The composition, extraction, analysis, bioactivities, bioavailability and applications in food system of flaxseed (Linum usitatissimum L.) oil: A review

Flaxseed (Linum usitatissimum L.) oil is an excellent functional oil containing various unsaturated fatty acids, mainly composed of linolenic acid, which is believed to have a variety of beneficial physiological and functional properties. However, the conversion efficiency of linolenic acid in the human body is low, and the research on flaxseed oil lacks a systematic review and evaluation. This review summarizes the research progress of flaxseed oil in recent years, including the main components, extraction and analysis methods of flaxseed oil; the main biological activities of flaxseed oil and its digestion, absorption, bioavailability and application in food; existing problems, possible solutions and prospects for future research. Flaxseed oil is rich in alpha-linolenic acid (ALA) and other active ingredients, but the stability of ALA and its conversion to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in human body are very low. Improving the stability of ALA can promote its digestion and absorption in the gastrointestinal tract, thereby playing a beneficial role. The establishment of fat emulsion delivery system is an effective way to improve the stability and bioavailability of flaxseed oil. This review could benefit comprehensive understanding the value of flaxseed oil and promote its nutrition research and commercial product development.