Study optimum ratio of major ingredients in Khaomak yogurt ice cream

Abstract

The objective of this research was to study optimal ratio of yogurt ice cream mix, blended Khaomak and water in Khaomak yogurt ice cream. Mixture Design was used for formulating mixture of yogurt ice cream mix (60–80%), blended Khaomak (5–15%) and water (0–20%). The viscosity and %overrun of Khaomak yogurt ice cream, 80% yogurt ice cream mix, 5% blended Khaomak and 15% water (trt1) gave the highest values which were 174 cP and 11.35%, respectively. Khaomak yogurt ice cream at ratio of 65:15:20 (trt3) gave the highest melting rate. Total soluble solid from Khaomak yogurt ice cream at ratio of 80:15:5 (trt2) and trt1 gave the highest values which were 26.97ºBrix and 25.83ºBrix, respectively. Treatment with high amount of blended Khaomak caused decreasing in L* and increasing in a* and b* (p≤0.05). The acidity of Khaomak yogurt ice cream was mainly from yogurt ice cream mix, trt2 gave the highest acidity which was 0.45% total acid and pH 4.85. Total bacteria of all treatments were in range of 7.50–7.90 log cfu g^-1 and lactic acid bacteria were in range of 7.40–7.80 log cfu g^-1, yeast and mold were less than 10 cfu g^-1. Microbiological analysis of all treatments met the requirement of fermented milk product standard issued by the Ministry of Public Health, Thailand. The ratio of yogurt ice cream mix, blended Khaomak and water at ratio of 80:5:15 (trt1) obtained the highest liking score in all attributes including overall liking (7.08) with just right higher than 50% in Just about right (JAR) test for all attributes.