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The objective of this exploratory research is to prove that high hydrostatic pressure can be used to modify binding properties of the casein micelle from bovine milk and transform the micelle into a natural nanocarrier (50-100 nm) for low molecular weight hydrophobic flavors and antimicrobials.
Non-Technical Summary: Many natural antimicrobials are small molecular weight (<400 Da) low solubility molecules. These molecules, while effective in in vitro studies, are not successfully used in real food systems because they cannot be permanently incorporated into the aqueous microenvironment where microorganisms grow. Similarly, the food industry faces great difficulty avoiding phase separation of highly hydrophobic low molecular weight flavor compounds that are volatile or hydrophobic. This one year proof-of-concept research proposal was designed to demonstrate that (1) native casein micelles (50-250 nm) from bovine milk can be structurally modified (through dissociation re-aggregation) into newly formed nano-micelles (50-100 nm) that (2) can be used as carrying/delivery systems for small molecular weight hydrophobic flavors and antimicrobials in aqueous systems. The scale (nanometers) and nature (hydrophobicity) of the proposed interaction between molecule (antimicrobial or flavor) and carrier (casein nano-micelle), will promote the long term stability of the system and facilitate the delivery to the target site of action. <P> Approach: Two main activities (tasks) will be conducted as part of this exploratory research. The first main activity (Task 1) will be the determination of the major environmental factors promoting re-aggregation of high pressure dissociated casein micelles. The objective will be to identify factors that markedly accelerate the re-aggregation of caseins submicelles into newly formed micelles with target diameter of 50-100 nm. Task 1 will take place during the first 4 months of the project.