Four cultivars (Bronowicka Ostra, Cyklon, Tornado, and Tajfun) of pepper fruit Capsicum annuum L. were studied for phenolics contents and antioxidant activity. Two fractions of phenolics, flavonoids (with phenolic acids) and capsaicinoids, were isolated from the pericarp of pepper fruit at two growth stages (green and red) and were studied for their antioxidant capacity. Both fractions from red fruits had higher activities than those from green fruits. A comparison of the capsaicinoid fraction with the flavonoid and phenolic acid fraction from red fruit with respect to their antioxidant activity gave similar results. Phenolic compounds were separated and quantified by LC and HPLC. Contents of nine compounds were determined in the flavonoid and phenolic acid fraction: trans-p-feruloyl-beta-d-glucopyranoside, trans-p-sinapoyl-beta-d-glucopyranoside, quercetin 3-O-alpha-l-rhamnopyranoside-7-O-beta-d-glucopyranoside, trans-p-ferulyl alcohol-4-O-[6-(2-methyl-3-hydroxypropionyl] glucopyranoside, luteolin 6-C-beta-d-glucopyranoside-8-C-alpha-l-arabinopyranoside, apigenin 6-C-beta-d-glucopyranoside-8-C-alpha-l-arabinopyranoside, lutoeolin 7-O-[2-(beta-d-apiofuranosyl)-beta-d-glucopyranoside], quercetin 3-O-alpha-l-rhamnopyranoside, and luteolin 7-O-[2-(beta-d-apiofuranosyl)-4-(beta-d-glucopyranosyl)-6-malonyl]-beta-d-glucopyranoside. The main compounds of this fraction isolated from red pepper were sinapoyl and feruloyl glycosides, and the main compound from green pepper was quercetin-3-O-l-rhamnoside. Capsaicin and dihydrocapsaicin were the main components of the capsaicinoid fraction. A high correlation was found between the content of these compounds and the antioxidant activity of both fractions. Their antioxidant activities were elucidated by heat-induced oxidation in the beta-carotene-linoleic acid system and the antiradical activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) decoloration test. The highest antioxidant activity in the beta-carotene-linoleic acid system was found for trans-p-sinapoyl-beta-d-glucopyranoside, which was lower than the activity of free sinapic acid. Quercetin 3-O-alpha-l-rhamnopyranoside had the highest antiradical activity in the DPPH system, which was comparable to the activity of quercetin. The activities of capsaicin and dihydrocapsaicin were similar to that of trans-p-feruloyl-beta-d-glucopyranoside in the DPPH model system.

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A b s t r a c tThe aim of the present investigations was to determine the cumulative effect of foliar treatment of lettuce plants with a CaCl 2 solution and the cold-storage period on the level of chlorophylls in the leaves of lettuce cv. Some plants were analysed immediately after the harvest; other specimens were cold-stored at a temperature of 4 o C for 7 and 14 days. Whole leaves and blades without the midrib were analysed. The results obtained indicated that the foliar application of 0.2M CaCl 2 in lettuce resulted in a decrease in the level of chlorophylls in fresh plants, compared with the control. A beneficial cumulative effect of the CaCl 2 application and storage period on the chlorophyll level in lettuce leaves was observed in the leaf blades of plants after foliar treatment with the 0.1M CaCl 2. solution and cold-stored for 7 and 14 days, in which increased levels of chlorophyll "a" and "b" and total chlorophyll, compared with the control, were found.

Luteina, zeaksantyna i β-karoten są związkami o właściwościach prozdrowotnych. Przedmiotem badań była ocena wybranych odmian dyni Cucurbita maxima D: 'Amazonki', 'Justynki', 'Ambar' i 'Otylii F1' pod względem zawartości wymienionych karotenoidów w próbkach liofilizowanych. Zawartość karotenoidów analizowano z wykorzystaniem HPLC-DAD. Stwierdzono, że liofilizowane owoce badanych odmian dyni są dobrym źródłem luteiny, zeaksantyny i β-karotenu. Dużą zawartość luteiny oznaczono w 1g liofilizatów otrzymanych z owoców odmiany 'Justynka' (0,186 mg) i 'Amazonka' (0,118 mg), podczas gdy najmniej luteiny było w liofilizatach z dyni odmiany 'Ambar', charakteryzujących się najwyższym poziomem β-karotenu (0,411 mg). Najmniejszą zawartością β-karotenu cechowały się liofilizaty otrzymane z owoców odmiany 'Otylia F1'. Stwierdzono, że liofilizaty z owoców dyni Cucurbita maxima D. odmiany 'Justynka', 'Amazonka' i 'Ambar' są bogate w naturalne karotenoidy i mogą być szeroko wykorzystywane w przemyśle spożywczym jako źródło bioaktywnych prozdrowotnych związków fitochemicznych.

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