Cookies Formulated with Gamma-Irradiated Virgin Coconut Oil are Less Rancid: Analysis By Metal Oxide-Based Electronic Nose and Support Vector Machines

In this study, hydrogenated vegetable fat in cookie is replaced by gamma-irradiation-induced (4.2 kGy) deodorized (rancid-acid odor removed) virgin coconut oil (VCO) with the aim to formulate antioxidant-rich cookies with good sensory acceptability up to 150 days, vis-a-vis the hydrogenated fat- and VCO-formulated cookies. Cookies formulated with hydrogenated fat, non-irradiated VCO and 4.2 kGy irradiated VCO serve as control, positive control, and sample sets, respectively. Rancidity of three sets of cookies is assessed for a period of 180 days at 25 +/- 2 degrees C, approximate to 75-80% RH using metal oxide gas sensor-based electronic nose (e-nose). The best combinations of sensors are selected employing support vector machines analysis to accurately predict rancidity development in the three sets of cookies during storage. Analyses of principal component analysis (PCA) plots of the e-nose sensor responses reveal that the progression of rancidity in the control and positive control sets of cookies is detected on day 90 and 120, respectively; whereas, the onset of rancidity is detected for sample set of cookies on day 150. Findings of sensory evaluation and e-nose analyses affirm that the newly formulated cookies can be safely consumed up to 150 days when stored at 25 +/- 2 degrees C, 75-80% RH.