Production of Gelatin Nanoparticles by Solvent Dissolution Method for Use as Food-grade

 Gelatin is one of the most widely used colloidal proteins, which has unique hydrocolloidal property. Gelatin is derived from collagen by changing the thermal nature. This product is widely used in food, pharmaceutical, biomedical, cosmetic and photography industries. Global gelatin demand for food and non-food products is increasing. Two important properties of nanoparticles are: Increasing the surface-to-volume ratio of nanoparticles causes the atoms on the surface to have a much greater effect on their properties than the atoms within the particle volume. The effects of quantum size, which is the second feature. Methods for preparing nanoparticles from natural macromolecules: In general, two major methods for making protein nanoparticles have been reported Emulsion-solvent evaporation method and sedimentation or phase separation method in aqueous medium. Numerous methods have been reported for the preparation of nanoparticles from natural macromolecules. The first method is based on emulsification and the second method is based on phase separation in aqueous medium. In the first method, due to the instability of the emulsion, it is not possible to prepare nanoparticles smaller than 500 nm with a narrow particle size distribution. Therefore, coagulation method or anti-solvent method which is based on phase separation was proposed to prepare nanoparticles from natural macromolecules.

 Type B (cow) gelatin was purchased from processing company with Bloom 260-240 food and pharmaceutical Iran solvent gelatin solution of 25% aqueous acetate glutaraldehyde from Iran Neutron Company. Two-stage anti-solvent method was used to produce gelatin nanoparticles. Then, to form nanoparticles, acetone was added dropwise while stirring until the dissolved acetone begins to change color and eventually turns white, which indicates the formation of nanoparticles. Finally, glutaraldehyde solution was added for cross-linking and finally centrifuged.

 The results showed that with increasing gelatin concentration, nanoparticle size and PDI increased significantly. According to the announced results, the solvent has a direct effect on the size. Therefore, the best mixing speed is determined to achieve the smallest particle size. Zeta potential is the best indicator for determining the electrical status of the particle surface and a factor for the stability of the potential of the colloidal system because it indicates the amount of charge accumulation in the immobile layer and the intensity of adsorption of opposite ions on the particle surface. If all the particles in the suspension are negatively or positively charged, the particles tend to repel each other and do not tend to accumulate. The tendency of co-particles to repel each other is directly related to the zeta potential. Fabricated gelatin nanoparticles have a stable structure, and are heat resistant. These nanoparticles are ready to be used to accept a variety of aromatic substances, compounds with high antioxidant properties, a variety of vitamins and heat-sensitive substances.

The results of this study showed that the optimal conditions for the production of a particle of 88.6 nm at 40 ° C, the volume of acetone consumption was 15 ml, concentration 200 mg and speed 1000 rpm, and the morphology of gelatin nanoparticles have resistant, spherical polymer structure and mesh with a smooth surface that can be clearly seen under an electron microscope.