PREDICTION OF TOMATOES FRESHNESS USING INFRARED THERMOGRAPHY

Abstract

The importance and benefits of Infrared thermography has been extended beyond industrial applications and now found more usefulness in different areas of agriculture, especially in predicting the quality of harvested produce. In Africa, Tomatoes consumption is very high as most African delicacies are incomplete or cannot be processed without the use of tomatoes. However, the authenticity in terms of quality and safety of the highly consumed tomatoes is subject to doubt. This problem is compounded by lack of fast and appropriate technologies to predict quality of agricultural produce. Fresh samples of Roma VF tomatoes (150 samples) seen to be free from any physical defects were acquired from three different vegetable markets in Ile-Ife, Nigeria to compare the level of freshness of the tomatoes available for consumption. The thermograms of the samples were taken using a FLIR T200 Infrared Camera. The thermograms were captured on the day the tomatoes were purchased (1) and thereafter every 24 hours for 5 consecutive days under a standard room temperature storage-condition. Thermograms were analyzed with a quick-report FLIR software. The result of the analysis at day 1 shows that 80% of the tomato samples had anomalies with a mean minimum temperature of 30 ºC and classified not as fresh as physically justified. The defected samples deteriorated faster than the remaining 20% without any noticeable anomaly that were classified fresh with a mean minimum temperature of 32.2 ºC. The fresh tomatoes were observed to have an extended shelf life and therefore recommended for consumption until after five days of storage when their mean temperature dropped below 31ºC. This study showed that infrared thermography is appropriate for tomatoes quality assessment as against visual inspection. Thermography is thereby presented as suitable in building a fast online system for predicting deterioration rate in tomatoes and other perishable food produce.