Shelf-life extension of tomatoes (Solanumlycopersicum), okra (<i>Abelmoschus esculentus</i>) and eggplant (<i>Solanum melongena</i>) using edible coating

Abstract

Post-harvest losses of fresh farm produce, especially fruits grown in Nigeria is high. This study was aimed at investigating the shelf-life extension of tomatoes, okra and eggplants stored at room temperature (29±2^oC), using edible coating involving beeswax, lime and pectin. Five edible films were formulated, namely: Beeswax alone (W), pectin alone (P), beeswax and pectin (WP), beeswax and lime (WL), beeswax, lime and pectin (WLP). Uncoated fruits served as control. The proximate composition of the beeswax and the potential spoilage microorganisms of the selected fruits were determined using standard methods. The results of the proximate composition revealed the following values for carbohydrate (46.25%), lipid (38.50%), moisture (8.85%), protein (5.25%), fibre (1.02%) and ash (0.53%). The WP combination gave the best results, extending the shelf life of the tomatoes, okra and eggplants by more than 23, 21 and 11 days, respectively more than the uncoated fruits. The least effective edible coating was the WLP combination, extending the shelf life of the tomatoes, okra and eggplants by more than 7, 2 and 5 days, respectively compared with the uncoated fruits. The log₁₀CFU/g microbial counts for bacterial and fungal isolates revealed the following ranges for tomato (3.50 to 5.89, 3.43 to 5.88), okra (3.47 to 5.86, 3.46 to 5.88) and eggplant (3.50 to 5.89, 3.49 to 5.90), respectively. The predominant bacteria and fungi were Escherichia coli (30.18%) and Aspergillus niger (23.76%), respectively. Overall, the formulations were all effective in reducing spoilage, thereby extending the shelf life of the fruits.