GC-MS and electronic nose analysis on off-flavor components in HDPE containers and correlation with sensory evaluation

Evaluation of off-odor from one gallon HDPE water containers was carried out using an electronic nose system (e-nose), GC-MS and sensory evaluation. In order to determine the effect of antioxidants and processing conditions on the release of volatile compounds from HDPE containers, container samples were fabricated using two antioxidants; α-Tocopherol and Irganox 1010 at two processing temperature conditions; normal (174°C) and abusive (204°C).; The e-nose system with Principal Components Analysis was capable of discriminating between volatiles released from the HDPE container samples produced using different antioxidants. This was in good agreement with GC-MS analysis. The e-nose system also demonstrated its potential to differentiate between volatiles released from the HDPE containers produced at 174°C and 204°C.; HDPE containers were filled with highly purified water and stored for six months. The water samples were then subjected to e-nose, GC-MS, and sensory analysis every three months. GC-MS analysis showed that higher nonanal levels were found in water packaged in the HDPE containers after storage indicating migration of some volatile compounds from HDPE containers into water. The water packaged in the HDPE containers also had higher unacceptable scores in comparison to water packaged in the glass container (reference) as revealed by sensory evaluation. After three months storage, Irganox 1010 samples produced at 204°C had the highest nonanal level, as well as the highest unacceptable score by the panelists. However, correlation between sensory evaluation and the e-nose system was not conclusive due to the low e-nose sensor responses from the water samples.