Viability of lactic acid microorganisms in the low fat probiotic ice-cream

Properties and indices of the ice-cream prepared with application of starter cultures with probiotic characteristics were studied. For receiving low fat ice cream cow milk, stabilizer, sugar and industrial starter cultures (3-5 %) were applied. Microparticulate of whey proteins (3 %) was also included in the recipe. It works as a stabilizer and emulsifier effecting physical-chemical indices of the ice-cream mixture and organoleptic properties. The microparticulare of whey proteins promotes improving of the product biological value and demonstrates prebiotic activity stimulating lactobacteria growth. The starter cultures were provisionally divided into 4 groups (according to the types of species). Each of the starters was presented by several samples from different producers. The mixture was coagulated at 37±1 °C during from5 to 10,5 hours depending on the starters group studied. The organoleptic analysis of the ice cream fermented to the acidity 75-85° T received the highest score. From the point of view of the technological process the optimal solution is to apply starter cultures containing symbiosis of microorganisms allowing to coagulate mixture for 7-9 hours. For getting preventive effect the lactic acid microorganisms levels in the probiotic ice-cream should be not less than 1 • 10 7 colonies forming units per g after 6 months storage. The ice-cream samples were stored in the cooling camera at the temperatures not higher than -18 °C. The levels of the lactic acid microorganisms were determined at the 1, 15, 30, 60 and 90 days. The samples inoculated with Lb.casei subsp. casei demonstrated the lowest viability degree: after 3 months storage the number of living cells was 0,5 • 10 6 colonies forming units per g. The count of lactic acid cultures from other groups at the end of the ice-cream storage life complied with requirements to the probiotic icecream. The pathogens were not detected in the trial samples in the course of storage. Two samples of the ice-cream received the highest score for their organoleptic indices. The number of lactic acid microorganisms in the samples at the end of the storing was 3 • 10 7 and 5 • 10 7 colonies forming units per g correspondingly. The choice of the starter cultures depends on the optimal regimes of the technological process taken by a producer and from the quality indices of the finish probiotic ice-cream both as a dessert and as a probiotic product.

low fat ice-cream, probiotic starter culture, whey protein particulate, organoleptic properties, keepability, low fat ice-cream, probiotic starter culture, whey protein particulate, organoleptic properties, keepability