The effects of various drying methods on the nutritional composition of Musa paradisiaca, Dioscorea rotundata and Colocasia esculenta

摘要

Food drying is one of the methods that are used to preserve some perishable food crops and this study was carried out to determine the effects of various drying techniques on these food crops. The effects of commonly used drying methods (viz; sun, oven and solar drying), on the nutritional composition of plantain (Musa paradisiaca), yam (Dioscorea rotundata) and cocoyam (Colocasia esculenta) were investigated. These food crops were dried using these various drying methods and their nutritional composition determined. Analyses of their nutritional composition showed that these drying methods significantly lowered the moisture content of these food samples (p<0.001), with solar dried samples having the lowest moisture content compared to the fresh samples. The carbohydrate content of all the dried samples were significantly lowered (p<0.01) compared to the fresh samples, however, the solar dried samples had the highest values except for the cocoyam sample. Protein and lipid contents of all the dried samples also decreased significantly (p<0.001). On the other hand, ash and fibre contents of all the dried samples increased significantly (p<0.001) compared to the fresh samples. Calcium content of the dried samples of yam and cocoyam decreased but that of the plantain samples increased, however, this increase was not significant except for the sun dried sample. The three drying methods used in this study resulted in an increase in the magnesium content of both plantain and yam samples, however, that of cocoyam decreased compared to the fresh samples. These results indicate that the effects of the various drying methods on the food samples were almost similar, with each drying method retaining the nutrients, without total loss of any nutrient; although, with some degree of loss to some nutrients.