Effects of initial oxygen concentration and oxygen-barrier property of film on fat oxidation rate of packed cookies

Abstract

Oxygen concentration in packs of cookies is one of the key factors that impacts on fat oxidation. The aim of this study was to investigate the influences of initial oxygen concentration (IOC) in packs and oxygen-barrier performance of packaging film on the fat oxidation rate of cookies. One batch of cookies was packed in high-barrier material PET/AL/ONY/PE bag with a condition of vacuum-packaging (IOC: 1.8%) and modified atmospheres (IOC: 3.5%, 10.3%, 20.9%, 65.5%), respectively; the other batch of cookies was packed with four films of different oxygen transmission rate with air filled in the packs. All samples were stored under the condition of dark, 40 °C and a relative humidity of 50% for more than 30 days, measuring the peroxide values (POV) of cookies during the storage. The results indicated that the fat oxidation rate increased with the increase in IOC in packs and oxygen transmission rate of the packaging films. High concentration of initial oxygen has a significant impact on the fat oxidation in packed cookies, which was not notable under low IOC and was effectively delayed under vacuum packaging. Besides, Logarithm of POV and store time under different IOC and packaging films had a relationship which successfully fitted by linear regression under the same temperature and relative humidity, and a linear correlation between the fat oxidation rate of the cookies and IOC was developed.