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This paper presents for the first time the results of investigations concerning the effect of treatment of whole pepper fruits with gaseous ozone and the refrigeration storage period conditions on pepper quality. The effects are reflected in changes in the flavonoid contents, the antioxidant activity of the phenolic compound fraction and the enzymes involved in phenylpropanoid metabolism. The investigations were carried out on a hot pepper fruit cultivar, Cyklon. It was found that the levels of a majority of flavonoids, in particular those of quercetin 3- O -rhamnoside and quercetin 3- O -rhamnoside-7- O- glucoside increased in the pericarp of fruits treated with ozone for 3 h and stored for 20 days (by 25% relative to the control). Simultaneously, reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activity were noted, which implies slight degradation of enzymes caused by the ozone treatment and enhancement of the polyphenol oxidase and guaiacol oxidase activity involved in response to increased oxidative stress. [ABSTRACT FROM AUTHOR]

Three flavonoid C-glycosides isolated from pepper fruit ( Capsicum annuum L.), var. Capel Hot (luteolin 6- C-glucoside, luteolin 6,8-di- C-glucoside and apigenin 6- C-glucoside-8- C-arabinoside), were investigated to determine their antioxidant activity and lipophilicity. The antioxidant activity was evaluated using in vitro methods to generate free radicals in hydrophilic (superoxide radical) and lipophilic (2,2-diphenyl-1-picrylhydrazyl (DPPH) and peroxide radicals) media. Parameters characterising the lipophilicity (log P) of the studied compounds were calculated using three commonly available software programs. The relationships between the calculated log P of the investigated compounds and the experimentally determined antioxidant activities are discussed. The chemical activity of the flavonoid C-glycosides and aglycones was variable depending on the type of assay used. Luteolin and its C-6 glucoside showed the greatest ability to scavenge superoxide radicals (generated in the enzymatic and non-enzymatic systems) and DPPH radicals and also had the strongest activity in inhibiting xanthine oxidase activity, followed by apigenin- C-glycoside and apigenin. A high positive correlation coefficient was found between the ability of tested C-glycosides to inhibit xanthine oxidase and the calculated log P values. The highest correlation coefficient was obtained for the ACD/log P (Advanced Chemistry Development, Inc.) method ( R = 0.790). In contrast, negative correlations were obtained between the abilities to scavenge superoxide, DPPH and lipid peroxyl radicals. The highest negative correlation coefficient was obtained in a β-carotene/linoleic acid model system and the Ghose-Crippen method ( R = −0.725). [ABSTRACT FROM AUTHOR]

Highlights: [•] Lyophilized pericarps of four pepper cultivars are rich source of flavonoid O-glycosides. [•] Ferulic acid derivatives dominate in fresh and freeze drying placenta of pepper fruit. [•] Antiradical activities correlate well with phenolic acid derivatives in pericarp. [•] The highest level of O- and C-glycosides are in pericarp of cv. Red Knight. [•] Fresh and lyophilized fruits of cv. Red Knight may be used in functional food production. [Copyright &y& Elsevier]

Background. The aim of this study was to isolate phenolic compounds fraction (PCF) from hot pepper and to characterise their composition and antiradical activity. Material and methods. PCF was isolated from hot pepper fruits by solid phase extraction technique and separated by medium pressure liquid chromatography on Büchi system. HPLC quantitative analysis of subfractions constituents and of standards was made on Empower-Pro chromatograph (Waters) with DAD detection. Total phenolics content was assessed by Folin-Ciocalteu method. Antioxidant activity was measured according to superoxide radical, generated in NADH/PMS model and DPPH radical. Results. The separation yielded three subfractions with different composition. In fraction 1, the predominant component was quercetin 3-O-rhamnoside-7-O-glucoside. The presence of luteolin 7-O-apiosyl-glucoside was observed in fraction 2, and the key component of fraction 3 was quercetin 3-O-rhamnoside. The highest antioxidant activity was noted for fraction 2, both in reducing superoxide radicals (IC50 = 97 μg⋅cm-3) and DPPH• (IC50 = 43 μg⋅cm-3). Conclusion. Pepper fruits are a rich source of phenolic compounds with a considerable lipophilicity and different chemical activity. They can be used as supplements to enhance food products. [ABSTRACT FROM AUTHOR]

Ethanol extracts of two types of pepper (sweet and hot) were separated into fractions with increasing lipophilicity. After drying the extracts and fractions, their chemical composition, anti-radical activity in the DPPH radical system, and cytotoxic activity against PC-3 and HTC-116 cells were determined. A detailed qualitative analysis of the fractions was performed with the LC-QTOF-MS method. It was found that the chemical composition of pepper fractions did not always reflect their biological activity. The highest antiradical activity was detected in the fraction eluted with 40% methanol from sweet pepper. The highest total content of phenolic compounds was found in an analogous fraction from hot pepper, and this fraction showed the strongest cytotoxic effect on the PC-3 tumour line. The LC-MS analysis identified 53 compounds, six of which were present only in sweet pepper and four only in hot pepper. The unique chemical composition of the extracts was found to modulate their biological activity, which can only be verified experimentally. [ABSTRACT FROM AUTHOR]

This study aimed to determine the health-promoting properties of sweet pepper by comparing the activity of fractions with variable lipophilicity. Fractions from red pericarp: aqueous (F1), 40% MeOH (F2), and 70% MeOH (F3) were analyzed for antiradical activity (with DPPH• and ABTS+•), and the contents of total phenolic compounds (TP), flavonoids (TF), and dihydroxycinnamic acids (TDHCA). The anticancer potential of the fractions was evaluated in vitro using different cancer cell lines: human colorectal carcinoma (HCT116) and PC-3 (prostate cancer cell). Fibroblast-like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. The highest content of TP, TF, and TDHCA along with the strongest antiradical activity was observed for fraction F2, while the strongest anticancer properties against PC-3 were observed in fraction F3. Fraction F3 primarily contained capsianoside derivatives, which had been isolated through chromatographic methods and identified by spectral methods. These analyses helped in identifying 8 compounds, including 3 new compounds. [ABSTRACT FROM AUTHOR]

The effect of treatment of pepper fruits with gaseous ozone and storage time following the ozonation process on changes in the content of lipophilic fraction is analyzed for the first time in this paper. The aim of the present study was to assess the impact of ozone treatment on the composition of lipophilic compound fraction and its antioxidant activity (AA). Pepper fruits of cv. Cyklon were ozonated for 1 and 3 h immediately after harvesting. Then, the fruits were stored for 30 days under refrigeration conditions. The total content of phenolic compounds and the AA of the lipophilic fraction isolated from the pericarp and placenta of the fruits were investigated after 10, 20, and 30 days of storage. Additionally, quantitative high-performance liquid chromatography diode array detection analysis of individual phenolic compounds was performed. The results revealed that the content and activity of secondary metabolites varied during storage, with the highest values recorded on the 20th day after harvest, both in control and ozonated fruits, regardless of the ozone dosage used. Treatment of the fruits with ozone for 3 h, but not for 1 h, exhibited a positive effect on the phenolic composition and AA during the prolonged storage of pepper fruits. Three hours of ozonation seems to be the appropriate time to increase the persistence of pepper fruits during storage. [ABSTRACT FROM AUTHOR]