Production of volatile representative aroma compounds of papaya (Carica papaya cv. \'Golden\') treated with methyl jasmonate and stored at low temperature

Author(s)

Deborah Oliveira De Fusco

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2015-02-24

Examining board members

Eduardo Purgatto; Roberta Ghedini Der Agopian; Angelo Pedro Jacomino

• Advisor: Eduardo Purgatto

Abstract

Brazil stands out as one of the world\'s largest producers of papaya, fruit appreciated worldwide for it taste and delicate pulp. The volatile compounds contribute to the formation of the flavor of the fruit, making them essential for the development of sensory characteristics that define their appreciation by consumers. The main papaya flavor compounds include mainly terpenes, esters, aldehydes, alcohols, organic acids and ketones, especially the monoterpene linalool which is the most abundant compound in the cultivar \'Golden\'. Although the biosynthesis of volatile compounds is particularly affected by postharvest treatments for conservation, those are essential for the marketing of papaya, in view of their high perishability. The use of low temperatures has been one of the most used methods for extension of papaya postharvest life. Previous literature indicate that postharvest treatment with methyl jasmonate (MJ) is capable of reducing possible adverse effects arising from storage at low temperature. Furthermore, the application of methyl jasmonate in fruits is able to stimulate the activity of the enzymes of volatiles production pathways. Thus, this study aims to evaluate the effects of postharvest application of MJ in papaya (Carica papaya L. cv \'Golden\'), focusing on the effects in the biosynthetic pathways of volatile aroma compounds in fruit ripened to temperature of 22ºC, as well as other stored at 10ºC followed by transfer to 22ºC for the complete maturation. In addition to the volatile compounds profiles were also evaluated respiration profiles, ethylene production, peel color, quantification of MJ and gene expression of linalool synthase (LIS). Given the importance of linalool to the characteristic aroma papaya, changes in the transcription of a linalool synthase gene were evaluated seeking to correlate them to the treatment effects on the production of volatile compounds. Treatment with MJ influence the production of volatile compounds, particularly linalool and hexanal in the groups kept at 10ºC. Fruits treated with the hormone had higher abundance of the compound when compared to the control group. Although the treatment protocol employee has not been able to recover the high levels found in fruits stored at 22ºC, do not exclude the possibility that other experimental designs can respond even more satisfactorily to this same treatment. (AU)

• FAPESP's process: 12/12649-9 - Production of volatile aroma compounds in papaya fruit(Carica papaya cv. Gold) treated with methyl jasmonate and stored at low temperature.
• Grantee: Deborah Oliveira de Fusco
• Support Opportunities: Scholarships in Brazil - Master