Electronic Nose-Based Detection of Spoilage of Coconut Milk-Based Filipino Dishes Using PCA and KNN Algorithms

To evaluate the spoilage of coconut milk-based dishes for food safety and quality control in Filipino cuisine based on their perishable nature, sensitive determination of spoilage of these dishes is essential. In the present study, the challenge of the subjective evaluation of spoilage is addressed, and the electronic nose system is developed to determine the freshness of coconut milk-based viands objectively. The developed system employs six MQ gas sensors connected to an Arduino Nano and a Raspberry Pi 4B for capturing volatile organic components emitted by two Bicol Express, Ginataang Langka, and Laing, as well as two native Filipino dishes: Bilo-bilo, Maja, and Guinumis. Data processing is facilitated by the PCA and KNN algorithms. As a result, the presented electronic nose has higher than 96.9% correct accuracy of spoilage detection. It provides correspondingly successful results of testing evaluation over two days, reaching the assessment of spoilage status corresponding to the actual review by 8 AM on the second day.