EFFECT OF DRYING METHODS ON THE CHEMICAL AND FUNCTIONAL PROPERTIES OF POTATO (Solanum tuberosum) AND SWEET POTATO (Ipomoea batatas) VARIETIES
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Date
2016-12
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Publisher
Nigerian Journal of Agriculture, Food and Environment.
Abstract
In order to minimize postharvest loss of Irish potato and sweetpotato due to their high perishability and to minimize quality deterioration of their dried products, Irish potato and two sweet potato varieties (orange-fleshed and white-fleshed) were dried using two drying methods (sun and solar drying) and their chemical and functional properties were evaluated. Drying methods had a significant effect (P<0.05) on all the chemical properties of the flours except protein, carbohydrate and energy values of Irish potato and orange fleshed-sweet potato flours. Significant difference (P<0.05) existed between the functional properties of sun and solar dried flours except for gelatinization temperature of Irish potato and bulk densities of orange-fleshed sweet potato and Irish potato. The moisture (3.18–8.09%), fat (1.21–2.21%) and protein (1.66–1.77%) contents of the tubers were low while ash (2.74–3.43%), fibre (1.19–4.86%), carbohydrate (83.20–88.91%) and energy value (353.79–374.27 Kcal per 100g) were high. The values for gelatinization temperature (72–78°C) for the flours were low, values for bulk density (0.558–0.836 g ml-1), swelling index (1.03–1.60%), water absorption capacity (2.60–3.80 gg-1) and oil absorption capacity (0.917–2.02 g g-1) were high. The flours were observed to have good functional properties and high calorific value. The chemical value and functional properties of orange-fleshed sweet potato flour were the highest and sun drying was observed to be the best drying method.
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Keywords
Sweet potato varieties, potato, drying methods, flour, quality attributes