Screening for Antifungal Indigenous Lactobacilli Strains Isolated from Local Fermented Milk for Developing Bioprotective Fermentates and Coatings Based on Acid Whey Protein Concentrate for Fresh Cheese Quality Maintenance

Abstract

The demand for healthy foods without artificial food additives is constantly increasing. Hence, natural food preservation methods using bioprotective cultures could be an alternative to chemical preservatives. Thus, the main purpose of this work was to screen the indigenous lactobacilli isolated from fermented cow milk for their safety and antifungal activity to select the safe strain with the strongest fungicidal properties for the development of bioprotective acid whey protein concentrate (AWPC) based fermentates and their coatings intended for fresh cheese quality maintenance. Therefore, 12 lactobacilli strains were isolated and identified from raw fermented cow milk as protective cultures. The safety of the stains was determined by applying antibiotic susceptibility, haemolytic and enzymatic evaluation. Only one strain, Lacticaseibacillus paracasei A11, met all safety requirements and demonstrated a broad spectrum of antifungal activity in vitro. The strain was cultivated in AWPC for 48 h and grew well (biomass yield 8 log10 cfu mL−1). L. paracasei A11 AWPC fermentate was used as a vehicle for protective culture in the development of pectin-AWPC-based edible coating. Both the fermentate and coating were tested for their antimicrobial properties on fresh acid-curd cheese. Coating with L. paracasei A11 strain reduced yeast and mould counts by 1.0–1.5 log10 cfu mL−1 (p ≤ 0.001) during cheese storage (14 days), simultaneously preserving its flavour and prolonging the shelf life for six days.

Antimicrobial activity and applications of fermentates from lactic acid bacteria – a review

“…7 The resulting fermentates from whey protein concentrate lack colour or avour additives, making them directly integrable to foods. 7 Additionally, whey protein concentrate can serve as an economical medium for LAB cultivation, offering an alternative for repurposing acid whey while avoiding the expenses associated with non-food grade LAB growth media like MRS broth and the associated biomass preparation procedures. LAB fermentation is considered an economical and scalable way to obtain bioactive ingredients once growth conditions that promote their production or release are established.…”

“…[4][5][6][7][8] Natural food preservation additives using bioprotective cultures could be an alternative to chemical preservatives. 7 Cell-free supernatants (CFS) from lactic acid bacteria (LAB) have been widely studied as antimicrobials since they contain the metabolites derived from fermentation and/or secondary microbial products from metabolism. 1 CFS from several LAB have demonstrated their efficacy as antimicrobials against bacteria and fungi.…”

“…An alternative approach to the commonly employed media to cultivate lactic acid bacteria (MRS broth) involves utilizing whey protein concentrate to produce acid-tolerant LAB biomass 7 fermentate, thereby using whey proteins, peptides, and naturally occurring sugars as a sustainable energy source for strain growth, in contrast to relying on MRS broth. The production of this fermentate presents a viable, innovative, natural, and cost-effective means of biomass growth.…”

“…The production of this fermentate presents a viable, innovative, natural, and cost-effective means of biomass growth. 7 The resulting fermentates from whey protein concentrate lack colour or flavour additives, making them directly integrable to foods. 7 Additionally, whey protein concentrate can serve as an economical medium for LAB cultivation, offering an alternative for repurposing acid whey while avoiding the expenses associated with non-food grade LAB growth media like MRS broth and the associated biomass preparation procedures.…”

Sheep’s Second Cheese Whey Edible Coatings with Oregano and Clary Sage Essential Oils Used as Sustainable Packaging Material in Cheese

“…The application of coatings based on whey proteins for cheeses is also limited. Whey protein isolates [ 59 , 60 ] and whey protein concentrates [ 61 , 62 , 63 ] have been used to elaborate coatings to wrap cheeses by incorporating antimicrobial compounds [ 59 , 60 ], natural plant extracts (cinnamon) [ 61 ], or protective lactic acid bacteria [ 62 , 63 ] to extend the shelf life of the product.…”