Characterization of cold-pressed oils extracted from seeds of different Capsicum species

The industrial utilization of sweet and hot peppers leaves abundant by-products, including lipid-rich seeds. The most studied pepper for seed oil production is Capsicum annuum, but interest in other species is increasing due to the growing global demand for authentic ethnic foods and spicy processed products. In this research six seed and oil samples obtained by cold mechanical pressing from four Capsicum species (C. annuum, C. baccatum, C. chinense and C. pubescens) were characterised by HPLC, gas chromatography, and Rancimat. The seeds contained 19.8–23.5 g protein, 49.0–55.2 g fiber and 9.2–12.0 g lipid in 100 g dry matter (DM). Cold pressing recovered 43–45% total lipids in oils rich in polyunsaturated fatty acids (67.9–75.6%), mainly linoleic acid. The C. annuum oils contained little capsaicinoids (not detected–10.7 mg/kg oil), while the other three species had abundant capsaicin (440.6–922.2 mg/kg) and dihydrocapsaicin (223.2–1109.7 mg/kg), imparting them pungency (11017–36155 Scoville units). Tocopherols, especially γ-tocopherol, were abundant (632–1181 mg/kg) and the carotenoids (4.4–47.1 mg/kg) gave the oils an appealing deep orange tinge. The low oxidation indices (acid value, peroxide value, p-anisidine, K232 and K268) make them suitable for human consumption. The varieties presented similar oxidative stability indices between 100 °C and 140 °C and the extrapolated shelf-life at 25 °C was 3.2–4.1 months. Capsicum oil is a product with high nutritional value, easily extracted from an abundant and inexpensive food by-product.