Physical and Chemical Properties of Cow's Milk Yogurt Added Whey Protein Concentrate (WPC)

Abstract

The purpose of this research was to examine the physical and chemical characteristics of cow's milk yogurt with the addition of WPC. The physical characteristics observed included color (L*, a*, b*, whiteness index, hue, chroma), texture (firmness, work of penetration, resistance to probe withdrawal), while the chemical characteristics observed included water content, total solids, and titratable acidity. The main research materials are fresh cow's milk, Whey Protein Concentrate (WPC), and starter yogurt. The study was conducted using a Completely Randomized Design (CRD) with 5 treatments and 4 replications. The treatments consisted of control (P0), adding WPC as much as 2% (P1), 4% (P2), 6% (P3), and 8% (P4) of the amount of milk. Data were analysed using analysis of variance and post-hoc orthogonal polynomial test. The results showed that the addition of WPC up to 8% caused a very significant difference to the water content, total solids, titratable acidity, firmness, and work of penetration of yogurt. However, the addition of WPC up to 8% did not cause a significant difference in the color characteristics of yogurt. Total solids of yogurt increased from 12.08% (control) to 17.74% along with the addition of WPC up to 8%. Based on the results of the research, it can be concluded that the addition of WPC up to 8% can decrease the water content, firmness, and work of penetration of yogurt, as well as increase the total solids and titratable acidity of yogurt. However, it did not cause a noticeable change in the color characteristics of yogurt. However, it did not cause a significant change in the color characteristics of yogurt.