STUDY ON DEVELOPMENT OF PROTOTYPE TO MEASURE RIPENING STAGE OF BANANA BASED ON REFLECTANCE LED LIGHTS OF GREEN (500-560 nm), ORANGE (580-610 nm), and RED (600-650 nm)

• Main Author: Kuncoro Pramono, Eko
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36647
• Institution: Institut Teknologi Bandung

Banana is usually harvested at green mature stage condition. Color of the peel becomes indicator to predict the ripeness stage. Prediction is usually done by comparing its peel color by standard color chart. But this method gives inconsistent results and very subjective depending on skill of the operator. On the other hand, the usage of instrument such as spectrophotometer and colorimeter is still considered expensive and not designed for comercial use. This gives opportunities to develop a cheap, accurate and non destructive device to estimate the ripeness stage of banana. In this study, a device is developed to estimate ripening stage of banana. The method is based on the changes of the peels color from green to yellow during ripening. The peels color changes due to the change of chlorophyll content in the peel. The contents of the chlorophyll decrease to zero during ripening. So in this study, a device is developed based on the reflectance of visible lights from the peel. The visible lights include green (500-560 nm), orange (580-610 nm) and red (600- 650 nm). A spectrophotometer that have spectral range 350-700 nm is used as comparison and a halogen lamp as illumination source to cover the spectrophotometer range. The result of reflectance measurements by the developed device was similar to the result by the spectrophotometer, especially for the results of red and orange lights which give coeficient correlation of R2 = 0.9632 adn 0.9119 for red and orange measurement respectively. On the other hand, the green light measurement gave low coeficient correlation of R2= 0.2609. The reflectance measurements of the red light gave range of reflectance at 30%-39%, 39%-49%, 49%-59%, 59%-67% and above 67% for ripening stage 2,3,4,5 and 6 respectively. The reflectance measurements of the orange light gave ranges of reflectance at 35%-45%, 45%- 50%, 50%-58%, 58%-67% and above 67% for ripeness stage 2,3,4,5 and 6 respectively. However, the green light gave result of reflectance ranges at similar range for all ripening stage. That can be concluded that the green light can not be used to measure the ripening stage of banana. In addition, for the ripening stage 7, the developed device gave a very wide range of reflectance due to the appearance of the brown spots randomly on the peel which cause error of the ripeness stage prediction. Therefore, the developed device can not be used to measure ripening stage 7. A test using 71 samples of cavendish banana at ripening stage 2 until 6 gave 55 correct predictions (77%), 11 underripe prediction (16%) and 5 overripe prediction (7%) for the red light measurements and gave 38 correct predictions (54%), 13 underripe prediction (18%) and 20 overripe prediction (28%) for the red light measurements.