Non-Destructive Evaluation of Oil Palm Fresh Fruit Bunch Quality Using Thermal Vision

Abstract

Oil palm (Elaeis Guineensis Jacq) is the main product of Indonesian agro-industry. It supports the country s economy. After harvest, the Fresh Fruits Bunch (FFB) should immediately be processed to extract the oil. Delayed will reduce the oil quality significantly. Nonetheless, due to poor road-conditions, the FFB often delivered to the palm mills beyond the acceptable time. To reduce the decrease of the fruit freshness, generally cold storage was applied. In this study, the FFB immediately freeze after harvest. Fruits stored at −20 °C, upon delivered to the mills. On arrival, acclimatization process was perform to restore fruit temperature before processing. A pseudo-color thermal vision used to monitor the fruits surface temperature continuously. Various fruits maturities observed in this study were: 120, 140, 160, 180, and 200 days after antheses (DAA). Temperature calibration was done by manually measured the fruit s surface using a thermometer. Models developed to correlate the actual surface temperature of fruits with pseudo-color displayed by the thermal-vision. Results showed the model of thermal vision correctly measured fruits temperature with R2 of 0.979, 0.973, 0.976, 0.976, and, 0.973 for stored fruits harvested at 120, 140, 160, 180, and 200 DAA respectively. The color of images on the camera can be used to observe the temperature of the fruits. The highest correlation obtained with redness index (R2 of 0.7677-0.8037), and the lowest is bluish index (R2 of 0.1101-0.561). FFB harvested at 180 DAA has the strongest correlation (R2) of temperature when observed by thermal-vision.