The effect of various drying methods on the nutritional composition of Lycopersicum esculentum and Abelmoschus esculentus L.

Abstract

Food drying is one of the methods for preserving perishable foods for long periods of time. The nutritional composition of tomato (Lycopersicum esculentus) and okra (Abelmoschus esculentum) was investigated using the commonly available drying methods (sun, oven, and solar drying). The nutritional compositions of these food crops were determined after they have been dried using various drying methods and milled to pass through mesh size. The moisture content of these food samples was significantly reduced with these drying processes employed, with solar dried samples having the lowest moisture content(7.45±0.50) as compared to fresh sample (80.85±0.60), The carbohydrate content of the dried samples was very low as compared to that of the fresh sample. The dried samples had a very high content of protein and lipid. The fibre and ash content shows a small rise in the dried sample as against the fall in the other nutrient content when compared to the fresh sample.The mineral composition of the dried samples was lower than that of the fresh samples, and the amount of nutrient retained is influenced by the drying method used. Generally, the higher the temperature, the higher the risk of nutrient loss, since vitamin C is such a sensitive nutrient, the degree to which it is retained in the dried sample okra and tomato (23.50±0.03 – 20.20±0.01; 16.05±0.03 – 15.00±0.01) respectively as compared to that of fresh sample okra and tomato (23.65±0.01, 17.25±0.02) respectively can be used as a yardstick of measurement in describing other nutrients retention in preserved food crop samples. This finding indicates that the effects of the drying methods employed are similar in nutrient retention with no complete loss of volatile minerals. Solar and oven drying were more hygienic and faster than Sun drying, but solar drying was more costefficient and offered the lowest moisture content analysis.

Keywords: food crops, nutrients, oven drying, preserving, sun drying, solar drying