ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Membrane deterioration during postharvest senescence of broccoli florets: modulation by temperature and controlled atmosphere storage.

Deschene, A.; Paliyath, G.; Lougheed, E. C.; Dumbroff, E. B.; Thompson, J. E.;

Postharvest Biology and Technology Year: 1991 Vol: 1 Issue: 1 Pages: 19-31 Ref: 32 ref.

1991

บทคัดย่อ

When freshly cut heads of broccoli (cultivars Commander and Green Duke) were stored in air at 23 deg or 10 deg C, the florets rapidly senesced. Chlorophyll levels declined by 80-90% within 4 days at 23 deg and within 10 days at 10 deg and, under the same storage conditions, microsomal phospholipid phosphate and fatty acids in the florets declined by 70-90%. The breakdown of membrane phospholipids was accompanied by a large decrease (approx. 35%) in bulk lipid fluidity of the membranes. These changes were temperature-dependent inasmuch as they were inhibited during storage for comparable periods in air at 5 deg . Also, the potential of microsomal membranes isolated from florets to degrade exogenous, radiolabelled phosphatidylcholine increased during storage in air at 23 deg or 10 deg , but not at 5 deg . Storage at 5 deg or 10 deg in a controlled atmosphere (5% CO2, 3% O2, 92% N2) at approx. 80% RH strongly inhibited loss of chlorophyll and the change in microsomal bulk lipid fluidity reflecting phospholipid breakdown. Thus, reduced integrity of thylakoids and membrane phospholipid degradation appear to be inherent features of broccoli floret senescence that are sensitive, directly or indirectly, to ambient CO2 and O2 concentrations. These observations confirm the potential of using controlled atmospheres to enhance the storability of broccoli and identify physiological and biochemical parameters of floret senescence that can be used to establish optimum controlled atmosphere conditions.