Assessment of Shelf Lives of Black Pepper and Small Cardamom Cookies by Metal Oxide-Based Electronic Nose Using Spoilage Index

E-nose technology has been successfully employed in determination of rancidity in nutraceutical-rich drop cookies. The cookies were formulated with extracts obtained by supercritical carbon dioxide extractions and post-extraction sample matrices of black pepper and small cardamom. Rancidity in cookies was estimated by comparing the odor profiles of stored cookies with the profiles of deliberately rancid cookies (training sets), using e-nose. PCA plots along with spoilage indices obtained from Mahalanobis distances calculated from e-nose responses revealed that the extracts and post-extraction sample matrices of these spices performed as natural antioxidants in preventing rancidity in cookies. Both the extracts enhanced the shelf lives of cookies by at least 120 days; post-extraction matrices of black pepper and small cardamom enhanced the same by 80 and 40 days, respectively. These findings were further affirmed by biochemical analyses and linear regression equations were generated for prediction of FFA content, PV, and MDA values from the spoilage indices of each type of cookie. Thus, spoilage indices can circumvent the requirement of conducting cumbersome biochemical assays for estimation of rancidity in cookies. Similar applications of e-nose technology and spoilage indices can be envisaged for other bakery products also.