2.9. Respiration rat and ethylene production Three fruits from each replication were randomly selected tomeasure respiration rate and ethylene production. Single fruitwere kept in 1.9 L airtight containers at 20◦C for 2 h. For deter-mination of CO2and C2H4concentration, one ml of gas from thesealed container was injected into a gas chromatograph (Claru-500,Perkin Elmer, USA) fitted with a stainless steel Porapak Q column(3 m × 3.125 mm, 50/80 mesh), thermal conductivity (150◦C) andflame ionization detectors (150◦C). Nitrogen served as the carriergas at a flow rate of 45 ml min−1. One ml certified standard gas wasused for calibration the instruments. The amount of CO2and C2H4production was expressed in ml kg−1h−1and l kg−1h−1, respec-tively.