CONTOUR DIAGRAM-BASED EVALUATION ON LOGISTICS STABILITY OF TABLE GRAPES UNDER VARIABLE TEMPERATURE

摘要

Table grapes are inherently perishable and unstable, tending to deteriorate afternharvest. The logistics stability of table grape that is closely related to productnquality tends to decline. This paper proposed a contour diagram-based graphicalnmethod in order to evaluate the logistics stability visually and easily under variablentemperature. Firmness was selected as the indicator of table grape quality andnshelf life prediction. Two kinds of experiments were designed to evaluate the proposednmethod by comparing with the kinetics method: one is isothermal experimentnwith five temperatures and the other is simulated variable temperature. Thenresults suggest that both methods have the ability to evaluate the logistics stabilitynat variable temperature, but the proposed method can provide a more accuratenevaluation of logistics stability intuitively and conveniently. Furthermore, two prerequisitenconditions are required for applying the proposed method, i.e., the timenratio for the equivalent logistics transformation at different temperatures mustnmatch in the kinetics theory and the primary state of the quality index shouldnequal the initial state of the corresponding contour diagram.