Effects of Heating Temperature and Seed Condition on the Yield and Quality of Mechanically Expressed Groundnut Oil

Abstract

Research has revealed that mechanical expression process could substantially improve the yield and quality of groundnut oil. In this study, experiments were carried out to study the effects of heating temperature and seed condition on the yield and quality of oil extracted from groundnut by mechanical means. The physiochemical analysis of the oil extracted was also determined. Samples of 3kg mass of grounded groundnut seeds were pressed at two different seed conditions (dehulled and undehulled) and four levels of temperatures (70,80,90 and 100 0 C) in a randomize complete block design (RCBD) and data obtained were subjected to statistical analysis using SPSS software. The result obtained revealed that oil yield increases with increase in temperature but tends to decreases as the temperature increase beyond 90 0 C and maximum oil yield was obtained when the seeds is in dehulled condition as compared to when the sample was pressed with the hulls. The physiochemical analysis of the oil extracted also revealed that the PH value, specific gravity, refractive index, peroxide value, free fatty acid (FFA) and total acid value of the oil decreases with increase in temperature irrespective of the seed conditions.