The Effects of Different Storage Temperatures on the Oxidative Stability of Breakfast and Kitchen Margarines

Abstract

In this study, different brands of breakfast (K1, K2, K3, K4 and K5) and kitchen margarines (M1, M2, M3, M4 and M5) were stored at 4 and 25°C for 12 weeks. During the storage period, samples were taken every 2 weeks and the oxidative stability of the margarines was evaluated by detecting changes in tocopherol contents, peroxide values (PV), thiobarbituric acid (TBA) values, conjugated diene (K232) and fatty acid compositions. In the margarine samples used in the study, it was determined that the initial values were compatible with the label values, but changed depending on the storage temperature and duration. In breakfast margarine samples kept at 4 °C and 25°C, K3 (11.08 meqO2 kg-1) and K4 (70.97 meqO2 kg-1) showed the highest PVs, respectively. In kitchen margarines stored at 4 °C and 25°C, M2 (9.22 meqO2 kg-1) and M1 (27.63 meqO2 kg-1) showed the highest PVs, respectively. The PVs of margarines kept at 4°C remained within legal limits (except K3). The breakfast margarines generally exceeded the legal limit after the 2nd week, and in the kitchen margarines after the 4th week in samples stored at 25°C. K232 and TBA values increased with storage temperature. The breakfast margarine samples showed higher K232 and TBA values than those of kitchen margarines. Margarines had different tocopherol contents which showed decreasing trend depending on increasing temprature and time. As the storage temperature and duration increased, the total saturated fatty acids contents of margarines increased and their total unsaturated fatty acids content decreased. Kitchen margarines showed higher oxidative stability than breakfast margarines due to their higher saturated fatty acids contents. For margarines, storage at 4°C is appropriate, while storage at 25°C led to deterioration after the first week. © 2018, Centenary University. All rights reserved.