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The food industry constantly seeks new starter cultures with superior characteristics to enhance the sensory and overall quality of final products. Starting from a collection of Algerian dairy (goat and camel) lactic acid bacteria, this work focused on the exploration of the technological and probiotic potential of Weissella cibaria (VR81 and LVT1) and Lactiplantibacillus plantarum R12 strains isolated from raw camel milk and fermented milk, respectively. These bioactive strains were selected for their high performance among ten other LAB strains and were used as starter cultures to develop a novel and nutritionally enhanced dairy-like plant-based yogurt using quinoa (Chenopodium quinoa Willd) as a raw matrix. The strains were evaluated for their antagonistic effects against Listeria innocua, Listeria ivanovii, Staphylococcus aureus, Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa, resilience to acidic and osmotic challenges, and tolerance to gastrointestinal mimicking conditions (i.e., pepsin and bile salt). Their aggregation and adhesion profiles were also analyzed. Furthermore, L. plantarum and W. cibaria were tested in single and co-culture for the fermentation and biocontrol of quinoa. The strains exhibited probiotic properties, including a high potential for biocontrol applications, specifically against L. innocua and P. aeruginosa (20 mm diameter zone with the neutralized cell-free supernatant), which disappeared after protease treatment, suggesting that bioactive peptides might be responsible for the observed antimicrobial effect. Additionally, they demonstrated resilience to acidic (pH 2) and osmotic challenges (1M sucrose), tolerance to gastro-intestinal conditions, as well as good aggregation and adhesion profile. Furthermore, the strains were able to produce metabolites of interest, such as exopolysaccharide (yielding up to 4.7 mg/mL) and riboflavin, reaching considerable production levels of 2.5 mg/L upon roseoflavin selection. The application of W. cibaria and L. plantarum as primary starters (both in single and co-culture) for fermenting quinoa resulted in effective acidification of the matrix (ΔpH of 2.03 units) and high-quality beverage production. in vivo challenge tests against L. innocua showed the complete inhibition of this pathogen when L. plantarum was included in the starter, either alone or in combination with W. cibaria. Both species also inhibited Staphylococcus and filamentous fungi. Moreover, the co-culture of mutant strains of L. plantarum R12d and W. cibaria VR81d produced riboflavin levels of 175.41 µg/100 g in fermented quinoa, underscoring their potential as starters for the fermentation, biopreservation, and biofortification of quinoa while also displaying promising probiotic characteristics. [ABSTRACT FROM AUTHOR]

The use of lactic acid bacteria (LAB) for the probiotic enrichment of minimally processed fruit is a well-established practice in the literature. In addition, several LAB demonstrated a strain-specific ability to control harmful microorganisms and decay agents, improving shelf life, maintaining quality, and promoting the safety of fruits and vegetables. Edible coatings can help modulate the phenomena of gas exchange and water loss by fruits, representing protection from physical damage and spoilage phenomena linked to oxidation and the development of undesired microorganisms. At the same time, the coating can represent an innovative delivery matrix for the LAB strains of potential interest to improve safety and quality in the postharvest management of fruits. In this work, five Lactiplantibacillus plantarum strains, previously characterised for their probiotic and antifungal activity, were incorporated into a sodium alginate coating to develop edible probiotic coatings with antifungal properties for table grapes cv. Italia. The bacterial transfer and their survival were evaluated by comparing coated and uncoated table grapes during 14 days of cold storage at 4 °C. The alginate edible coating increased the number of viable cells transferred to the surface of the berries from about 5 to more than 7 Log CFU/g, with a crucial impact on the potential functional attributes of the final product. The ability of the functionalised coatings to counteract the decay development was evaluated on table grape berries artificially contaminated with Aspergillus niger CECT 2805. A significant reduction in lesion diameter was observed in the alginate coating with L. plantarum 11-A, with a reduction from 15.40 ± 1.14 mm of uncoated berries to 8.40 ± 1.14 mm of berries coated with L. plantarum 11-A. The lesion diameter reduction was also accompanied by a reduction in the symptoms of infection, such as browning around the wound. These results suggest the application of selected strains of L. plantarum as promising bio-resources to enhance the overall value of ready-to-eat fruits and vegetables, particularly in combination with edible coating as a carrier matrix. While a strain-dependent effect was not detected with respect to the improvement in the number of cells in the edible coating, a variability depending on the biotype used was detected for the properties linked to biocontrol, suggesting that the inclusion in edible packaging may represent an innovative criterion in the selection of lactobacilli to be applied postharvest. [ABSTRACT FROM AUTHOR]

The ongoing occurrence of foodborne diseases and the imperative need for efficient spoilage and pathogen control in food products constitute a critical challenge for the food industry. The rising demands of consumers for safe, healthy, and clean-label food products have led to an increased interest in natural antimicrobial alternatives. Lactic acid bacteria (LAB) have proven their value in the food industry in recent years, also in reason of their antagonistic properties against undesired microbes and their significant related protechnological attributes. The natural antimicrobial compounds produced by LAB exhibit inhibitory effects on pathogens and effectively inhibit the activities of food spoilage-related organisms. Applying secondary metabolites of LAB, notably bacteriocins, organic acids, and others, has found commercial utility across multiple food sectors, effectively preventing the proliferation of undesirable microorganisms and simultaneously enhancing the sensory properties and overall quality of various food products. This review comprehensively explores the natural microbial compounds produced by LAB, specifically focusing on their antimicrobial action in supporting effective and sustainable microbial management. Additionally, it highlights their strategic application across various technological contexts within the food industry. [ABSTRACT FROM AUTHOR]

The topic of microbial interactions is of notable relevance in oenology, being connected with their impact on microbial biodiversity and wine quality. The interactions among different couples of microorganisms, in particular yeasts and lactic acid bacteria representative of the must/wine microbial consortium, have been tested in this study. This interaction's screening has been implemented by means of plate assays, using culture medium, grape juice, and wine agar as substrates. Different antagonistic phenomena have been detected, belonging to the following interaction categories: yeast-yeast, yeast-bacteria, bacteria-yeast, and bacteria-bacteria. In general, the inhibitory activity has been observed in all three media agar used as substrates, resulting in more frequent on culture medium, followed by grape juice and, finally, wine. Specifically, the work is one of the first reports demonstrating the reciprocal interactions between non-Saccharomyces yeasts (NSY) and malolactic bacteria. The findings shed new light on the co-inoculation of the yeast starter culture with malolactic bacteria, as well as the biocontrol potential of Lactic Acid Bacteria (LAB) strains. Highlighted microbial interactions are relevant for the management of alcoholic fermentation, malolactic fermentation, and the development of distinctive aroma profiles, control of spoilage yeasts, and the selection of tailored mixed starter cultures. In addition, the plate assay method could be a fast, cheap, and suitable method to exclude negative interactions among Saccharomyces spp., NSY, and malolactic bacteria during trials from regional spontaneous fermentations with the aim to select tailored mixed starter cultures. [ABSTRACT FROM AUTHOR]

Winemaking depends on several elaborate biochemical processes that see as protagonist either yeasts or lactic acid bacteria (LAB) of oenological interest. In particular, LAB have a fundamental role in determining the quality chemical and aromatic properties of wine. They are essential not only for malic acid conversion, but also for producing several desired by-products due to their important enzymatic activities that can release volatile aromatic compounds during malolactic fermentation (e.g., esters, carbonyl compounds, thiols, monoterpenes). In addition, LAB in oenology can act as bioprotectors and reduce the content of undesired compounds. On the other hand, LAB can affect wine consumers' health, as they can produce harmful compounds such as biogenic amines and ethyl carbamate under certain conditions during fermentation. Several of these positive and negative properties are species- and strain-dependent characteristics. This review focuses on these aspects, summarising the current state of knowledge on LAB's oenological diversity, and highlighting their influence on the final product's quality and safety. All our reported information is of high interest in searching new candidate strains to design starter cultures, microbial resources for traditional/typical products, and green solutions in winemaking. Due to the continuous interest in LAB as oenological bioresources, we also underline the importance of inoculation timing. The considerable variability among LAB species/strains associated with spontaneous consortia and the continuous advances in the characterisation of new species/strains of interest for applications in the wine sector suggest that the exploitation of biodiversity belonging to this heterogeneous group of bacteria is still rising. [ABSTRACT FROM AUTHOR]

Climate change threatens food systems, with huge repercussions on food security and on the safety and quality of final products. We reviewed the potential of food microbiology as a source of biotechnological solutions to design climate-smart food systems, using wine as a model productive sector. Climate change entails considerable problems for the sustainability of oenology in several geographical regions, also placing at risk the wine typicity. The main weaknesses identified are: (i) The increased undesired microbial proliferation; (ii) the improved sugars and, consequently, ethanol content; (iii) the reduced acidity and increased pH; (iv) the imbalanced perceived sensory properties (e.g., colour, flavour); and (v) the intensified safety issues (e.g., mycotoxins, biogenic amines). In this paper, we offer an overview of the potential microbial-based strategies suitable to cope with the five challenges listed above. In terms of microbial diversity, our principal focus was on microorganisms isolated from grapes/musts/wines and on microbes belonging to the main categories with a recognized positive role in oenological processes, namely Saccharomyces spp. (e.g., Saccharomyces cerevisiae), non-Saccharomyces yeasts (e.g., Metschnikowia pulcherrima, Torulaspora delbrueckii, Lachancea thermotolerans, and Starmerella bacillaris), and malolactic bacteria (e.g., Oenococcus oeni, Lactobacillus plantarum). [ABSTRACT FROM AUTHOR]

Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to consistent economic losses in the wine industry. Considering the interest in reducing sulfur dioxide use during winemaking, in recent years, biological alternatives, such as the use of tailored selected yeast and bacterial strains inoculated to promote AF and MLF, are actively sought as biocontrol agents to avoid the 'Bretta' character in wines. Here, we review the importance of dedicated characterization and selection of starter cultures for AF and MLF in wine, in order to reduce or prevent both growth of B. bruxellensis and its production of volatile phenols in the matrix. [ABSTRACT FROM AUTHOR]

This study reports the first application of a next generation sequencing (NGS) analysis. The analysis was designed to monitor the effect of the management of microbial resources associated with alcoholic fermentation on spontaneous malolactic consortium. Together with the analysis of 16S rRNA genes from the metagenome, we monitored the principal parameters linked to MLF (e.g., malic and lactic acid concentration, pH). We encompass seven dissimilar concrete practices to manage microorganisms associated with alcoholic fermentation: Un-inoculated must (UM), pied-de-cuve (PdC), Saccharomyces cerevisiae (SC), S. cerevisiae and Torulaspora delbrueckii co-inoculated and sequentially inoculated, as well as S. cerevisiae and Metschnikowia pulcherrima co-inoculated and sequentially inoculated. Surprisingly, each experimental modes led to different taxonomic composition of the bacterial communities of the malolactic consortia, in terms of prokaryotic phyla and genera. Our findings indicated that, uncontrolled AF (UM, PdC) led to heterogeneous consortia associated with MLF (with a relevant presence of the genera Acetobacter and Gluconobacter), when compared with controlled AF (SC) (showing a clear dominance of the genus Oenococcus). Effectively, the SC trial malic acid was completely degraded in about two weeks after the end of AF, while, on the contrary, malic acid decarboxylation remained uncomplete after 7 weeks in the case of UM and PdC. In addition, for the first time, we demonstrated that both (i) the inoculation of different non-Saccharomyces (T. delbrueckii and M. pulcherrima) and, (ii) the inoculation time of the non-Saccharomyces with respect to S. cerevisiae resources (co-inoculated and sequentially inoculated) influence the composition of the connected MLF consortia, modulating MLF performance. Finally, we demonstrated the first findings of delayed and inhibited MLF when M. pulcherrima, and T. delbrueckii were inoculated, respectively. In addition, as a further control test, we also assessed the effect of the inoculation with Oenococcus oeni and Lactobacillus plantarum at the end of alcoholic fermentation, as MLF starter cultures. Our study suggests the potential interest in the application of NGS analysis, to monitor the effect of alcoholic fermentation on the spontaneous malolactic consortium, in relation to wine. [ABSTRACT FROM AUTHOR]

Strawberry is a highly perishable soft fruit susceptible to microbial contaminations, with Botrytis cinerea among the main spoilers in post-harvest. Lactic Acid Bacteria (LAB) are well-known food-grade bacteria, usually employed in food fermentation for their protechnological and probiotic properties. Moreover, LAB strains are also used as biocontrol agents for their ability to synthesise antimicrobial metabolites. However, applications of selected LAB to improve the overall quality in the fruit sector are still underexplored. In this study probiotic Lactiplantibacillus plantarum strains showing anti- Botrytis activity were grown in strawberry juice (SJ). Probiotics were transferred to strawberries through dipping in fermented SJ, and the impact of the carrier matrix on their survival was evaluated in a simulated oro-gastrointestinal model. The best candidates were selected to investigate the postharvest quality of strawberries at different levels including functional (i.e., viability of probiotics at the end of the shelf life); safety (i.e., ability to control the growth of foodborne pathogenic bacteria); shelf life (i.e., biocontrol of B. cinerea); nutritional and sensory. The probiotic survival under simulated gastrointestinal conditions was up to 2.5 Log higher when strawberry was used as carrier. In co-inoculation assays on strawberries, L. plantarum 11 A and CB56 were able to reduce the growth of Listeria monocytogenes and Escherichia coli of about 1 Log after 7 days of cold storage. Moreover, live L. plantarum were able to control the growth of B. cinerea of about ten and five folds for strain 11 A and CB56, respectively, and a lower bioprotective effect was detected on strawberries dipped in the cell-free SJ fermented by L. plantarum 11 A. No significant effect was observed in terms of the main nutritional compounds, while improved descriptors related to the appearance of the fruit were observed. Therefore, this study allows us to elucidate the potential of selected LAB strains to improve the overall post-harvest quality of strawberries by using a thorough food-grade approach. • SJ was suitable to grown probiotic L. plantarum strains with anti- Botrytis activity. • Strawberry increased the survival of probiotics in simulated gastrointestinal model. • Dipping in fermented SJ was effective to transfer probiotics or antimicrobials. • Dipping in fermented SJ inhibited B. cinerea on artificially contaminated strawberry. • Dipping in fermented SJ enhanced the safety and overall quality of strawberry. [ABSTRACT FROM AUTHOR]