A laser reflection method to detect strawberry fruit defects

Abstract:This study aims to use the method of laser reflection from the surface of strawberry fruits to classify different strawberry defects to facilitate the process of sorting the fruits during the handling process. The study was conducted on exposing the strawberry fruits (festival variety) by laser radiation with wavelengths of 543.5 and 632.8 nm, after dividing the fruits into six groups according to strawberry defects, to measure the amounts of reflected radiation and generated electricity. The results obtained were the following: a) For the physical and chemical properties of strawberry fruits: It was found that there is no dispersion in (height, width, length, volume, weight, total soluble solids (Brix) and the pH value of the fruits). Their variance values indicate that there is stability of the physical and chemical characteristics in this variety of strawberries., b) The results of the T-test showed that there is a significant difference between the light density reflected or the amount of generating electricity from the surface of standard strawberry fruits and the surface of defective strawberry fruits at every defect (mold, insects, green end, white shoulder, green), in the case of using different levels of the laser beam with a wavelength of 543.5 or 632.8 nm. Then, the amount of reflected radiation or the amount of electrical energy generated can be used to separate the affected fruits from the healthy ones., c) The results of the One Way Anova analysis showed that there was a statistically significant correlation between the light density reflected from strawberry fruits (as a result of using laser beams at 543.5 or 632.8 nm wavelengths) and the amount of electricity generated on the surface of the photovoltaic cells., and d) It’s possible to use laser reflection light or the amount of generating electricity to classify and sort strawberry fruits according its defects