Improving the stability of citrus flavors (i.e., citral) in low pH beverages has challenged food industry for decades, and is a long-standing industry need. We bring several unique approaches to the proposed research: (a) to use nanoemulsions for beverage applications; (b) to significantly enhance citral stability in emulsions, including nanoemulsions, by slowing the acid catalyzed rearrangements using cationic biopolymeric emulsifiers prepared from ε-poly(lysine); (c) to use a chemical reaction of a specially designed probe that reacts with antioxidants to determine the fraction of the antioxidant in the interfacial region and the relation between antioxidant distribution and efficiency; and (d) to use special nuclear magnetic resonance techniques to estimate the fraction of oil interfacial regions of emulsions composed of food-grade components. We plan to achieve the following objectives: (1) To encapsulate citral in micelles and nanoemulsions formed from cationic hydrophobically-modified ε-poly(lysine) as the emulsifier and to determine the distributions of antioxidants, such as polyphenols like black tea theaflavins by using a special chemical kinetic method to better understand how antioxidant structure affects its efficiency. (2) To characterized physical properties of nano and micro emulsions containing citral prepared by high-speed homogenization and to emulsify natural food oils with food grade emulsifiers. (3) To characterize the effect antioxidant distribution, emulsion sizes, emulsifiers and oils types on the total content of citrus flavor and off flavor products to develop the optimum conditions for citral emulsion preparation and stabilization. The results should provide more meaningful scales of antioxidant efficiency in emulsions composed of food grade components that will benefit not only the food/beverage industry, but also pharmaceutical and cosmetic industries, and provide added value by extending shelf life, preventing oxidation/hydrolysis, and improving handling characteristics.
|Effective start/end date||9/1/09 → 8/31/12|
- National Institute of Food and Agriculture (National Institute of Food and Agriculture (NIFA))