Preparation of soybean protein isolate-quercetin particles and its application in curcumin-camellia oil Pickering emulsion

In order to improve the stability and bioavailability of camellia oil, as well as expanding its application in aqueous, a complex (SPIQU) was prepared using soybean protein isolate (SPI) and quercetin (Qu) as material. The structural composition, emulsification properties, and antioxidant properties of SPIQU were evaluated using infrared, particle size, contact angle, bromophenol blue binding rate, and free radical clear rate tests. On this basis, Pickering emulsions were prepared using SPIQU as wall material and curcumin dissolved in camellia oil as core material, and the emulsion properties, antioxidant activity, microstructure, rheology and stability tests were performed on Pickering emulsions. The results showed that when quercetin was added 1.0%, the particle size of SPIQU was 514.61 ± 16.35 nm, the complex binding rate was 89.06%, and the ABTS radical scavenging rate was 78.72%, showing good surface hydrophobicity and emulsification properties. The prepared Pickering emulsion had uniform droplets and good emulsification characteristics, with an average particle size of 8.3 ± 2.7μm. It was a pseudoplastic fluid by rheological test, and Pickering emulsion showed good stability in storage, centrifugation and heat within four weeks. Therefore, SPIQU can form a stable Pickering emulsion system from oil and oil-soluble substances, which can be used as a good emulsion preparation method in the field of food, pharmaceuticals, and cosmetics.