Improving the nutritive value of Nigerian rubber kernel (Hevea brasiliensis) products through processing. I. Chemical and nutritional composition

Abstract

Rubber seeds were decorticated and the resulting kernels processed by sun-drying, oven-drying, roasting, autoclaving, and soaking. The meals (full-fat and fat-extracted) were analysed for proximate components, gross energy (GE), and amino acid contents. The acid-ether extract fractions of rubber kernel meal were analysed for fatty acid constituents. Mean GE of full-fat rubber kernel meal was 27.6 MJ kg·1 dry matter (DM) while crude protein content ranged from 168 to 223 g kg·1 in the full-fat samples with the corresponding values for the fat-extracted samples being 285-362 g kg·1. Amino acid profile of rubber kernel meal indicated high levels of arginine, valine, leucine, and phenylalanine in that order; moderate levels of lysine and threonine; and low levels of tryptophan, cystine, and methionine. Rubber kernel oil was high in linoleic (364 g kg·1 oil) and linolenic (313 g kg·1 oil) acids. The chemical compositions of the rubber kernel products are discussed in relation to processing methods. The potential value and implications of using rubber kernel products as animal feed are also highlighted.