Emulsion-based extraction of β-sitosterol and carotenoids from sea buckthorn (Hippophae rhamnoides) pomace

Abstract

In the present work, we investigated oil-in-water (O/W) emulsion-based extraction of β-sitos- terol and carotenoids from sea buckthorn pomace. We compared this new green extraction method with conventional extraction using organic solvents and oils. The objective of the present work was to evaluate the efficiency of these different extraction systems on the yields of bioactive compounds from plant-based materials, and to determine the optimum extraction conditions for maximum extraction yield. Our results indicated that O/W emulsions, prepared without emulsifier using a high-pressure homogeniser, had the highest extraction capability for β-sitosterol and carotenoids, as compared to the other extraction systems. The optimum conditions were 65°C for 1 h extraction, using emulsifier-free soybean O/W emulsions. Under these conditions, the extracted amounts were up to 32.0 mg/g dw (dry weight) for β-sitosterol and 1.44 mg/g dw for total carotenoids. The obtained compounds were relatively stable at 5°Cand 25°C for up to 28 days of storage. This emulsion-based extraction method is promising for the extraction of β-sitosterol and carotenoids that can be further applied into dietary nutritional supplements and fortified food.

Keywords: green extraction method, bioactive compound, triacylglycerol, oil-in-water emulsion, organic solvent, extraction yield