Non-destructive Measurement Of Soluble Solids Of Apple Using Near-infrared Spectroscopy

摘要

One-hundred apples were chosen, using the method of partial least squares (PLS). In this study the potential of visible and near-infrared reflectance & transmission spectroscopy as non-destructive measurement technique for measuring quality characteristics of apples is evaluated. The results of experiment are: Thirty samples are used to found model between reflectance spectrums and the soluble solids in apples' surface, obtain a validation correlative coefficient (R) of 0.99695, and the standard error of calibration (SEC) value is 0.0903; the other seventy samples are used to predict, the validation R of value is 0.97642, and the standard error of prediction (SEP) value is 0.287. Choosing forty samples from one hundred apples, thirty samples are used to found model between reflectance spectrums and the soluble solids in apples, obtain a validation R of 0.98541, and the SEC value is 0.171; the other ten samples are used to predict, the validation R of 0.98747, and the SEP value is 0.322. So, Near-infrared Spectroscopy (NIRS) is able to reach the soluble solids in apples' surface & apples demanded in practice. However, the same forty samples, thirty samples are used to found model between transmission spectrums and the soluble solids in apples, obtain a validation R of 0.78690, and the SEC value is 0.619; the other ten samples are used to predict, the validation R of 0.81326, and the SEP value is 1.804. The transmission results is unreasonable, the possible cause is the lower precision of apparatus, so, the transmission experiment is going on.