In this study, the nutritional composition and phytochemical composition of the rosehip seed, and the fatty acid and sterol compositions of the seed oil were investigated. The rosehip seed contained valuable phytochemicals such as phenolic compounds (2554 μg/g), carotenoids (2.92 μg/g), and ascorbic acid (1798 μg/g). Furthermore, the rosehip-seed oil was rich in polyunsaturated fatty acids, linoleic acid (54.05%), linolenic acid (19.37%), and phytosterols, mainly β-sitosterol (82.1%). The rosehip seed and seed oil were found to have antioxidant activity measured by trolox equivalent antioxidant capacity assay. It can be concluded that the rosehip seed and seed oil may be utilized as a source of phytonutrients.

This study presents a combined approach of establishing cultivar differences between Aegean olive oils, obtained from economically important olive oil producing cultivars (cv. Ayvalik and Memecik), based on chemometric evaluation of their content and in particular composition of the minor compounds. Evaluation of minor compounds with principal component analysis and linear discriminant analysis (LDA) indicated differentiation according to the cultivars. LDA produced a 100% correct group classification. Moreover, stigmasterol, apparent b-sitosterol and total sterols were found to have the highest discriminating power. Memecik oils were characterized by the highest content of antioxidant compounds (a-tocopherol, phenolic compounds and total phenolic compounds). On the other hand, Ayvalik oil had the highest level of total sterols. The data were analyzed statistically to evaluate the differences according to variety and crop season. The minor compounds of Ayvalik and Memecik oils presented statistically significant differences (p \ 0.01) according to variety, except for the hydroxytyrosol and clerosterol content. The amount of a-tocopherol, total phenolic compounds, apparent b-sitosterol and total sterols varied with respect to crop season. A good correlation was observed between the amount of a-tocopherol, total phenolic compounds, apparent b-sitosterol and total sterols and some climatic variables.

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The aim of this study was to investigate the effects of brewing conditions (infusion time and temperature) on the antioxidant properties of rosehip tea beverage. The ascorbic acid content, total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) of rosehip tea beverage were analysed. A two-factor and three-level central composite design was applied to evaluate the effects of the variables on the responses. The best quadratic models were obtained for all responses. The generated models were validated under the optimal conditions. At the optimal conditions, the rosehip tea beverage had 3.15 mg 100 mL of ascorbic acid, 61.44 mg 100 mL of TPC, and 2591 µmol of FRAP. The best brewing conditions for the rosehip tea beverage were found to be an infusion time of 6-8 min at temperatures of 84-86 °C.

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