium containing a 25 % addition of sea buckthorn juice. Lactobacillus plantarum K816 and Lactobacillus brevis CCM 1815 grew better in this mixture than in pure growth medium. Moreover, we focused on finding a suitable ratio of sea buckthorn and apple juice for Lactobacillus plantarum CCM 7039, leading to malolactic fermentation, which results in an increase in the pH value and an improvement in the sensory properties of juices. The intention was to incorporate the highest possible addition of sea buckthorn juice while maintaining the viability of Lactobacillus plantarum CCM 7039 for malolactic fermentation to occur. The best results were achieved using 40 % sea buckthorn juice. Practical application of the results points to the possibility of preparing a fermented fruit beverage and a dairy product containing sea buckthorn juice. The results of this work extend the current options of sea buckthorn juice processing increasing thus the consumption of healthy juice.

Production and Characterization of a Novel Gluten-Free Fermented Beverage Based on Sprouted Oat Flour

This study investigates the use of sprouted oat flour as a substrate to develop a novel gluten-free beverage by fermentation with a probiotic (Lactobacillus plantarum WCFS1) starter culture. Physicochemical, microbiological, nutritional and sensory properties of sprouted oat fermented beverage (SOFB) were characterized. After fermentation for 4 h, SOFB exhibited an acidity of 0.42 g lactic acid/100 mL, contents of lactic and acetic acids of 1.6 and 0.09 g/L, respectively, and high viable counts of probiotic starter culture (8.9 Log CFU/mL). Furthermore, SOFB was a good source of protein (1.7 g/100 mL), β-glucan (79 mg/100 mL), thiamine (676 μg/100 mL), riboflavin (28.1 μg/100 mL) and phenolic compounds (61.4 mg GAE/100 mL), and had a high antioxidant potential (164.3 mg TE/100 mL). Spoilage and pathogenic microorganisms were not detected in SOFB. The sensory attributes evaluated received scores higher than 6 in a 9-point hedonic scale, indicating that SOFB was well accepted by panelists. Storage of SOFB at 4 °C for 20 days maintained L. plantarum viability and a good microbial quality and did not substantially affect β-glucan content. SOFB fulfils current consumer demands regarding natural and wholesome plant-based foods.

Evaluation and Application of Different Cholesterol-Lowering Lactic Acid Bacteria as Potential Meat Starters

ABSTRACT

A total of 115 isolates of lactic acid bacteria were screened from traditional fermented foods in Guizhou Province, People's Republic of China. The cholesterol removal rates of 86 isolates ranged from 7.29 to 25.66%, and 18 isolates showed a cholesterol removal rate of more than 15%. According to the results of physiological and biological tests, 13 isolates were selected to determine the fermentation performance; 9 isolates-MT-4, MT-2, PJ-15, SR2-2, SQ-4, SQ-7, ST2-2, ST2-6, and NR1-7-had high tolerance of bile salt and acid and had a survival rate of more than 96% under pH 3.0 and 0.3% bile salt. ST2-2, SR2-2, NR1-7, SQ-4, and MT-4 had high survival rate in different concentrations of NaCl and NaNO2 under different temperatures. According to BLAST comparison results of the 16S rRNA sequence in the GenBank database and the genetic distance of the 16S rRNA sequence with an ortho-connected algorithm, SR2-2, NR1-7, and ST2-2 were identified as Lactobacillus plantarum, MT-4 was identified as Lactobacillus pentosus, and SQ-4 was identified as Lactobacillus paraplantarum. Moreover, strains SQ-4 and MT-4 were added to fermented beef. Results showed that the fermented beef had delicious taste and was popular to consumers because of its proper pH, pleasant colors, high viable cell count, and suitable content of bound and immobilized water. These results provide a basis for the development of new starter formulation for the production of high-quality fermented meat products.

HIGHLIGHTS

Screening of GABA-Producing Lactic Acid Bacteria from Thai Fermented Foods and Probiotic Potential of Levilactobacillus brevis F064A for GABA-Fermented Mulberry Juice Production

Gamma-aminobutyric acid (GABA), the inhibitory neurotransmitter, can be naturally synthesized by a group of lactic acid bacteria (LAB) which is commonly found in rich carbohydrate materials such as fruits and fermented foods. Thirty-six isolates of GABA-producing LAB were obtained from Thai fermented foods. Among these, Levilactobacillus brevis F064A isolated from Thai fermented sausage displayed high GABA content, 2.85 ± 0.10 mg/mL and could tolerate acidic pH and bile salts indicating a promising probiotic. Mulberry (Morus sp.) is widely grown in Thailand. Many mulberry fruits are left to deteriorate during the high season. To increase its value, mulberry juice was prepared and added to monosodium glutamate (MSG), 2% (w/v) prior to inoculation with 5% (v/v) of L. brevis F064A and incubated at 37 °C for 48 h to obtain the GABA-fermented mulberry juice (GABA-FMJ). The GABA-FMJ obtained had 3.31 ± 0.06 mg/mL of GABA content, 5.58 ± 0.52 mg gallic acid equivalent/mL of antioxidant activity, 234.68 ± 15.53 mg cyanidin-3-glucoside/mL of anthocyanin, an ability to inhibit growth of Bacillus cereus TISTR 687, Salmonella Typhi DMST 22842 and Shigella dysenteriae DMST 1511, and 10.54 ± 0.5 log₁₀ colony-forming units (CFU)/mL of viable L. brevis F064A cell count. This GABA-FMJ was considered as a potential naturally functional food for human of all ages.

Edible plant Jiaosu: manufacturing, bioactive compounds, potential health benefits, and safety aspects

Edible plant Jiaosu (EPJ), a type of plant-based functional food fermented by beneficial bacteria, has gained publicity in recent years for its potential benefits to health. Important progress in relevant manufacturing technology has been made in the past decade with respect to raw materials, fermentation microorganisms and fermentation conditions. Current research has revealed that EPJ contains abundant nutrients and bioactive compounds, such as minerals, amino acids, polyphenols, organic acids and polysaccharides. Thus, many studies have focused on the beneficial effects of EPJ in preventing lifestyle diseases, such as hyperglycemia, hyperlipidemia, non-alcoholic fatty liver, obesity, diabetes and some cancers, although limited studies have involved the related active compounds and their protective mechanisms. Furthermore, very few studies have investigated the potential safety risks associated with the consumption of such food. In this review, we present a brief summary of the current research progress pertaining to the manufacturing, bioactive compounds, potential health benefits and safety aspects of EPJ. However, as a result of the complex components in EPJ, further studies on the bioactive compounds with relevant beneficial effects in EPJ and the safety evaluations of EPJ consumption are needed. © 2020 Society of Chemical Industry.

Mitigation of relative humidity (RH) on phytochemicals and functional groups of dried pineapple (Ananas comosus) slices

As part of finding a mechanism to ameliorate the decomposition of phytochemicals and antioxidant in drying processing, this research was conducted. To achieve this, pineapple slices was dried using relative humidity (RH) dryer at varied temperature (60–80 °C) combined with RH (10–30%) conditions. The results revealed that higher RH retained with significantly difference (p <0.05) the phytochemical and antioxidant concentrations and preserved the color and functional groups of dried pineapple under varying drying temperatures. The result also shows that concentrations of these compounds may differ as a result of disparities in the chemical composition which may be worsening by drying conditions such as higher temperature and lower RH. In effect, RH could savage the intensity of losses of these compounds and could therefore play a critical role in drying technology. Practical application: The loss of phytochemicals including polyphenols and antioxidant remains one of the challenging phenomena in drying technology. This research finds ameliorative option for mitigating against the loss of polyphenols and antioxidant by exploring the use of relative humidity (RH). The result shows that RH could savage the intensity of loss of these compounds and could therefore play a critical role in drying technology.

Lactobacillus plantarum PMO 08 as a Probiotic Starter Culture for Plant-Based Fermented Beverages

Lactobacillus plantarum PMO 08 was evaluated as a starter culture for plant-based probiotic beverages. Its viability under various culture conditions and acidification ability in standardized tomato medium, fermentation parameters, and beverage properties were assessed. Lactobacillus plantarum PMO 08 could grow under various culture conditions; there was a high correlation between the incubation time to reach the optimal conditions and the inoculation concentration of lactic acid bacteria (LAB) (r² = 0.997). Acidity (0.958 ± 0.002%) and LAB count (9.78 ± 0.14 Log₁₀ CFU/mL) were significantly higher when fermented with L. plantarum than with the yogurt starter culture. A survival rate of 96% and 95% in artificial gastric juice and artificial intestinal juice, respectively, indicated that the probiotic requirements were met. The total polyphenol and glutamine content, and antioxidant activity increased after fermentation. The proline content significantly increased in L. plantarum PMO 08- fermented beverage. Thus, L. plantarum PMO 08 is an effective starter culture for non-dairy probiotic beverages whose functional quality may be improved by fermentation.

Fruits and fruit by-products as sources of bioactive compounds. Benefits and trends of lactic acid fermentation in the development of novel fruit-based functional beverages

Current awareness about the benefits of a balanced diet supports ongoing trends in humans towards a healthier diet. This review provides an overview of fruits and fruit-by products as sources of bioactive compounds and their extraction techniques, and the use of lactic acid fermentation of fruit juices to increase their functionality. Fruit matrices emerge as a technological alternative to be fermented by autochthonous or allochthonous lactic acid bacteria (LAB such as Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and other Lactobacillus species), and also as probiotic vehicles. During fermentation, microbial enzymes act on several fruit phytochemicals producing new derived compounds with impact on the aroma and the functionality of the fermented drinks. Moreover, fermentation significantly reduces the sugar content improving their nutritional value and extending the shelf-life of fruit-based beverages. The generation of new probiotic beverages as alternatives to consumers with intolerance to lactose or with vegan or vegetarian diets is promising for the worldwide functional food market. An updated overview on the current knowledge of the use of fruit matrices to be fermented by LAB and the interaction between strains and the fruit phytochemical compounds to generate new functional foods as well as their future perspectives in association with the application of nanotechnology techniques are presented in this review.

The effect of fermented Huyou juice on intestinal microbiota in a high-fat diet-induced obesity mouse model

This study mainly discussed the effect of fermented Huyou juice (FHJ) on modulating the intestinal microbiota of human, and anti-obesity mechanisms. Through the way of metagenomics, the effect of FHJ on gut flora has been summarized with a mice model of obesity induced by human flora-associated (HFA) high-fat diet. The results showed that the FHJ ameliorated the gut dysbiosis caused by obesity. When receiving FHJ treatment, a dramatic decrease in Firmicutes/Bacteroidetes occurred. What's more, having experienced 8 weeks of FHJ intervention, KEGG pathways of two-component system, ATP-binding cassette (ABC) transporters, and biosynthesis of amino acids made the most differentially expressed genes more abundant, the unigene numbers are 16781,480, and 1,221, respectively. Our results may be of great significance to the use of FHJ which serves as a functional fermented beverage product with the underlying effect of treating the obesity induced by high-fat diet. The FHJ helps to improve the host health by regulating the intestinal flora and affecting some metabolic pathways. PRACTICAL APPLICATIONS: The fermentation of Huyou juice is one of the important ways to develop and utilize fruit resources. It is a common way of fruit and vegetable juice fermentation with mixed strains. After fermentation, the juice produces a large number of bioactive peptides, and sugar, toxic substances, and antinutritional material will be reduced, the nutritional value of the fruits and vegetables were improved. At the same time, the fermented juice industry could develop various functional health products, which is conducive to the transformation, upgrading, and sustainable development of Changshan Huyou.

Evaluation of fermentation assisted by Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) on antioxidant compounds and organic acids of an orange juice-milk based beverage

The impact of fermentation assisted by four different lactic acid bacteria (LAB) on polyphenols, carotenoids, organic acids, and antioxidant capacity of orange-juice milk based beverages was evaluated. Lactobacillus brevis POM, and Lactobacillus plantarum (TR-7, TR-71, TR-14) were used to promote the fermentation of the beverages for 72 h at 37 °C. The bacteria population increased with the elapse of fermentation period, except for beverages inoculated with L. plantarum TR-7. After fermentation period, total polyphenols, total carotenoids and total antioxidant capacity were increased compared to the control ones (non-fermented). Two phenolic acids (DL-3-phenylactic acid and 3-4-dihydroxyhydrocinnamic acid) and lactic acid were identified after 72 h fermentation. Overall, it is possible to conclude that orange-juice milk beverages are a good medium for the growth of L. brevis POM, and L. plantarum (TR-71, TR-14), observing higher antioxidant properties in the fermented beverages compared to the control ones.

Mutual influence of polyphenols and Lactobacillus spp. bacteria in food: a review

This paper presents the effect of polyphenols on microorganisms inhabiting the human gastrointestinal tract (mainly bacteria belonging to the Lactobacillus genus) and pathogenic microorganisms classified as the most common food contaminants. Plant secondary metabolites have the ability to modulate the growth of many microorganisms. Due to the metabolic changes induced by their presence in the environment, many pathogenic microorganisms are unable to grow, which in turn cause a significant reduction in their pathogenic potential. These processes include primarily the induction of ruptures in the cell membrane and disturbance of cell respiration. Often, the lack of integrity of cell membranes also leads to the disturbance of intracellular homeostasis and leakage of cellular components, such as proteins, ATP molecules or intracellular ions. Autoxidizing polyphenols also act as pro-oxidative substances. Hydrogen peroxide formed in the process of oxidation of polyphenolic compounds acts as a bactericidal substance (by induction of DNA breaks). With regard to intestinal microbiota, polyphenols are considered prebiotic substances that increase the number of commensal bacteria. They can positively influence the growth of Lactobacillus bacteria, which have the ability to metabolize undigested antioxidants in the digestive tract of humans and animals. Depending on the pH of the environment and the presence of ions, plant polyphenols in the human digestive tract can act as substances with antioxidant potential or become pro-oxidants. Thus, combining functional food with polyphenols and Lactobacillus bacteria not only protects food products against the development of undesirable and pathogenic microbiota, but also has a positive effect on human health. The paper also describes the possibility of changes in the genome of Lactobacillus bacteria (under the influence of polyphenols) and the influence of Lactobacillus spp. bacteria on the antimicrobial properties of polyphenols. The enzymatic abilities of bacteria of the genus Lactobacillus, which influence the transformation of polyphenolic compounds, were also described.

Biotransformation of two citrus flavanones by lactic acid bacteria in chemical defined medium

Microbial processes are being developed to transform flavonoid glycosides to varieties of metabolites with higher bioavailability. The aim of this study was to determine the metabolic activity and survival of five lactic acid bacteria (LAB) stains (L. rhamnosus LRa05, L. casei LC89, L. plantarum N13, L. acidophilus LA85, and L. brevis LB01) in two different citrus flavanone standards (hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside). The enzymatic activity, metabolites, antioxidant activities, and α-glucosidase inhibition property in the two standards were also investigated before and after incubated with LAB. The medium contained standards permitted survival of the five LAB stains. All strains exhibited β-glucosidase activity. Of the five LAB strains tested, just L. plantarum N13 and L. brevis LB01 have the ability to metabolize hesperetin-7-O-rutinoside, only L. plantarum N13, L. acidophilus LA85, and L. brevis LB01 could metabolize naringenin-7-O-rutinoside, moreover, L. acidophilus LA85l was the strain with the highest biotransformation ratio of naringenin-7-O-rutinoside. L. acidophilus LA85 and L. plantarum N13 can degrade naringenin-7-O-rutinoside into naringenin. L. brevis LB01 can degrade hesperetin-7-O-rutinoside into hesperetin, 3-(4'-hydroxyphenyl)-2-propenoic acid, 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid, and 3-(4'-hydroxyphenyl)propionic acid. Incubation of L. acidophilus LA85 in naringenin-7-O-rutinoside solution supposed no apparent influence in the biological activities that tested. L. acidophilus LA85 may potentially contribute to the bioavailability of citrus flavanones, and to be applied as functional cultures to obtain more bioavailable and bioactive metabolites in food products or in the human gastrointestinal tract.

Pretreatment methods affecting the color, flavor, bioactive compounds, and antioxidant activity of jujube wine

In the case of wine production, the selection of optimal pretreatment methods and starter cultures are the 2 key points before fermentation. In this research, the fresh jujube was separately underwent alcoholic fermentation at 20°C with 3 different pretreatment methods (with peel, without peel, and juice) and 5 different starter cultures, respectively. Color analysis, electronic sense analysis, bioactive compound analysis, and antioxidant activity analysis combined with multivariate statistical analysis were applied to evaluated the effects of pretreatment methods and starter cultures on the overall quality of jujube wine. It was found that both pretreatment methods and starter cultures have effects on the quality of jujube wines, in which pretreatment methods have much more significant effects. The jujube wines fermented with different pretreatment methods were classified clearly by their overall quality, and that of the jujube wines fermented with peel was the best among all, since it can not only enhance the color and flavor quality of the wine, but also maximize the preservation of bioactive compounds and antioxidant activity of jujube for better consumer acceptance. This will provide a theoretical reference and application basis for the quality improvement of jujube wine.

Papaya Fruit Pulp and Resulting Lactic Fermented Pulp Exert Antiviral Activity against Zika Virus

There are a several emerging and re-emerging RNA viruses that are prevalent around the world for which there are no licensed vaccines or antiviral drugs. Zika virus (ZIKV) is an example of an emerging virus that has become a significant concern worldwide because of its association with severe congenital malformations and neurological disorders in adults. Several polyphenol-rich extracts from plants were used as nutraceuticals which exhibit potent in vitro antiviral effects. Here, we demonstrated that the papaya pulp extracted from Carica papaya fruit inhibits the infection of ZIKV in human cells without loss of cell viability. At the non-cytotoxic concentrations, papaya pulp extract has the ability to reduce the virus progeny production in ZIKV-infected human cells by at least 4-log, regardless of viral strains tested. Time-of-drug-addition assays revealed that papaya pulp extract interfered with the attachment of viral particles to the host cells. With a view of preserving the properties of papaya pulp over time, lactic fermentation based on the use of bacterial strains Weissella cibaria 64, Lactobacillus plantarum 75 and Leuconostoc pseudomesenteroides 56 was performed and the resulting fermented papaya pulp samples were tested on ZIKV. We found that lactic fermentation of papaya pulp causes a moderate loss of antiviral activity against ZIKV in a bacterial strain-dependent manner. Whereas IC₅₀ of the papaya pulp extract was 0.3 mg/mL, we found that fermentation resulted in IC₅₀ up to 4 mg/mL. We can conclude that papaya pulp possesses antiviral activity against ZIKV and the fermentation process has a moderate effect on the antiviral effect.

Biotransformation of phenolic profiles and improvement of antioxidant capacities in jujube juice by select lactic acid bacteria

The objective of this study was to investigate the effects of four commercial lactic acid bacteria (LAB), namely L. acidophilus, L. casei, L. helveticus and L. plantarum, on the phenolic profiles, antioxidant capacities and flavor profiles of jujube juices prepared from two crop varieties (Ziziphus Jujuba cv. Muzao and Hetian). Results showed that both jujube juices were excellent matrices for LAB growth with more than 11 log CFU/mL of viable counts at the end of fermentation. LAB fermentation dramatically increased total phenolic content, while decreased total flavonoid content of jujube juices. However, antioxidant capacities based on DPPH and FRAP methods were significantly improved by LAB fermentation and positively correlated with caffeic acid and rutin contents. Furthermore, a total of 74 volatile compounds were identified and increased in total content by LAB fermentation, which resulted in 22 and 19 new flavor volatiles formation in Muzao juice and Hetian juice, respectively.

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

BACKGROUND

Lactic acid fermentation has been widely used to improve the nutritional and functional properties of food products. Cherry silverberry (Elaeagnus multiflora Thunb.) is considered as an invasive plant species with known medicinal and functional properties. In this study, improvement of the biological activity and health benefits of cherry silverberry fruit through lactic acid fermentation was investigated.

RESULTS

Extracts of cherry silverberry fruits fermented by pure cultures of Lactobacillus plantarum KCTC 33131 and L. casei KCTC 13086 exhibited favorable physicochemical properties and enhanced phytochemical content, antioxidant properties (DPPH radical scavenging activity, reducing power, superoxide dismutase-like property and hydrogen peroxide scavenging activity) and α-glucosidase and tyrosinase enzyme inhibitory activity as compared with unfermented fruits. Despite a decrease in the specific phenolic acid contents among the fermented samples, the cherry silverberry fruit fermented by mixed cultures of L. plantarum and L. casei contained superior total polyphenols (3.78 ± 0.22 mg GAE g^-1 ) and total (0.66 ± 0.12 mg QE g^-1 ) and individual flavonoid contents in comparison with fruits fermented by single cultures and unfermented ones. Multivariate analysis also showed strong association among total phytochemical contents and biological activities.

CONCLUSIONS

This work has elucidated the effect of fermentation with L. plantarum KCTC 33131 and L. casei KCTC 13086 on the improvement of the physicochemical properties and biological activity of cherry silverberry fruit. It also revealed the potential application of fermented cherry silverberry in the production of food materials beneficial for health. © 2020 Society of Chemical Industry.