Quality properties of yoghurt produced from cow milk and soymilk

Abstract

The effect of base materials (whole cow milk, powdered milk and soymilk) on the physicochemical,
 microbial and organopletic properties of yoghurt were determined in a nested procedure of completely randomized experimental design. The results showed that significantly (P < 0.001) higher titratable acidity and total fats values of 2.09% and 3.07% were recorded on whole cow milk yoghurt (WCMY) and lower values of 1.46% and 2.07% recorded on soymilk yoghurt (SMY), respectively The total solids of 13.40% obtained on SMY was significantly different (P < 0.001) from 16.00% and 15.74% obtained on WCMY and powdered milk yoghurt (PMY), respectively. The total protein of PMY (3.48%) was the highest and significantly different from the 3.03% obtained on WCMY, which was also different from the 2.96% obtained on SMY. No significant difference was recorded on total microbial load due to base material. The Ca values of WCMY (1.704 to 2.086 g/ 0 were higher than those (1.101 to 1.282 gll) of PMY, which were higher. than those (0.512 to 0.564 gi0 of SMY (P < 0.05). The concentration of Cu in SMY produced with 2.5 g/l inoculant was significantly the highest. The taste of PMY rated pleasant (3.4) was significantly (P < 0.001) higher than those of WCMY rated fair (2.5) and SMY rated indifferent (2.0). Also the overall acceptability rating of 3.5 (between fair and pleasant) for PMY was significantly (P < 0.001) higher than ratings for WCMY and SMY (2.5 and 2.1, respectively). It was concluded that qualitative and acceptable yoghurt could be produced from the three base materials.