The Aquaphotomics Approach as a Tool for Studying the Influence of Food Coating Materials on Cheese and Winter Melon Samples

Food packaging and coatings have the well-known and established functions of containment, protection and handling facilitation of the food packaged inside. Fast methods able to classify, sort and identify the quality and the stability characteristics associated with the various packaging and coating materials are required along the food chain in order to validate their properties. Innovative products deriving from organic polymers, recently submitted for Italian patent (no. 102015000018950), were used as coatings both in the food industry for two types of cheese (provola and caciotta) and in postharvest management to modulate fruit ripening of winter melons during storage at 13°C. This work aimed at studying the effect of the differences in performance and permeability properties of the coatings after their application and during the ripening and storage period by using near infrared spectroscopy and exploiting the aquaphotomics approach, where information on the absorption bands can provide a distinct knowledge of water vibrations and intrinsic interactions between water and other components of the aqueous system. Applying multivariate spectral analysis, it was found that changes of water matrix under perturbation reflect other molecules surrounded by water, allowing the identification of specific fingerprints associated with coating characteristics and with the ripening/storage trends. Each coating generated a specific fingerprint for the same product suggesting that aquagrams could be a useful and fast procedure able to distinguish the effects of different coating materials on the same matrices. It was also proved that starting from similar aquagrams it was possible to follow and monitor the storage trends.