Effect of fat replacers on kefir quality.

The purpose of the study was to determine the effects of fat replacers on the quality of non-fat kefir. Skim milk fortified with Dairy Lo (DL) and inulin (INU) was fermented with kefir grains to manufacture kefir. The results of compositional, microbiological, rheological and sensorial analyses were compared with whole kefir (WK) and non-fat kefir (NFK) controls. Results for dry matter, pH and lactic acid ranged between 82.4 and 109.1 g kg(-1), 4.26 and 4.40, and 7.0 and 9.2 g L(-1), respectively. Acetaldehyde and ethanol contents of samples were between 2.89 and 7.28 mg L(-1), and 151.46 and 323.89 mg L(-1), respectively. In all samples, Lactobacillus spp., Streptococcus spp. and yeast counts were between 9.1 and 9.9, 9.3 and 9.9, and 5.2 and 5.6 log cfu mL(-1), respectively. Kefir samples had non-Newtonian behaviour and pseudoplastic fluid with thixotropy. At the first day, DL had the highest apparent viscosity (3.119 Pa s) while NFK had the lowest value (1.830 Pa s). In the sensory evaluation, odour and taste scores of samples were not different. Dairy Lo and inulin could be used without any adverse effect for the production of non-fat kefir.