Binding of Flavor Compounds and Whey Protein Isolate as Affected by Heat and High Pressure Treatments

Riddet Centre, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
Journal of Agricultural and Food Chemistry (Impact Factor: 3.11). 10/2008; 56(21):10218-24. DOI: 10.1021/jf801810b
Source: PubMed

ABSTRACT The interactions of whey protein isolate (WPI) and flavor compounds (2-nonanone, 1-nonanal, and trans-2-nonenal) were investigated, and the influence of flavor compound structure and heat and high pressure denaturation on the interactions were determined by using headspace solid-phase microextraction (SPME) and gas chromatography (GC). The binding of WPI and the flavor compounds decreased in the order trans-2-nonenal > 1-nonanal > 2-nonanone. The differences in binding can be explained with hydrophobic interactions only in the case of 2-nonanone, whereas the aldehydes, in particular trans-2-nonenal, can also react covalently. Heat and high pressure treatment affected protein-flavor interactions depending on the structure of the flavor compound. Upon both heat and high pressure denaturation, the binding of 2-nonanone to WPI decreased, while the binding of 1-nonanal remained unchanged, and the affinity for trans-2-nonenal increased rapidly. The results suggest that hydrophobic interactions are weakened upon heat or high pressure denaturation, whereas covalent interactions are enhanced.

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