Development of Detection System Maturity of Fresh Fruit Bunches (FFB) Palm Oil Based on Visible Spectrum

Abstract

Palm oil is one of the most famous commodities in Indonesia, seen from the growth area significantly. Since 2005, Indonesia overtake Malaysia as the largest palm oil exporter and currently holds more than 50% global market share (USDA 2012). But the problem is the crude palm oil (CPO) quality with the content of free fat acid (FFA) more than 5%, it means that FFA content more than the international standard which required less than 3%. This problem caused decreasing of the price or discount rate for CPO from Indonesia. The best harvesting time of palm oil is when the CPO maximum and FFA minimum. Harvesting of palm oil in the over maturity stage caused FFA content more than 5%, and if the harvesting of palm oil in the under maturity stage, the content of both FFA and CPO low (Fauziet al.2007). The precision of harvesting time would be very difficult if using human resources which considered on the fraction or percentage of palm oil fruits which fall in the soil surface. These human resources methods was low accuracy, it was caused by many external factors like as the fruit would be hold on the palm oil stems and in the rainy season FFB would release from the bunches before maturity stages. One of the best ways to solve these problems is using censors for maturity detection of FFB. To get the precise censor would need optical characteristics tests of palm oil FFB using Uv-Vis spectrophotometer. Resulted data from these measurements was in the reflectance characteristics from the FFB spectrum, and then these data would be used for maturity detections system of palm oil FFB. The objectives of this research are studying of FFB spectrum characteristics based on the maturity stages using visible wave reflectances method, studying about the interactions between chemical contents with visible wave spectrum of palm oil FFB, and creating oil palm FFB maturity detection system using censors, displays, and recorders. Materials used for this research are 87 palm oil FFB from the Marihat, Selapan Jaya, and Dumpy clones. Number of samples of each clone is 29 pieces consisting of four (4) level of maturity that is raw (fraction 0), less mature (fraction 1) mature (fraction 2 and fraction 3), over-mature (fraction 4). This research using ocean optics spectrometer USB 650, fiber optic solids, digital spotting scope (bushnell 15 – 45x, LCD 22x), red laser pointer (660nm, 100 mW), lux meter, halogen lamps (1000 and 6000 Watt), black fabric, distance meter, laboratory instruments for FFB chemical tests, computer and it’s components. The first step is classified of integration time with measuring white reference reflectan and black in the spesific distances of measuring. Using references was be done for standarized of measuring. FFB spectrum would be cauthed by digital spotting scope and FFB reflectances would be read by spectrometer ocean optics USB 650 (fiber optic solid) in the wave lenght 200-850 nm. To ensure the point of FFB measurement, laser pointer was used and FFB spectrum would be displayed by display in the digital spotting scope. Reading was vi be done using ocean optic spectarsuite which connected to spectrometre USB 650 of fiber optic solids. Analysis of oil content and free fatty acid (FFA) conducted in the chemical laboratory PT. Nirmala Agro Lestari. Sampling for testing ALB performed directly after harvest TBS while sampling for analysis of oil content TBS performed after measurement of reflectance using a spectrophotometer. The results of this research showed that maturity stage of Marihat, Dumpy, and Selapan Jaya clone could be determinated in the wave legth rate from 650 to 690 nm. On this wave length indicated the diffferences of maturity and immaturity fruit color. Differences characteristics was occured in the maturity stages of each clone. Optimal oil content of Marihat clone was occured in fraction 2, and for Dumpy and Selapan Jaya clones was occured on fraction 1. Β caroten contents would increased and then decreased on the spesifics stages, optimum β caroten for Marihat and Selapan Jaya was occured on fraction 3 and Dumpy clone was occured on fraction 2. Based of reflectances data in indoor measurements, the most affected wave length to predict the FFB oil contents the wavelength range of 650 - 690 nm. Based of reflectances data in indoor measurements, the most affected wave length to predict the FFB oil contents the wavelength range of 650 - 690 nm for Marihat clone was in 672 nm with R2 0,407, Dumpy clone 685 nm with R2 0,638, and Selapan Jaya clone 685 nm with R2 0,795. While the wavelength of the most influential in predicting FFB oil content in the wavelength range 650-690 nm to 663 nm Marihat clones with R2 values of 0.764, clone Dumpy 685 nm with R2 values of 0.984 and 669 clones of Jaya Selapan nm with R2 values of 0.878 . System test results for clone detection TBS Marihat maturity, Dumpy and Selapan Jaya shows the calibration model prediction accuracy of 100%, while the validation of models each - amounting to 50%, 60%, and 70%.