A considerable research effort is focused on developing effective delivery systems for hydrophobic nutraceuticals. beta-carotene, a pro-vitamin A carotenoid, requires encapsulation to improve its water dispersibility and chemical stability in foods. In this study, beta-carotene was encapsulated in oil-in-water nanoemulsions fabricated using high-pressure dual-channel microfluidization. Two types of natural emulsifier, quillaja saponins (Q-Naturale) and whey protein isolate (WPI), were capable of producing nanoemulsions (d(32) = 0.14-0.16 mu m) using this novel homogenization method. The physical and chemical stability of these nanoemulsions were characterized during storage at neutral pH conditions at refrigeration (4 degrees C), ambient (25 degrees C), and elevated (55 degrees C) temperatures. At 4 and 25 degrees C, all nanoemulsions remained physically stable throughout 14 days storage, with little change in particle size or evidence of creaming. At 55 degrees C, WPI nanoemulsions were also physically stable, but a small amount of droplet aggregation occurred in saponin nanoemulsions. The rate of beta-carotene degradation increased with increasing storage temperature, but did not depend strongly on emulsifier type. This study showed that dual-channel microfluidization is an efficient method of continuously producing carotenoid-loaded nanoemulsions from natural emulsifiers. This knowledge may be useful for developing nutraceutical delivery systems for application within commercial food, beverage, and pharmaceutical products. (C) 2016 Elsevier Inc. All rights reserved.