Evaluation of physico-mechanical properties of Rosehip (Rosa canina L.) fruits

Rosehip (Rosa canina L.) is a widely distributed wild fruit species in Türkiye that is increasingly important for food, pharmaceutical, and industrial applications. While many studies have examined its chemical composition and nutritional value, information on its physical and mechanical properties relevant to harvesting, handling, and processing remains limited. Thus, the objective of this study was to evaluate the physico-mechanical properties of rosehip fruits collected from natural populations in Isparta Province. The physical and mechanical characteristics were determined: fruit dimensions, mass, projected area, moisture content, fruit-to-seed ratio, flesh thickness, firmness, friction coefficient, angle of repose, color parameters, and mechanical behavior under detachment and puncture loading. All measurements were performed on 50 randomly selected fruit samples. The moisture content of the fruits and seeds was measured using the oven-drying method at 105 °C. The mechanical properties were evaluated using detachment, puncture, and firmness tests. The flow properties were characterized by determining the friction behavior and angle of repose. The average moisture content of fruits and seeds (wet basis, w.b.)  was 32.46% and 18.90%, respectively, and the fruit-seed ratio was 58.75% fruit and 41.25% seed. Mean detachment and puncture forces were 8.19 N and 2.84 N, respectively. The angle of repose (12.3°) and friction coefficient values indicated favorable flow behavior, while color measurements showed moderate brightness with predominant red (a*) and yellow (b*) components. Overall, the results provide baseline engineering data that can support the design and optimization of harvesting, handling, and processing systems for rosehip fruits.