In vivo study of the immunomodulatory capacity and the impact of probiotic strains on physicochemical and sensory characteristics: Case of pasta filata soft cheeses.

Nowadays, there is a great interest of food industries on the development of innovative dairy products containing probiotic bacteria. Beyond yoghurt, cheeses could be a suitable matrix for the incorporation of probiotics. This work aimed to study the impact of the addition of two probiotic lactobacilli (L. rhamnosus GG and L. acidophilus LA5), either individually or combined, on the physicochemical and sensory characteristics of pasta filata soft cheeses and to evaluate the immunomodulating capacity of the product using an in vivo model. Four cheese types were produced: CC (control cheese); L-C (added with L. acidophilus LA5); GG-C (added with L. rhamnosus GG) and GGL-C (added with both probiotics). No differences in gross composition were found. An increase in secondary proteolysis was observed in GGL-C cheeses which correlated with a greater bitter and aftertaste. On the contrary, the L-C cheese received the highest overall quality score. The translocation assay was negative. Moreover, the three experimental cheeses were able to modulate the immune system of mice by reducing the secretion of pro-inflammatory cytokines in the intestine, downregulating the levels of interleukin (IL)-10 and increasing the secretion of Secretory Immunoglobulin A (S-IgA). No synergistic effect was detected when both probiotics were added.

Effect of storage temperature on the chemical, microbiological, and sensory characteristics of pasta filata soft cheese containing probiotic lactobacilli.

The aim of this study was to manufacture pasta filata cheeses added with two probiotic lactobacilli: Lactobacillus rhamnosus GG and Lactobacillus acidophilus LA5, either individually or combined, and to evaluate the effect of the storage temperature (4 and 12 °C) on their chemical, microbiological, and sensorial characteristics. Three cheese types were made: (i) G: containing L. rhamnosus GG, (ii) L: containing L. acidophilus LA5, and (iii) GL: containing both probiotic strains. Gross composition, pH, microbiological, and sensory characteristics were determined. No differences in gross composition were found among them. pH values remained above 5.2 in cheeses stored at 4 °C. However, a postacidification was observed in cheeses ripened at 12 °C. L. acidophilus LA5 was not able to grow, while L. rhamnosus GG grew 1.5 log10 CFU/g in G and GL cheeses stored at 12 °C, reducing the pH from day 8 onwards. These results emphasize the importance of the storage temperature since the good characteristics of probiotic cheeses are kept if the cold-chain is respected. Thus, the selection of probiotics, together with the food matrix and the starter, should be carefully evaluated.