Palm oil quality in different packaging materials-sensory and physicochemical parameters

Changes in stored palm oil were studied under three conditions in seven different structured film packages. Six chemical parameters including moisture, free fatty acids (FFA), peroxide values (PV), Kreis tintometric and absorbance/transmittance values, and sensory profiling were examined on a set of 13 odor notes at periodic intervals until the end of the shelf life of the oil or the end of 180 d. Correlation among all the parameters was determined. PV showed high correlations with Kreis test values (as absorbance at 547 nm), while Kreis test values correlated with heated oil and rancid and musty odors. The sensory attributes showed poor correlation among themselves indicating their independent identity and justifying their inclusion in the odor profile descriptors. FFA development positively correlated to harsh odor note. Among the sensory attributes of odor, distinct segregation of desirable notes from defective notes was used to classify different quality grades. Correlation between physicochemical and odor profiles of palm oil suggests that the Kreis test as optical density had the potential to predict deterioration in oil quality. Principal component analysis was carried out on 6 chemical parameters, 13 sensory attributes, and 2 physical properties of the films. The total dimensionality was reduced to 16 variables, and the pathway of quality change during oil storage was traced. Damage to oils was more pronounced when they were stored under 30–40% relative humidity (RH) and 45°C, showing a combined effect of moisture and temperature greater than high RH alone (92%), even at lower temperatures of 27°C. The quality deterioration was comparatively less in films containing polyamide as one of the layers, and leakage rates were minimal in films containing ethylene acrylic acid as the sealant layer.