Effect of moisture content and heat treatment on peroxide value and oxidative stability of crude palm kernel oil

Abstract

Effect of moisture content, roasting time and temperature on peroxide value (PV) and oxidative stability (OS) of unrefined palm kernel oil was studied using response surface methodology at five levels of moisture content (4, 7, 10, 13 and 16% wet basis), roasting time (5, 10, 15, 20 and 25 min) and roasting temperature (50, 70, 90, 110 and 130 °C). Within the studied range, mean PV of palm kernel oil was recorded to be 13.06±5.13 meq/kg. Least PV of 7.3 meq/kg was obtained at 10% moisture content, 15 min roasting time and 130 °C temperature. Maximum stability time of 27.0 h was achieved at 10% moisture content, 15 min roasting at 130 °C. This treatment produced unrefined palm kernel oil stable for 388 days. All the studied parameters significantly influenced flavour rating and shelf life of unrefined palm kernel oil at P < 0.05.