RESPONSE SURFACE METHODOLOGY OPTIMIZATION OF VACUUM-FRIED GOLD KIWIFRUIT SLICES BASED ON ITS MOISTURE, OIL AND ASCORBIC ACID CONTENTS

Abstract

Response surface methodology was used to investigate the effects of a higher level of maltodextrin (MD) (40–70%) as a pretreatment for gold kiwifruit slices and the temperature and time used during vacuum frying of the samples on the moisture, oil and ascorbic acid contents of the products. The moisture content of vacuum-fried gold kiwifruit slices decreases with increases in frying temperature. The oil content of the sample increases with increases in frying temperature and time. The ascorbic acid content of the sample decreases with increases in frying temperature and MD level. When processing vacuum-fried gold kiwifruit slices, there is a need to use frying temperatures of 72.0–76.3C, frying times of 35.0–65.0 min and an MD level of 40% in order to achieve a product with moisture contents of 8.4–8.9% (dry basis) and acceptable qualities. PRACTICAL APPLICATIONS The use of response surface methodology enabled the derivation of mathematical models for describing the effects of the independent variables on the dependent variables for vacuum-fried kiwifruit. Vacuum frying is one of the latest preservation method applied to fruits. This method processes the fruits at lower temperatures and reduced pressure, which enables the production of dried products with superior sensory and nutritional qualities. The information provided in this work will be very useful in producing vacuum-fried gold kiwifruit slices at optimal pretreatment and vacuum-frying conditions.