The effect of carboxymethyl cellulose (CMC) and banana puree (Musa acuminata Colla) addition on the characteristics and microstructure of goat milk yogurt

Yogurt is one of the fermented products which may have increased functional value. However, yogurt made from goat milk has a weak gel strength and high level of syneresis which may reduce consumer acceptance. The addition of CMC and banana puree was expected to improve the characteristics of yogurt. The aim of this research was to study the effect of the addition of CMC (0.75; 1; and 1.25%) and banana puree (10 and 20%) on the characteristics of goat milk yogurt (viscosity, syneresis, total lactic acid bacteria, total acid, and pH). Further analysis was carried out using Scanning Electron Microscopy (SEM) to study the microstructure of goat milk yogurt in depth. The results showed that the addition of CMC had a significant effect on the viscosity, while the addition of banana puree had a significant effect not only on the viscosity, but also total acid and pH. There was an interaction between these two factors on the syneresis. The best treatment was obtained at the addition of 1% CMC and 20% banana puree with the viscosity of 7991 cP, syneresis of 6.23%, total lactic acid bacteria of 2.4 x 10⁸ CFU/mL, total acid of 1.49% and pH of 4.49. The microstructure of best treatment goat milk yogurt had denser, more compact and smaller voids than those of control one.