Influence of Controlled Moisture Levels on the Dimensional, Gravimetric, Frictional, and Mechanical Characteristics of Grape (Vitis vinifera L.) Seeds for Optimized Processing and Storage: An Attempt Towards Circular Economy

This study evaluates the effects of varying moisture levels on the physicochemical, dimensional, gravimetric, frictional, and mechanical properties of grape seeds, essential for optimizing processing and handling. Results revealed that seed dimensions, including length, width, and thickness, significantly (P<0.05) expanded by 4.55%, 5.37%, and 5.47%, respectively, as moisture increased. Mean diameters (arithmetic and geometric), sphericity, and volumetric properties such as volume and surface area also increased, indicating structural changes in response to moisture. The volumetric expansion coefficient rose accordingly, the aspect ratio remained stable, while the elongation ratio decreased slightly. As moisture content increased, rupture force, deformation at the rupture point, energy absorption at the rupture point, hardness, and toughness of grape seeds decreased significantly (P<0.05). Understanding the connection between hardness and moisture content, as well as loading in the processing of grape seed, could be crucial to energy conservation. Furthermore, the nutritional composition analysis revealed that grape seeds contain 8.74% ± 0.21 moisture, 12.03% ± 0.11 crude protein, 19.27% ± 0.19 fat, 3.02% ± 0.05 ash, and 42.66% ± 0.25 total carbohydrates. These findings will contribute to a better understanding of how moisture affects grape seed properties, which could apprise strategies for optimizing processing and handling.