Capsaicinoids and Carotenoids in Capsicum annuum L.: optimization of the extraction method, analytical characterization and evaluation of its biological properties

The aim of this study was to determine the capsaicinoid and carotenoid content in different tissues of an Algerian pepper (Capsicum annuum L.) extract and evaluate its biological activity. For the capsaicinoid extraction, the effect of different solvents, temperatures, and time was tested. The optimized extraction conditions (75 % of methanol at 100 °C for 20 min) allowed a satisfactory recovery of both capsaicin and dihydrocapsaicin (89.8 and 83.4 %, respectively). Five capsaicinoids were identified and quantified in fresh and dried tissues by liquid chromatography coupled to photodiode array and mass spectrometry detection. Among the identified carotenoids, lutein was the main compound (54.4 % of total carotenoids) followed by zeaxanthin and β-carotene, and in total, a number of six was here identified and reported for the first time. The antioxidant activity of carotenoids was higher than capsaicinoids, thus explaining its good anticancer activity (90 % of U937 inhibited at 200 μg/mL). The capsaicinoid extract was active against pathogen bacteria except Klebsiella pneumoniae and inactive against two beneficial bacteria Lactobacillus rhamnosus and Bifidobacterium longum. The results of this study show that this variety may be considered a viable source of such compounds with antioxidant and antimicrobial activity useful for functional food production.