Our research was aimed at assessing the effect of accumulation of carotenoids, polyphenols, vitamin C and ripening stage in the rosehip fruits of two species—Rosa canina, Rosa rugosa and two cultivar—Rosa rugosa ‘Rubra’ and Rosa rugosa ‘Alba’. The amounts of carotenoids, polyphenols and vitamin C were determined using the high-performance liquid chromatography (HPLC) method. The obtained results showed that the significantly highest amount (107.15 mg 100 g−1) of total carotenoid was determined in the fruits of Rosa canina at ripening Stage V. While results indicated that significant amount of total polyphenols were established at Stages I and II in the Rosa Rugosa ‘Alba’ and Rosa rugosa ‘Rubra’ cultivars (110.34 mg 100 g−1, 107.88 mg 100 g−1 and 103.20 mg 100 g−1 103.39 mg 100 g−1). At ripening Stage I, in the fruits of Rosa rugosa the greatest increases were established in the contents of vitamin C (3036.08 mg 100 g−1).

Carotenoids, polyphenols, and ascorbic acid are valuable and important biologically active compounds that contribute to the health benefits of different foods, and rosehips are known for their high biologically active substance contents. The aim of this research is to identify and compare the contents of carotenoids, polyphenols, and ascorbic acid in the flesh and seeds of different rosehip species grown organically. A field experiment was conducted during the period 2017–2018 on an organic farm in Lithuania. Rose fruits were collected at full ripening in September. The quantitative and qualitative determinations of polyphenols and carotenoids in rosehips flesh and seeds were conducted by HPLC methods. The following polyphenolic compounds were identified: five different flavonoids (rutin, kaempferol-3-O-glucoside, luteolin, quercetin, and quercetin-3-O-glucoside) and five phenolic acids (gallic, chlorogenic, caffeic, p-coumaric, and ferulic) from different rose fruit fleshes and seeds species. In addition, six carotenoids (β-carotene, α-carotene, lutein, zeaxanthin, cis-lycopene, and trans-lycopene) in rosehip flesh and five different carotenoids in rosehip seeds (α-carotene, lutein, zeaxanthin, cis-lycopene, and trans-lycopene) were identified. Overall, the results of this study demonstrate that the highest content of total phenolic acid is in rosehip seeds, while higher concentrations of carotenoids, flavonoids, and ascorbic acid are present in rosehip flesh.

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.

Studies on the mineral content of different rosehip species/cultivars during the ripening period are very limited. Therefore, the objective of this research was to evaluate the content and composition of the mineral elements of two species and two rosehip cultivars growing on an organic farm. The rosehip fruits were harvested at different ripening stages, five time per season. Mineral composition (K, Ca, Mg, P, Fe, Na, Ti, Cu, B, Mn, Al, Zn, Cr, Co, Ni, As, Mo, Cd and Pb) was analyzed by means inductively coupled plasma mass spectrometry (ICP–MS). The results showed that the ripening stage and species/cultivars had an effect on the contents of the mineral elements. Significantly, the highest content of mineral elements was determined at ripening stage I (Ca, Mg, Ti, Mn, Al and Cr) and IV (K, P, Fe, Cu and B). Species of the Rosa canina accumulated the highest content of mineral elements. Correlation analysis showed that the hue angle had a positive and very strong relationship with six mineral elements: K (r = 0.909), Ca (r = 0.962), Mg (r = 0.965), P (r = 0.945), Fe (r = 0.929) and Ti (r = 0.944).

Rosehips of various Rosa spp. are well known for having human health-promoting compounds like mineral nutrients, vitamins, fatty acids, and phenolic compounds. However, little is known about rosehip characteristics which describe the fruit quality and may indicate appropriate harvest times. Our study evaluated the pomological (width, length, and weight of fruits, flesh weight, and seed weight), texture, and CIE colour parameters (L*, a*, and b*), chroma (C), and hue angle (h°) of rosehip fruits of Rosa canina, Rosa rugosa, and genotypes of Rosa rugosa ‘Rubra’ and ‘Alba’, harvested at five ripening stages (I–V). The main results revealed that genotype and ripening stage significantly affected parameters. The significantly longest (R. canina) and widest fruits (R. Rugosa) were measured at ripening stage V. Genotypes of R. rugosa ‘Rubra’ and ‘Alba’ had significantly higher fruit and flesh weights at ripening stage V. Rosehips of all investigated genotypes expressed darkness (lower L*) during ripening, and had the highest hue angle h° values at ripening stage I while the lowest was at stage V. The significantly lowest skin elasticity of rosehips was found at stage V. However, R. canina was distinguished by the highest fruit skin elasticity and strength. As our results show, the desired pomological, colour, and texture features of various species and cultivars rosehips can be optimised according to the harvest time.