The development of a model to describe the influence of temperature and relative humidity on respiration rate of prickly pear cactus stems
Juan Garlos Guevara, Elhadi M. Yahia , Randolph M. Beaudry, L.M.M Tijskens and Luis Cedeno
9th Controlled Atmosphere Research Conference (CA2005). Program and Abstract.Michigan State University, East Lansing, Michigan, USA. July 5-10, 2005. page51
2005
บทคัดย่อ
The development of a model to describe the influence of temperature and relative humidity on respiration rate of prickly pear cactus stems
Respiration rate (R02) of prickly pear cactus stems (Opuntia spp.) was measured as a function of four temperature (T) and 6 relative humidity (RH) combinations for O2 partial pressures between 15 and 0.8 kPa, which were considered to support aerobic respiration.The rate of respiration (R2) was determined based on O2 depletion of the atmosphere in sealed containers containing 1 kg of stems.The O2 partial pressure declined linearly over time and the slopes of the fitted lines were used to calculate the rate of O2 uptake. The rate of O2 uptake increased with increasing temperature and decreased with increasing relative humidity. The respiratory rate at 25ºC was approximately 30 to 40 times higher than at 5ºC.The respiratory rate at 65% RH was between 30 and 90% greater than at 90% RH, depending on the temperature.Data for In(R02) for each RH level were regressed against the inverse of the temperature (K-1) to determine.Arrhenius constants and calculate the apparent Ea of respiration for the six RH conditions.The Ea was similar for each RH level, varying between a low of 113 to a high of 131 kJ-mole.1.An equation having an R2 of 0.95 was developed describing respiration as a function of RH and temperature (ºC) using only four constants.