Food Process Safety Investigated Through NIR Water Absorption Variations

This paper aimed to study the Aquaphotomics application, as NIR water absorption variations, to monitor and address food dehydration processes for food safety and preservation. A solar drying micro-system with a fan always active at the bottom was used. Two matrices were tested: eggplant and apple slices. The water activity (aw) content was determined at the end of the drying process. The NIR spectra were collected in reflectance mode from 900 to 1600 nm using a MicroNIR 1700 (VIAVI Solutions, Italy). The pre-treated and averaged absorbance spectra were displayed on radial axes defined by the activated water absorbance bands. PCA, and MBM (Moving Block Model) were then built up. Some critical points were identified: a) the positioning and the isolation of the NIR probe; b) the working temperature; c) the sample size; d) the identification of the process end. The applicability of Aquaphotomics for the continuous monitoring of food drying processes using an adequate NIR probe can be a good opportunity to understand product safety better. Aquagrams can help to identify the actual endpoint of the process. The PCA loadings confirmed the critical contribution of the water absorption independently from the food matrix. The selection of few wavelengths to study food processes and quality can optimise the transfer of instrumental data to IT platforms and networks. Further investigations are in progress to check the possibility of transfer the obtained results on a pilot scale for future applicability of these applications.