Effect of Prolonged Postharvest Physiological Deterioration on the Color Hues of Cassava Dried Chips and Flour

摘要

Off colors that accrue from oxidative postharvest physiological deterioration (PPD) of stored cassava tuberous roots pose a serious limitation to its large scale processing. Twelve white fleshed cassava genotypes were used to evaluate the effect of prolonged PPD on the color hues of cassava flour and dried chips produced from them at 1st, 7th and 9th day of storage. After relevant chemical/biochemical analyses (moisture, carotene) of the fresh and stored cassava roots, sensory analyses that used a color scale of 1(tan) to 10(white) was used to analyze the obtained color hues of the experimental dry feeding materials. The results showed that the freshly harvested roots had 0.89-1.75μg/g carotene and 31.68-42.37g/100g dry matter contents. Percentage retention of the carotene content at 7th and 9th day of root storage was 45.49-80.00% and 29.15-56.70% respectively. The color scores of cassava flour samples from these genotype were 5.4 to 7.6 on first day of storage, and 4.0 to 5.9 on 9th day of storage with the ‘low cyanide’ TMS 4(2)1425 cultivar maintaining appreciable good color stability. On the 9th day of storage, dried chips from TMS 4(2)1425 cultivar had a color score of 6.7 while others had color scores of 3.0 to 5.0. It could, however, be concluded that more work need to be done to deduce the reason why this low cyanide cassava cultivar gave the best product color hues more so, as cyanide is known to inhibit the mitochondrial oxidative electron transport chain that could have assisted in suppressing the oxidative PPD.