Effects of process parameters on recovery and quality of groundnut oil

Abstract

In the present study effects of particle size and heat treatment on recovery and quality of groundnut oil was determined. Various physico-chemical parameters viz., colour, density, iodine value, peroxide value and saponification value were determined using standard methods. The results revealed that size reduction of groundnut kernels increased the oil yield, but it deteriorated the quality of oil, whereas heat treatment (60°C for 1 h), improved the oil yield as well as quality. The oil yield was highest (48.14%) for finely ground kernels with heat treatment and was lowest for whole kernels without heat treatment (35.20%). The saponification value, iodine and peroxide value of oil extracted from the whole kernels with heat treatment was found to be the minimum 106.34 mg KOH/g, 99.24 mg I2/g oil and 0.65 M eq/kg respectively. The maximum value of oleic acid content and linoleic acid content of 51.39% and 31.44% was found in the oil sample of raw groundnut kernels with heat treatment respectively. It was observed that the groundnut oil extracted fromwhole kernels with heat treatment (60°C for 1 h) is superior in quality in terms of colour, fatty acid composition with a comparatively longer shelf life and resistance to rancidity and oxidation.