Filtration initiated selective homogeneity (FISH) desolvation: A new method to prepare gelatin nanoparticles with high physicochemical consistency

Biopolymer nanoparticles (NPs) have garnered much interest in the food industry as encapsulating materials for flavors, nutraceuticals and other bioactive compounds. The ability to control and reproduce NP physicochemical properties is a crucial step in the utilization of nanoscale formulations for food based and sustainable packaging applications. Conventional preparations of gelatin NPs involve a range of solution based methods with inconsistent nanoscale properties. Integrating a filtration step prior to gelatin NP formation obtained highly consistent physicochemical properties between two different gelatin types. The average diameter of the entire population was 143 +/- 12 nm with a low polydispersity index of 0.07 +/- 0.03. Volume distributions revealed a single peak confirming the existence of uniformly sized NPs. Gelatin NPs obtained high chemical crosslinking extents (>= 87%) with synonymous chemical bonding determined via FTIR. Rhodamine 110 fluorescent agent incorporation maintained consistent diameters (similar to 140 nm) with significantly higher fluorescence measurements compared to empty particles. Our results indicate that greater control and reproducibility of gelatin nanoscale properties is dependent on gelatin molecular weight homogeneity prior to NP synthesis. The production of consistent NP properties is anticipated to propel the translation of gelatin NPs as bioactive encapsulators in food and sustainable packaging applications.