1. Prepare and characterize delivery systems of lipophilic antimicrobials by encapsulating them in derivatized skim milk powder. </P>
2. Evaluate antimicrobial activities of delivery systems against foodborne pathogens in microbial growth medium, milk, and Hispanic cheese.
Naturally occurring food antimicrobials can be used as an additional hurdle to improve the microbiological safety of dairy products. Many food antimicrobials are very effective in microbial growth media, but lose their effectiveness in complex foods because they interact with the food matrix. USDA NIFA grant TEN02010-03476 is supporting nano encapsulation of these antimicrobials that can effectively enhance food safety and biosecurity. Foodborne disease caused by contaminated soft-style fresh Hispanic cheese, such as Queso fresco is a major concern for the dairy industry. The high moisture, neutral pH environment of these cheeses provide little hurdle for outgrowth of bacteria. </P>DRI's Supplemental Support program will study delivery systems of plant polyphenols that are effective against broad spectrum of Gram-positive and Gram-negative bacteria and viruses. Researchers have demonstrated that the delivery system based on whey protein isolate-maltodextrin conjugates evenly distributes polyphenols at a level well-above the solubility limit and is effective in skim milk. In this project, the antimicrobial activities of delivery systems against foodborne pathogens will be tested in microbial growth medium, milk with different fat levels, and Hispanic cheese such as Queso Fresco. </P>The project contributes to the development of dairy ingredient-based delivery systems to improve the microbiological safety of Hispanic cheeses such as Queso Fresco.