Studies on the determination of the optimal harvest time of rosehips are very limited. Therefore, the aim of this research was to ascertain the effect of the ripening stage on the quality and content of fatty acids of organic rosehip seeds. A two-factor field experiment with two rosehip species and cultivars (Rosa rugosa, Rosa canina, and Rosa rugosa cv. 'Rubra', Rosa rugosa cv. 'Alba') was conducted during two growing seasons (2018-2019) on an organic farm. The fruits were harvested five times per season. The fatty acid composition of rosehip seeds was determined using a Gas Chromatograph with Split/Splitless Injector Liners. The highest amounts of fat were recorded in all rosehip seeds at ripening stage IV. The most dominant fatty acids in the seed samples were polyunsaturated fatty acids (PUFAs) (73.88-79.52%), followed by monounsaturated fatty acids (MUFAs) (14.67-18.89%) and saturated fatty acids (SUFAs) (5.22-7.36%). The highest amount of PUFAs was established in Rosa rugosa cv. 'Alba' seeds harvested at fully ripe stage V. It can be concluded that the rosehip seeds may be utilized as a source of fatty acids, especially PUFAs.
Keywords: linoleic acid; oleic acid; palmitic acid; ripening stage; rosehip seeds.