ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Changes in respiration and ethylene production of apples in response to internal and external oxygen partial pressures.

Dadzie, B. K.; Banks, N. H.; Cleland, D. J.; Hewett, E. W.;

Postharvest Biology and Technology Year: 1996 Vol: 9 Issue: 3 Pages: 297-309 Ref: 18 ref.

1996

บทคัดย่อ

Variations in respiration rate and ethylene production of Cox's Orange Pippin and Granny Smith apples in response to reduced O2 partial pressures were characterized by studying O2, CO2 and C2H4 partial pressure differences between the internal and external atmospheres ( DELTA pO2, DELTA pCO2 and DELTA pC2H4, Pa) of individual fruits maintained in different O2 atmospheres at 20 plus or minus 1 deg C. DELTA pO2 decreased at low O2 levels, reflecting the decreased rate of O2 uptake in low O2 partial pressures. O2 uptake relative to that in air (relrO2) approximately followed Michaelis-Menten kinetics, with a half-maximal rate at 3.3 kPa O2 for internal O2 (piO2) and 10.4 kPa O2 for external O2 (peO2). An equation was developed to describe aerobic and anaerobic components of CO2 production relative to that in air (relrCO2) as a function of peO2 or piO2. The relationship between rate of C2H4 production relative to that in air (relrC2H4) and piO2 was reasonably described by a Michaelis-Menten type hyp

erbolic curve, confirming the expectation that small changes in O2 partial pressure would have a much greater effect on relrC2H4 at low piO2 than they do at high piO2. In contrast, presence of the skin as a diffusion barrier resulted in development of an apparent lag phase in the relationship between relrC2H4 and peO2 such that it became essentially sigmoidal. These differences are attributed to differences in O2 partial pressure between internal and external atmospheres.