Characteristics of hemp (Cannabis sativa L.) seed oil extracted with supercritical CO_2

摘要

Hemp cultivation (Cannabis sativa L.) of different cultivars (Felina, Finola, Uso 31, Chamaleon) characterized by a low concentration of δ-9-tetrahydrocannabinol (THC) (<0.2%), has been reintroduced in Carnia (Friuli Venezia Giulia) both for oil and fiber. About 25-35% of the weight of hempseed is an edible oil. Hempseed oil is of high nutritional value because its 3:1 ratio of the two essential polyunsaturated fatty acids (EFAs), especially linoleic acid (C18:2ω6) and linolenic acid (C18:3ω3) which matches the balance required by the human body [1]. These fatty acids are important in relation to the pathogenesis (and prevention) of coronary heart disease and hypertension and during pregnancy and breastfeeding, besides showing a hypocholesterolemic effect when used as food supplements. The oil, because of its EFAs content and the presence of γ-linolenic acid (C18:3ω6), is also ideal as an ingredient for light body oils and lipid-enriched creams known for their high penetration into the skin. Among vegetable oils, hemp seed oil contains one of the highest levels of PUFAs (poly-unsaturated fatty acids)≈80-81%) [2]. Antioxidant property of cold-pressed hemp seed oil has been investigated [3,4] and its effectiveness in inhibiting free radicals resulted higher than olive oil (extra-virgin). Antioxidants are well recognized for their potential in health promotion and prevention of aging-related diseases, including cancer and heart disease. The versatility of the hempseed lends itself to the development of numerous products for food, cosmetic, therapeutic, functional food and nutraceutical industries. Even though there are numerous reports on the SC-CO_2 extraction of oil from various seeds, there is little information on the SC-CO_2 extraction of oil from hempseed. The aim of this work was to establish a preliminary set of supercritical fluid extraction conditions through experimental design to obtain high quality hempseed oil.