Facile solid-phase synthesis of starch-fatty acid complexes via mechanical activation for stabilizing curcumin-loaded Pickering emulsions

This work presented that the rice starch-fatty acid complexes were successfully fabricated by mechanical activation method. The V-type rice starch-fatty acid complexes exhibited a higher digestion resistance than NRS due to partial rapidly digestible starch convention to resistant starch, which were further used as a stabilizer to stabilize Pickering emulsions for the encapsulation of curcumin. The resulting Pickering emulsion loaded with curcumin showed good encapsulation and delivery performance in storage stability and in vitro digestion assays. This study not only offers a simple and efficient method for the preparation of starch-fatty acid complexes, but also facilitates the preparation of Pickering emulsions with superior stability for encapsulation of lipophilic substances. [Display omitted] •Efficient synthesis of rice starch-fatty acid complexes using the mechanical activation method.•MA process can enhance the dispersion of long chain fatty acids in starch and the formation of starch-fatty acid complexes.•Curcumin-loaded Pickering emulsions show superior encapsulation and delivery properties. Starch-fatty acid complexes used as emulsifiers have caught great attention because of their renewability and excellent emulsifying property, the development of a simple and efficient synthesis method for the fabrication of starch-fatty acid complexes is still greatly challenging. Herein, the rice starch-fatty acid complexes (NRS-FA) were successfully prepared by mechanical activation method using different long chain fatty acids (myristic acid, palmitic acid, and stearic acid) and native rice starch (NRS) as the raw materials. The results showed that the prepared NRS-FA with a V-shaped crystalline structure exhibited a higher digestion resistance than NRS. Moreover, when the chain length of fatty acids increased from 14 to 18 carbons, the contact angle of the complexes was much closer to 90°, and the average particle size was smaller, deriving the better emulsifying property of NRS-FA18 complexes, which were suitable to be used as an emulsifier to stabilize curcumin-loaded Pickering emulsions. The results of storage stability and in vitro digestion showed that the curcumin retention could reach 79.4 % after 28 days of storage and 80.8 % of curcumin was retained in the system after simulated gastric digestion, showing good encapsulation and delivery performance of prepared Pickering emulsions, which attributed to the enhancement of the coverage of particles