Effects of Shea (Vitellaria paradoxa C. F. Gaertn) Nuts Storage Environments on the Quality of Shea Butter in Dry Savannah Environment of Adamawa State, Nigeria

Abstract

An experiment was conducted from September, 2009 to June, 2010 at the Modibbo Adama University of Technology, Yola to study the effects of storage environments on shea nuts as it affects the quality of shea butter in Yola. A Randomized Complete Block Design (RCBD) was used for the experimental design. The treatment consisted of two storage environments (open space and laboratory, under ambient condition). The physicochemical parameters and fatty acid composition determined were oil yield, oil density, refractive index, specific gravity, iodine value, saponification value, unsaponifiable matter, free fatty acid, stearic acid, oleic acid, linoleic acid, linolenic acid and palmitic acid. The results showed that storage environments significantly affected refractive index, iodine value, saponification value, free fatty acid, stearic acid, oleic acid, linoleic acid and linolenic acid (P<.01).Based on the parameters measured, laboratory storage environment performed better in terms of oil yield 42.24%, oil density 0.937 g/cm3, free fatty acid 2.53%, iodine value 50.89 I2g/100g, linoleic acid 5.05 % and palmitic acid 6.13% as compared to open space storage environment which had oil yield 39.41%, oil density 0.936 g/cm3, free fatty acid 4.61 %, iodine value 49.43 I2g/100g, linoleic acid 4.94 % and palmitic acid 6.17%. It was therefore, concluded that laboratory storage environment was a better choice for storage of shea nuts than open space. It may be recommended that local structures like the thatch house with adequate ventilation should be raised to provide shade as an alternative to laboratory during storage of shea nuts for better quality shea butter.