บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Permeance to gases, internal atmosphere modification and ripening of coated pears.

Amarante, C.; Banks, N. H.; Ganesh, S.;

Postharvest Horticulture Series - Department of Pomology, University of California Year: 1997 Issue: No. 16 Pages: 145-150 Ref: 9 ref.

1997

บทคัดย่อ

Permeance to gases, internal atmosphere modification and ripening of coated pears.

Doyenne du Comice pear fruits were treated at harvest with a wax coating diluted to 0, 5, 10, 20, 40 and 100% (v/v) of the commercial formulation, and assessed for gas exchange and ripening at 20 deg C and 60-70% RH after 2 months in cold storage. Fruit permeance to water (P'H20) was reduced by a third by increasing coating concentration from 0 to 20%, with further increases in wax concentration resulting in progressively smaller reductions, reaching a maximum of 43% for undiluted coating. Permeance to O2 (P'02) decreased exponentially with increasing coating concentration with P'02 being reduced more than P'C02 (92 and 75% decrease, respectively, for undiluted coating), with a resultant increase in the P'C02:P'02 ratio from 1 for 0% coating concentration to 3 for 100% coating concentration. Increasing coating concentration therefore resulted in a more accentuated change in the internal partial pressure of O2 (pi02) than of CO2 (piC02). Rates of respiration (rC02), change in firmness (dF/dt) and

 change in hue angle (dH/dt) were consistent with a Michaelis-Menten model for effects of pi02 whilst piC02 had no explanatory power for these variables. The Km values for effects of pi02 on rC02, dF/dt and dH/dt were 1.1, 0.6 and 18.9 kPa, respectively. Therefore, colour change was readily impaired by small modification of pi02 created by the fruit coating, while firmness was less affected. Despite a pi02 of approx. 0 kPa for the higher coating concentrations, there was no evidence of fruit fermentation.