Contour Diagram‐Based Evaluation on Logistics Stability of Table Grapes under Variable Temperature

Table grapes are inherently perishable and unstable, tending to deteriorate after harvest. The logistics stability of table grape that is closely related to product quality tends to decline. This paper proposed a contour diagram‐based graphical method in order to evaluate the logistics stability visually and easily under variable temperature. Firmness was selected as the indicator of table grape quality and shelf life prediction. Two kinds of experiments were designed to evaluate the proposed method by comparing with the kinetics method: one is isothermal experiment with five temperatures and the other is simulated variable temperature. The results suggest that both methods have the ability to evaluate the logistics stability at variable temperature, but the proposed method can provide a more accurate evaluation of logistics stability intuitively and conveniently. Furthermore, two prerequisite conditions are required for applying the proposed method, i.e., the time ratio for the equivalent logistics transformation at different temperatures must match in the kinetics theory and the primary state of the quality index should equal the initial state of the corresponding contour diagram. Practical Applications The proposed method could be applied to evaluate the logistics stability for any products and provide the cold chain management.