Study of food preservation in defective pouches: The effect of oxygen permeation through a channel leak, induced in a seal of a package, on preservation of the food product ham sausage

Abstract

Introduction Packaging integrity is critical for the purpose of food quality, food safety and consumer trust. In 58% of the cases, seal contamination is the main reason for defective packaging (Dudbridge, M.; Turner, R. (2009): Seal integrity and the impact on food waste. WRAP. ). In this research the effect of a channel leak in the seal area on the preservation of ham sausage is studied. Materials and methods A commercial food packaging barrier film (PET/PE-EVOH-PE 12/50) from Amcor Flexibles (Belgium) is sealed by heat conductive sealing into pouches. 40 three-sided seal pouches (15 x 20 cm), are studied in a food preservation test. In 20 of these pouches one channel leak with an approximate diameter of 50 µm is induced by adding, and after sealing, removing a human hair in the seal area. All 40 pouches are packed with sliced ham sausage and finally sealed under modified atmosphere. All samples are stored at 4°C with an alternating 12 hours of light and 12h of darkness. Each day of analysis three samples of each package (with and without channel leak) are tested on physicochemical parameters (gas mixture in the headspace, pH, water activity), microbial growth and chemical parameters (peroxide value, free fatty acid content). At the end of the test (after 29 days), the oxygen transmission rate (=OTR) of two flat films are determined using fluorescence sensor technology. These measurements are used to calculate the OTR of the pouches with and without channel leak. Results and conclusions The OTR of the pouches with a channel leak is approximately 6 times higher than the OTR of the intact film. An intact pouch has a calculated OTR of 0,035 ± 0,001 cc/day, the channel leak adds 0,176 ± 0,003 cc/day to this OTR. During the food preservation test the pouches with a channel leak have a higher O2-concentration in the headspace than those without a channel leak. After four days of storage, O2-concentrations were 0,50% for the pouches with channel leak and 0,10 % for the pouches without channel leak. Throughout the storage of 29 days, the O2-concentrations are never exceeding 1%. Moreover, there are no effects of the presence of a channel leak on pH, water activity, microbial growth, peroxide value and free fatty acid content of the packed ham sausage. In contrast to the pouches without channel leak, a discoloration of the ham sausage is however observed in the pouches with channel leak, possibly due to the interaction of the higher O2-concentration with light exposure. This could lead to rejection of the meat packages by consumers.