64-2 |
|
X. LIU1, S. Clark1, J. R. Powers1, B. G. Swanson1, and H. H. Hill, Jr.2. (1) Dept. of Food Science & Human Nutrition, Washington State Univ., 106 FSHN Bldg., PO Box 646376, Pullman, WA 99164-6376, (2) Dept. of Chemistry, Washington State Univ., PO Box 644630, Pullman, WA 99164-4630 When fat is substituted with fat replacers in reduced-fat products, flavor is often perceived as sharp and unbalanced. Modification of whey proteins by high hydrostatic pressure (HHP) may enable development of food ingredients with improved functional properties, including flavor-binding. The effects of HHP treatment on flavor-binding properties of WPC80 were determined with heptanone, nonanone, octanone, diacetyl, and benzaldehyde, flavors often involved in product development. After HHP treatment (600MPa, 50oC, 0, 10, 30min), flavor-binding properties of WPC80 solutions were studied by fluorescence titration method (Cogan et al., 1976). Increase in binding sites and decrease in dissociation constant indicate improvement in flavor-binding properties. For benzaldehyde, 30min HHP treatment increased the number of binding sites from 0.20 to 0.36, and the apparent dissociation constant from 2.7*10-8M to 4.7*10-8M. HHP treatment of 10min improved the binding affinity for diacetyl, with a decrease of apparent dissociation constant from 2.7*10-8M to 1.5*10-8M and no significant influence on number of binding sites. HHP treatment of come-up time and 30min increased the number of binding sites and improved the binding affinity of WPC80 for heptanone and octanone. Best improvement was found after come-up time treatment, with an increase of the number of binding sites form 0.22 to 0.39 for heptanone, and from 0.21 to 0.40 for octanone. Come-up time treatment also improved the binding affinity of WPC80 for heptanone and octanone, with a decrease of apparent dissociation constant from 2.5*10-8M to 1.9*10-8M for heptanone and from 2.2*10-8M to 1.7*10-8M for octanone. Nonanone showed better binding affinity than native WPC80 after 30min HHP treatment. These results show that HHP treatments can enhance the flavor-binding properties of WPC80; the effects depend on flavors and HHP treatment time. Come-up time and 30min of HHP treatment to WPC80 may enhance certain flavor-binding properties and potentially improve the flavor of reduced fat products.
Session 64, Dairy Foods: Milk proteins
|