2.4.2. Respiration and ethylene production
A slice fromeach treatment and grower was removed fromthe 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 concentrations 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 determinewhether
a build-up of CO2 or ethylene in the packaging before and after HPP treatment
might have given false measures of respiration rate. Concentrations
of CO2 and ethylene were expressed as μmol kg−1 s−1 and
nmol kg−1 s−1, respectively.