Optical Probe for Precision Fruits (ARD/303)

The fruit industry is a major industry in many countries, including China. Fruit quality detection is needed during pre- and post-harvest to deliver high grade produce to the market. High quality produce increases market competitiveness and profits. Thus, there is a high demand for low-cost portable sensing device for fruit sorting and grading. Moreover, nondestructive measuring methods are preferred over that of destructive ones. Destructive methods are time consuming, involving multi-steps such as fruit selection and juicing; requiring multiple instruments, such as refractometer and weighing balance. Another drawback for the current devices is that they cannot probe small fruits such as berries. Nondestructive optical devices available in the market are mainly based on detection and analysis of near infrared signals below 1000nm, which gives a reasonable reading of brix level. However, for modern precision fruits sensing, further improvement in sensitivity is required, therefore, optical instrument covering extra bandwidth is needed. In this project, a nondestructive portable brix meter is to be developed using chip based NIR detector, plus an extra channel at 1450nm using LED based emitter/detector. In order to sense object of size <15mm, fiber optics sensor is used to reduce the size of the probing head.