Is there an impact of the dairy matrix on the survival of Lactobacillus casei Lc-1 during shelf life and simulated gastrointestinal conditions?

BACKGROUND: The selection of the food matrix to be used as a vehicle for a probiotic culture is important because its chemical composition and physicochemical characteristics can affect probiotic survival during the shelf-life of the product and under simulated gastrointestinal conditions (SGIC). The present study aimed to evaluate the influence of the dairy matrix (chocolate fermented milk beverage, chocolate flan or passion fruit flan) on the survival of Lactobacillus casei Lc-1 during refrigerated storage (4 °C for 21 days) and SGIC. RESULTS: Chocolate fermented milk beverage and chocolate and passion fruit flans could be considered as matrices for the incorporation of L. casei, providing suitable counts (6.38-7.84 log cfu g-1 ) during storage. The type of matrix had an impact on the inicial probiotic counts in the products and on the probiotic resistance to the SGIC. The chocolate fermented milk beverage presented higher initial probiotic counts (7.72 versus 6.65-7.28 log cfu g-1 ). The higher pH (5.3-6.8), solid matrix and increased fat content (65.0-72.9 g 100 g-1 ) contributed to the higher resistance to the SGIC of the chocolate and passion fruit flans, allowing recovery of viability during the enteric phase (increases of 1-1.5 log cycles). CONCLUSION: The type of dairy matrix has an impact on the inicial probiotic counts in the products and on the probiotic resistance to the SGIC. Chocolate and passion fruit flans proved to be more suitable options than chocolate fermented milk beverage for the incorporation of Lactobacillus casei Lc-1. © 2019 Society of Chemical Industry.

Dried tomato-flavored probiotic cream cheese with Lactobacillus paracasei.

UNLABELLED: A dried tomato-flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc-37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10(7) CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. PRACTICAL APPLICATION: Lactobacillus paracasei Lpc-37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato-flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.