Chemical analysis has shown that cashewnut meal extracted froin whole kernels contains about 42 % crude protein, about 1% crude lipid, a low content of crude fibre and 0.5 and 0.2% calcium andphosphorrrs, respectively. The weal has good quality protein containing 4 . 6 % lysine, I . 3 tryptophan, about 2% cystine, and 1.6 The content o/sulphrrr-containing amino acids is higher thun that of soyabean and groundnut meals. The meal from cashewnut is shown to be superior to that of soyabean meal, judging from the weight gains obtained and 'protein score' calculated at 97 for cashew and 93 for soyabean meal.
methionine.
IntroductionMUCH interest has been shown recently in finding a better use for the cashewnut tree (Anacardium occidentale L.). Its cultivation is especially suited t o tropical zones and is expanding with the introduction of mechanised processing.As well as edible kernel, a liquid extract is obtained from the cashewnut mesocarp; it is composed of mono-and dihydroxyalkylbenzenes and alkylphenolic acids.' This liquid extract has various industrial uses; the kernel is principally used in the confectionery industry. There has been limited research done on the chemical and nutritional qualities of the kernel. Recently, however, some systematic work has been initiated exclusively on the characteristics of the oil by the Istituto di Industrie Agrarie of the University of Bologna (Pallotta, U., Capella, P., & Losi, G., personal communication).
Experimental Extraction and analysisThe kernels were kindly supplied by the Oltremare Company of Bologna and were obtained from nuts that had undergone a mechanical processing cycle developed by the same Company. This process consisted of an initial wetting and a successive heat treatment carried out by steeping the nuts in a shell 'liquid' bath (liquid extracted from the mesocarp) for 1-2 min. The shell 'liquid' bath was kept at a temperature of 195"c. In this way the mesocarp loses part of its liquid fraction thereby permitting a partial polymerisation of this liquid, which enhances the mechanical extraction of the kernel. The kernels were ground with care to avoid heating and also t o enhance defattening of the product with hexane. The solvent was eliminated by ventilation at room temperature.The usual analytic determinations were carried out on the kernels as well as on the extracted meal: crude protein, crude fibre, nitrogen-free extractives, ash,2 calcium and phosp h o r~~.~ Further determinations were made on the meal, such as the total amino acid content (with a BeckmanSpinco Amino Acid Analyzer),4 and tryptophan content by the method of E g g~m .~
Biological studiesSome biological studies have been carried out with the product, using young, growing rats, with the aim of comparing the nutritional values of the cashewnut meal, roasted soyabean meal and casein.The method used was the same as that proposed by A.0.A.C.O White Wistar strain rats were used. Their * Present address: Department of Animal Science, University of Ibadan, Ibadan, Nigeria.initial weights were...
