Impact of myco-induced postharvest deterioration on the proximate composition of roots of sweetpotato (<i>Ipomoea batatas</i> [L] Lam) grown in Ebonyi State

Abstract

Fungal pathogens have been indicted as important agents responsible for postharvest losses of either quantitative or qualitative terms. This study was aimed at investigating the impact of postharvest rot induced by morphologically and Partial Internal Transcribed Spacer rDNA Sequence characterized fungi- A. flavus, Penicillium expansum, A. awamori, A. niger, Rhizopus oryzae, Fusarium solani and Botrydiplodiae theobromae isolated from rotted sweetpotato roots on the proximate composition of sweetpotato roots. Using a Completely Randomized Design with two replications, samples of healthy roots and fungi-infected roots of two sweetpotato cultivars- ‘Tupiaochi’ and ‘Oyorima’ were analyzed for moisture, crude fibre, crude protein, ash, fat, carbohydrate and dry matter and the data were subjected to Analysis of Variance using SPSS and significant treatment means separated using Duncan’s New Multiple Range Test. Results revealed the corresponding proximate values for the sweetpotato cultivars- Tupiaochi and Oyorima to be 75.25% and 70.50%Moisture, 2.92 and 1.99%Crude Fibre, 2.62 and 5.05% Protein, 2.24 and 1.48% Ash, 0.44 and 1.34% Fat and 16.33 and 19.64% Carbohydrates respectively. Findings from the fungi impact assessment revealed that fungal attack depletes important proximate components such as Carbohydrates, crude fibre and moisture while increasing crude protein, fat and ash of the roots, indicating that sweetpotato roots attacked by these test fungi beyond two weeks are unfit for consumption as they will be deficient of the major food nutrients they should have supplied to the body. Proper handling, storage and mitigation of fungal spoilage of sweetpotato roots will ensure the conservation of their nutritional components.

Keywords: Impact, Myco-induced, Proximate Composition, Postharvest Deterioration, Sweetpotato