摘要：In this study, the effect of using hydrolysed whey concentrate (HWC) (30% TS; 50% lactose hydrolization rate) on some properties of set yoghurt was investigated. HWC was added to yoghurt milk to give an increase in dry matter at the level of 0% (K), 1% (A), 3% (B), 5% (C). These mixtures were standardized to 15% total solids, by the addition of dried skim milk powder and then those milk were used for set yoghurt manufacture. Samples were examined for titratable acidity, lactic acid, acetaldehyde, tyrosine value, viscosity, wheying-off and organoleptic quality at the 1. and 14. days of storage. Incubation time, total solids, fat and ash content were also determined at the first day of storage. It was concluded that, titratable acidity, lactic acid, tyrosine value increased and curd stability was weakened gradually (decreased viscosity, increased whey off) with increasing level of HWC. In contrast to this an increase was observed in lactose and acetaldehyde content. During the storage, titratable acidity, lactic acid, curd stability of yoghurt samples increased while lactose, acetaldehyde content decreased and tyrosine value remained unchanged. No significant differences between control and yoghurt samples of A, B were determined with the respect to flavour and aroma, consistency, appearance, odour. But the highest flavour and aroma score was given to sample C. As a result of overall score, sample C was found to be the best.
