Defatted seed residues after the extraction of rose oil have their potential not fully described in the existing literature. The aim of this study was to determine and characterize the components important for the human body that are found in Rosa rugosa defatted seeds, including dietary fibers, proteins, selected minerals, polyphenols and antioxidant activity. Rosa rugosa seeds defatted with CO2 in supercritical conditions are a rich source of dietary fibers (approx. 65%) and proteins (15%); their macronutrients include the following: Ca (175.9), Mg (83.9), K (199.2) and Na (3.5 mg/100 g). They also contain polyphenols, including flavanols (0.9%) and total ellagic acid (0.5%), and they exhibit antioxidant activity (143.8 µM TAEC/g). Tellimagrandin I and II and rugosin A were found in the extracts, and ellagitannins with a yet-indeterminate structure were also present. The seeds also contained ellagitannin derivatives-galloyl-HHDP-glucose and bis-HHDP-glucose-at the same time, and they are characterized by a low-fat content-0.4%. The energy value of defatted rose seeds is about half the energy value of popular seeds used in the food industry. The findings of the present study suggest that defatted rosehip seeds, the by-product of rosehip processing, could be an important source of bioactive components like dietary fibers, flavanols, ellagitannins and mineral compounds. Therefore, defatted rose seeds are very promising and require further research, because they can potentially be used as a natural source of chemopreventive agents.
Keywords: antioxidant activity; dietary fiber; ellagitannins; polyphenols; rosa defatted seeds.