Impact of lactic acid fermentation on acids, sugars, and phenolic compounds in black chokeberry and sea buckthorn juices

Malolactic fermentation in lingonberry juice and its use as a preservative

Lingonberry is a common wild berry that is often sold as jams and beverages. It naturally contains high amounts of the weak acid preservative benzoic acid making it an interesting ingredient for shelf-life extension. Despite this, their use as a raw ingredient is limited by the inherently intense sour taste. This study aimed to improve the taste of lingonberry juice by subjecting it to malolactic fermentation in order to reduce the sourness, and to investigate the benzoic acid in lingonberries as a natural preservative in juice blends by determining the microbial stability. After initial screening of lactic acid bacteria, a Lactiplantibacillus plantarum strain was used as the starter for subsequent investigations. Upon raising the pH, all malic acid was completely converted to lactic acid after seven days. The fermented juice was mixed with blackcurrant juice in different proportions. Challenge tests of the blends showed Listeria monocytogenes could not grow in any juice samples, while Candida albicans only grew in the pure blackcurrant juice. Aspergillus brasiliensis growth was delayed in all samples containing benzoic acid in a concentration-dependent manner. The sourness and astringency were substantially reduced in the juice with added L. plantarum compared to the unfermented juice.

A new plant-based probiotic from juá: Source of phenolics, fibers and antioxidant properties

The objective of this study was to evaluate the viability of juá pulp for fermentation by monoculture L. casei (Lc - 01) and L. acidophilus (La - 05) and co-culture (25 and 37 °C) for 72 h. Viable strain values (> 7 log CFU/g), pH reduction (below 3.7), fructose and glucose and increased of lactic acid showed that the pulp of juá served as a good matrix for fermentation. Catechin, epicatechin, epigallocatechin procyanidin B1, and gallic acid were the main phenolics that contributed to antioxidant activity. Fermentation by mono or co-culture increased or reduced the content of phenolics and antioxidant activity. Results showed that culture, time and temperature have effects in the fermentation of juá pulp. The co-cultivation of La - 05 + Lc - 01 contributed to improving the bioaccessibility of gallic acid (72.9%) of the jua pulp. Finding indicate juá pulp as a promising substrate to obtaining a new probiotic plant-based fermented beverage.

Evaluation of black grape pomace, a fruit juice by-product, in shalgam juice production: Effect on phenolic compounds, anthocyanins, resveratrol, tannin, and in vitro antioxidant activity

The aims of this research were to investigate the usability of black grape pomace in the production of shalgam juice, which is a traditional fermented Turkish beverage, to transform the pomace into the high value-added product and to enrich the shalgam juice with phenolic compounds. Black grape pomace and black carrot were used as the sources of polyphenols and five different formulations were obtained according to the amounts of black carrot and black grape pomace. During the fermentation, the samples were taken at different periods and analyzed for anthocyanins, phenolic compounds, antioxidant activity, and tannin content. Gentisic, caffeic, ferulic, coumaric, and chlorogenic acids, catechin, glucosides of kaemferol and isorhamnetin, resveratrol, rutin, cyanidin-3-xylosylglucosylgalactoside, cyanidin-3-xylosylgalactoside, cyanidin-3-xylosylglucosylgalactoside acylated with sinapic acid, ferulic acid, or coumaric acid, and glucosides of cyanidin, petunidin, and malvidin were identified in the shalgam juices that contained both black grape pomace and black carrot in their formulation. Some of these polyphenols were not detected detect in the shalgam juices that were produced from only the black carrot or black grape pomace. During the fermentation, a decrease in the amount of anthocyanins originated from black carrots and an increase in the amount of anthocyanins orginated from black grape pomace were determined. Black grape pomace addition to the formulation before the fermentation caused an increase in the amount of tannin in the shalgam juice samples. Consequently, it is thought that black grape pomace can be fruitfully evaluated in shalgam juice production and can be enhanced by polyphenolic profile of shalgam juice.

Enhancing the Quality of Low-Alcohol Navel Orange Wine through Simultaneous Co-Fermentation Using Saccharomyces cerevisiae SC-125, Angel Yeast SY, and Lactiplantibacillus plantarum BC114

To date, there has been limited research on the interactive effects of yeast and lactic acid bacteria (LAB) on the sensory qualities of navel orange wine. In this study, using Jintang navel orange juice as the raw material, multi-microbial fermentation was conducted with Saccharomyces cerevisiae SC-125 and Angel yeast SY, as well as Lactiplantibacillus plantarum BC114. Single yeast and co-fermentation with Lactiplantibacillus plantarum were used as the control groups. The research aimed to investigate the physicochemical parameters of navel orange wine during fermentation. Additionally, headspace solid-phase microextraction gas chromatography-mass spectrometry (HP-SPME-GC-MS) was employed to determine and analyze the types and levels of flavor compounds in the navel orange wines produced through the different fermentation methods. The co-fermentation using the three strains significantly enhanced both the quantity and variety of volatile compounds in the navel orange wine, concomitant with heightened total phenol and flavonoid levels. Furthermore, a notable improvement was observed in the free radical scavenging activity. A sensory evaluation was carried out to analyze the differences among the various navel orange wines, shedding light on the impact of different wine yeasts and co-fermentation with LAB on the quality of navel orange wines.

Non-volatile and volatile compound changes in blueberry juice inoculated with different lactic acid bacteria strains

BACKGROUND

Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice.

RESULTS

This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L-1 in La-fermented blueberry juice, 5.86 g L-1 in Lp-fermented blueberry juice, and 6.41 g L-1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography-ion mobility spectrometry (GC-IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC-IMS data effectively differentiated between unfermented and fermented blueberry juices.

CONCLUSION

This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. © 2023 Society of Chemical Industry.

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.

Lactobacillus co-fermentation of Cerasus humilis juice alters chemical properties, enhances antioxidant activity, and improves gut microbiota

Fermentation with Lactobacillus has been shown to improve the nutritional value of juice. In this study, Cerasus humilis juice was fermented using two commercial probiotics, namely, Lactobacillus acidophilus and Lactobacillus plantarum. The total antioxidant capacity (TAOC), viable count, chemical properties, antioxidant activity after in vitro digestion, and alterations in the gut microbiota composition of the fermented juice were investigated. After fermentation, the TAOC increased from 107.66 U mL-1 to 126.72 U mL-1; viable count increased from 5.85 lg (CFU mL-1) to 8.17 lg (CFU mL-1); and the contents of total phenols, total flavonoids, proanthocyanins, four organic acids, and 29 amino acids had changed. Overall, 47 compounds were identified in the juice, 20 of which were enriched after fermentation. Furthermore, Lactobacillus co-fermentation improved the antioxidant properties of the juice after in vitro digestion and increased the abundance of probiotics to regulate the gut microbiota. These findings illustrate the potential use of Lactobacillus acidophilus and Lactobacillus plantarum in the co-fermentation of C. humilis juice to enhance its nutritional and functional properties.

Adjustment of impact phenolic compounds, antioxidant activity and aroma profile in Cabernet Sauvignon wine by mixed fermentation of Pichia kudriavzevii and Saccharomyces cerevisiae

Mixed fermentation using saccharomyces cerevisiae and non-saccharomyces cerevisiae has become one of the main research strategies to improve wine aroma. Hence, this study applied the mixed fermentation technique using Pichia kudriavzevii and Saccharomyces cerevisiae to brew Cabernet Sauvignon wine and to investigate the effects of inoculation timing and inoculation ratio on the polyphenolics, antioxidant activity and aroma of the resulting wine. The results showed that mixed fermentation significantly improved the amounts of flavan-3-ols. In particular, S1:5 had the highest amounts of (-)-catechin and procyanidin B1 (73.23 mg/L and 46.59 mg/L), while S1:10 had the highest (-)-epicatechin content (57.95 mg/L). Meanwhile, S1:10 showed the strongest FRAP, CUPRAC and ABTS + activities (31.46 %, 25.38 % and 13.87 % higher than that of CK, respectively). In addition, mixed fermentation also increased the amounts of phenylethanol, isoamyl alcohol and ethyl esters, which enhanced the rose-like and fruity flavor of wine. This work used a friendly non-saccharomyces cerevisiae alongside appropriate inoculation strategies to provide an alternative approach for improved wine aroma and phenolic profile.

Improving flavor, bioactivity, and changing metabolic profiles of goji juice by selected lactic acid bacteria fermentation

Lactic acid bacteria (LAB) have exhibited strain/species specificity for different food matrices. We investigated the impact of LAB fermentation on the flavor, chemical profile, and bioactivity of goji juice. The colony counts of five selected strains reached above 8.5 log CFU/mL. The fermentation increased the organic acids, decreased the sugars, and improved the sensory quality of goji juice. The majority of the strains had increased acetic acid, heptanoic acid, ethyl phenylacetate, and linalool levels. Specific strains suppressed α-glucosidase and pancreatic lipase activities and increased the antioxidant activities of fermented goji juice. Based on non-targeted metabolomics and activities, 23 important differential metabolites were screened among 453 metabolites. The quantification results showed that isoquercitrin and m-coumaric content varied among strains, reflecting the strain specificity in flavone and flavonol biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis. These findings will provide useful information for fermented goji juice biochemistry research.

Dynamics changes in physicochemical properties, volatile metabolites, non-volatile metabolites, and physiological functions of barley juice during Bifidobacterium infantis fermentation

The purpose of this research was to explore the potential of Bifidobacterium infantis fermentation to modify the composition and physiological properties of barley juices. B. infantis JFM12 showed a potent capability to decrease the total sugar contents from 0.39 ± 0.01 mg/mL to 0.35 ± 0.01 mg/mL within 24 h of fermentation. The volatile metabolite profiles were enriched after B. infantis JFM12 fermentation, leading to the changes of 13 aldehydes, 11 ketones, 10 acids, 7 alcohols, and 6 esters. A total of 98 key non-volatile metabolites were identified in the barley juice between before and after B. infantis JFM12 fermentation, including 80 non-volatile metabolites that were remarkably increased and 18 non-volatile metabolites that were remarkably reduced. Furthermore, the antioxidant activities and lipase inhibitory activities of fermented barley juice were higher than those of unfermented barley juice. Overall, B. infantis JFM12 was beneficial in increasing the quality of barley juice.

In Vitro Evaluation of Antioxidant and Protective Potential of Kombucha-Fermented Black Berry Extracts against H2O2-Induced Oxidative Stress in Human Skin Cells and Yeast Model

The fruits of R. nigrum L., A. melanocarpa Michx., and V. myrtillus L. are well-known natural plant materials with proven antioxidant activity. This work attempts to compare the antioxidant properties of extracts of these plants and ferments obtained during their fermentation using a consortium of microorganisms referred to as kombucha. As part of the work, a phytochemical analysis of extracts and ferments was carried out using the UPLC-MS method and the content of the main components was determined. The antioxidant properties of the tested samples and their cytotoxicity were assessed with the use of DPPH and ABTS radicals. The protective effect against hydrogen peroxide-induced oxidative stress was also assessed. The possibility of inhibiting the increase in the intracellular level of reactive oxygen species was carried out on both human skin cells (keratinocytes and fibroblasts) and the yeast Saccharomyces cerevisiae (wild-type strains and sod1Δ deletion mutants). The conducted analyses showed that the ferments obtained are characterized by a greater variety of biologically active compounds; in most cases they do not cause a cytotoxic effect, show strong antioxidant properties, and can reduce oxidative stress in both human and yeast cells. This effect depends on the concentration used and the fermentation time. The results obtained indicate that the tested ferments can be considered as an extremely valuable raw material protecting cells against the negative effects of oxidative stress.

Aroma profiles of sweet cherry juice fermented by different lactic acid bacteria determined through integrated analysis of electronic nose and gas chromatography-ion mobility spectrometry

Sweet cherries are popular among consumers, with a recent explosion in sweet cherry production in China. However, the fragility of these fruits poses a challenge for expanding production and transport. With the aim of expanding the product categories of sweet cherries that can bypass these challenges, in this study, we prepared sweet cherry juice fermented by three different lactic acid bacteria (LAB; Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus rhamnosus GG), and evaluated the growth, physiochemical, and aroma characteristics. All three strains exhibited excellent growth potential in the sweet cherry juice; however, Lactobacillus acidophilus and Lactobacillus plantarum demonstrated more robust acid production capacity and higher microbial viability than Lactobacillus rhamnosus GG. Lactic acid was the primary fermentation product, and malic acid was significantly metabolized by LAB, indicating a transition in microbial metabolism from using carbohydrates to organic acids. The aroma profile was identified through integrated analysis of electronic nose (E-nose) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) data. A total of 50 volatile compounds characterized the aromatic profiles of the fermented juices by HS-GC-IMS. The flavor of sweet cherry juice changed after LAB fermentation and the fruity odor decreased overall. Lactobacillus acidophilus and Lactobacillus plantarum significantly increased 2-heptanone, ethyl acetate, and acetone contents, bringing about a creamy and rummy-like favor, whereas Lactobacillus rhamnosus GG significantly increased 2-heptanone, 3-hydroxybutan-2-one, and 2-pentanone contents, generating cheesy and buttery-like odors. Principal component analysis of GC-IMS data and linear discriminant analysis of E-nose results could effectively differentiate non-fermented sweet cherry juice and the sweet cherry juice separately inoculated with different LAB strains. Furthermore, there was a high correlation between the E-nose and GC-IMS results, providing a theoretical basis to identify different sweet cherry juice formulations and appropriate starter culture selection for fermentation. This study enables more extensive utilization of sweet cherry in the food industry and helps to improve the flavor of sweet cherry products.

Effects of Lactic Acid Bacteria Fermentation on Physicochemical Properties, Functional Compounds and Antioxidant Activity of Edible Grass

Fermented foods are known worldwide for their functional health properties. In order to promote the relative product development of edible grass, Lactobacillus plantarum (Lp) and Lactobacillus rhamnosus (Lr) were used to ferment edible grass in this study. Effects of fermentation using Lp and Lr in monoculture and binary mixture on physicochemical properties, the contents of functional compounds and the antioxidant activity of edible grass at different fermentation times were investigated by colorimetric method and high-performance liquid chromatography (HPLC). Results show that the pH value and total sugar content of the three fermented edible grasses at the 4th day were lower than those of unfermented water extract (defined as the control sample) and kept almost unchanged at the 7th day. The total polyphenol content and total flavonoid content of the three fermented edible grasses were lower than those of the control sample by the oxidation of phenolic compounds caused by polyphenol oxidases. The highest soluble protein content and superoxide dismutase (SOD) activity were found in the binary mixture of Lp and Lr fermentation at the 7th day, which were respectively 11 and 1.78 times higher than those of control sample. The oxalic acid content of all fermented edible grasses shows a significant decrease with increasing fermentation time, especially for the binary mixture at the 7th day, reaching only 24% of the control sample. However, the contents of lactic acid and succinic acid of the three fermented edible grasses were higher than those of the control sample because of the metabolism of the microorganism. Functional compounds including soluble protein, SOD, lactic acid and succinic acid played the main positive roles in antioxidation, while oxalic acid had a negative correlation with antioxidation. Therefore, the antioxidant activity of edible grass was dramatically enhanced by Lactobacillus strain fermentation.

Effect of Starters on Quality Characteristics of Hongsuantang, a Chinese Traditional Sour Soup

Hongsuantang (HST) is a traditional Chinese and famous sour soup. However, the quality of naturally fermented HST is not controllable. We investigated the effects of different lactic acid bacteria starters on HST acid production, color, antioxidant capacity, total phenols, total carotenoids, organic acids, volatile substances, and sensory properties to determine the most suitable strain for HST production. The results showed that among the seven lactic acid bacteria strains used to inoculate fermented HST, Lactiplantibacillus plantarum SQ-4 exhibited the most excellent fermentation characteristics. SQ-4 rapidly reduced the HST’s pH by 0.77. It significantly increased the HST’s color, organic acids, total phenols, carotenoids, lycopene, and free radical scavenging ability. Lactiplantibacillus plantarum SQ-4 was an excellent starter for preparing HST with good acid production capacity, moderate sourness and spiciness, and good sensory and other characteristics. Each starter produces its distinct flavor components. α-Pinene, myrcene, α-copaene, and guaiol were vital aroma compounds in HST fermentation by the starter. This study laid a foundation for selecting HST starters and potential industrial production.

Nutritional Evaluation of Sea Buckthorn “Hippophae rhamnoides” Berries and the Pharmaceutical Potential of the Fermented Juice

Sea buckthorn is a temperate bush plant native to Asian and European countries, explored across the world in traditional medicine to treat various diseases due to the presence of an exceptionally high content of phenolics, flavonoids and antioxidants. In addition to the evaluation of nutrients and active compounds, the focus of the present work was to assess the optimal levels for L. plantarum RM1 growth by applying response surface methodology (RSM), and to determine the impact of juice fermentation on antioxidant, anti-hypertension and anticancer activity, as well as on organoleptic properties. Sea buckthorn berries were shown to contain good fiber content (6.55%, 25 DV%), high quality of protein (3.12%, 6.24 DV%) containing: histidine, valine, threonine, leucine and lysine (with AAS 24.32, 23.66, 23.09, 23.05 and 21.71%, respectively), and 4.45% sugar that provides only 79 calories. Potassium was shown to be the abundant mineral content (793.43%, 22.66 DV), followed by copper and phosphorus (21.81 and 11.07 DV%, respectively). Sea buckthorn juice exhibited a rich phenolic, flavonoid and carotenoid content (283.58, 118.42 and 6.5 mg/g, respectively), in addition to a high content of vitamin C (322.33 mg/g). The HPLC profile indicated that benzoic acid is the dominant phenolic compound in sea buckthorn berries (3825.90 mg/kg). Antioxidant potentials (DPPH and ABTS) of sea buckthorn showed higher inhibition than ascorbic acid. Antimicrobial potentials were most pronounced against Escherichia coli BA12296 (17.46 mm). The probiotic growth was 8.5 log cfu/mL, with juice concentration, inoculum size and temperature as the main contributors to probiotic growth with a 95% confidence level. Fermentation of sea buckthorn juice with L. plantarum RM1 enhanced the functional phenolic and flavonoid content, as well as antioxidant and antimicrobial activities. The fermentation with L. plantarum RM1 enhanced the anti-hypertension and anticancer properties of the sea buckthorn juice and gained consumers’ sensorial overall acceptance.

Biological and Cosmetical Importance of Fermented Raw Materials: An Overview

The cosmetics industry is currently looking for innovative ingredients with higher bioactivity and bioavailability for the masses of natural and organic cosmetics. Bioferments are innovative ingredients extracted from natural raw materials by carrying out a fermentation process with appropriate strains of microorganisms. The review was conducted using the SciFinder database with the keywords “fermented plant”, “cosmetics”, and “fermentation”. Mainly bioferments are made from plant-based raw materials. The review covers a wide range of fermented raw materials, from waste materials (whey with beet pulp) to plant oils (F-Shiunko, F-Artemisia, F-Glycyrrhiza). The spectrum of applications for bioferments is broad and includes properties such as skin whitening, antioxidant properties (blackberry, soybean, goji berry), anti-aging (red ginseng, black ginseng, Citrus unshiu peel), hydrating, and anti-allergic (aloe vera, skimmed milk). Fermentation increases the biochemical and physiological activity of the substrate by converting high-molecular compounds into low-molecular structures, making fermented raw materials more compatible compared to unfermented raw materials.

Effect of Six Lactic Acid Bacteria Strains on Physicochemical Characteristics, Antioxidant Activities and Sensory Properties of Fermented Orange Juices

Six lactic acid bacteria strains were used to study the effects on physicochemical characteristics, antioxidant activities and sensory properties of fermented orange juices. All strains exhibited good growth in orange juice. Of these fermentations, some bioactive compositions (e.g., vitamin C, shikimic acid) and aroma-active compounds (e.g., linalool, 3-carene, ethyl 3-hydroxyhexanoate, etc.) significantly increased in Lactiplantibacillus plantarum and Lactobacillus acidophilus samples. DPPH free radical scavenging rates in L. plantarum and Lacticaseibacillus paracasei samples increased to 80.25% and 77.83%, respectively. Forty-three volatile profiles were identified, including 28 aroma-active compounds. 7 key factors significantly influencing sensory flavors of the juices were revealed, including D-limonene, linalool, ethyl butyrate, ethanol, β-caryophyllene, organic acids and SSC/TA ratio. The orange juice fermented by L. paracasei, with more optimization aroma-active compounds such as D-limonene, β-caryophyllene, terpinolene and β-myrcene, exhibited more desirable aroma flavors such as orange-like, green, woody and lilac incense, and gained the highest sensory score. Generally, L. paracasei fermentation presented better aroma flavors and overall acceptability, meanwhile enhancing antioxidant activities.

Production and Shelf-Life Study of Probiotic Caja (Spondias mombin L.) Pulp Using Bifidobacterium animalis ssp. Lactis B94

The highly nutritional caja fruit (Spondias mombin L.) is an accessible source of vitamins and antioxidants that are indispensable for the human diet. The objective of the present work was to study the production of a probiotic caja pulp using Bifidobacterium animalis ssp. lactis B94. Firstly, a kinetic study was performed on the fermentation of the caja pulp with Bifidobacterium animalis ssp. lactis B94 to determine the optimum conditions of the process. Growth kinetics revealed that the ideal time for ending the fermentation would be at 22 h because it corresponds to the end of the exponential phase. Both the whole pulp and the probiotic pulp were characterized for pH, acidity, total soluble solids, water content, phenolic content, reducing carbohydrates, ascorbic acid, and total carotenoids. Physicochemical characterization revealed similar results between the whole and the probiotic pulp. The stability test demonstrated that the probiotic pulp is stable and preserved the probiotic attributes of the final product. In conclusion, our results reveal that caja pulp can be considered a favorable medium for the Bifidobacterium animalis ssp. lactis B94 growth and consequently can be explored biotechnologically for new food products.

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

Three commercial lactic acid bacteria (LAB), namely Lactobacillus acidophilus 85 (La85), Lactobacillus helveticus 76 (Lh76) and Lactobacillus plantarum 90 (Lp90), were employed to investigate the effects on the phenolic compounds, antioxidant capacities and flavor volatiles of kiwifruit juices prepared from two cultivars (Actinidia deliciosa cv. Xuxiang and Actinidia chinensis cv. Hongyang). Results showed that both kiwifruit juices were favorable matrices for LAB growth and the colony counts remained above 9.0 log CFU/mL after fermentation. Total phenolics and flavonoids in Xuxiang and Hongyang juices were increased dramatically by Lh76. Correspondingly, antioxidant capacities based on DPPH, ABTS and FRAP methods were improved significantly and positively correlated with protocatechuic acid and catechin contents (p < 0.05), two newly formed phytochemicals in fermented kiwifruit juices. Furthermore, results of hierarchical cluster analysis revealed that flavor profiles were improved significantly by LAB, and there were noticeable differences between fermented Xuxiang and Hongyang juices.

Phenolics Profile, Antioxidant Activity and Flavor Volatiles of Pear Juice: Influence of Lactic Acid Fermentation Using Three Lactobacillus Strains in Monoculture and Binary Mixture

The aim of this study was to evaluate the effects of lactic acid fermentation using three Lactobacillus strains (Lactiplantibacillus plantarum 90, Lactobacillus helveticus 76, and Lacticaseibacillus casei 37) in monoculture and binary mixture on phenolics profile, antioxidant activity and flavor volatiles in pear juice. Results showed that the colony counts of binary mixture were higher than monoculture in fermented pear juice. The total content of phenols was increased, while that of flavonoids was decreased significantly during fermentation (p < 0.05). Antioxidant activities in fermented peer juice including DPPH and ABTS radical scavenging abilities and ferric reducing antioxidant power (FRAP) were significantly improved (p < 0.05). Binary mixture of Lactiplantibacillus plantarum 90 and Lacticaseibacillus casei 37 fermentation exhibited strong DPPH radical scavenging ability, due to the increase in vanillic acid and arbutin contents. Furthermore, lactic acid fermentation improved the formation of alcohols, esters, acids and terpenoids, and reduced the contents of aldehydes and ketones. Thirty new compounds including 15 alcohols, seven esters, five acids, and three terpenoids were observed in fermented pear juice. Hierarchical cluster revealed that flavor volatiles in pear juice were improved dramatically by Lactobacillus strains fermentation, and there were dramatic differences between monoculture and binary mixture.

Widely targeted metabolomics analysis of enriched secondary metabolites and determination of their corresponding antioxidant activities in Elaeagnus angustifolia var. orientalis (L.)Kuntze fruit juice enhanced by Bifidobacterium animalis subsp. Lactis HN-3 fermentation

Elaeagnus angustifolia var. orientalis (L.)Kuntze fruit contains a large number of naturally occurring molecules present as glycoside, methylated, and methyl ester conjugates, which should be hydolysed or transformed to become bioactive forms. For this purpose, Bifidobacterium animalis subsp. lactis HN-3 was selected to ferment Elaeagnus angustifolia var. orientalis (L.)Kuntze fruit juice (EOJ). After fermentation, the total phenolic content (TPC) and antioxidant capacity of the EOJ increased significantly compared to the non-fermented EOJ. Using widely-targeted metabolomics analysis, polyphenolic compounds involved in the flavonoid biosynthetic pathway were determined to be up-regulated in the fermented EOJ. In addition, the metabolites generated by 8 deglycosidation, 5 demethylation, 5 hydrogenation, and 28 other reactions were detected in higher concentrations in the fermented EOJ compared to the non-fermented EOJ. Interestingly, these up-regulated metabolites have higher antioxidant and other biological activities than their metabolic precursors, which provide a theoretical basis for the development of Bifidobacterium-fermented plant products with stronger functional activities.

Controlled fermentation of curly kale juice with the use of autochthonous starter cultures

The aim of this paper was to evaluate the influence of different indigenous lactic acid bacteria isolates - as a single culture or bacterial consortium - on the functional and physicochemical properties of fermented curly kale juice. All tested variants exhibited good growth parameters, manifested by efficient pH lowering, increases in acidity, and fructose and glucose metabolism, as well as a significant inhibition of pathogens. A slight increase in total phenolic content was observed, while antioxidant activity remained unchanged. L. sakei and MIX A were associated with an increase in riboflavin and pyridoxine content, while L. plantarum only contributed to an increase in vitamin B₆ content. Bioconversion of individual phenolic compounds, carotenoids, and glucosinolates strongly depended on the strain-specific metabolism. In the process, the levels of ferulic acid and other hydroxycinnamic acids were maintained, while the content of 9-cis lutein increased. Considering presented results and our previous research regarding probiotic features of LAB strains, among tested starter cultures - L. plantarum seemed to possess the best characteristics as a potential starter culture for controlled fermentation of curly kale 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.

NMR-based metabolomics approach on optimization of malolactic fermentation of sea buckthorn juice with Lactiplantibacillus plantarum

This work investigated the impact of malolactic fermentation on the metabolomic profile of sea buckthorn juice to optimize the fermentation process for flavor modification. Six strains of L. plantarum were used with varied pH of the juice, cell acclimation, and fermentation time. ¹H-NOESY spectra were acquired from fresh and fermented juices with a total of 46 metabolites identified. Less sugars and quinic acid were metabolized at pH 2.7 while oxidation of ascorbic acid was reduced at pH 3.5. l-Malic acid, essential amino acids, and nucleosides were consumed early during fermentation while sugars in general were consumed later in the fermentation. If deacidification is the main target of fermentation, strains that produce less acids and ferment less sugars, shorter fermentation time, and lower starter pH should be used. Higher starter pH and longer fermentation time promote formation of antimicrobial compounds and potentially increase antioxidant stability.

Production and Characterization of a Novel Low-Sugar Beverage from Red Jujube Fruits and Bamboo Shoots Fermented with Selected Lactiplantibacillus plantarum

Red jujube fruits and bamboo shoots are rich in many nutrients and have the advantage of high yield in China. However, the storage of fresh fruits is difficult, and there are no fermented products using both as raw materials. In order to develop the two raw materials into novel products and improve their nutritional value, this study reports the production and characterization of a beverage via fermentation of red jujube fruits and bamboo shoots with Lactiplantibacillus plantarum. L. plantarum TUST-232 was selected as the starter from several different strains by comparing pH value and the number of viable cells, which reached 8.91 log CFU/mL in the beverage fermented for 14 h at 37 °C with 0.3% inoculation. After fermentation, the beverage showed improvement in the contents of several nutrients and antioxidant indices, with a decrease of 44.10% in sucrose content, along with increases of 11.09%, 12.30%, and 59.80% in total phenolic content, total antioxidant capacity, and superoxide anion scavenging ability, respectively. These results indicate that L. plantarum fermentation of red jujube fruits and bamboo shoots could be an effective way to develop a new beverage with high nutritional value, high antioxidant capacity, and high dietary fiber content. This research provided experimental support for the development of new fermentation products with the functions of improving health and body functions.

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.

Exploitation of Sea Buckthorn Fruit for Novel Fermented Foods Production: A Review

Sea buckthorn fruit is abundant with essential nutrients and bioactive substances, yet it remains less sought after. Therefore, it is valuable to explore new ways of sea buckthorn fruit processing, which can boost consumer acceptance of sea buckthorn fruit and also lead to formulation of new functional foods. In the presented review, we summarize studies focused on development of foods utilizing sea buckthorn fruit or its components and bacterial food cultures. Firstly, we discuss the impact of malolactic fermentation on content and profile of organic acids and polyphenols of sea buckthorn fruit juice. During this process, changes in antioxidant and sensory properties are considerable. Secondly, we address the role of sea buckthorn fruit and its components in formulating novel probiotic dairy and non-dairy products. In this regard, a synergic effect of prebiotic material and probiotic bacteria against pathogens is distinguished. Overall, the potential of sea buckthorn fruit as a botanical ingredient for application in novel foods is highlighted.

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.

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.

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.

Optimization of Initial Cation Concentrations for L-Lactic Acid Production from Fructose by Lactobacillus pentosus Cells

In this study, Box-Behnken design was applied to optimize the initial concentrations of 4 cations for L-lactic acid production from fructose by homologous batch fermentation of Lactobacillus pentosus cells. The optimum initial cation concentrations were obtained as 6.542 mM Mg²⁺, 3.765 mM Mn²⁺, 2.397 mM Cu²⁺, and 3.912 mM Fe²⁺, respectively. The highest L-lactic acid yield and productivity were obtained as 0.935 ± 0.005 g/g fructose and 1.363 ± 0.021 g/(L × h), respectively, with a maximum biomass concentration of 7.97 ± 0.17 g/L. The effectiveness of the optimization by Box-Behnken design was confirmed based on the small errors between predicted results and experimental results shown as 0.3%, - 0.2%, and - 1.2%, respectively. The quadratic models with high accuracy and reliability can be applied to mathematically forecasted the fermentation performance. After the optimization, the lactic acid yield and productivity were significantly improved by 3.7% and 21.0%, respectively.

Health promoting properties and sensory characteristics of phytochemicals in berries and leaves of sea buckthorn (Hippophaë rhamnoides)

Sea buckthorn (Hippophaë rhamnoides L., SB), as a multi-functional plant, is widely grown in Asia, Europe and Canada. The berries and leaves of SB contain a diverse array of health-supporting phytochemicals, which are also related to the sensory qualities of berry and berry products. This review summarizes the biologically active key-compounds of the berries and leaves of SB, their health-promoting effects, as well as the contributions to the sensory quality of the berries. The target compounds consist of sugars, sugar derivatives, organic acids, phenolic compounds and lipophilic compounds (mainly carotenoids and tocopherols), which play an important role in anti-inflammatory and antioxidant functions, as well as in metabolic health. In addition, these compounds contribute to the orosensory qualities of SB berries, which are closely related to consumer acceptance and preference of the products. Studies regarding the bioavailability of the compounds and the influence of the processing conditions are also part of this review. Finally, the role of the sensory properties is emphasized in the development of SB products to increase utilization of the berry as a common meal component and to obtain value-added products to support human health.

An overview of the perception and mitigation of astringency associated with phenolic compounds

Astringency, as a kind of puckering, drying, or rough sensation, is widely perceived from natural foods, especially plants rich in phenolic compounds. Although the interaction and precipitation of salivary proteins by phenolic compounds was often believed as the major mechanism of astringency, a definitive theory about astringency is still lacking due to the complex oral sensations. The interaction with oral epithelial cells and the activation of trigeminal chemoreceptors and mechanoreceptors also shed light on some of the phenolic astringency mechanisms, which complement the insufficient mechanism of interaction with salivary proteins. Since phenolic compounds with different types and structures show different astringency thresholds in a certain regularity, there might be some relationships between the phenolic structures and perceived astringency. On the other hand, novel approaches to reducing the unfavorable perception of phenolic astringency have been increasingly emerging; however, the according summary is still sparse. Therefore, this review aims to: (a) illustrate the possible mechanisms of astringency elicited by phenolic compounds, (b) reveal the possible relationships between phenolic structures and perception of astringency, and (c) summarize the emerging mitigation approaches to astringency triggered by phenolic compounds. This comprehensive review would be of great value to both the understanding of phenolic astringency and the finding of appropriate mitigation approaches to phenolic astringency in future research.

Effect of wet sea buckthorn pomace utilized as an additive on silage fermentation profile and bacterial community composition of alfalfa

To effectively preserve nutrients, alfalfa silage was treated without (control) or with Lactobacillus plantarum (LP) and their mixture (LP + SBP). Results showed that SBP decreased (P < 0.05) final pH value and ammonia-N of total N, increased (P < 0.05) lactic, acetic and propionic acid contents, resulting in more residual water soluble carbohydrate and crude protein contents and less fiber content in relative to control. Moreover, SBP decreased (P < 0.05) the number of observed species, richness index of ACE and diversity index of Shannon at early stage of ensiling, while Lactobacillus plantarum, Lactococcus lactis, and/or Lactobacillus brevis dominated in silages. In particular, LP + SBP enhanced the growth of Lactococcus lactic at early stage and Lactobacillus plantarum at late stage of ensiling, resulting in higher lactic and acetic acid contents and lower propionic acid content as compared with LP. These confirmed that SBP could be used as an additive for improving silage quality of alfalfa.

Objective measures of greengage wine quality: From taste-active compound and aroma-active compound to sensory profiles

This study is sought to identify the components in greengage wine that predict the sensory properties. Taste-active compounds and aroma-active compounds of 20 commercially available greengage wines from different regions were characterized. The relationship between these compounds, wine samples and sensory attributes was modeled by partial least squares regression. The regression analysis indicated the taste-active compounds, alanine, leucine, proline, glutamic acid, lysine, malic acid, citric acid, sucrose, glucose, gallic acid, caffeic acid and tannin made a great contribution to the characteristic taste or mouthfeel of greengage wine. Meanwhile, the aroma-active compounds, including ethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, 3-methylbutanol, 5-hydroxymethylfurfural, octanoic acid and benzaldehyde, modeled well with the flavor characteristic of greengage wine. The study revealed new insights into the relationship between chemistry and wine sensory characters, which has implications for developing an objective measurement system for determining greengage wine quality.

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.