To make the detection of moisture content and color change in jujube slices more convenient and without interrupting the drying process, a real‐time detection system was established. An algorithm of wave data filtering and a real‐time moisture content detection program was designed using VISA module of virtual instrument. The key technology of image processing was studied, concluding image acquisition, storage, reading, grayscale, enhancement, morphological operation, restoration, and the conversion algorithm to obtain the value of lightness (L*), redness (a*), yellowness (b*). The jujube slices drying experiment was done, the average relative error of moisture content and the value of L*, a*, b* between the system and manual detection was 1.4%, 1.7%, 6.3%, 3.9%, respectively. The work provides useful references on real‐time nor‐destructive quality inspection and macro‐control in the agricultural products drying process.
Practical applications
In this study, we established a real‐time detection system of moisture content and color change during drying process. The filter algorithm of moisture content detection has been studied, the automatic system can detection the moisture content of the jujube slices effectively. The image processing procedures have been studied and the real time detection system can provide useful data of the color change to forecast and control the drying process of the jujube slices which may be interest to the food preservation industry.