Effects of added Lactobacillus acidophilus and Bifidobacterium lactis probiotics on the quality characteristics of goat ricotta and their survival under simulated gastrointestinal conditions

This study evaluated the effects of incorporating the probiotics Bifidobacterium animalis subsp. lactis Bb-12 (B. lactis) or Lactobacillus acidophilus La-05 (L. acidophilus) into goat ricotta on the technological, physicochemical, physical and sensory parameters of this product during refrigerated storage, as well as the protective effects of the goat ricotta on the survival of the tested probiotics during exposure to simulated gastrointestinal conditions. Incorporating the tested probiotics did not affect the yield or syneresis of the obtained goat ricotta. The counts of L. acidophilus and B. lactis during the chosen storage period were approximately 6 log CFU/g. The ricotta samples containing a probiotic strain presented smaller and greater amounts of lactose and lactic acid, respectively, and exhibited greater hardness and lower brightness after storage compared with the samples lacking a probiotic. No differences were observed in the fatty acid profiles of the goat ricotta containing or not containing a probiotic. All of the ricotta samples were described as a soft cheese with a homogeneous texture; however, the goat ricotta cheeses containing L. acidophilus or B. lactis were described as having a more acidic flavor. At the end of a challenge using experimental human digestive conditions, the counts of each of the tested probiotic strains were approximately 6 log CFU/g if it had been incorporated into goat ricotta. These results demonstrated the feasibility of incorporating L. acidophilus or B. lactis into goat ricotta because these probiotics did not negatively affect the quality characteristics of this product and suggested that goat ricotta is an efficacious food matrix for maintaining the viability of these probiotics during storage and under the stressful conditions imposed by the human gastrointestinal tract.