The sugar content of loquat can be predicted by NIR hyperspectral camera

In this study, a 400-1000nm hyperspectral camera was applied, and FS13, a product of Hangzhou Color Spectrum Technology Co., LTD., could be used for related research. The spectral range is 400-1000nm, the wavelength resolution is better than 2.5nm, and up to 1200 spectral channels can be reached. The acquisition speed can reach 128FPS in the full spectrum, and the maximum after band selection is 3300Hz (support multi-region band selection).

The nutritional value of loquat is rich, the fruit skin is thin and juicy, sweet and sour. Kaiyang, Guizhou province is one of the planting places of loquat, and the soil in Kaiyang is rich in selenium, which makes Kaiyang loquat rich in selenium popular. However, loquat fruit is more delicate, in the process of picking and storage, the quality of the fruit will decline, and the change of sugar content is very obvious. With the respiration of loquat fruit, sugar content will gradually increase, which will lead to poor sweetness and sour degree of fruit, affect the taste and flavor of loquat, and lead to the decrease of its economic value. Although the traditional detection method of fruit sugar content in China has high accuracy, it is destructive, inefficient and time-consuming. However, there is no uniform standard for judging fruit quality by experience, which leads to the randomness of the result and inaccurate quality sorting. Therefore, in the fruit quality sorting, whether it is the traditional detection method or the subjective judgment of personal experience, the fruit quality is uneven, and it is difficult to reflect the competitive advantage of China's fruit market. Kaiyang Loquat is a characteristic fruit in Guizhou province. The quality grading of its fruit can accurately locate its market price and maintain its regional brand status. It can be seen that it is of practical significance to establish a set of rapid and non-destructive sugar content detection method for loquat fruit to monitor its quality and guide the market price.

In order to realize rapid non-destructive detection of fruit quality, grade fruit, and enhance the economic value of fruit, a method based on visible/near-infrared hyperspectroscopy and chemometrics was proposed to predict the sugar content of Kaiyang se-rich loquat. First, spectral data of loquat samples were obtained by hyperspectral camera, and the actual sugar content of loquat samples was measured. Then, the spectral data of the samples were extracted and pre-treated by SNV and MSC. PCR and PLSR models for predicting sugar content of loquat were established based on the original and pre-treated spectra.