DEVELOPMENT OF A FRESH PASTA FILATA SOFT CHEESE ADDED OF Lactobacillus rhamnosus GG

CUFFIA, FACUNDO; GEORGE, GUILLERMO ANDRÉS; RENZULLI, PABLO; REINHEIMER, JORGE; MEINARDI, CARLOS; BURNS, PATRICIA

Cesena

Conferencia; FOOD INNOVA 2017; 2017

Universidad de Bologna

Pasta filata cheeses encompass a wide range of cheese varieties such as Mozzarella, Scamorza, Provolone and Caciocavallo. Several challenges are related to the addition of probiotics to Fior di Latte cheese (a high-moisture cow milk Mozzarella cheese), being the most important the survival of probiotic bacteria during cheese making (temperature and time of stretching) and storage.The aim of this work was to adjust technological parameters (acidification of the curd, time and stretching temperature) in order to make a pasta filata soft cheese carrying a probiotic bacterium at levels higher than 10EXP7 CFU/g during its self life.Among bacteria tested L. rhamnosus GG was the most heat resistant strain (cell death < 1 log10 CFU/mL) so it was selected as adjunt culture for incorporation during the manufacture of Fior di Latte cheese. The acidification of the curd was done in 2 stages, under the whey and over the wheying table at ~25°C, until a pH of 5.8 and 5.2, respectively. Stretching was performed over 10 min in waterat 80 ± 1 ºC (core temperature of the curd of 62.5 ± 0.05°C). The level of L. rhamnosus GG was 7.59 ± 0.00 log10 CFU/mL and 8.57 ± 0.03 log10 CFU/g in milk and curd, respectively. After 10 min of stretching L. rhamnosus GG showed a cell death of 0.44 ± 0.12 log10 CFU/g and at the end of ripening its level remains in 7.55 ± 0.09 log10 CFU/g exceeding the level of probiotic bacteria required for a probiotic food. No differences were found in pH and gross composition for both CC and PC cheeses. The addition of L. rhamnosus GG increased secondary proteolysis and the production of diacetyl, acetoin and acetic acid. Lactic acid concentration was increased in PC. Differences in cohesiveness, odor, astringency, acid taste, and residual flavor were found. The presence of L. rhamnosus GG increased significantly values for odor, astringency, acid taste and residual flavor while cohesiveness was significantly higher in CC. There was significantly less cell load reduction when the probiotic was incorporated into the cheese matrix after gastric, duodenal and intestinal digestion. This work demonstrates that the setting of the technological variables (acidification of the curd and time and temperature of stretching) was satisfactory in order to maintain the viability of L. rhamnosus GG during cheese making and storage at 4ºC. Hot stretching during cheese manufacture,caused slight log reductions 0.44 log10 CFU/g and no viability loss was observed during refrigerated,storage. The probiotic strain remained above 7.55 log10 CFU/g during its shelf life and exhibited high,resistance to gastrointestinal digestion.