231 - Electrical Conductivity, Color, and Tenderness Values of Fresh and/or Cooked Beef

Abstract: A study with fresh and cooked beef loins, beef jerky, and water types was conducted to evaluate electrical conductivity (EC) measurements as a procedure in quality appraisal. Six full strip loins x 6 steaks per loin x 2 types provided 72 electrical conductivity (CV) observations, and 72 measurements of color variables (chroma, hue, L*, a* b*) of loins. Six core samples per cooked steaks provided 216 Warner-Bratzler shear force (WBSF) values. EC was also measured on three water types and saline (n=20), and commercial beef jerky samples (n=72). Procedures used for EC were developed in our lab and consisted of using emulsified samples enclosed in a silicon vessel with copper electrodes connected to a digital multimeter. Microsiemens (µS) were measured over 60 s with a sampling rate of two per s. Color variables were measured using a Varian Cary 50 Series Spectrophotometer. Data were analyzed using ANOVA and Pearson correlation coefficients. EC means (µS) were 14.4, 42.5, 34.9, 22.9, 16.1 and 24.7 for fresh steaks (P= .07); and 7.8, 16.5, 6.4, 10.7, 5.2, and 8.0 for cooked steaks (P=.36). Means for all color variables were different (P < 0.05) across fresh steaks. Correlation of EC to each color variable was negative: chroma -0.013, hue -0.050, L*-0.009, a*-0.131, b*-0.110. Only a* was significantly correlated (P < 0.05) to EC. WBSF tenderness (kg/f) means were not different (P > 0.05) across steaks but did differ (P < 0.05) within steaks. Correlations of EC to tenderness was not significant (P > 0.05). EC mean of beef jerky was 106.9 (SEM 5.05). EC of water types differed (P < 0.05) - deionized 0.40, purified 1.56, tap 1.30. EC for saline was 0.04. These data indicate that EC of beef can be effectively measured, but high variations across EC, color, and tenderness values decreased the overall probability of finding relationships.