Evaluation of Pediococcus acidilacticiAS185 as an adjunct culture in probiotic cheddar cheese manufacture

A novel probiotic Pediococcus acidilactici AS185, isolated from traditional Chinese fermented foods, was used as an adjunct culture for probiotic cheddar cheese production. The physicochemical composition, textural, free amino acids (FAAs), short-chain fatty acids (SCFAs) profiles, sensory properties, and microbial survival, was evaluated during the 90-day ripening period. The addition of P. acidilactici AS185 did not influence the physicochemical composition of cheddar cheese but significantly decreased the hardness without affecting its textural profile. During ripening, P. acidilactici AS185 was able to grow and promote the generation of FAAs and SCFAs, but did not alter the overall sensory properties; it rather improved the flavor and taste of cheese. In addition, the cheese matrix protected strain P. acidilactici AS185 during transit throughout the simulated gastrointestinal system. These results demonstrated that P. acidilactici AS185 adjunct cultures might be useful for producing high-quality probiotic cheddar cheese.

Histamine-forming ability of Lentilactobacillus parabuchneri in reduced salt Cheddar cheese

Lentilactobacillus parabuchneri, a member of the non-starter microbiota in cheese, was recently associated with fast and effective histamine-formation ability, a safety issue. The present study was performed to investigate Lentilactobacillus parabuchneri KUH8, a histamine-producer (HP) in reduced-salt Cheddar cheese. Four cheeses were manufactured: 1) normal-salt (NS); 2) reduced-salt (RS); 3) normal-salt with HP (NS+HP); 4) reduced-salt with HP (RS+HP). Two replicates were produced with milk from the same batch, and the cheeses ripened at 10 and 15 °C. Cheeses were sampled immediately after manufacture and after 1, 3 and 6 months of ripening. Ultra-high-performance-liquid chromatography indicated that with the HP, histamine reached higher levels in reduced-salt cheeses (3.5-3.7% S/M) at 15 °C (86, 1112, 2149 and 3149 mg kg^-1), compared to normal-salt cheeses (5.4-6.3% S/M) at 10 °C (78, 584, 593 and 1389 mg kg^-1), at each respective cheese-sampling point. Higher salt-content reduced the growth rate of non-starter microbiota, but after six months the levels in all cheeses were similar, according to the ripening temperature: at 10 °C (8.05-8.30 log₁₀ cfu g^-1), and at 15 °C (6.00-6.94 log₁₀ cfu g^-1). A correlation between increased histamine levels, non-starter-cell development and pH was found. This study highlights the importance of normal-salt content and low-ripening temperature as measures to control histamine-formation and to improve safety in cheese.

Diversity of non-starter lactic acid bacteria in autochthonous dairy products from Western Balkan Countries - Technological and probiotic properties

The aim of this review was to summarize the data regarding diversity of non-starter lactic acid bacteria (NSLAB) isolated from various artisanal dairy products manufactured in Western Balkan Countries. The dairy products examined were manufactured from raw cow's, sheep's or goat's milk or mixed milk, in the traditional way without the addition of commercial starter cultures. Dairy products such as white brined cheese, fresh cheese, hard cheese, yogurt, sour cream and kajmak were sampled in the households of Serbia, Croatia, Slovenia, Bosnia and Herzegovina, Montenegro, and North Macedonia. It has been established that the diversity of lactic acid bacteria (LAB) from raw milk artisanal dairy products is extensive. In the reviewed literature, 28 LAB species and a large number of strains belonging to the Lactobacillus, Lactococcus, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Weissella genera were isolated from various dairy products. Over 3000 LAB strains were obtained and characterized for their technological and probiotic properties including: acidification and coagulation of milk, production of aromatic compounds, proteolytic activity, bacteriocins production and competitive exclusion of pathogens, production of exopolysaccharides, aggregation ability and immunomodulatory effect. Results show that many of the isolated NSLAB strains had one, two or more of the properties mentioned. The data presented emphasize the importance of artisanal products as a valuable source of NSLAB with unique technological and probiotic features important both as a base for scientific research as well as for designing novel starter cultures for functional dairy food.

Complete Genome Sequence of Lactobacillus paracasei EG9, a Strain Accelerating Free Amino Acid Production during Cheese Ripening

Lactobacillus paracasei EG9 is a strain isolated from well-ripened cheese and accelerates free amino acid production during cheese ripening. Its complete genome sequence was determined using the PacBio RS II platform, revealing a single circular chromosome of 2,927,257 bp, a G+C content of 46.59%, and three plasmids.

Lactobacillus paracasei EG9 is a strain isolated from well-ripened cheese and accelerates free amino acid production during cheese ripening. Its complete genome sequence was determined using the PacBio RS II platform, revealing a single circular chromosome of 2,927,257 bp, a G+C content of 46.59%, and three plasmids.