Use of response surface methodology to compare vacuum and atmospheric deep-fat frying of papaya chips impregnated with blackberry juice

Abstract

Vacuum and atmospheric deep-frying were employed to obtain blackberry-based snacks using unripe papaya as matrix. Papaya slices were osmotically impregnated with blackberry juice and fried between 126°C and 154°C at atmospheric pressure and between 110°C and 127°C under vacuum conditions. A response surface methodology (RSM) was used to define which responses (water activity, moisture and oil content, L*, C*, H*, hardness and degree of liking (DOL)) were significantly related to frying parameters (time and temperature). Then a principal component analysis (PCA) was applied to choose which ones related to DOL. PCA demonstrated that hardness and hue were the main drivers of liking for atmospheric frying, while for vacuum frying they were color and oil content. A second RSM was calculated to choose optimal processing conditions. Optimum conditions were 6 min at 117°C in vacuum frying and 6 min at 130°C and 3 min at 150°C in atmospheric pressure.