Pengaruh Metode Perlakuan Awal (Ultrasonikasi dan Pembekuan) dengan Lama Penggorengan Vakum terhadap Mutu dan Sensori Keripik Tapai Ubi Jalar Ungu Beserta Indeks Glikemiknya

Abstract

The objective of this research was to find out the effect of the pretreatment methods and the vacuum frying times and the interaction of both on theiquality and sensory of purple sweetipotato tapai chips and their glycemic index values. This studyiused a Complete RandomizediDesign (CRD) with twoifactors, namelyithe pretreatment methods (A): (without treatment, freezing, ultrasonication, and ultrasonication and freezing) and the of vacuum frying times (B): (60 minutes and 90 minutes). The parametersianalyzed were wholeness, color index, moisture, ash, fat, protein, carbohydrate, dietary fiber, free fatty acids, hedonicivalue of color, aroma, taste, texture, generaliacceptance, and glycemiciindex in the best treatment. The results showedithat the pretreatment method had a highly significant effect (P<0.01) on color index, protein, free fatty acids, dietary fiber, color hedonic, taste hedonic, aroma hedonic, texture hedonic, and general acceptance hedonic, the effect wasisignificant (P<0.05) on moisture content. The vacuum frying times had a highlyisignificantieffect (P<0.01) on fat, protein, carbohydrate, free fatty acids, dietary fiber, color hedonic, flavor hedonic, texture hedonic, and general acceptance hedonic. The effect wasisignificant (P<0.05) on the color index, moisture, and hedonic aroma. The interaction between the pretreatment method and the vacuum frying times had a highlyisignificant effect (P<0.01) on dietary fiber, color hedonics, and general acceptance hedonics, and the effectiwas significant (P<0.05) on taste hedonics. The best treatment determined based on de Garmo's (1984) method was A3B1 treatment with ultrasonication pretreatment method and vacuum frying time of 60 min. The best treatment was tested for glycemic index with a value of 36.80 (low category).