The effect of genotype, location and season on cassava starch extraction

Abstract

When cassava is harvested too early, it often leads to reduction in yield, while delayed harvest leads to development of woody and fibrous tuberous roots, and reduction in starch content. The optimum harvest time is not known. The objectives of this study were to determine the effect of genotype, location and season on starch extraction in order to find an optimum harvest regime for cassava, and to find the best parameter for monitoring starch levels in cassava tuberous roots. Results showed that genotypic effect was large for starch weight, starch extraction rate on fresh weight basis, and root dry matter content. This suggested that high starch weights could be realised by selection of suitable varieties for starch extraction. It was found that cassava harvesting and starch extractions should be done between October and November since the highest starch extraction rates were achieved during that period, and drying of the extracted starch using the open air method was fast and convenient. The results also suggested that starch levels can efficiently be monitored using starch extraction rate on fresh root weight basis. Starch content on fresh root basis and root dry matter content can also be used to determine the optimum time to harvest cassava for starch extraction but were inferior to starch extraction on fresh root weight basis.