Preparation of DHA-Loaded Emulsions Based on SBP–WPI Conjugates

Poor oxidation stability restricts the further application of docosahexaenoic acid (DHA) in the food industry. To resolve this challenge, sugar beet pectin (SBP)–whey protein isolate (WPI) conjugates were prepared to encapsulate algal oils as DHA-loaded emulsions. Then, the properties of the conjugates were characterized, and the physicochemical stability of the emulsions was investigated. The results revealed that when the ratio of SBP to WPI was 2:1 and the reaction time was 11 h, the grafting degree (GD) reached 44.75% at its maximum and the surface hydrophobicity (H0) was 4.75 × 105 at its minimum. Additionally, the conjugates generated a thick interfacial layer and steric hindrance coated DHA to protect oil droplets against environmental stresses. Besides, the formed reduction substances enhanced the oxidation stability of the conjugate-stabilized emulsion when compared to the complex. In conclusion, the SBP–WPI conjugates encapsulate algae oil more effectively and exhibit promising application prospects in the food industry.