Krill Lecithin as Surfactant for Preparation of Oil/Water Nanoemulsions as Curcumin Carriers

Abstract

Curcumin is a component in Curcuma longa L. with documented bioactive properties but has low bioavailability. To overcome this problem, curcumin nanoemulsions are prepared employing omega-3-rich phospholipids from krill oil as a surfactant and serve as curcumin carrying systems. The phospholipids are obtained through aqueous (LAD) and ethanolic (LED) degumming processes. The data obtained shows that LAD has a recovery of 70.7 ± 0.51% (w/w) phospholipids, being more efficient than LED with 45.97 ± 1.27% (w/w). Also, a higher content of omega-3 fatty acids is found in LAD with 36 ± 2.14% (w/w). From the critical micellar concentration (CMC) as an assessment of emulsifying capability, it is found that the krill oil (KO), LAD, and LED has a CMC in the range 0.666-0.700 g L −1 . Two formulations with different surfactant levels are developed: experiment A with 9.5% and experiment B with 4.75% (w/w) of krill lecithin are obtained by aqueous degumming. In the formulation of nanoemulsions average particle sizes of 139 ± 2.5 and 142 ± 5.3 nm are produced for experiments A and B, respectively. These results indicate that krill lecithin is an omega-3 rich good surfactant which can be employed to encapsulate curcumin. Practical applications: An interest has emerged in the food industry to develop surfactants with nutritional value. Phospholipids are natural emulsifiers that are widely used to form nanoemulsions because of their elevated interfacial activity. Krill oil has been reported to be an important source of phospholipids and omega-3 fatty acids, which are mainly esterified to phospholipid moieties. Because of these properties, krill oil phospholipids could form micelles and function as carrier systems for bioactive compounds, thus increasing their permeability in the intestine. Consequently, the present work focused on obtaining a nanostructure using a natural surfactant that possesses fatty acids with nutritional value such as omega-3 fatty acids. This will provide an added value to the product obtained, as well as improve the bioavailability of non-polar bioactive compounds. The results obtained could justify the use of krill oil as a useful functional food additive.