Ultra-accelerated Shelf-life Test for Shelf-Life Determination of Oxygen-Sensitive Foods in Polymeric Packaging Materials

Abstract

An effective analysis method with multiple accelerant factors is crucial for shelf-life determination and prediction for food products with low errors and reduced analysis time. Temperature is the most common accelerant used in the shelf-life analysis of oxygen-sensitive food. Although the rate-limiting step in oxidation is independent of the oxygen concentration, literatures have shown the partial pressure of oxygen at low levels (<0.21 kPa) influences the product oxidation significantly when coupled with moderate temperatures. This approach has the potential to decrease the shelf-life analysis time, but little data is available. Mango smoothie containing whey protein fortified with vitamins A, B1, C and D3 was developed as the model food to investigate the effect of environmental oxygen pressure on product shelf life in polyethylene terephthalate (PET). PET was chosen due to its widespread use in the beverage industry and is a highly recyclable material, providing an opportunity for packaging sustainability. Bottles filled with model food were placed in a high-pressure (138 kPa) environment with 100% oxygen using custom-made chambers at 4ºC (UASLT). Control samples (ASLT) were subjected to the same temperature without additional pressure. The changes in color and vitamin degradation were monitored for both storage conditions. In 40 days, UASLT treatment showed excessive browning of the samples compared to ASLT with ΔE of 7.8±0.5 and 1.8±0.2, respectively, due to rapid degradation of ascorbic acid. The degradation (%) of vitamins A, B1, C and D3 were 20.0±3.5, 13.6±1.6, 27.2±2.8, 26.3±0.9, respectively. The degradation (%) in ASLT were 11.8±4.4, 5.1±1.7, 13.3±1.9, 17.0±2.0, respectively. The addition of oxygen pressure significantly increased the degradation reaction rates of the vitamins due to the rapid influx of oxygen. The results indicated that elevated external oxygen pressure can be used as an accelerant along with moderate temperatures for rapid shelf-life testing of products in polymeric packaging. This new approach has potential application in the food industry for faster shelf-life analysis of food and selection of packaging materials.