The degreening of lemon and grapefruit in ethylene atmosphere: A cost analysis

Abstract

Lemons and grapefruit are harvested commercially before the fruit have reached their characteristic colour and are submitted to a process of degreening in special chambers before entering the retail chain. The aim of this work is to make a cost analysis of this process for different times of harvest. The period analysed ran from October to December in 2012 and 2013. Fruit were harvested on six occasions in each year (T1–T6) and the fruit classified into seven lots each time (three for lemon and four for the grapefruit cultivars studied). The lemon cultivars studied were ‘Eureka’, ‘Fino 49’ and ‘Lisbon’ on Citrus macrophylla and the grapefruit cultivars were ‘Marsh’, ‘Red Blush’, ‘Río Red’ and ‘Star Ruby’ on the mandarin Cleopatra. Each lot remained in the ethylene chamber for 7 days, and the colour coordinates were measured every 2 days to obtain the Colour Index (CI*) of the fruit for each harvesting date. The data showed that the greener the fruit when they entered the ethylene chamber, the greater the degreening rate. The different costs of degreening were estimated for each harvesting date and cultivar. The findings showed that the costs involved in degreening the grapefruit cultivars ‘Red Blush’ and ‘Rio Red’ were three times greater than the costs associated with ‘Marsh’ and ‘Star Ruby’. The costs of degreening lemon did not differ during the first half of the harvesting period and fell gradually during the second half. The findings provide a useful tool for calculating the cost of degreening as a function of harvesting date for each cultivar.