Ultra-stable β-carotene emulsion stabilized by polyglycerol esters

Abstract

Ultra-stable β-carotene emulsion enhances the stability of related products. In this paper, thermally stable β-carotene emulsions were developed by adjusting the types and proportions of polyglycerol esters (PGEs). The phase separation of the emulsion could be strongly inhibited by compounding polyglycerol-10 laurate (10-1-L, high hydrophile-lipophile balance (HLB) value, 14.7) and polyglycerol-10 decaoleate (10-10-O, low HLB value, 3.3). Importantly, the thermal stability of the prepared emulsion could be enhanced by adding polyglycerol-10 myristate (10-1-M, high HLB value, 15.7) significantly. With the increase of 10-1-M, the variation in droplet size decreased after heating for 3 h at 120 °C. Emulsions with higher 10-1-M content exhibited superior stability during accelerated aging (4,37,and 55 °C, for 4 weeks), showing minimal particle size variation (ΔD[4,3] <9 nm) and color retention (ΔE <1.0 CIELAB units) at 55 °C. The ultra-stable mechanism derives from the created composite interfacial architectures through the rapid emulsification of 10-1-L (interfacial tension: 2.72 mN/m at 1 %) and the thermo-induced formation of robust interfacial film (∼3.7 nm) of 10-1-M. The emulsion stabilized by mixed PGEs also had a great bioaccessibility of β-carotene (21.95 %–24.88 %). This work provides mechanistic insights for designing functional stable emulsions to protect heat-labile bio-actives in thermo-processed foods.