Sorting Agricultural Products by New Type of DLE Apparatus

DLE Characteristics of Apple from the Point of Sorting

Abstract

DLE characteristics of Apples were investigated by new type of DLE measurement apparatus to obtain the basic data for automatical evaluation of quality during the sorting procedure, and the following results were obtained.
1. Relation between dark period and DLE intensity was investigated. Maximum DLE intensity was obtained under the dark period beyond 10min (Fig. 4).
2. The highest DLE intensity was obtained with an exciting illumination of 4000lx for 4 to 5sec (Fig. 5).
3. The DLE intensity were saturated with exciting illumination of 2000lx, 1000lx and 500lx for decay period of 0.4 to 0.5sec, 0.7sec and 1.0sec respectively (Fig. 6).
4. DLE intensity of apple was affected by fruit temperature. DLE intensity had peak value at higher temperature under the shorter decay period (Fig. 7).
The exciting conditions for obtaining high and stable DLE intensity were established as follows; Dark period; 10min, Illumination intensity; 4000lx, Exciting time; 5sec, Decay period; 0.5sec.
5. DLE intensity of Apples changed remarkably according to the harvesting maturity. The optimum harvesting time can be determined by measuring DLE (Table 1).
6. Saturation of peel color had a high correlation with DLE intensity of Apples. Evaluation of peel color and maturity of Apples is possible by means of DLE (Fig. 8).
7. Chlorophyll content of Apple peel had a high linearity with the intensity of DLE (Fig. 9).