Edible Coatings from Plant Leaf Extracts: Preserving Quality and Mitigating Fungal Contamination in Stored Tomato (Solanum lycopersicum L.) Fruits

The objective of this work was to determine the effect of Moringa, Neem and Bitter leaf as edible coatings for extended storage life and quality retention of tomato fruits. The presence of decay is a very serious defect which renders tomatoes unmarketable. Fungi are the most important and prevalent pathogens infecting a wide range of fruits and causing destructive and economically important losses of fruits during storage, transportation and marketing. The use of edible coating has also received more attention in recent years due to the growing interest in reducing environmental pollution, the need to prolong the shelf life of foods and the increasing demand for healthier ecological foods. The impact of extracts from plant leaves as edible coatings on quality retention of tomato (Solanum lycopersicon L.) fruits after inoculation with fungal isolates was investigated. The experiment was conducted in the Botany Laboratory of the Benue State University, Makurdi. Healthy tomato fruits of the Roma variety were collected at semi ripe stage from the experimental farm. A total of five fungi namely; Aspergillus flavus, Penicillium waksmanii, Lasiodiplodia theobromae, Fusarium oxysporum and Colletotrichum asianum were artificially inoculated into the healthy tomato fruits. The inoculated tomato fruits were coated with leaf extracts of Moringa, Neem and Bitter leaf at 80%w/v and 100% w/v and stored at room temperature. Quality parameters of tomato fruits evaluated include; Beta-carotene content, Lycopene content, pH and Total soluble solids. Analysis of Variance (ANOVA) was used to analyze data. Leaf extract of Moringa, Neem and Bitter leaf at 100% w/v gave the best quality retention of tomato fruits. There was a significant increase (P≤ 0.05) in Beta-carotene and lycopene content of tomato fruits treated with Moringa, Neem and Bitter leaf extracts at 100% w/v over the storage period. pH and total soluble solids content of tomato fruits treated with Moringa, Neem and Bitter leaf extracts decreased with increased rate of concentration over the duration of storage. Lycopene is the major carotenoid compound in tomatoes, it gives the fruit its characteristic red colour. It was observed that lycopene content from all treatments increased as the concentration increased over storage time with the untreated having the least lycopene content. The increase in lycopene content of fruits treated with leaf extract might be due to the faster ripening rate of fruit which leads to the conversion of chloroplasts to chromoplasts and lycopene accumulation in the internal membrane system. Plant extracts have the potential to maintain the quality parameters of tomato fruits during storage. The use of leaf extract of Moringa, Neem and Bitter leaf at 100% w/v concentration should be utilized in coating tomato fruits to maintain their quality parameters during storage. Improvement in methods of coating and the number of additives should be enhanced to effectively impact the overall quality of food products during storage.