Physical and chemical characteristics of yoghurt produced from whole milk with different levels of somatic cell counts

Abstract

For yoghurts were made from milk with different levels of somatic cell count (SCC) (low 95,000 cells ml^{− 1}, intermediate 398,000 cells ml^{− 1} and high 1,150,000 cells ml^{− 1}). Yoghurt samples were analysed for the degree of proteolysis, lipolysis (free fatty acid (FFA) content), acidity, pH and apparent viscosity on days 1, 14 and 28. The SCC had no significant effect (p>0.05) on either the acidity or the pH of the yoghurt after 1 day of cold storage. However, significant effects (p < 0.05) of SCC were observed after 14 and 28 days of storage. Yoghurt samples made from intermediate and high SCC milk showed higher viscosity (p < 0.05) and lower (p < 0.05) casein content on days 14 and 28 of cold storage than yoghurt made from low SCC milk. High FFA concentrations (p < 0.05) were observed only in yoghurt made from high SCC milk. High SCC in milk increased both proteolysis and lipolysis in yoghurt during storage.

Keywords::

• apparent viscosity
• proteolysis
• lipolysis
• somatic cell count
• yoghurt quality