Design Of Simplified Optical Devices For The Agrofood Sector: Case Studies From Pre-Harvest To Post-Harvest

The Italian agri-food system is mostly characterized by small and medium-sized enterprises (SME). Due to their size and the small possibility of significant investments in analytical instrumentation, they are characterized by the lack of crucial information for the management and control of their processes. The main parameters related to important information to better lead the decision-making stages of the production process (e.g. decide the harvest time, monitoring fermentations, monitoring shelf life and post-harvest life, etc.) need to be measured in a simple, quick and objective way. From this point of view, the optical techniques based on visible near-infrared spectroscopy (vis/NIR) are an established, simple and rapid application for the analysis of many productions quality related parameters. A number of vis/NIR and NIR optical systems are available on the market. These devices potentially represent a valid support to the various supply chains. Nevertheless, the available optical systems are complex and expensive devices and their real use in SME is still very limited. The aim of the research was to design, build and test concepts and prototypes of low-costs and user-friendly devices useful for different applications from pre-harvest to post-harvest. Tests for the selection of specific wavelengths for the analysis of grapevine leaf water status, for grape and blueberry ripening evaluation, and for senescence monitoring of fresh-cut baby leaf salad during shelf life were conducted. In particular, for the grape ripeness analysis a Light Emitting Diode (LED) based prototype equipped with a customized optical fiber for the measurement of the spectral reflectance at four specific wavelengths (630, 690, 750 and 850 nm) was proposed and tested. The use of these devices could be helpful for a more rational and objective monitoring of the products quality, leading to an optimization of the supply chains to provide a better product to the final consumer.