Production and selected properties of bioghurt made from goat milk and cow-goat milk mixtures by ultrafiltration and addition of skim milk powder

Abstract

In this study, bioghurt was produced from goat milk (A) and 70% goat-30% cow (B), 50% goat-50% cow milk (C) mixtures, and stored 14 days at 4 × 1°C. Two concentration methods of ultrafiltration (UF) and skim milk powder addition (MP) were applied to milk mixtures, therefore six different bioghurt samples were obtained. Selected physical, chemical, microbiological, and sensory properties of bioghurt samples were analyzed at 1st, 7th, and 14th day of storage. Effects of milk type, concentration method, and storage period on physico-chemical and microbiological properties of samples were investigated. The effect of concentration method on titratable acidity (°SH), penetration value, and whey off values of all bioghurts was significant (p < 0.05). The milk type had no significant effects on total solids, fat content, titratable acidity, pH, and whey off values of bioghurts (p > 0.05), but only the protein contents of bioghurt concentrated with skim milk powder showed significant (p < 0.05). The sensory evaluation showed that bioghurt produced with the mixture of 50% goat milk + 50% cow milk and concentrated by addition of skim milk powder had the highest overall scores.