Abstract:
Abstract: The equipment structures, data processing methods and research progresses in the agricultural products quality detection of the biospeckle technology were reviewed in this paper. Biospeckle technology was one of the optical non-destructive testing technologies, which was low-cost, fast, real-time and could achieve qualitative/ quantitative measurement. Because the biospeckle activity had the close relationships with the physiological properties of the agricultural products such as the cytoplasmic streaming and organelles size, the physicochemical indicators could be assessed by this technology, including the peel thickness, ripeness, acidity, soluble solid content, starch content, water content and respiratory rate, etc. According to the previous researches, the biospeckle technology was firstly divided into the static and dynamic biospeckle method in this review. The static biospeckle method had been widely used over the past few decades, because the image features could be obtained by simple image processing techniques. Although the image processing speed was fast, the number and accuracy of detectable indicators were limited by the static biospeckle method. In term of dynamic biospeckle method, the video processing speed would hinder the development and extension of this technology, and hence, it could be applied for the point-of-sale quality evaluation at present. The use of advanced hardware such as the high speed camera and improvement of video processing and analysis software might promote the application of dynamic biospeckle method in on-line quality detection. Furthermore, the measuring equipments should be improved to make the laser source more stable, and several suggestions were proposed in this review such as using the polarizers in the light path or choosing different equipment layouts (stereo or planer optical path arrangement) on basis of various tested samples and conditions. In addition, the principle of measurement needs understanding in the molecular level to realize standardization and commercialization. In this respect, the combination use of the biospeckle technology and microscopic technique was suggested to explain the light transmission rules in the agricultural products. It was believed that the understanding of the light transmission rules would improve the detection accuracy. Also, the comparison of fixed and zoom lens used in biospeckle experiments was analyzed qualitatively by biospeckle test platform in our lab, and the obtained result demonstrated that the camera with zoom lens could acquire clearer image and much more information. This review might have benefit for the biospeckle technology development in the agricultural products field.