Evaluating the efficacy of formulations containing hexanal, moringa leaf extracts, and carboxy methylcellulose as postharvest treatments for fresh tomatoes (Solanum lycopersicum L.).

Abstract

Tomato fruit have a relatively short shelf life due to their highly perishable nature. This presents a challenge for long distance transportation of tomatoes. The use of non-refrigerated trucks (used by most commercial entities in South Africa) for transportation exacerbates the loss of fresh tomatoes. The adoption of low temperature storage units during transit is an expensive technology for farmers in developing countries. The application of postharvest treatments such as chemical treatments is used to reduce these losses. However, chemical treatments contain residues that negatively impact the environmental and human health. In addition, it causes off-flavours which negatively affects consumer acceptability and market value of tomatoes. The inefficiency of chemical treatments and the pressure experienced by producers to meet the increase in demand for fresh tomatoes without any hazardous residues by both consumers and regulatory agencies, encourages further research to investigate eco-friendly and sustainable treatments as an alternative to chemical treatments. The use of total soluble solids as a predictor of tomato quality does not provide an accurate description of internal biochemical changes. The use of accurate predictors such as sugar content and sweetness indices, provides a precise description of internal quality and estimation of shelf-life capacity. However, conventional measurements of these parameters are laborious. Thus, probing the use of a rapid and non-destructive technology (Vis/NIRS) to predict and determine sugar content and sweetness indices, in order to facilitate quality management and accurate grading of tomato produce along the supply chain. The research findings obtained in this present study, demonstrated the ability of the hexanal formulation and moringa based edible coating to optimise organoleptic quality and improve the nutritional quality of tomato fruit, harvested at different maturity stages. Vis/NIRS accurately predicted important internal quality parameters relating to the market value of tomatoes such as sugar content and sweetness indices. Results obtained by evaluating the effects of these treatments to extend shelf life and reduce losses of tomato show the potential of adopting these treatments to serve as an alternative to the currently used treatments in the tomato industry. The successful prediction and accurate determination of sugar content and sweetness indices using Vis/NIRS, has the potential to enable rapid and precise grading of tomato produce.