ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Reducing gas exchange of fruits with surface coatings.

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

Postharvest Biology and Technology Year: 1993 Vol: 3 Issue: 3 Pages: 269-284 Ref: 31 ref.

1993

บทคัดย่อ

Surface coatings can increase a fruit's skin resistance to gas diffusion, modify its internal atmosphere composition and depress its respiration rate; effects on transpiration tend to be comparatively small. A steady state mathematical model which considered diffusion through cuticle and pores separately was used to investigate 2 possible mechanisms by which coatings achieve these effects: either by acting as a film wrap or by blocking pores. It was concluded that coatings mainly exert their effects on skin resistance to diffusion of the permanent gases by blocking a greater or lesser proportion of the pores on the fruit surface. Both covering of the cuticle and blocking pores were important for resistance to water vapour diffusion. Coupled with a proposed differential resistance of the skin to oxygen, carbon dioxide and water vapour, this accounts for the observed effects of coatings on internal atmosphere modification, respiration and transpiration rates. Coating treatments which achieved subs

tantial reductions in transpiraton rates were associated with the fruit becoming anaerobic. Inherent variability in skin resistance to gas diffusion and fruit respiration rate, and differing proportions of pores blocked by coating, appear to be responsible for the highly variable response of individual fruits to a given coating treatment. It is suggested that surface coatings may be better suited to treating fruits destined for processing, in which fruit-to-fruit variability may be less critical, than to fruits destined for the fresh market, in which uniformity of individual fruit quality is of paramount importance.