Cherimoya (Annona cherimola Miller) is a highly perishable tropical fruit rich in bioactive polyphenols, whose valorization through fermentation could enable the development of a candidate functional beverage. This study evaluated the impact of lactic fermentation on phenolic profile distribution, antioxidant capacity, in vitro inhibition of carbohydrate-digesting enzymes, and sensory acceptance of cherimoya juice. Pasteurized cherimoya juice (30%, w/v) was fermented for 48 h at 30 degrees C with three fruit-origin LAB strains: Lactiplantibacillus plantarum CRL2051, Lpb. plantarum CRL2030, and Lacticaseibacillus rhamnosus CRL2049. All strains grew efficiently in the juice matrix, reaching 8.2-8.9 log CFU/mL, while pH decreased from 4.5 to 3.5-3.7 after fermentation. Total phenolic content (1243-1382 mg GAE/L) and radical scavenging activity showed no major differences between fermented and unfermented juices (DPPH: similar to 55-58%; ABTS: similar to 71-75%). However, fermentation significantly enhanced the in vitro inhibitory activity of the juices against carbohydrate-digesting enzymes, with lower IC50 values, with a stronger effect observed for alpha-glucosidase than for alpha-amylase. LC-ESI-QToF analysis tentatively identified 37 phenolic compounds and semi-quantitatively estimated total phenolics at 1070-1203 mg/L, dominated by flavan-3-ols (catechins and procyanidins), representing >96-99% of total quantified phenols. Hedonic sensory evaluation (n = 105) showed no significant differences between unfermented juice and FChJ-CRL2051 across attributes (scores 5.1-6.6), indicating comparable consumer acceptance. Overall, lactic fermentation, particularly with CRL2051, may represent a feasible strategy for developing a fermented cherimoya-based beverage, showing enhanced in vitro carbohydrate-digesting enzyme inhibitory activity while largely preserving phenolic composition and sensory quality under the evaluated conditions.

Lactic acid bacteria (LAB) produce selenium-nanoparticles (SeNPs). However, the molecular and genetic mechanisms involved in these biotransformation processes are not yet fully understood. This work aimed to physicochemically characterize the SeNPs produced by Fructobacillus tropaeoli CRL2034 and Lactiplantibacillus plantarum CRL2051, study the differential expression of genes related to SeNPs synthesis and to analyze the relative expression of genes and proteins of selenized and non-selenized cells (control). The SeNPs produced by F. tropaeoli CRL2034 and L. plantarum CRL2051 showed an average size of 216.05 ± 19 and 286.14 ± 44 nm and ζ of –59.42 ± 5 and –56.77 ± 7 mV, respectively. The SeNPs produced showed spectroscopic signals compatible with Se–Se bonds and functional groups that confirm a biological coating composed of proteins, polysaccharides, and lipids. These SeNPs showed a dual structure, amorphous and crystalline. F. tropaeoli CRL2034 glutathione reductases and thioredoxin reductase could be involved in Se metabolism and SeNPs synthesis, while in L. plantarum CRL2051 a different strategy for SeNPs synthesis could be implicated. Selenized cells of L. plantarum differentially expressed proteins related to fatty acid metabolism and overexpressed a lysozyme/muramidase, which could be related to membrane and cell wall adaptation to Se-induced stress. Selenized cells of both strains repressed energy metabolism-related enzymes, which could be harmful to cell survival. The SeNPs produced by both LAB strains have suitable characteristics to be used in nutrition and/or biomedicinal applications. Moreover, the selenized LAB strains could have improved stress resistance properties and/or better adhesion to intestinal cells.

Pomegranate is rich in polyphenols with demonstrated antioxidant activity and health benefits, including protection against intestinal disorders. This study evaluated the impact of fermentation with two Lactiplantibacillus plantarum strains isolated from fruits (CRL2051 and CRL2030) on the phenolic composition of pomegranate juice (PJ) after 48 h of incubation at 30 degrees C (PJ48), in comparison with fresh unfermented juice (PJ0) and juice stored for 48 h at 30 degrees C (PJ48). Both strains successfully grew in the pomegranate matrix, maintaining high viable counts and preserving total phenolic content, although CRL2051 conserved the integrity of most phenolic groups more effectively than CRL2030. Based on these results, FPJ-CRL2051 was further tested in Caco-2 human colonic cells to assess cell viability and redox status. No cytotoxic effects were detected after 24 h at realistic concentrations of juice (0.1-10 mu g/mL). PJ0 and PJ48 decreased reactive oxygen species (ROS) generation and glutathione peroxidase (GPx) activity, while increasing intracellular glutathione (GSH) without modifying glutathione reductase activity. In contrast, FPJ-CRL2051 reduced GSH levels and enhanced GPx at the highest concentration tested, likely due to its polyphenolic profile. A hedonic sensory analysis comparing PJ48 and FPJ-CRL2051 revealed no significant differences in colour, texture, taste or overall acceptability, although FPJ-CRL2051 was perceived as slightly more acidic and less astringent. Correlation analysis indicated that texture and taste were strongly linked to overall acceptability in both products. These results suggest that the lactic fermentation preserves the phenolic composition and biological potential of pomegranate juice, while maintaining favourable sensory attributes, supporting FPJ-CRL2051 as a promising health-promoting functional beverage.

This study explores microbial selenization as a strategy for delivering selenium (Se) and seleno-nanoparticles (SeNPs) in a mango and passion fruit juice fermented by indigenous lactic acid bacteria (LAB). The fruit juice was fermented by a mixed culture of Se-enriched cells of Fructobacillus tropaeoli CRL2034 and Lactiplantibacillus paraplantarum CRL2051 at 30 °C for 24 h. The fermented beverages' intracellular Se and SeNPs content, antioxidant activity, microbial ability to survive gastrointestinal conditions, and sensory properties were evaluated. The mixed starter culture grew 2.04 ± 0.17 log CFU/mL in the fruit juice after 24 h and produced lactic acid, acetic acid, and mannitol. After gastrointestinal digestion, the fermented juice exhibited high antioxidant activity (14.20 ± 0.19 µM TE/mL) and a good survival rate (8.29 ± 0.06 log CFU/mL). The SeNPs were detected after digestion by scanning electron microscopy. The fermented and non-fermented juices were accepted by the consumers indiscriminately and their consumption intention was similar (41.7

AIMS:Fructobacillus requires electron acceptors (fructose, pyruvate, or oxygen) for glucose metabolism. They metabolize fructose as an energy source by using fructokinase (FK) and glucose-6-phosphate isomerase (GPI), and as an electron acceptor, reducing it to the low-calorie sugar mannitol by using mannitol 2-dehydrogenase (MDH) enzyme. We aimed to study the physiological and biochemical traits of Fructobacillus sp. CRL 2054 and F. tropaeoli CRL 2034, belonging to two different genomic clades, to further improve their mannitol production. METHODS AND RESULTS:Microbial growth and mannitol production under different carbon sources, saccharide concentrations, and electron acceptors were assayed. The activities and gene expression of the enzymes involved in carbohydrate metabolism and mannitol production by Fructobacillus, along with their genomic context, were determined. Both strains grew up to 40% (w v-1) carbohydrates, while mannitol production decreased with 20% (w v-1) of sugars. Pyruvate competed with fructose as an electron acceptor, reducing mannitol production and MDH activity in both strains. The mdh gene was upregulated while fk and gpi genes were downregulated under glucose, regulating the use of fructose as electron acceptor. CONCLUSIONS:Both Fructobacillus strains were highly osmotolerant. Mannitol production decreased with sugar concentrations above 15% (w v-1), suggesting its use as a compatible solute against osmotic stress. Pyruvate competed with fructose as an electron acceptor, reducing mannitol production, while fructose was reduced to mannitol in the presence of glucose by regulating genes involved in fructose metabolism.

People worldwide are increasingly aware of the benefits of consuming functional fermented foods for improving well-being and preventing chronic diseases. Dairy-fermented foods, as well as fermented meats and vegetables, have long been part of many diets, while non-alcoholic fermented fruit products have been consumed to a lesser extent. However, fermented fruit juices are gaining popularity due to their absence of cholesterol, lactose, and allergenic proteins. Several studies have explored the production of non-alcoholic fruit juice fermentations by different microorganisms, primarily lactic acid bacteria (LAB). LAB, whether indigenous to the fruit environment or confirmed as probiotics, have been used to enhance the technological and/or health benefits of fruit juices. Fermentation can improve the sensory, nutritional, and bioactive properties of fruit beverages. Various in vitro and in vivo studies conducted with animal models have reported antioxidant, anti-inflammatory, antilipidemic, and anti-obesity activities, and micronutrient enrichment in functional fruit beverages. While alterations in the gut microbiota are linked to various chronic diseases, studies revealing the impact of fermented fruit juices on this microbiome are still limited. Nevertheless, existing research has shown positive results, including improved intestinal dysbiosis, increased beneficial bacteria and decreased pathogens, and increased production of short-chain fatty acids and phenolic compounds. Despite these benefits, the development of fermented fruit juices faces challenges, such as unraveling the specific interactions between the fruit matrix and microbes, improving sensory acceptance, and conducting clinical trials to validate preclinical results. In this sense, gut microbiota modulation by fermented fruit juices remains underexplored, especially in human clinical settings.

Calafate is a native barberry of Patagonia, used in culinary and medicinal practices since ancient times. The aim of this work was to analyze the ability of lactic acid bacteria (LAB) isolated from calafate fruits and flowers, to increase the phenolic compound concentration and antioxidant capacity as well as to inhibit metabolic-related enzymes in fermented calafate juices. The sensory attributes of the selected fermented juice were also analyzed. The LAB strains grew between 1.33 ± 0.03 and 2.61 ± 0.30 log CFU/ml in the calafate juices at 24 h. Fructobacillus fructosus B7 consumed glucose and fructose the most (2.30 ± 0.45 g/L and 3.73 ± 0.44 g/L, respectively) and produced mannitol (3.89 ± 0.77 g/L). The fermented juice by Lacticaseibacillus paracasei B4 showed the highest total phenolic compound concentration (2662.58 ± 344.51 mg GAE/100 ml) and antioxidant capacity (38916.42 ± 2157.52 µmol TE/100 ml). The fermented juices inhibited the activity of metabolic syndrome-related enzymes. The lower IC50 for α–glucosidase activity was observed for F. fructosus B7 and L. paracasei B4 (0.56 ± 0.10 and 0.64 ± 0.05 mg GAE/ml, respectively) fermented juices, while for α-amylase the lowest IC50 values were determined for the L. curvatus B34 and L. paracasei B4 (0.34 ± 0.01 and 0.37 ± 0.06 mg GAE/ml, respectively) juices. The relative amount of isorhamnetins, which can induce GLUT4 translocation to the plasma membrane preventing hyperglycemia, was increased in the L. paracasei B4 fermented juice. The L. paracasei B4 fermented juice had acceptable sensorial values for consumption.

The aim of this study was to formulate a Selenium (Se)-bioenriched fermented beverage using selenized lactic acid bacteria (LAB) with desirable sensory attributes and shelf-life. The fruit-origin strains Lactiplantibacillus paraplantarum CRL 2051 and Fructobacillus tropaeoli CRL 2034 were grown in MRS-fructose with 5 mg/L Se before inoculation. Then, the selenized strains were inoculated separately or together in a fruit juice and cowmilk beverage and allowed to ferment at 30 °C for 14 h. During microbial growth, the strains accumulated 62.8–93.5 µg/L of total Se, with 32.7–47.8 µg/L composed of the amino acids selenocysteine (SeCys), and 6.1–12.7 µg/L of selenomethionine (SeMet). The beverages fermented by L. paraplantarum CRL 2051 alone and by the mixed culture showed the highest levels of general acceptance and best sensory attributes. The latter fermented beverage exhibited high microbial resistance to cold storage after 52 days and to gastrointestinal tract conditions as well as an acceptable sensory shelf-life of 42 days. For the first time, microbial selenization previous to food fermentation successfully allowed Se fortification and the formulation of a functional Se-enriched beverage with desirable sensory properties and shelf-life.

Selenium (Se) is an essential trace element present as selenocysteine (SeCys) in selenoproteins, which have an important role in thyroid metabolism and the redox system in humans. Se deficiency affects between 500 and 1000 million people worldwide. Increasing Se intake can prevent from bacterial and viral infections. Se deficiency has been associated with cancer, Alzheimer, Parkinson, decreased thyroid function, and male infertility. Se intake depends on the food consumed which is directly related to the amount of Se in the soil as well as on its availability. Se is unevenly distributed on the earth's crust, being scarce in some regions and in excess in others. The easiest way to counteract the symptoms of Se deficiency is to enhance the Se status of the human diet. Se salts are the most toxic form of Se, while Se amino acids and Se-nanoparticles (SeNPs) are the least toxic and most bio-available forms. Some bacteria transform Se salts into these Se species. Generally accepted as safe selenized microorganisms can be directly used in the manufacture of selenized fermented and/or probiotic foods. On the other hand, plant growth-promoting bacteria and/or the SeNPs produced by them can be used to promote plant growth and produce crops enriched with Se. In this chapter we discuss bacterial Se metabolism, the effect of Se on human health, the applications of SeNPs and Se-enriched bacteria, as well as their effect on food fortification. Different strategies to counteract Se deficiency by enriching foods using sustainable strategies and their possible implications for improving human health are discussed.

This study investigated the health-functional properties of a lactic fermented pomegranate juice (FPJ) enriched with pomegranate seed oil (FPJO) by using the fruit-origin strain Lactiplantibacillus paraplantarum CRL 2051 (FPJO-CRL2051). For this aim, the in vitro human antiplatelet aggregation effect and antioxidant activities were determined in the fermented juices while in vivo studies using high-fat-diet (HFD) C57BL/6 mice fed with a high-fat diet or pomegranate fermented juices for 8 weeks were performed. A high anti-platelet aggregation activity for FPJO-CRL2051 was determined. The formulated juice was administered to C57BL/6 HFD mice over 8 weeks, which showed a significant decrease in triglycerides, LDL-C, and pro-inflammatory cytokines levels. The FPJO-CRL2051 administration was effective in ameliorating liver damage caused by HFD, reducing fat accumulation and oxidative biomarkers, and improving the liver fatty acid profile by incorporation of conjugated fatty acids. This study shows the significance of lactic fermentation in developing novel fermented plant-based beverages with enhanced functional activities with a circular economy approach for the prevention of metabolic disorders.

Mannitol is a natural polyol used in the food, medical and pharmaceutical industries. In this work, a simplified low-cost culture medium using fructose syrup as a carbon source was formulated for mannitol production by Fructobacillus sp. CRL 2054 and F. tropaeoli CRL 2034. To this end, the effect of different medium components in bacterial growth and mannitol synthesis was assessed by applying the Plackett-Burman statistical design. The formulated FSYP-min was used for fermentations at constant pH of 5.0 in a 2 L bioreactor, where two concentrations of fructose syrup (10 and 20 %, w/v, of total sugars) were evaluated. High mannitol concentrations (ca. 90 g/L) and volumetric productivities (3.7 g/L*h) were achieved by both strains using 20 % (w/v) of sugars; these mannitol values are one of the highest reported for LAB to date. Finally, high -purity mannitol crystals were successfully extracted after fermentation with the formulated culture medium.

Mannitol is a natural polyol extensively used in the food, medical and pharmaceutical industries. In this work, a simplified low-cost culture medium using fructose syrup as a carbon source was formulated for mannitol production by Fructobacillus sp. CRL 2054 and F. tropaeoli CRL 2034. To this end, the effect of different medium components in bacterial growth and mannitol synthesis was assessed by applying the Plackett-Burman statistical design. The formulated FSYP-min was used for fermentations at constant pH of 5.0 in a 2 L bioreactor, where two concentrations of fructose syrup (10 and 20%, w/v, of total sugars) were evaluated. High mannitol concentrations (ca. 90 g/L) were achieved by both strains under 20% (w/v) of sugars. Finally, high-purity mannitol crystals were successfully isolated after fermentation with the formulated low-cost culture medium.

This study investigated the ability of Lactiplantibacillus paraplantarum CRL2051 and Lactiplantibacillus plantarum CRL2030, two lactic acid bacteria isolated from fruits, to ferment pomegranate juice to produce beverages with extended shelf life and functional properties. Lactic acid bacteria consumed glucose and fructose as carbon sources, producing mainly lactic acid. Both strains were initially grown in juice at 30 degrees C for 48 h, then refrig-erated at 4 degrees C for 28 days. During fermentation and cold storage, the total phenolic content and antioxidant capacity were conserved in fermented pomegranate juices. The functionality studies of the fermented beverages administered to C57BL/6 mice fed a high-fat diet were evaluated over 6 weeks. Pomegranate juice supple-mentation led to a marked improvement in glucose and triglycerides serum profile, which decreased around 40% and up to 48%, respectively, and counteracted fat deposition and body weight gain. The high-fat diet treatment significantly incremented the aspartate aminotransferase activity in the liver, whereas fermented pomegranate juice consumption slightly reduced it. Liver histological changes associated with a high-fat diet were significantly reverted in juice-treated animals. Our findings evidenced the biological benefits of a novel functional beverage obtained by lactic fermentation of pomegranate juice; this functional drink may protect against weight gain, liver damage, and dyslipidemia induced by a high-fat diet consumption.

The Fructobacillus genus is a group of obligately fructophilic lactic acid bacteria (FLAB) that requires the use of fructose or another electron acceptor for their growth. In this work, we performed a comparative genomic analysis within the genus Fructobacillus by using 24 available genomes to evaluate genomic and metabolic differences among these organisms. In the genome of these strains, which varies between 1.15- and 1.75-Mbp, nineteen intact prophage regions, and seven complete CRISPR-Cas type II systems were found. Phylogenetic analyses located the studied genomes in two different clades. A pangenome analysis and a functional classification of their genes revealed that genomes of the first clade presented fewer genes involved in the synthesis of amino acids and other nitrogen compounds. Moreover, the presence of genes strictly related to the use of fructose and electron acceptors was variable within the genus, although these variations were not always related to the phylogeny.

The fruit-origin strain Fructobacillus tropaeoli CRL 2034 can biotransform selenium into seleno-nanoparticles and selenocysteine. The proteomic analysis of F. tropaeoli CRL 2034 exposed to 5 and 100 ppm of Se showed a dose-dependent response since 19 and 77 proteins were deregulated, respectively. In the presence of 5 ppm of Se, the deregulated proteins mainly belonged to the categories of energy production and conversion or had unknown functions, while when cells were grown with 100 ppm of Se, most of the proteins were grouped into amino acid transport and metabolism, nucleotide transport and metabolism, or into unknown functions. However, under both Se conditions, glutathione reductases were overexpressed (1.8–3.1-fold), while mannitol 2-dehydrogenase was downregulated (0.54–0.19-fold), both enzymes related to oxidative stress functions. Mannitol 2-dehydrogenase was the only enzyme found that contained SeCys, and its activity was 1.27-fold increased after 5 ppm of Se exposure. Our results suggest that F. tropaeoli CRL 2034 counteracts Se stress by overexpressing proteins related to oxidative stress resistance and changing the membrane hydrophobicity, which may improve its survival under (food) storage and positively influence its adhesion to intestinal cells. Selenized cells of F. tropaeoli CRL 2034 could be used for producing Se-enriched fermented foods. • Selenized cells of F. tropaeoli showed enhanced resistance to oxidative stress. • SeCys was found in the Fructobacillus mannitol 2-dehydrogenase polypeptide chain. • F. tropaeoli mannitol 2-dehydrogenase activity was highest when exposed to selenium.

The fiber, vitamin, and antioxidant contents of fruits contribute to a balanced human diet. In countries such as Argentina, several tropical fruits are witnessing a high yield in the harvest season, with a resulting surplus. Fruit fermentation using autochthonous starter cultures can provide a solution for food waste. However, limited knowledge exists about the microbiota present on the surfaces of fruits and the preceding flowers. In the present exploratory study, the microbiomes associated with the surfaces of tropical fruits from Northern Argentina, such as white guava, passion fruit and papaya were investigated using a shotgun metagenomic sequencing approach. Hereto, one sample composed of 14 white guava fruits, two samples of passion fruits with each two to three fruits representing the almost ripe and ripe stage of maturity, four samples of papaya with each two to three fruits representing the unripe, almost ripe, and ripe stage of maturity were processed, as well as a sample of closed and a sample of open Japanese medlar flowers. A considerable heterogeneity was found in the composition of the fruits’ surface microbiota at the genus and species level. While bacteria dominated the microbiota of the fruits and flowers, a small number of the metagenomic sequence reads corresponded with yeasts and filamentous fungi. A minimal abundance of bacterial species critical in lactic acid and acetic acid fermentations was found. A considerable fraction of the metagenomic sequence reads from the fruits’ surface microbiomes remained unidentified, which suggested that intrinsic species are to be sequenced or discovered.

Adequate fruit consumption helps to prevent several chronic age-related diseases. Selenium (Se) is an elemental micronutrient with antioxidant capacity. In general, fruits and Se ingest by humans are below the recommended daily intake value. Fresh fruits are highly susceptible to deterioration during storage. Fermentation can improve the storage period, sensory profile, and bioactive compound content of foods; moreover, some lactic acid bacteria can accumulate organic Se intracellularly. In this work, microbial growth and Se accumulation by Levilactobacillus brevis CRL2051 and Fructobacillus tropaeoli CRL2034 in tropical fruit juices were evaluated. The strains could grow 1-2 log cfu/mL, alone or combined, in mango, passion fruit, and mango/passion fruit juices, although they could not completely eliminate native microorganisms in unpasteurised juices. In pasteurised trials, both strains consumed fruit carbohydrates producing lactic acid, in addition to acetic acid, and mannitol by F. tropaeoli. Both strains accumulated Se intracellularly in the fruit juices, especially (123.0 mu g/L) in the passion fruit juice fermented by the mixed culture. Finally, the Fructobacillus strain increased 3.42 times the phenolic compound concentration in the mango/passion fruit juice with added Se after 24 h. The assayed LAB strains could be used for preparing functional fermented fruit beverages bio-enriched in Se.

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.

This work was carried out to elaborate selenium (Se) bio-enriched fermented Mediterranean fruit juices. To this purpose, pomegranate and table red grape juices were added with sodium selenite (Na2SeO3) and fermented by Levilactobacillus brevis CRL 2051 and Fructobacillus tropaeoli CRL 2034 individually or combined. To better evaluate the effect of selenite addition and starter strain inoculums on the total bacterial community of the fruit juices, fermentation trials were performed with raw and pasteurized fruit juices. No statistical significant differences were observed for total mesophilic microorganisms (TMM) and rod-shaped lactic acid bacteria (LAB) levels among raw and pasteurized juices inoculated with the starter strains, while significant differences between those juices with and without selenite were registered. LAB cocci, Pseudomonadaceae and yeasts were detected only for the raw juice preparations. The dominance of L. brevis CRL 2051 and F. tropaeoli CRL 2034 was confirmed by randomly amplified polymorphic DNA (RAPD)-PCR analysis. After fermentation, pH dropped for all inoculated trials and control raw juices. The soluble solid content (SSC) levels of the raw juices were higher than the corresponding pasteurized trials. The thermal treatment affected consistently yellowness of grape juice trials and redness of pomegranate juices. No microbial Se accumulation was registered for pomegranate juices, while F. tropaeoli CRL 2034 accumulated the highest amount of Se (65.5 μg/L) in the grape juice. For this reason, only trials carried out with raw grape juices were investigated by metagenomics analysis by Illumina MiSeq technology. Non-inoculated grape juices were massively fermented by acetic acid bacteria while Fructobacillus and Lactobacillus (previous genus name of Levilactobacillus) represented the highest operational taxonomy units (OTUs) relative abundance % of the trials inoculated with the starter strains as confirmed by this technique.