Determination of the respiration rate of tomato fruit using flow analysis
Fagoni F. Calegario, Ricardo G. Cosso, Fernanda V. Almeida, Anibal E. Vercesi and Wilson F. Jardim
Postharvest Biology and Technology. Volume 22, Issue 3, July 2001, Pages 249-256.
2001
บทคัดย่อ
A continuous-flow method using a conductometric detector was developed to measure CO2 resulting from respiration of tomato fruit (Lycopersicon esculentum var. Santa Clara). The fruit are inserted into a 3.4-l vessel and the atmosphere in the vessel continuously monitored for CO2, using a closed-loop system. The CO2 produced from fruit respiration diffuses through a Teflon® membrane, dissociates in the acceptor stream of deionized water, and the conductivity (mainly of H+ and HCO3-) is monitored. The conductance increase in the acceptor stream is proportional to the carbon dioxide concentration in the gaseous sample. Each determination is performed in 7 min, a time interval short enough to prevent respiration inhibition due to high levels of CO2 inside the respiration vessel. The relative error of measurement is -3.0% (n=7) for a CO2 level of 589 ppmv. Average respiration rates for the tomatoes var. Santa Clara of various stages of maturity ranged from 40 to 120 mg kg-1 h-1 evolved CO2. These results had low levels of variance between measurements, were consistent between repetitions, and were comparable with published data.