A new method to assess the quality degradation of food products during storage

This study consists of introducing a new method that may be used to globally quantify the quality degradation of a food product during storage or commercialization. The new concept is based on defining and formulating a single index called the Global Stability Index (GSI), varying between zero and one and taking simultaneously into account the time variations of all pertinent quality indices proper to the food product under study. This index enables one to judge the degradation of the microbiological, the physicochemical and the sensory quality of the food product during storage in a global fashion. The new method, referred to as the GSI method, has been successfully tested in studying the stability of an orange based carbonated beverage by simultaneously considering the time variations of the brix and the CO2 partial pressure of the drink. It is particularly recommended that the proposed index is to be used in comparing the quality degradation rates of a given food product stored under different conditions or those of different products stored under a common set of conditions. (c) 2005 Elsevier Ltd. All rights reserved.