Valorization of hemp hearts oils by advanced extraction techniques and their comparative physicochemical characterization
Abhiroop Mookerjee, Venu Babu Borugadda, Ajay K. Dalai, Venkatesh Meda
Abstract
Industrial hemp hearts were subjected to three different extraction techniques-advanced extraction techniques like microwave and ultrasound extraction and primitive extraction technique like mechanical cold pressing in order to extract oils. The extraction yield varied between 41.0 ± 2.1% (w/w) and 54.0 ± 2.7% (w/w). Linoleic acid (LA) was reported to be the major polyunsaturated fatty acid (PUFA) followed by α−Linolenic acid (ALA). The ratio of LA to ALA was found to be close to 3:1 which is considered optimal for nutrition. The ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA) was in the range of 6.7 to 9.1. Several minor compounds like ɣ-Sitosterol, stigmasterol, rhodoxanthin, carotene, and methyl cholate as well as antioxidants like β-Carotene and ɣ-Tocopherol have been identified in the oils. The physicochemical properties of the oils like the acid value, iodine value, and oxidative stability indicated that they have higher quality and that the level of unsaturation was very high. Furthermore, free radical scavenging activity of the oils revealed that the oils exhibited 94% of activity in the first 2 h. A perfect combination of unsaturated fatty acids and saturated fatty acids, an appropriate medley of different antioxidants not only qualifies hemp seed oil as an excellent source of nutrition but also as an important plant-based (vegetable) oil for the higher value nutraceutical and pharmaceutical industries.