USE OF SOME PROBIOTIC BACTERIA AS ADJUNCT CULTURE IN THE PRODUCTION OF WAGASHI (PEULH) CHEESE
Project no. 21636 · Status: Kapanmış · 2020
Summary
This study aimed at incorporating different probiotic strains into Wagashi cheese. For this purpose, a focus was put on their viability during cheese production and storage, and their significance on cheese’s physicochemical, salt content, texture profile analysis (TPA), colour, proteolysis, acid degree value (ADV), organic acid, functional (antioxidant and phenolic content), microbiological and sensory features was evaluated during 30 days using standard methods and a qualitative and quantitative reference frame specific for Wagashi. Raw cow milk was used for the production of the experimental cheeses which were denoted Rc for control and RwLc, RwLp, RwLr, and RwEf for the Wagashi cheese added with Lactobacillus casei 39 (L. casei 39), Lactobacillus plantarum (L. plantarum), Lactobacillus rhamnosus (L. rhamnosus) and Enterococcus faecium K65E2 (E. faecium K65E2) respectively. Probiotic bacteria were added to the cheeses following heat treatment. Addition of probiotic strains did not affect protein content during storage contrary to fat, dry matter, pH and titratable activity, which were influenced by strains and storage time. Counts of probiotics during storage exceeded the minimum of 7 log cfu/g requested for probiotic cheeses. Yeast and moulds count decreased in all cheese samples except for RwLc whose value rather increased. Probiotic cheese samples, except RwLc, were similar considering their mesophilic lactic acid bacteria (LAB) counts conversely to the differences denoted for their thermophilic LAB counts. All the cheeses exhibited antioxidant activity at all storage intervals with RwLp (2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity) and RwLc (metal chelating activity) presenting the highest values at the end of storage time. Likewise, the total phenolic content (TPC) was affected by the strains and the highest value was found in the control (Rc) at the end of the storage period. ADV was not affected by storage period expect for the control cheese (Rc) during the first 14 days and the concentration of oleic acid in RwEf increased constantly throughout storage in contrary to RwLc, RwLp and RwLr whose values increased only during the first 2 weeks of storage. Additionally, the higher lipase activity of L. plantarum in comparison with the rest was denoted. The degree of proteolysis was found to increase significantly (p<0.05) in Rc, RwLc, and RwEf during the first 2 weeks, in contrary to RwLr’s proteolysis degree that increased constantly (p<0.05) throughout storage. Rc at the end of the storage period, revealed the presence of butyric, formic, citric and lactic acid. Other cheeses displayed the presence of propionic and malic acid in addition to those previously mentioned. Salt content was affected by storage time, strains and cheese's physical and chemical properties. Cheeses' textural features except for springiness displayed a similar effect as denoted for salt content. Adding L. plantarum and L. rhamnosus did not alter the whiteness (L*) of cheeses. All cheeses obtained a score higher than 5, and RwLp, RwLr had a significantly higher acceptability. With a focus on the previously mentioned key features, which were not negatively affected during storage, the results found in the present study, highlight the suitability of Wagashi cheese as a dietary source of probiotic bacteria. Similarly, the lack of data on probiotic Wagashi cheese makes our findings an useful reference for future researches.