Physicochemical, Sensory, and Microbiological Analysis of Fermented Drinks Made from White Kidney Bean Extract and Cow's Milk Blends during Refrigerated Storage.

Due to its low dietary impact and bioactive compounds, such as polyphenols and flavonoids, white kidney bean extract is an attractive raw material for fermented drinks. It can be utilized either on its own or blended with cow's milk, offering a promising solution to help meet dairy product demand during mid-season shortages. Therefore, this study aimed to explore the physicochemical characteristics, sensory properties, and microbiological profile of fermented milk-like drinks made from white kidney bean extract, cow's milk and their blends during 28 days of storage at 4 °C. Three blends of fermented milk-like drinks (FMLDs) were prepared from different ratios of cow's milk (CM) and kidney bean extract (BE): FMLD1 (CM 30%:BE 70%); FMLD2 (CM 50%:BE 50%), FMLD3 (CM 70%:BE 30%), along with plain fermented kidney been extract (FBE; CM 0%:BE 100%), and plain fermented cow's milk (FCM; CM 100%:BE 0%). The mixtures were pasteurized at 92 °C for 25 min and fermented with a probiotic-type starter culture (S. thermophilus, B. bifidum, L. acidophilus) at 43 °C. FBE exhibited the lowest levels of carbohydrates (2.14%), fat (0.11%), and protein (1.45%) compared to fermented cow's milk and blends. The FBE and the fermented blends with a higher ratio of bean extract had lower viscosity and lactic acid contents, greener hue, more pronounced aftertaste and off-flavors, and received lower overall acceptability scores. Although the FCM had higher counts of S. thermophilus and L. acidophilus, the FBE displayed significantly higher counts of B. bifidum. This study demonstrated the potential of using white kidney bean extract and its blends with cow's milk to create unique fermented products with a lower dietary impact, highlighting the importance of further optimizing the formulations to enhance sensory qualities and reduce the beany off-flavors in the products with added kidney bean extract.

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.

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.

Application of Edible Coating Based on Liquid Acid Whey Protein Concentrate with Indigenous Lactobacillus helveticus for Acid-Curd Cheese Quality Improvement.

Edible coatings as carriers for protective lactic acid bacteria (LAB) can enhance hygienic quality to dairy products. Thus, the aim of this study was to improve the quality of artisanal acid-curd cheese by applying liquid acid whey protein concentrate based edible coating with entrapped indigenous antimicrobial Lactobacillus helveticus MI-LH13. The edible fresh acid-curd cheese coating was composed of 100% (w/w) liquid acid whey protein concentrate (LAWPC), apple pectin, sunflower oil, and glycerol containing 6 log10 CFU/mL of strain biomass applied on cheese by dipping. The cheese samples were examined over 21 days of storage for changes of microbiological criteria (LAB, yeast and mould, coliform, enterobacteria, and lipolytic microorganism), physicochemical (pH, lactic acid, protein, fat, moisture content, and colour), rheological, and sensory properties. The coating significantly improved appearance and slowed down discolouration of cheese by preserving moisture during prolonged storage. The immobilisation of L. helveticus cells into the coating had no negative effect on their viability throughout 14 days of storage at 4 °C and 23 °C. The application of coating with immobilised cells on cheeses significantly decreased the counts of yeast up to 1 log10 CFU/g during 14 days (p < 0.05) of storage and suppressed growth of mould for 21 days resulting in improved flavour of curd cheese at the end of storage. These findings indicate that LAWPC-pectin formulation provided an excellent matrix to support L. helveticus cell viability. Acting as protective antimicrobial barrier in fresh cheeses, this bioactive coating can reduce microbial contamination after processing enabling the producers to extend the shelf life of this perishable product.

Indigenous Lactococcus lactis with Probiotic Properties: Evaluation of Wet, Thermally- and Freeze-Dried Raisins as Supports for Cell Immobilization, Viability and Aromatic Profile in Fresh Curd Cheese.

Indigenous Lactococcus lactis enriched raisins were incorporated in fresh curd cheese in wet, thermally dried, and freeze-dried form to produce a novel probiotic dairy product. Symbiotic cheese represents a rising trend in the global market. The viability of L. lactis cells was assessed in the cheeses during storage at 4 °C for 14 days and the effect of the added enriched raisins on physicochemical parameters, microbiological characteristics, and sugar content, aromatic profile, and sensory acceptance of cheeses were evaluated. Immobilized L. lactis cells maintained viability at necessary levels (>6 log cfu/g) during storage and significantly increased the acceptability of cheese. The addition of raisins enhanced the volatile profile of cheeses with 2-furanmethanol, 1-octanol, 3-methylbutanal, 2-methylbutanal, 2-furancarboxaldehyde, 1-(2-furanyl)-ethanone, 5-methyl-2-furancarboxaldehyde. The obtained results are encouraging for the production of novel fresh cheeses with improved sensorial and nutritional characteristics on industrial and/or small industrial scale.