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BACKGROUND The genus Rosa comprises economically important horticultural plants belonging to the family Rosaceae. Recently, the use of different Rosa species has increased owing to their multipurpose properties (ornamental, food and medicinal uses). In this study, 21 accessions of Rosa genotypes were compared for fruit phytochemical composition and color parameters. RESULTS The highest antioxidant activity (37.86 mg AAE g−1 FW) and total phenolic (8.17 mg GAE g−1 FW), total flavonoid (2.53 mg QUE g−1 FW), total carotenoid (20.21 mg g−1 FW) and ascorbic acid (84.27 mg g−1 FW) contents were observed in G20 (R. canina), G8 (R. canina), G9 (R. canina), G5 (R. damascena) and G10 (R. moschata) respectively. Chlorogenic acid and gallic acid were found as the main phenolic constituents of Rosa fruits. High amounts of apigenin, rutin, quercetin, p‐coumaric acid, cinnamic acid, chlorogenic acid, caffeic acid and gallic acid were obtained in fruit extracts of G6, G14, G6, G8, G19, G9, G19 and G12 respectively. Moreover, the level of color parameters also varied among genotypes. The highest values of a*, b*, L* and chroma were obtained in G4 (R. canina). Based on hierarchical clustering analysis with heat‐map, five groups of accessions were identified. CONCLUSION Different Rosa genotypes are rich in certain phytochemical compounds, with significant variations in their levels being observed. Hence evaluation of Rosa genetic resources can supply valuable data for screening accessions containing high levels of individual phenolics, antioxidants and other bioactive compounds for use in breeding programs and food and pharma industries. © 2019 Society of Chemical Industry

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Flavor is one of the most important quality properties of cacao beans, playing a key role in the admissibility of cocoa products, such as cocoa powder. This study examined the industrial processes influencing the flavor of cacao beans. The Ivory Coast cacao beans were used after their alkaline treatment with potassium carbonate (up to pH 7.5–8) and being roasted at 115–120°C for 60–70 min. The volatile components were extracted using Likens–Nickerson simultaneous distillation–extraction (SDE) apparatus. The volatile compound profiles were identified by means of gas chromatography–mass spectrometry (GC–MS), as a result of which several compounds (alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines) were recognized. Alkalization and roasting were shown to be two important steps in the cacao beans processing that can affect the final cocoa powder flavor. In addition, pyrazines and esters were two major groups of flavor compounds formed during the roasting stage by the Maillard reaction. The percentage of 2,3,5,6‐tetramethylpyrazine was detected in the cacao beans equal to 0.5%. After the liquor pressing stage, tetramethylpyrazine increased to its highest amount (3%) in cocoa powder. It was found that the cocoa powder contained 2.69% of tetramethylpyrazine, 3.22% isobutyl benzoate, and 1.38% linalool. The highest percentage of increase in the mean amounts of 2,3,5,6‐tetramethylpyrazine, isobutyl benzoate, and linalool were observed in the roasting stage, after which the percentages diminished.

A new triiodide ion‐selective PVC membrane sensor based on diprotonated ketoconazole‐triiodide, as (KCH2)(I3)2, ion pair, was proposed. The electrode has a linear dynamic range between 2.0×10−3 and 7.0×10−6 M with a Nernstian slope of −59.9±1.6 mV per decade and a detection limit of 3.0×10−6 M. The potentiometric response is independent of the pH of the solution in the pH range 2–8.5. The electrode can be used for at least 3 months without any considerable divergence in potential. It was applied as indicator electrode in potentiometric titration of ascorbic acid, hydroquinone from pharmaceutical preparations and triiodide ions in solution. The proposed triiodide membrane sensor was also used in development of a new, simple, fast, inexpensive and precise method for the determination of Ketoconazole in formulations.