Quality of Tomato Slices Freshly Cut from Fruit Treated with Methyl Jasmonate

Abstract

The objective of this study was to determine if treatment with methyl jasmonate (MJ), a naturally occurring substance, would extend the shelf life of tomato slices, specifically when slices were cut from fruit previously treated with this natural product. Tomatoes were harvested at breaker stage. The fruit were divided into four lots. The first three lots were treated with MJ right after harvest at the breaker stage. Fruit from the first lot were sliced immediately after MJ treatment. Fruit from the second lot were placed at 20 °C and allowed to ripen to red stage before slicing. Fruit from the third lot were treated the same way as those in the second lot except they received an additional MJ treatment just before slicing. Fruit from the fourth lot were placed at 20 °C and allowed to ripen to red stage before MJ treatment and slicing. Each lot also included an untreated control. MJ treatments were carried out in 200-L airtight containers. MJ was spotted onto filter paper at final vapor concentration of 10-5 M. Fruit were cut with a meat slicer to obtain slices with 5-mm thickness. Slices were placed in 1-L clear plastic trays with lids and stored at 5 °C. Samples were transferred daily from 5 to 20 °C for evaluation. Fresh-cut tomatoes treated with MJ and sliced at breaker stage (lot 1) had less decay, better quality, and longer shelf life than the untreated slices. However, no differences were found between the control slices and treated slices at the red stage regardless the time of MJ treatment and whether or not additional MJ treatments were applied (lots 2, 3 & 4). The results indicate that the effectiveness of MJ in reducing decay and maintaining quality is affected by the stages of ripeness of tomatoes and the types of decay.