Probiotic Potential and Application of Indigenous Non-Starter Lactic Acid Bacteria in Ripened Short-Aged Cheese.

There are massive sources of lactic acid bacteria (LAB) in traditional dairy products. Some of these indigenous strains could be novel probiotics with applications in human health and supply the growing needs of the probiotic industry. In this work, were analyzed the probiotic and technological properties of three Lactobacilli strains isolated from traditional Brazilian cheeses. In vitro tests showed that the three strains are safe and have probiotic features. They presented antimicrobial activity against pathogenic bacteria, auto-aggregation values around 60%, high biofilm formation properties, and a survivor of more than 65% to simulated acid conditions and more than 100% to bile salts. The three strains were used as adjunct cultures separately in a pilot-scale production of Prato cheese. After 45 days of ripening, the lactobacilli counts in the cheeses were close to 8 Log CFU/g, and was observed a reduction in the lactococci counts (around -3 Log CFU/g) in a strain-dependent manner. Cheese primary and secondary proteolysis were unaffected by the probiotic candidates during the ripening, and the strains showed no lipolytic effect, as no changes in the fatty acid profile of cheeses were observed. Thus, our findings suggest that the three strains evaluated have probiotic properties and have potential as adjunct non-starter lactic acid bacteria (NSLAB) to improve the quality and functionality of short-aged cheeses.

Brazilian indigenous nonstarter lactic acid bacteria enhance the diversification of volatile compounds in short-aged cheese.

There is growing interest in using autochthonous lactic acid bacteria (LAB) that provide unique sensory characteristics to dairy products without affecting their safety and quality. This work studied the capacity of three Brazilian indigenous nonstarter LABs (NSLAB) to produce biogenic amines (BAs) and evaluated their effect on the volatile organic compounds (VOCs), microbial LAB communities, and physicochemical profile of short-aged cheese. Initially, the strain's potential for biosynthesis of BAs was assessed by PCR and in vitro assays. Then, a pilot-scale cheese was produced, including the NSLAB, and the microbial and VOC profiles were analyzed after 25 and 45 days of ripening. As a results, the strains did not present genes related to relevant BAs and did not produce them in vitro. During cheese ripening, the Lactococci counts were reduced, probably in the production of alcohols and acid compounds by the NSLAB. Each strain produces a unique VOC profile that changes over the ripening time without the main VOCs related to rancid or old cheese. Particularly, the use of the strain Lacticaseibacillus. paracasei ItalPN16 resulted in production of ester compounds with fruity notes. Thus, indigenous NSLAB could be a valuable tool for the enhancement and diversification of flavor in short-aged cheese.

Draft Genome Sequence and Comparative Genome Analysis Reveal Potential Functional Properties in Lacticaseibacillus paracasei ItalPN16.

Nowadays, there is a great interest on rapid and effective methods for initial identification of probiotic bacteria. In this work, potential probiotic features of the lactic acid bacteria strain ItalPN16 isolated from a traditional Brazilian cheese were studied using bioinformatic tools. The complete genome sequence was obtained, and in silico analyses were carried out to identify the strain and its potential probiotic properties. The sequenced genome (3.02 Mb) presented 3126 protein-coding sequences distributed on 244 SEED subsystems, classifying the strain as nomadic lactobacilli. Phylogenetic and ANI analyses allowed to locate the ItalPN16 strain as a member of the Lacticaseibacillus paracasei group, due to the highest number of orthologous genes in common with reference L. paracasei strains (>98%). In silico analyses revealed the presence of CDSs related to microbe-host interactions, such as adhesion proteins and exopolysaccharide biosynthesis genes. The comparative analysis reveals the presence of a strain-specific glycosyl transferases, compared with other three L. paracasei strains and a high level of protein expression (92%) with the probiotic L. paracasei BL29. The results obtained here indicated interesting probiotic features of the strain L. paracasei ItalPN16 that could favor a future application in the food industry.

Improved functional properties of the potential probiotic Lacticaseibacillus paracasei ItalPN16 growing in cheese whey.

The production of probiotic bacteria requires specific and expensive culture media for maintain their viability and metabolic response during gastro-intestinal transit and cell adhesion process. The aim of this study was to compare the ability of the potential probiotic Laticaseibacillus paracasei ItalPN16 to grow in plain sweet whey (SW) and acid whey (AW), evaluating changes in some probiotic properties related to the culture media. Pasteurized SW and AW were suitable media for L. paracasei growth, since counts above 9 Log CFU/ml were achieved using <50% of the total sugars in both whey samples after 48 h at 37°C. The L. paracasei cells obtained from AW or SW cultures showed increased resistance to pH 2.5 and 3.5, higher autoaggregation, and lower cell hydrophobicity, as compared with the control of MRS. SW also improved the biofilm formation ability and cell adhesion capability to Caco-2 cells. Our results indicate that the L. paracasei adaptation to the SW conditions, inducing metabolic changes that improved its stability to acid stress, biofilm formation, autoaggregation, and cell adhesion properties, which are important functional probiotic properties. Overall, the SW could be considered as low-cost culture medium for sustainable biomass production of L. paracasei ItalPN16.

Ácido linoleico conjugado (CLA) - benefícios para saúde, sua presença e estabilidade em produtos lácteos / Conjugated Llnoleic acid (CLA) - health benefits, its presence and stability in dairy products

O crescente interesse pelo CLA (conjugated linoleic acid) se iniciou com a descoberta de que inibia tumores induzidos quimicamente. Este grupo de substâncias está associado à gordura do leite bovino que é a fonte natural mais rica em CLA. O teor de CLA originalmente encontrado no leite pode ser aumentado de 3 maneiras. O aumento pode ser conseguido com mudanças na dieta dos animais, pela síntese por bactérias láticas e probióticas na fermentação do leite e pela adição de CLA sintético aos produtos lácteos com teor reduzido de gordura. Igualmente importantes são as pesquisas sobre a relação entre parâmetros do processamento de produtos lácteos e o conteúdo de CLA. Estes conhecimentos forneceram fundamentos para a fabricação de produtos lácteos com teores elevados de CLA que possam ter benefícios a saúde. O objetivo deste trabalho foi realizar uma revisão crítica da literatura sobre os benefícios à saúde relacionados ao CLA e sua presença e estabilidade em produtos lácteos.

O crescente interesse pelo CLA (conjugated linoleic acid) se iniciou com a descoberta de que inibia tumores induzidos quimicamente. Este grupo de substâncias está associado à gordura do leite bovino que é a fonte natural mais rica em CLA. O teor de CLA originalmente encontrado no leite pode ser aumentado de 3 maneiras. O aumento pode ser conseguido com mudanças na dieta dos animais, pela síntese por bactérias láticas e probióticas na fermentação do leite e pela adição de CLA sintético aos produtos lácteos com teor reduzido de gordura. Igualmente importantes são as pesquisas sobre a relação entre parâmetros do processamento de produtos lácteos e o conteúdo de CLA. Estes conhecimentos forneceram fundamentos para a fabricação de produtos lácteos com teores elevados de CLA que possam ter benefícios a saúde. O objetivo deste trabalho foi realizar uma revisão crítica da literatura sobre os benefícios à saúde relacionados ao CLA e sua presença e estabilidade em produtos lácteos.