The study of the shea kernel in relation to the traditional processing of the shea fat

Abstract

Information concerning the description of the shea tree, its ecology and some of the factors influencing the availability of the kernel for processinq have been collated. An account of the traditional methods of processing shea butter in Ghana is given and the shortcomings of the methods discussed. The browning of the kernel after harvesting and the eventual coloration of the extracted fat is investigated in detail. The nitrogenous component of the defatted shea residue has also been investigated and its contribution to the economic value of the fat discussed. Details of the experimental methods are presented and the results obtained tabulated. The results obtained have shown that the coloration of the kernel is basically due to enzymic browning reactions by polyphenol oxidases, naturally present in the kernel,: together with flavonoid compounds acting as substrates. The results further showed that in the presence of simple sugars and amino acids naturally present in the kernel, non-enzymic forms of browning also account for some of the brown coloration during the elaborate heating and roasting processes at various stages of' the preparation of the kernel. The results, obtained from the examination of the nitrogenous constitution of the defatted kernel, showed that protein constitutes about 50%. Allantoin, a nitrogenous compound and an important ingredient in pharmaceutical preparations, was found to constitute about 28% of the total nitrogen. The remaining portion of the nitrogenous matter is made up of peptides, as shown by electrophoretic patterns