Development of Electronic Nose for early spoilage detection of potato and onion during post-harvest storage
Keywords:Electronic Nose (e-Nose), Volatile Organic Compound (VOC), Metal Oxide Semiconductor (MOS), Principal Component Analysis (PCA), Probabilistic Neural Network (PNN), Partial Least Square (PLS)
Every year, roughly around one-third of the horticultural commodities worldwide are lost in post-harvest stages due to various abiotic stresses like temperature, humidity and water, and biotic stresses like pathogens, insects and pests. This calls for the need of continuous monitoring of health of stored fruits and vegetables for early detection of spoilage of these perishable and semi-perishable items. For all practical purposes, regular manual physical inspection of the storage area is not a feasible solution. Vegetable aging, spoilage and infection are associated with emission of volatile organic compounds (VOCs) often with foul odour. GC-MS based chemical analysis shows that vegetable effused VOCs during storage vary significantly and the concentration of VOCs increases with more degree of spoilage. Regular chemical analysis is not a practical solution because of high cost and lead time of such process. A probable alternative solution is rapid, low-cost, in-situ and online testing employing electronic nose (e-Nose). This study attempts a novel way of early detection of spoilage of stored potato and onion employing an e-Nose, named e-POT, designed and developed for the purpose. The study shows encouraging results and may further be exploited for making it suitable for commercial applications.