Antioxidant Profile of Pepper (Capsicum annuum L.) Fruits Containing Diverse Levels of Capsaicinoids

Abstract

Capsicum is the genus where a number of species and varieties have pungent features due to the exclusive content of capsaicinoids such as capsaicin and dihydrocapsaicin. In this work, the main enzymatic and non-enzymatic systems in pepper fruits from four varieties with different pungent capacity have been investigated at two ripening stages. Thus, a sweet pepper variety (Melchor) from California-type fruits and three autochthonous Spanish varieties which have different pungency levels were used, including Piquillo, Padrón and Alegría riojana. The capsaicinoids contents were determined in the pericarp and placenta from fruits, showing that these phenyl-propanoids were mainly localized in placenta. The activity profiles of catalase, total and isoenzymatic superoxide dismutase (SOD), the enzymes of the ascorbate–glutathione cycle (AGC) and four NADP-dehydrogenases indicate that some interaction with capsaicinoid metabolism seems to occur. Among the results obtained on enzymatic antioxidants, the role of Fe-SOD and the glutathione reductase from the AGC is highlighted. Additionally, it was found that ascorbate and glutathione contents were higher in those pepper fruits which displayed the greater contents of capsaicinoids. Taken together, all these data indicate that antioxidants may contribute to preserve capsaicinoids metabolism to maintain their functionality in a framework where NADPH is perhaps playing an essential role.

Bioactive Compounds and Antioxidant Capacity of Valencian Pepper Landraces

“…These values are similar to others reported in studies conducted in commercial sweet pepper and chili cultivars [56,57] and other traditional pepper ecotypes [30]. Higher values have also been recorded by Osuna-García et al [58] and Palma et al [59] in their studies carried out in sweet pepper and chili varieties, and also by Antonius et al [26], Orobiyi et al [60], and Ribes-Moya et al [4] in traditional landraces, especially red fruit.…”

“…The relation between ascorbic acid and fruit ripening, particularly the increment of this nutraceutical compound in fresh peppers as fruit advanced, has been previously described in commercial cultivars [ 32 , 33 , 34 , 36 , 58 , 63 , 64 ]. Palma et al [ 59 ] did not find any differences in ascorbate concentration upon maturity in Melchor and Piquillo varieties, but they did in Padrón and Alegría. These authors pointed out a likely stabilizing role of ascorbate to assure capsaicinoids levels when oxidized by peroxidases during maturity.…”

Identification of Compounds with Potential Therapeutic Uses from Sweet Pepper (<em>Capsicum annuum</em> L.) Fruits and Their Modulation by Nitric Oxide (NO)

“…Peppers are a good source of antioxidants vitamin C (ascorbic acid, ascorbate), vitamin A (-carotene as a precursor) and diverse minerals. As a matter of fact, 50-80 g of pepper fruits are sufficient to provide 100% and 25% of the recommended dietary allowance (RDA) of vitamin C and A, respectively [6][7][8][9][10][11][12][13][14]. Vitamin C, which might be considered as the paradigm of the low molecular weight antioxidants, is essential in animals and humans since it participates in many metabolic pathways and in the prevention of a number of pathologies [12][13][14][15][16][17][18].…”

“…Capsaicinoids are secondary metabolites produced exclusively by the Capsicum genus, responsible for the pungency of hot pepper fruits [7,13,29]. This is a family of about 23 compounds where capsaicin and dihydrocapsaicin are the two main chemicals accounting for about 95% of total capsaicinoids [6,13,30].…”

Evaluation of Pseudomonas stutzeri and Bacillus subtilis Strains for Plant Growth Promotion Potential on Capsicum annuum L.

“…Besides this chilli contains a significant level of health promoting substance like carotenoids, flavonoids and polyphenols. Chilli is a significant source of income for many farmers in agro-industrial area (Palma et al, 2020).…”