Phytochemicals in native Peruvian Capsicum pubescens (Rocoto)

Abstract

Peru is considered a hotspot with maybe the highest diversity of domesticated chili peppers. Capsicum pubescens is the least explored domesticated chili pepper, especially with regard to its chemical composition. Thirty-two different C. pubescens (Rocoto) accessions, out of the national Peruvian Capsicum germplasm collection at the Instituto Nacional de Innovación Agraria, were selected for investigating the phytochemical content and its variability. After drying and milling, the fruits were analyzed for the three major capsaicinoids (capsaicin, dihydrocapsaicin and nordihydrocapsaicin), flavonoid aglycons (quercetin, kaempferol, luteolin, apigenin), total polyphenol content, antioxidant capacity, tocopherol (α-, β- and γ-) content, fat content, ascorbic acid content, surface color and extractable color. The concentrations for selected traits ranged as follows: total capsaicinoids from 55 to 410 mg/100 g (corresponding to ca. 8400–60,000 SHU), total polyphenols from 1.8 to 2.5 g gallic acid equivalents/100 g, antioxidant capacity from 2.4 to 4.6 mmol Trolox/100 g and tocopherols from 6.8 to 18.4 mg/100 g. Only very few of the accessions contained detectable amounts of the major chili flavonoid quercetin. The results indicate that C. pubescens is generally less diverse and exhibits a lower content of almost all analyzed traits when compared to 147 Peruvian chili pepper accessions belonging to the other four domesticated species.