Assessment of the stage of maturity and post-harvest quality of ‘Thai red’ guavas

Abstract

In guavas, the ripening process happens fast after the harvest, which causes quick changes on the colour, texture, among other characteristics, making them have a short conservation period, which makes their trade impossible for certain locations. For a correct post-harvest quality maintenance, the harvest needs to be done at proper stages of maturity. The early harvest stops the fruit from fully developing, not acquiring the desired qualities, while with a late harvest, the fruit presents a fast quality loss, thus decreasing its life span. Considering what has been presented, this paper aimed to assess the maturity of guavas through conventional techniques and through Biospeckle, which is a low-cost, simple to implement technique, consisting of lighting a biological material in order to acquiring images to be processed, obtaining from them information about biological activity of the analysed material.

Thai red guavas were used, harvested at four stages of maturity, and epidermis colour, respiratory rate, and physicochemical assessments were performed. The sugar levels (ºBrix), respiratory rate, TSS/TTA ratio (total soluble solids/total titratable acidity), and darkening index increased as the stages of maturity advanced, while the total titratable acidity decreased. The analyses performed with Biospeckle did not present significant differences among the treatments.