15C-8 |
Manufacture of fermented lactic beverages containing probiotic cultures |
M. NOGUEIRA DE OLIVEIRA1, I. Sodini2, F. Remeuf2, and G. Corrieu2. (1) Department of Pharmaceutical and Biochemical Technology, São Paulo University, Av. Prof. Lineu Prestes, 580. B 16, São Paulo, 05508-900, Brazil, (2) Laboratoire de Génie et Microbiologie des Procédés Alimentaires, Institut National Agronomique Paris-Grignon, 78850 Thiverval-Grignon, Grignon, France Probiotic bacteria are microrganims having beneficial effect on intestinal function and promoting good health. Lactic beverages are fermented products containing milk and whey. They don't have a precise characterization and are formulated with yogurt, whey, and others raw materials and allowed additives. By the moment, nothing has been published about fermented lactic beverages containing probiotics. The objective of this work was to verify the viability of probiotic bacteria as Lactobacillus acidophilus and Lactobacillus casei ssp. rhamnosus, and to study the stability, postacidification, rheological characteristics, and microstructure of lactic beverages. Three different yogurts were manufactured using commercial cultures of S. thermophilus (ST7), L. bulgaricus (LB10), L. acidophilus (LA5), and L. rhamnosus (LC35). Pasteurized standardized milk with 26 g/L of fat and 130 g/L of total solids, and supplemented with casein hydrolysate (20 g/L) was used. The lactic beverages were prepared by mixing the probiotic yogurts with whey (10% total solids), then adding sugar (6.5%) and strawberry pulp (6.0%). Microbiological counts, postacidification, stability and rheological analyses were performed during 28 days of storage at 4 °C. Our results showed that although counts decreased, the products contained 5.3 x 106 CFU/mL of probiotics, in average, at 28 days of storage. The rheograms showed that the samples behaved as a pseudoplastic fluid, with presence of thixotropy, and that the Ostwald-de-Waele model was the most suitable to data. Apparent viscosity and pH decreased slightly with storage time. Lactic beverages showed phase separation increasing until 35% at 14 days of storage and stabilized after. Finally, microstructure showed the classical appearance of an acidic gel with the presence of polysaccharide appendages. The results suggest that high viable counts of probiotics were provided, and described the characteristics of the products during shelf life. Therefore, the feasibility of the manufacture of lactic beverages containing probiotics seems to be demonstrated.
Session 15C, Dairy Foods
|