Nowadays, we can see on market mainly fermented milk products with addition of probiotic microorganisms, especially strains of Lactobacillus and Bifidobacterium. We can meet also other types of probiotic products. It is recommended to consume at least 100 grams of fermented milk products with minimal concentration of 106 of probiotics in one gram or mililitr of product daily for reaching positive effect on men’s health. During fermentation of the carbohydrates, proteins and lipids are disunite and many of aromatic compounds ane compose. They give a typical sensory characteristic to fermented milk products. For quality and quantity level of probiotics, changes of pH value and sensory quality of five kinds of fermented milk product Yoghurt Drink with different flavour were analyzed during the whole expiration period (28 days). Obtained results were statistically evaluated via the analysis of variance and the method of multiple comparison according to Tukey test (P < 0,010) and (P < 0,001). During the minimal endurance time lactic acid bacteria and Bifidobacterium sp. were evaluated and changes of descriptors and pH value were detected. Number of LAB was up to 107 CFU/ml in all samples during 28 days of analysis. Only at sample 2 the number of LAB was 106 CFU/ml. Bifidobacterium sp. grew about degree. The number of LAB and Bifidobacterium sp. of yoghurt drink correspond with public notice number 77/2003 Sb, LAB 107 nad Bifidobacterium sp. 106 KTJ / ml. During 28 days of storage the pH value decreased. The biggest pH drop was recorded between 21. and 28. days of storage in all samples. The beginning pH value was 4.03–4.07 and the final value was between 3.80–3.95.The results of sensory evaluation processed by analysis of dispersion according to type were statistically conlusive in descriptors thickness, texture, intensity of smell, pleasantness of taste and general impression. The results of sensory evaluation processed by analysis of dispersion according to days of storage were statistically conlusive in descriptor pleasantness of smell.
Effects of ultrasound on the fermentation profile of fermented milk products incorporated with lactic acid bacteria
