Morphological Changes Associated with Postharvest Fruit Deterioration and Physical Parameters for Early Determination of Shelf Life in Capsicum chinense Jacq.

Abstract

Thirty four pepper accessions (Capsicum chinense Jacq.) from the Caribbean were evaluated under controlled environmental conditions viz. darkness, 21.8 °C, and 90% relative humidity (RH) to determine the genetic variation and morphophysiological changes associated with loss of shelf life. The experiment was arranged in a randomized complete block design with three replications and 10 fruits per replication. The following parameters were recorded over a period of 20 days: fruit weight, shrivelling score, and proportion of fruits showing incipient pedicel necrosis, up to 20% pedicel necrosis, total pedicel/calyx necrosis (but with no pericarp necrosis), incipient pericarp necrosis. Water loss overtime, water loss slope and intercept, and days to incipient pedicel necrosis, 20% pedicel necrosis, total pedicel/calyx necrosis, and incipient pericarp necrosis were derived from the data. There were significant differences (P < 0.05) among accessions with respect to all parameters measured. Deterioration under storage initiated as incipient necrosis of the pedicel tip, which proceeded along the entire pedicel and calyx and subsequently into the pericarp. Shelf life varied from 6.6 to 16.9 days based on days to 20% pedicel necrosis and up to 19.5 days based on days to incipient pericarp necrosis. Shelf life based on days to 20% pedicel necrosis, total pedicel/calyx necrosis, and incipient pericarp necrosis were highly autocorrelated (r = 0.94 to 0.99, P < 0.01) and paralleled water loss from fruits. Pepper accessions with heavier fresh fruit weights had lower water loss rates and longer shelf lives than those with lighter fruits. Days to 20% pedicel necrosis and incipient pericarp necrosis were the best measures of shelf life as they best predicted marketability and usability of fruits as early as 8 days after harvest (DAH) (R2 = 0.94) and 9 DAH (R2 = 0.82), respectively, thus reducing the time of shelf life studies by half. Based on days to 20% pedicel necrosis, five accessions with shelf lives over 15 days were identified.