76D-11 |
Properties of combination gels of beef salt-soluble protein and pre-heated whey protein isolate |
K. M. Hendrix1, C. J. Williams2, and D. M. SMITH1. (1) Dept. Food Science and Toxicology, University of Idaho, Moscow, ID 83844-2201, (2) Division of Statistics, University of Idaho, Moscow, ID 83844-1104 Whey proteins are known to improve the yield and color of processed meat products. The effect of whey proteins on the textural attributes of meat systems is variable, as whey proteins do not form gels at cooking temperatures commonly used by meat processors. The gelation temperature of whey proteins can be reduced using a controlled pre-heating step. Our objective was to determine how processing conditions used to prepare pre-heated WPI influence the properties of WPI and beef skeletal muscle salt-soluble protein (SSP) gels under high salt buffer conditions often used to study meat systems. The effect of three pre-heating variables (pH, heating temperature, heating time) at five levels on properties of pre-heated WPI and SSP combination gels was modeled using a rotatable second order design. Pre-heated WPI (8% w/v protein) was prepared in deionized water using pre-heating processes comprised of 18 experimental points including four center points, six axial points and eight factorial points. Failure properties (hardness and deformability), syneresis and expressible moisture of gels (1:1, 6% total protein) prepared from pre-heated WPI and SSP were determined in 0.4 M NaCl, 0.05 M Na phosphate buffer, pH 6.5, upon heating to 68°C. Multiple regression and analysis of covariance methods were used to fit the model. Models were developed to explain 81%, 90% and 70% of the variability in gel hardness, deformability and syneresis, respectively. Response surface plots were drawn to illustrate the main effects of the pre-heating process variables. A better understanding of interactions between whey and meat proteins may allow for increased use of whey products in meat products where gel formation at low temperatures is desirable. Pre-heated WPI may substitute for common low-temperature gelling agents used in value-added meat products, such as starches, gums and other non-meat proteins.
Session 76D, Muscle Foods II
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