15C-22 |
New high quality fat replacers from whey proteins |
F. H. HSIEH and M. R. Pan. Dept. of Food Science, Univ. of Missouri, Columbia, 248 Agricutural Engineering Bldg., Columbia, MO 65211 Whey protein has been processed in both acidic and neutral pH conditions to make fat replacers. However, these fat replacers can only be applied in food systems within a limited range of pH values otherwise the texture became unacceptable. Alpha-lactalbumin is believed to cause this texture change. We hypothesize that trypsin modification of whey protein isolate (WPI) may degrade this protein to improve product quality. Our objective was to use trypsin to modify WPI to determine if the hydrolysis could improve the quality of fat replacers. Trypsin proteolysis was conducted at 20% WPI solution at an initial pH of 7.0 for 1 h. Hydrolyzed WPIs with1-2% lecithin were then cooked at 84 or 88°C with stirring at 50-200 rpm. Three treatments with the smallest particle size were selected to prepare reduced-fat ranch style salad dressings for a descriptive analysis (DA) panel. A consumer study was also conducted to study their preference. Our results showed that a smooth and semisolid texture was obtained by cooking trypsin-hydrolyzed WPIs. Results of DA suggested no significant differences were found in aroma and flavor notes of the reduced-fat dressings when compared to the full-fat one; however, reduced-fat dressings were slight thinner and felt less salty. The results of consumer study suggested that one reduced-fat dressing was not significantly different from the full-fat one in degree of likings for "overall sensations." These results suggest that a-lactalbumin could cause grainy texture in fat replacers. The hydrolysis of a-lactalbumin in WPI resulted in smooth texture with good stability in broader pH range. Therefore, cooking trypsin-modified WPI solutions with stirring could create a unique semisolid, its texture was very different from the traditional heat-induced gels and showed a great potential to be used as "fat replacers".
Session 15C, Dairy Foods
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