ผลของการเติมน้ำมันรำข้าวก่ำต่อคุณสมบัติของไอศกรีมดัดแปลงข้าวก่ำ

Abstract

The purpose of this research was to study the result of various factors that affect to the quality of modified purple rice ice cream which was added purple rice bran extract. The results showed that the chemical quality of purple rice solution obtained from purple dry rice per water in the ratio 1:2, 1:4 and 1:10 were increased the amount of protein , fat, total solids , ash and phenolic compounds, when the amount of water, which is as solvent, are decreased. Whereas the amount of anthocyanin is decreased. About the antioxidant properties, when water which is as solvent reduced, it tended to increase antioxidant properties. According to this study, the basic appropriate modified purple rice ice cream ratio composes of purple rice dry rice per water in the ratio 1:4 as 55%, coconut milk 30% and sugar 15%. About the study of stabilizer (gelatin, carageenans, xanthan gum and tapioca starch intake by 0.1, 0.2 and 0.3%), the results showed that adding gelatin at a concentration of 0.3% and 10% of purple rice bran oil extract by weight of mixtured ice cream are the most appropriate modified purple rice ice cream ratio, due to the best of physical properties, chemical properties, antioxidants activity and the sensory characteristics of ice cream. The study of the quality change in ice cream control set and ice cream with 10 % of purple rice bran oil extract, preserving in -10 and -20 oC for 0, 15, 30, 45, 60, 75 and 90 days, the result showed that the duration of storage significantly (p ≤ 0.05) to the chemical properties and the physical properties after the longer period preserving. Preserving in the temperature of -20.0 oC had better physical properties of ice cream than preserving in -10.0 oC. It is similar to the chemical properties; phenolic compounds and anthocyanin are more stabilized than preserving in the temperature of -10.0 oC. The ice cream control set and ice cream with 10 % of purple rice bran oil extract that were preserved for 90 days had the microbial quality according to standard of ice cream production as noticed from the Ministry of Public Health issue number 222 in 2011. Moreover the study of sensory characteristics of ice cream control set and ice cream with 10 % of purple rice bran oil extract that were preserved in the temperature of -10 and -20.0 oC for 0, 15, 30, 45, 60, 75 and 90 days showed that the duration of storage and preserving temperature did not significantly to all of the sensory characteristics assessment. The average score on the features; color, appearance, firmness, smoothness, sweetness, smell and taste of ice cream and also accepting score of the ice cream control set are in score range 6.08-6.83 (the least satisfaction). And ice cream with 10 % of purple rice bran oil extract is in score range 6.25-7.05 (the least satisfaction to the moderate satisfaction).

Keywords: Ice cream, Purple rice, Stabilizer, Rice bran oil, Storage time.