2.4.2. Respiration and ethylene production
A slice from each treatment and grower was removed from the pouch and carefully placed in a 69-mL container, flushed with ethylene-and co2-free air ,sealed and left for 1 h at 20°C. Two 1- mL samples were removed and co2 and ethylene concentration were measured using gas chromatography as described elsewhere (Besada,jackman,Olsson, &Woolf,2010). This measurement was repeated on the same samples 17 h after HPP treatment ( holding tissue at 20°C) to determine whether a build-up of co2 or ethylene in the packaging before and after HPP treatment might have given false measures of respiration rate. Concentration of co2 and ethylene were expressed as µmol kg-1 s-1 and nmol kg-1s-1, respectively.