Extraction method impact on the physicochemical characteristics of lipids from chia nutlets applicable to long-term storage studies

Abstract

Lipids are relevant during the seed aging process, for which it is pertinent to choose an extraction method that does not alter their nature. Thus, three methods were applied to extract lipids from chia seeds: one used as reference (Soxhlet) and two at room temperature using hexane/ethanol (COBio) and hexane/isopropanol (COHar). The fatty acid composition and the tocopherol content of the oils were analyzed. Also, their oxidative status through the peroxide index, conjugated dienes and trienes, and malondialdehyde were determined. Besides, biophysical techniques, such as DSC and FT-IR, were applied. The extraction yield was not affected by the extraction method, while the fatty acid composition presented slight differences. Despite the high content of PUFAs, the oxidation level was low in all cases, especially in COBio, associated with the high content of α-tocopherol. DSC and FT-IR outcomes coincided with those obtained by conventional studies, resulting in efficient and fast characterization tools.