14A-39 |
Feasibility of incorporation of commercial acid whey powders in probiotic yogurt |
R. M. PARMAR1, G. G. Singhal1, R. I. Dave1, and C. Ren2. (1) MN-SD Dairy Foods Research Ctr., South Dakota State Univ., Dairy Science Dept., Box 2104, Brookings, SD 57006, (2) Plant Science Dept., South Dakota State Univ., 204 Agricultural Hall, Box 2207-A, Brookings, SD 57007 Acid whey powder could be used as a functional ingredient in preparation of yogurt to obtain benefits such as probiotic effect, neutraceutical benefits, texture improvement, reduced syneresis and cost effectiveness. Probiotic yogurts, control and treated, were prepared using milk (2% fat) fortified with skim milk powder and two commercially available acid whey powders (AWP) respectively with two different starter cultures (ABT-1 & ABT-4). AWP from Main Street Ingredients (MS) was of cottage cheese whey and the one from Century Foods (CF) was of acid casein whey. Yogurt samples were analyzed for changes in titratable acidity, pH and counts of yogurt and probiotic bacteria during manufacture. Fresh yogurts were also analyzed for viscosity, firmness and syneresis. Changes in acidity, pH and bacterial counts were also recorded over a period of 10, 20, 30 and 40 days of storage at 40C. Yogurts were also subjected to organoleptic evaluation by a panel of expert judges. Use of AWPs reduced the incubation time to 9 h compared to 12 h in case of control yogurts (P<0.001) with ABT-1 culture. Addition of AWPs to a level of 0.5% protein supplementation had no adverse effect on viscosity and firmness of yogurt but increasing the level to 1% protein supplementation gave a weak body. Addition of AWPs at 1% protein supplementation reduced syneresis (P<0.05). Fortification of AWP (MS) helped maintain the viability of Lactobacillus acidophilus above 10 6 cfu/gm for up to 20 days (P<0.05). The viable counts of Bifidobacteria and Streptococci remained almost similar (>107 cfu/gm) throughout the storage in control and AWP fortified yogurts. Yogurts made using cottage whey powder had sensory qualities as good as that of control yogurts but the yogurts supplemented with acid casein whey powder had a typical whey flavor.
Session 14A, Dairy Foods: General developments in dairy technology I
|