Online postharvest assessment of quality in spinach plants using near-infrared spectroscopy
Dry matter (DM) and soluble solid content (SSC) are important attributes to assess the quality and freshness in spinach plants. Currently, these parameters are evaluated using time-consuming and destructive methods. However, over recent years there has been an increasing interest from the vegetable processing industry to incorporate near infrared (NIR) spectroscopy as a non-destructive analytical technology to assess and classify vegetables by quality, which makes it necessary to simulate the working conditions of the industrial processes. The main challenge of this work was to optimize the NIR measurement process and to develop robust and accurate models by means of multivariate analysis strategies for the prediction of DM and SSC in spinaches. For this purpose, 128 spinach plants grown in open-air fields in the provinces of Cordoba and Seville (Spain) were online scanned in reflectance mode, using a fourier transform (FT)-NIR instrument (Matrix-F), working in the spectral range of 834-2,502.40 nm, equipped with a conveyor belt for the movement of the sample. For the construction of the calibration models for the parameters previously cited, modified partial least squares (MPLS) regression and various spectral signal pretreatments were tested. The results obtained showed that NIRS technology has a great potential for the rapid, accurate and non-destructive online determination of DM and SSC in the industry, with a view to guarantee the quality of the processed vegetables.
Torres, I., Pérez-Marín, D., Entrenas, J.A. and Sánchez, M.T. (2021). Online postharvest assessment of quality in spinach plants using near-infrared spectroscopy. Acta Hortic. 1311, 157-162
spinach plants, dry matter, soluble solid content, NIR instrument, online analysis