Preparation of water-in-oil Pickering emulsion stabilized by Camellia oleifera seed cake protein and its application as EGCG delivery system
Chuanjian Cui, Ziqi Wei, Zhibo Hong, Jian-Fa Zong, Hongfang Li, Chuanyi Peng, Huimei Cai, Ruyan Hou
Abstract
The use of plant proteins as stabilizers for Pickering emulsions is attracting attention in the food industry. Herein, a protein extract with a high hydrophobic content (extraction ratio up to 21.6%) was obtained from the byproduct generated by the extraction of oil from Camellia oleifera. The effects of different oil-towater ratios and protein concentrations on the stability and rheological properties of the Pickering emulsions were investigated. A stabile emulsion that exhibited gel characteristics was made using an oil:water ratio of 6.5:3.5 and a protein concentration of 3%. The EGCG encapsulation efficiency of the Pickering emulsion was 82.3%. The emulsion remained stable during different environmental pressures (pH, ionic strength, heat, UV) and long-term storage, effectively protecting EGCG from chemical degradation in extreme environments. In vitro digestion results showed that the Pickering emulsion significantly delayed the release of EGCG from 80.52% to 26.81% and that the bioaccessibility of the EGCG was increased by 30.8% in the intestine when incorporated into the Pickering emulsion compared to free EGCG. This research indicates that Camellia oleifera seed cake could be used in plant-based protein emulsions for improved nutrient delivery.