Lactic Acid Fermentation of Pomegranate Juice as a Tool to Improve Antioxidant Activity

The Impact of Fermentation on the Antioxidant Activity of Food Products

From ancient times to the present day, fermentation has been utilized not only for food preservation but also for enhancing the nutritional and functional properties of foods. This process is influenced by numerous factors, including the type of microorganisms used, substrate composition, pH, time, and temperature, all of which can significantly alter the characteristics of the final product. Depending on the parameters, fermentation enhances the bioactive content of the products and imparts the necessary properties, such as antioxidant characteristics, for the products to be considered functional. The enhancement of these properties, particularly antioxidant activity, enriches foods with bioactive compounds and functional attributes, contributing to improved health benefits. Through a review of recent research, this study elucidates how different fermentation processes can enhance the bioavailability and efficacy of antioxidants, thereby improving the nutritional and functional qualities of foods. This study investigated the multifaceted effects of fermentation on antioxidant properties by exploring various types and conditions of fermentation. It highlights specific examples from dairy products and other food categories as well as the valorization of food waste and byproducts. The findings underscore the potential of fermentation as a sustainable method to produce health-promoting foods with elevated antioxidant activities, offering new perspectives for food science and technology.

Blackberry Juice Fermented with Two Consortia of Lactic Acid Bacteria and Isolated Whey: Physicochemical and Antioxidant Properties during Storage

Fermenting fruit juices with lactic acid bacteria (LAB) is a sustainable method to enhance fruit harvests and extend shelf life. This study focused on blackberries, rich in antioxidants with proven health benefits. In this research, we examined the effects of fermentation (48 h at 37 °C) at 28 days on whey-supplemented (WH, 1:1) blackberry juice (BJ) inoculated with two LAB mixtures. Consortium 1 (BJWH/C1) included Levilactobacillus brevis, Lactiplantibacillus plantarum, and Pediococcus acidilactici, while consortium 2 (BJWH/C2) comprised Lacticaseibacillus casei and Lacticaseibacillus rhamnosus. All of the strains were previously isolated from aguamiel, pulque, and fermented milk. Throughout fermentation and storage, several parameters were evaluated, including pH, lactic acid production, viscosity, stability, reducing sugars, color, total phenolic content, anthocyanins, and antioxidant capacity. Both consortia showed a significant increase in LAB count (29-38%) after 16 h. Sample BJWH/C2 demonstrated the best kinetic characteristics, with high regression coefficients (R2 = 0.97), indicating a strong relationship between lactic acid, pH, and fermentation/storage time. Despite some fluctuations during storage, the minimum LAB count remained at 9.8 log CFU/mL, and lactic acid content increased by 95%, with good storage stability. Notably, sample BJWH/C2 increased the total phenolic content during storage. These findings suggest that adding whey enhances biomass and preserves physicochemical properties during storage.

Exploring the synergistic potential of pomegranate fermented juice compounds against oxidative stress-induced neurotoxicity through computational docking and experimental analysis in human neuroblastoma cells

This study explored the neuroprotective potential of fermented pomegranate (PG-F) against hydrogen peroxide (H2O2)-induced neurotoxicity in human neuroblastoma SH-SY5Y cells and elucidated the underlying molecular mechanisms. The fermentation process, involving probiotics, transforms the hydrolyzable tannins in pomegranate juice into ellagic acid (EA) and gallic acid (GA), which are believed to contribute to its health benefits. Molecular docking simulations confirmed the stable interactions between EA, GA, and proteins associated with the antioxidant and anti-apoptotic pathways. PG-F significantly enhanced the viability of H2O2-treated cells, as evidenced by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, cell morphology observations, and Hoechst 33342 staining. PG-F mitigated the H2O2-induced intracellular reactive oxygen species (ROS) levels, restored mitochondrial membrane potential, and upregulated antioxidant gene expression. The PG-F treatment also attenuated the H2O2-induced imbalance in the Bax/Bcl-2 ratio and reduced the cleaved caspase-3, caspase-7, and caspase-9 levels, suppressing the apoptotic pathways. Further insights showed that PG-F inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and facilitated the nuclear translocation of nuclear factor-erythroid 2-related factor (Nrf2), highlighting its role in modulating the key signaling pathways. A combined treatment with equivalent concentrations of EA and GA, as found in PG-F, induced remarkable cellular protection. Drug combination analysis using the Chou-Talalay method revealed a synergistic effect between EA and GA, emphasizing their combined efficacy. In conclusion, PG-F has significant neuroprotective effects against H2O2-induced neurotoxicity by modulating the antioxidant and anti-apoptotic pathways. The synergistic action of EA and GA suggests the therapeutic potential of PG-F in alleviating oxidative stress-associated neurodegenerative diseases.

Impact of Lactic Acid Bacteria Fermentation on (Poly)Phenolic Profile and In Vitro Antioxidant and Anti-Inflammatory Properties of Herbal Infusions

Recently, the development of functional beverages has been enhanced to promote health and nutritional well-being. Thus, the fermentation of plant foods with lactic acid bacteria can enhance their antioxidant capacity and others like anti-inflammatory activity, which may depend on the variations in the total content and profile of (poly)phenols. The present study aimed to investigate the impact of fermentation with two strains of Lactiplantibacillus plantarum of several herbal infusions from thyme, rosemary, echinacea, and pomegranate peel on the (poly)phenolic composition and whether lacto-fermentation can contribute to enhance their in vitro antioxidant and anti-inflammatory effects on human colon myofibroblast CCD18-Co cells. HPLC-MS/MS analyses revealed that fermentation increased the content of the phenolics present in all herbal infusions. In vitro analyses indicated that pomegranate infusion showed higher antioxidant and anti-inflammatory effects, followed by thyme, echinacea, and rosemary, based on the total phenolic content. After fermentation, despite increasing the content of phenolics, the antioxidant and anti-inflammatory effects via reduction pro-inflammatory markers (IL-6, IL-8 and PGE2) were similar to those of their corresponding non-fermented infusions, with the exception of a greater reduction in lacto-fermented thyme. Overall, the findings suggest that the consumption of lacto-fermented herbal infusions could be beneficial in alleviating intestinal inflammatory disorders.

Fermentation of Orange Peels by Lactic Acid Bacteria: Impact on Phenolic Composition and Antioxidant Activity

Orange processing generates peel by-products rich in phenolic compounds, particularly flavanones like hesperidin and narirutin, offering potential health benefits. Utilizing these by-products is of significant interest in supporting Spain's circular bioeconomy. Therefore, the aim of this study was to investigate the fermentation of orange peels by different lactic acid bacteria (LAB) strains and its impact on phenolic composition and antioxidant activity. Three different LAB strains, two Lactiplantibacillus plantarum, and one Levilactobacillus brevis were utilized. The phenolic compounds were measured by HPLC-ESI-TOF-MS, and antioxidant activity was assessed using DPPH and ABTS methods. The growth of the LAB strains varied, showing initial increases followed by gradual declines, with strain-specific patterns observed. Medium acidification occurred during fermentation. A phenolic analysis revealed an 11% increase in phenolic acids in peels fermented by La. plantarum CECT 9567-C4 after 24 h, attributed to glycosylation by LAB enzymes. The flavonoid content exhibited diverse trends, with Le. brevis showing an 8% increase. The antioxidant assays demonstrated strain- and time-dependent variations. Positive correlations were found between antioxidant activity and total phenolic compounds. The results underscore the importance of bacterial selection and fermentation time for tailored phenolic composition and antioxidant activity in orange peel extracts. LAB fermentation, particularly with La. plantarum CECT 9567 and Le. brevis, holds promise for enhancing the recovery of phenolic compounds and augmenting antioxidant activity in orange peels, suggesting potential applications in food and beverage processing.

Spontaneous fermentation improves the physicochemical characteristics, bioactive compounds, and antioxidant activity of acerola (Malpighia emarginata D.C.) and guava (Psidium guajava L.) fruit processing by-products

This study aimed to investigate the effects of spontaneous fermentation on physicochemical characteristics, bioactive compounds, and antioxidant activity of acerola and guava fruit industrial by-products. Viable cell counts of lactic acid bacterial (LAB) in acerola and guava by-products were ≥ 5.0 log CFU/mL from 24 h up to 120 h of fermentation. Fermented acerola and guava by-products had increased luminosity and decreased contrast. Contents of total soluble solids and pH decreased, and titrable acidity increased in acerola and guava by-products during fermentation. Ascorbic acid contents decreased in acerola by-product and increased in guava by-product during fermentation. Different phenolic compounds were found in acerola and guava by-products during fermentation. Fermented acerola and guava by-products had increased contents of total flavonoids, total phenolics, and antioxidant activity. The contents of total flavonoids and total phenolics positively correlated with antioxidant activity in fermented acerola and guava by-products. These results indicate that spontaneous fermentation could be a strategy to improve the contents of bioactive compounds and the antioxidant activity of acerola and guava by-products, adding value and functionalities to these agro-industrial residues.

Impact of Lactic Acid Bacteria Fermentation on Phenolic Compounds and Antioxidant Activity of Avocado Leaf Extracts

The growing global consumption of avocados, associated with contents including bioactive compounds with numerous health-promoting properties, is producing a large amount of agro wastes around the world. Different management approaches are available for the recovery of bioactive compounds from wastes as potential ingredients for use in the production of functional foods and nutraceuticals. Lactic acid fermentation can be used to exploit nutritional potential and add value to agro wastes. In this study, fermentations with lactic acid bacteria were carried out in avocado leaves, and the total phenolic content and the antioxidant activity were determined by DPPH and FRAP assays from hydroalcoholic extracts obtained from fermented avocado leaves. Fifteen new phenolic compounds were identified for the first time in avocado leaves by HPLC-ESI-TOF-MS. L. plantarum CECT 748T and P. pentosaceus CECT 4695T showed the highest antioxidant activity. The sum of phenolic compounds was increased by 71, 62, 55 and 21% in fermentations with P. pentosaceus CECT 4695T, L. brevis CECT 5354, P. acidilactici CECT 5765T and L. plantarum CECT 9567, respectively, while it was reduced in the fermentation with L. plantarum 748T by 21% as demonstrated by HPLC-ESI-TOF-MS. Biotransformations induced by bacterial metabolism modified the phenolic compound profile of avocado leaves in a strain-specific-dependent manner. P. pentosaceus CECT 4695T significantly increased kaempferol, P. pentosaceus 4695T, L. brevis 5354 and L. plantarum 9567 increased rutin, and dihydro-p-coumaric acid was increased by the five selected lactic acid bacteria. Total flavonoids were highly increased after fermentations with the five selected lactic acid bacteria but flavonoid glucosides were decreased by L. plantarum 748T, which was related to its higher antioxidant activity. Our results suggest that lactic acid bacteria led the hydrolysis of compounds by enzymatic activity such as glycosidases or decarboxylase and the release of phenolics bound to the plant cell wall, thus improving their bioavailability.

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.

Biodegradation of Punicalagin into Ellagic Acid by Selected Probiotic Bacteria: A Study of the Underlying Mechanisms by MS-Based Proteomics

Pomegranate (Punica granatum L.) is a well-known source of bioactive phenolic compounds such as ellagitannins, anthocyanins, and flavanols. Punicalagin, one of the main constituents of pomegranate, needs to be biodegraded by bacteria to yield metabolites of medicinal interest. In this work, we tested 30 lactic acid bacteria (LAB) and their capacity to transform punicalagin from a punicalagin-rich pomegranate extract into smaller bioactive molecules, namely, ellagic acid and urolithins. These were identified and quantified by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS²). Further, we evaluated the molecular mechanism governing this transformation through label-free comparative MS-based proteomics. All tested LAB strains were capable of transforming punicalagin into ellagic acid, while the biosynthesis of urolithins was not observed. Proteomic analysis revealed an increase of generic transglycosylases that might have a hydrolytic role in the target phenolic molecule, coupled with an increase in the quantity of ATP-binding cassette (ABC) transporters, which might play a relevant role in transporting the resulting byproducts in and out of the cell.

Fruit juices as a carrier of probiotics to modulate gut phenolics and microbiota

Here we attempted to deliver probiotics to the human gut using fruit juices as a carrier, which is less common despite the newest trend to incorporate probiotics into non-dairy food. Phenolic-rich fruit juices, including blueberry, black cherry, concord grape and pomegranate were fortified with Lactobacillus casei, and then compared and comprehensively assessed to develop novel non-fermented probiotic juices. In black cherry juice, probiotics had the most significant retention of viability after 14 days of storage at 4 °C, the least reduction in phenolics (14.59%) after in vitro gastrointestinal digestion, the highest concentration of phenolic metabolites and a significant increase in anaerobic bacteria after faecal fermentation (48 h). 16s rRNA gene sequencing showed that probiotic-enriched juice treatments were associated with highly distinctive Bacteroidota and Bacteroides vulgatus population. Overall, black cherry juice has the highest potential to be developed as a probiotic carrier with benefits in modulating the gut microbiota.

Comparative Evaluation of Yield and Fruit Physico-Chemical Characteristics of Five Commercial Cultivars of Pomegranate Grown in Southeastern Italy in Two Consecutive Years

This study, conducted over two consecutive seasons (2018–2019), evaluates the yield and fruit physico-chemical traits of five commercial cultivars (‘Mollar’, ‘Dente di Cavallo’, ‘Acco’, ‘Jolly red’ and ‘Wonderful’) grown in the orchard at Foggia (Puglia region, southeastern Italy). The results show significant variations among the investigated cultivars for many measured parameters; seasons also significantly affected some data. As an average of the years, both ‘Dente di Cavallo’ and ‘Wonderful’ significantly showed the highest numbers (16.8 and 15.2, respectively) and weights (9.3 Kg, respectively) of fruit per tree. ‘Jolly red’ had the highest percentage of edible portions (58.5%), the most intense red color in juice (a* value, 11.7), a light-red skin color (despite its name) (a*value, 31.1) and the smallest fruits (26.7% of diameter ≤ 80 mm). Total soluble solids of all cultivars were considerable above the minimum value (12 °Brix) required for commercial use. ‘Wonderful’ significantly presented the highest value of juice acidity (2.5 g citric acid 100 mL−1) and the lowest MI value, and therefore it was classified as sour. Both ‘Dente di Cavallo’ and ‘Wonderful’ had significantly higher phenolic contents (591.0 and 519.1 mg 100 mL−1, respectively) than the other cultivars, while ‘Dente di Cavallo’ significantly showed the highest antioxidant activity value (6.4 mmol TE 100 L−1). The Stepwise Discriminant Analysis procedure allowed a significant differentiation among the cultivars. Correlation analysis showed a considerable relation among the different fruit traits. The present data are helpful in the selection of elite desirable pomegranate cultivars to be used for commercial production.

Valorization of Lactic Acid Fermentation of Pomegranate Juice by an Acid Tolerant and Potentially Probiotic LAB Isolated from Kefir Grains

The present study describes the application of an acid tolerant and potentially probiotic L. paracasei SP3 strain, recently isolated from kefir grains, in the production of a novel functional beverage based on the fermentation of pomegranate juice. The fermentation ability of the novel strain was assessed during pomegranate juice fermentations at 30 °C for 24 h and storage at 4 °C for 4 weeks. Various parameters were assessed such as residual sugar, organic acid and alcohol levels, total phenolics content, antioxidant activity, astringency, cell viability, and consumer acceptance. Residual sugar was decreased by approximately 25%, while respectable amounts of lactic acid were determined (4.8 g/L) on the 28th day of storage, proving that the novel strain was effective at lactic acid fermentation. The concentration of ethanol was maintained at low levels (0.3–0.4 % v/v) and low levels of acetic acid were detected (0.6 g/L). The viability of L. paracasei SP3 cells retained high levels (>7 log cfu/mL), even by the 4th week. The total phenolic content (123.7–201.1 mg GAE/100 mL) and antioxidant activity (124.5–148.5 mgTE/100 mL) of fermented pomegranate juice were recorded at higher levels for all of the studied time periods compared to the non-fermented juice. The employment of the novel strain led to a significant reduction in the levels of hydrolysable tannins (42%) in the juice, reducing its astringency. The latter was further proven through sensorial tests, which reflected the amelioration of the sensorial features of the final product. It should be underlined that fruit juices as well as pomegranate juice comprised a very harsh food matrix for microorganisms to survive and ferment. Likewise, the L. paracasei SP3 strain showed a significant potential, because it was applied as a free culture, without the application of microencapsulation methods that are usually employed in these fermentations, leading to a product with possible functional properties and a high nutritive value.

Taify Pomegranate Juice (TPJ) Abrogates Acrylamide-Induced Oxidative Stress Through the Regulation of Antioxidant Activity, Inflammation, and Apoptosis-Associated Genes

Acrylamide (ACR) has various effects on biological systems, including oxidative stress and its associated metabolic disorders. Previous research reports that plants growing at high altitude have a different profile of antioxidants. In the current report, the Taify pomegranate juice (TPJ) of the Taify pomegranate growing at the Taif region (high altitude), Saudi Arabia, was investigated for its protective activity from ACR-induced oxidative stress. Rats were treated with ACR, TPJ, or TPJ+ACR, and various assays, including blood chemistry, liver function biomarkers, gene expression of endogenous antioxidant enzymes, oxidative stress regulatory genes, inflammation biomarkers, and apoptosis, were estimated using biochemical, real-time PCR, histopathological, and immunohistochemical analysis. TPJ showed a protective function of ACR-induced alteration of AST, ALT, GGT, urea, total proteins, albumin, MDA, and NO. It also increased the level of the endogenous antioxidative enzymes, including SOD, catalase, and GSH. It showed anti-inflammatory activity by reduction the TNF-α, IL-6 secretion and the enhancing of IL-10 levels. At the gene expression level, TPJ upregulated the expression of endogenous antioxidant genes (SOD and catalase) and of antioxidant-regulating genes Nrf2 and HO-1; downregulated the expression of inflammatory genes TGF-β1, COX2, and the apoptotic gene caspase-3; and upregulated the expression of antiapoptotic gene Bcl2. At the histological level, TPJ showed a protective effect from the ACR-induced hepatic histological damage. Results of this study conclude that TPJ has a protective effect from ACR-induced oxidative stress and its associated metabolic alterations through its antioxidant and anti-inflammatory activities.

Sour beer production in India using a coculture of Saccharomyces pastorianus and Lactobacillus plantarum: optimization, microbiological, and biochemical profiling

The study's objective was to develop a co-fermentation process with appropriate fermentation parameters to produce a sour beer (similar to a Belgium sour beer) with an ethanol content of 6-8% (v/v) using a coculture of Saccharomyces pastorianus and Lactobacillus plantarum. Statistical optimization was conducted to determine fermentation conditions to produce a sour beer with ~ 3 mg/mL of lactic acid, similar to the traditional sour beer levels. Studies were conducted on the microbial dynamics and volatile compounds produced during this fermentation and aging process. GC-MS studies revealed the generation of novel bioactive compounds as well as the depletion of some volatile compounds during co-fermentation. The study detailed a 5-day co-fermentation process of S. pastorianus and L. plantarum and a 21-day aging process to prepare a sour beer with biochemical properties along the lines of traditional lambic beers. The interrelationship between the two microorganisms and the biochemical changes in the sour beer fermentation process was elucidated and the sensorial attributes have been described.

The Anti-Inflammatory, Anti-Apoptotic and Antioxidant Effects of a Pomegranate-Peel Extract against Acrylamide-Induced Hepatotoxicity in Rats

The Acrylamide is a toxic compound generated under oxidative stress arising from intracellular ROS production and induced toxicity. It is frequently used in industry and generated through the heating of tobacco and foods high in carbohydrates. The exact mechanism of its toxicity is still unclear. In this study, an extract of the peels of pomegranate (Punica granatum L.), a nutritious and visually appealing fruit with a diverse bioactive profile, was examined for its potential anti-apoptotic, antioxidant, and anti-inflammatory effects. A total of 40 adult male Wistar rats were allocated into four groups of 10 rats each: Group 1 was a negative-control group (CNT) and received normal saline; Group 2 was a positive-control acrylamide group and received acrylamide orally at a dose of 20 mg/kg/bw; in Group 3, the rats were supplemented with pomegranate-peel extract (P.P; 150 mg/kg/bw) orally on a daily basis for 3 weeks, administered simultaneously with the acrylamide treatment described for Group 2; Group 4 was a protective group, and the animals received the pomegranate-peel extract and acrylamide as stated for Groups 2 and 3, with the pomegranate-peel extract (P.P. extract) administered 1 week earlier than the acrylamide. The results indicate that acrylamide exposure increased the serum levels of AST, ALT, creatinine, interleukin-1 beta, and interleukin-6 in an extraordinary manner. In addition, it increased the lipid peroxidation marker malondialdehyde (MDA) and simultaneously weakened antioxidant biomarker activities (SOD, GSH, and catalase) and reduced the levels of interleukin-10. The pomegranate-peel extract was shown to reduce the inflammatory blood markers of interleukin-1 beta and IL-6. Glutathione peroxidase, superoxide dismutase, catalase, and interleukin-10 were all significantly elevated in comparison to the acrylamide-treatment group as a result of the significant reduction in MDA levels induced by the P.P extract. In addition, the pomegranate-peel extract normalized the cyclooxygenase-2 (COX2), transforming growth factor-beta 1 (TGF-β1), and caspase-3 levels, with a significant upregulation of the mRNA expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2 (Nrf2), and Bcl-2. Therefore, these data reveal that pomegranate peel has anti-inflammatory, antiapoptotic, free-radical-scavenging, and powerful antioxidant activity that protects against acrylamide toxicity.

Advancements in the Use of Fermented Fruit Juices by Lactic Acid Bacteria as Functional Foods: Prospects and Challenges of Lactiplantibacillus (Lpb.) plantarum subsp. plantarum Application

Lactic acid fermentation of fresh fruit juices is a low-cost and sustainable process, that aims to preserve and even enhance the organoleptic and nutritional features of the raw matrices and extend their shelf life. Selected Lactic Acid Bacteria (LAB) were evaluated in the fermentation of various fruit juices, leading in some cases to fruit beverages, with enhanced nutritional and sensorial characteristics. Among LAB, Lactiplantibacillus (Lpb.) plantarum subsp. plantarum strains are quite interesting, regarding their application in the fermentation of a broad range of plant-derived substrates, such as vegetables and fruit juices, since they have genome plasticity and high versatility and flexibility. L. plantarum exhibits a remarkable portfolio of enzymes that make it very important and multi-functional in fruit juice fermentations. Therefore, L. plantarum has the potential for the production of various bioactive compounds, which enhance the nutritional value and the shelf life of the final product. In addition, L. plantarum can positively modify the flavor of fruit juices, leading to higher content of desirable volatile compounds. All these features are sought in the frame of this review, aiming at the potential and challenges of L. plantarum applications in the fermentation of fruit juices.

Previously published ethno-pharmacological reports reveal the potentiality of plants and plant-derived products used as traditional home remedies by Bangladeshi COVID-19 patients to combat SARS-CoV-2

Several plants have traditionally been used since antiquity to treat various gastroenteritis and respiratory symptoms similar to COVID-19 outcomes. The common symptoms of COVID-19 include fever or chills, cold, cough, flu, headache, diarrhoea, tiredness/fatigue, sore throat, loss of taste or smell, asthma, shortness of breath, or difficulty breathing, etc. This study aims to find out the plants and plant-derived products which are being used by the COVID-19 infected patients in Bangladesh and how those plants are being used for the management of COVID-19 symptoms. In this study, online and partially in-person survey interviews were carried out among Bangladeshi respondents. We selected Bangladeshi COVID-19 patients who were detected Coronavirus positive (+) by RT-PCR nucleic acid test and later recovered. Furthermore, identified plant species from the surveys were thoroughly investigated for safety and efficacy based on the previous ethnomedicinal usage reports. Based on the published data, they were also reviewed for their significant potentialities as antiviral, anti-inflammatory, and immunomodulatory agents. We explored comprehensive information about a total of 26 plant species, belonging to 23 genera and 17 different botanical families, used in COVID-19 treatment as home remedies by the respondents. Most of the plants and plant-derived products were collected directly from the local marketplace. According to our survey results, greatly top 5 cited plant species measured as per the highest RFC value are Camellia sinensis (1.0) > Allium sativum (0.984) > Azadirachta indica (0.966) > Zingiber officinale (0.966) > Syzygium aromaticum (0.943). Previously published ethnomedicinal usage reports, antiviral, anti-inflammatory, and immunomodulatory activity of the concerned plant species also support our results. Thus, the survey and review analysis simultaneously reveals that these reported plants and plant-derived products might be promising candidates for the treatment of COVID-19. Moreover, this study clarifies the reported plants for their safety during COVID-19 management and thereby supporting them to include in any future pre-clinical and clinical investigation for developing herbal COVID-19 therapeutics.

Commercial Organic Versus Conventional Whole Rye and Wheat Flours for Making Sourdough Bread: Safety, Nutritional, and Sensory Implications

Organic farming is gaining a broad recognition as sustainable system, and consumer demand for organic products has increased dramatically in the recent past. Whether organic agriculture delivers overall advantages over conventional agriculture is, however, contentious. Here, the safety, nutritional, and sensory implications of using commercial organic rye, soft, and durum wheat flours rather than conventional-made sourdough bread have been investigated. Culture-dependent and culture-independent approaches were used to explore the microbial architecture of flours and to study their dynamics during sourdough propagation. Besides biochemical features, the main nutritional (amino acid content, asparagine level, and antioxidant activity) characteristics of sourdoughs were investigated, and their effect on the structural, nutritional, and sensory profiles of breads assessed. Overall, the organic farming system led to flours characterized by lower content of asparagine and cell density of Enterobacteriaceae while showing higher concentration of total free amino acids. Differences of the flours mirrored those of sourdoughs and breads. The use of sourdough fermentation guaranteed a further improvement of the flour characteristics; however, a microbial and sensory profile simplification as well as a slight decrease of the biochemical parameters was observed between breads with sourdough after one-cycle fermentation and 10 days of propagation.

Impact of Sugar Type Addition and Fermentation Temperature on Pomegranate Alcoholic Beverage Production and Characteristics

The present study focuses on the production of pomegranate alcoholic beverage (PAB) from juice of the Wonderful variety. The effect of fermentation temperature (15 and 25 °C) and type of sugar added (adjustment to 20 °Brix) on the physicochemical characteristics, bioactive compounds, and volatile composition were studied. Sucrose, concentrated pomegranate juice, concentrated grape juice, and honey were used to increase the initial sugar content. The produced PABs contained ethanol in concentrations ranging from 7.9 to 10.0% v/v and glycerol from 4.8 to 6.1 g L⁻¹. A decrease in total phenolics content, free radical-scavenging activity, and total monomeric anthocyanin content was observed following fermentation. Total flavonoids content appeared to increase after fermentation only in the cases of concentrated pomegranate and grape juice addition. In general, 22 volatile compounds were identified in PABs (13 esters, 2 fatty acids, and 7 alcohols). Major compounds detected were 3-methyl-1-butanol, 2-methyl-1-butanol, 2-phenylethanol, and ethyl acetate. These findings demonstrate the production prospect of PABs with increased ethanol content, while elaborating on the importance of fermentation temperature and the differences between the selected types of added sugars on end-product composition.

Selenium bio-enrichment of Mediterranean fruit juices through lactic acid fermentation

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.

Therapeutic properties of Punica granatum L (pomegranate) and its applications in lung-based diseases: A detailed review

Respiratory diseases are the prime cause of death and disability worldwide. The majority of lung-based diseases are resistant to treatment. Hence, research on unique drugs/compounds with a more efficient and minimum side effect for treating lung diseases is urgent. Punica granatum L (pomegranate) fruit has been used in the prevention and treatment of various respiratory disorders in recent times. In vivo and in vitro studies have demonstrated that pomegranate fruit, as well as its juice, extract, peel powder, and oil, exert anti-proliferative, anti-oxidant, anti-microbial, anti-inflammatory, anti-cancer, and anti-tumorigenic properties by attenuating various respiratory conditions such as asthma, lung fibrosis, lung cancer, chronic obstructive pulmonary disease (COPD), and alveolar inflammation via modulating various signaling pathways. The current review summarizes the potential properties and medical benefits of pomegranate against different lung-based diseases, also highlighting its possible role in the lung fibrinolytic system. The available data suggest that pomegranate is effective in controlling the disease progressions and could be a potential therapeutic target benefiting human health status. Furthermore, this review also outlines the preclinical and clinical studies highlighting the role of pomegranate in lung diseases further evoking future studies to investigate the effect of intake of this anti-oxidant fruit in larger and well-defined human clinical trials. PRACTICAL APPLICATIONS: This review outlines the putative pharmacologic benefits of P. granatum L (pomegranate) in treating various chronic lung-based diseases such as lung cancer, COPD, ARDS, asthma, lung fibrosis, and cystic fibrosis. This review also highlights the possible inhibitory role of P. granatum L (pomegranate) in the lung fibrinolytic system triggering the fibrinolytic markers. This review summarizes the preclinical and clinical studies using in vitro, in vivo, and human models highlighting the potential role of P. granatum L (pomegranate) in lung diseases. This review evokes future research to investigate the effect of intake of pomegranate fruit in well-defined human clinical trials.

Functional Exploitation of Carob, Oat Flour, and Whey Permeate as Substrates for a Novel Kefir-Like Fermented Beverage: An Optimized Formulation

This study investigated the fortification of a carob-based kefir-like beverage (KLB) with whey permeate (WP) and oat flour (OF). The response surface method was used to show the effect of WP and OF concentrations on lactic acid bacteria and yeast cell densities, pH, total titratable acidity (TTA), total phenolics content (TCP), DPPH radical scavenging activity, and overall acceptability (OA) in KLB. The statistical design provided thirteen formulations where OF concentration varied from 3% to 5% and WP from 10% to 15%. The enrichment of carob pods decoction with WP and OF had a positive effect on biomass production. Overall fermentation was shown to increase TPC of KLB. Furthermore, OF supplementation led to the higher levels of TPC and antiradical activity. WP negatively affected OA at linear and quadratic levels, whereas no effect of OF was observed at the linear level. The optimum point was found by using WP at 11.51% and OF at 4.77%. Optimized KLB resulted in an enrichment of bioavailable phenolics derivatives and highly digestible proteins.

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.

Pomegranate (Punica granatum L.) Extract and Its Anthocyanin and Copigment Fractions-Free Radical Scavenging Activity and Influence on Cellular Oxidative Stress

Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, "copigments" (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC-PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC-PDA-ESI-MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.

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.