# Probiotics and Beneficial Microorganisms in Biopreservation of Plant-Based Foods and Beverages
## 4 Biopreservative Properties of Probiotics
### Miscellaneous Food Items  
Modern-day consumers are interested in healthier diets. The cholesterol content in dairy products and allergic reactions to milk proteins have led to the development of non-dairy probiotic products. A plethora of possibilities for probiotic product development is offered by plant materials like legumes, cereals, vegetables, fruits, and their combinations [24]. There is an increasing demand for the use of natural antimicrobial substances to safeguard foods and to replace synthetic additives in foods. Different probiotic microorganisms, specifically lactic acid bacteria, can be a promising fulfilment of this demand or consumer request. The metabolites produced by probiotics are hydrogen peroxide, diacetyl compounds, acetone, acetaldehyde, ethanol, reutericyclin, reuterin, carbon dioxide and most importantly natural acids and bacteriocins. The ability to use the metabolite bacteriocin produced by probiotics shows its effectiveness as a biopreservative. This antibacterial methodology could be a potential solution for raising concerns about pathogenic bacteria and antibiotic-resistant strains in plant-based foods. Recombinant probiotics with good antimicrobial characteristics can be developed using probiotic microorganisms [79]. _Lactiplantibacillus plantarum_ is one of the species of LAB that is used as an important element of the fermentation process employed in probiotic fermented food products. _Lb. plantarum_ produces exopolysaccharides, lactic acid and bioactive compounds that are antibacterial in nature. These show a potential activity against the foodborne pathogens present inside a human intestine [80]. The antifungal strains of LAB act as high-potential biological substance that produces 'bread' of improved quality, safety, and nutrition. The shelf-life extension can be achieved either by the involvement of probiotics in bread formulations or by their incorporation into active packaging as antimicrobial films [81]. Plant-based yoghurt alternatives are predominantly produced using soy or coconut (low in protein and high in saturated fat). _Lacobacillus xylosus_ exhibits probiotic, as well as bacteriocin, activities. These species produced bacteriocins that inhibited _S. aureus_ and _E. coli_. The antibacterial activity was found to be retained at a wide range of pH and temperature treatments. Reduction in bacterial load was observed due to the presence of bacteriocins. This study reveals the usage of _L. xylosus_ strain as potential probiotics and usage of their bacteriocins as bio-preservatives [82]. Hence, _L. xylosus_ can be potentially used in plant-based food and beverages as well. The lactic acid bacteria isolates, derived from a coconut palm nectar which is fermented naturally, were subjected to assessments to determine antibiotic sensitivity, antimicrobial activity, and antioxidant properties. The isolates exhibited good probiotic properties, along with promising antifungal and antibacterial activities. This shows that lactic acid bacteria isolated from coconut palm nectar is favorable to be used as preservatives in functional fermented foods [83]. The synergistic action of lactic acid bacteria which is a probiotic can be used to bio preserve emulsified foods and cosmetic products. Besides adding the biomolecules that possess antimicrobial properties directly, adding living bacteria with a bioprotective nature is a promising approach to produce safer food products [84]. _Lacobacillus brevis_ SG1, a potent bacteriocin-producing probiotic strain, isolated from a traditional Nigerian fermented cereal showed promising antifungal effects against _Candida albicans_ and _Penicillium citrinum_. Brevicin SG1 is the responsible bacteriocin isolated from this strain and reported to exert its antagonistic effects through fungiolytic activity. Moreover, the bacteriocin is stable at a broad pH range, an attribute which makes it a suitable candidate both for biopreservation and probiotic usage [85]. Various probiotics used in biopreservation of plant-based food products are given in Table 2.