Composition and physicochemical characteristics of restructured beef steaks containing walnuts as affected by cooking method

The study was conducted to determine the influence of various cooking methods - conventional oven, microwave oven, electric grill and pan-frying on the composition and physicochemical characteristics of restructured beef steaks formulated as low fat (L, 2.0% fat), medium fat (M, 13.0% fat) and 20% added walnut (W, 12.6% fat). Composition, retention coefficients for different compounds, cooking loss (CL) and texture were affected by both formulation and cooking. There was considerable retention of moisture, fat and minerals (as ash) in W samples after cooking. CL was highest (P<0.05) in M sample and lowest (P<0.05) in W samples. Microwaved restructured steaks had higher (P<0.05) kramer shear force (KSF) and bind strength (BS), while pan-fried and conventionally oven-cooked steaks had lower (P<0.05) KSF. The thiobarbituric acid-reactive substances (TBARS) content was low in all restructured steaks but was affected by both cooking and formulation. Although cooking can change the proximal composition of steaks, lipid retention (>90%) was greatest in the case of the W sample, thus assuring that the ultimate objective of these restructured meats, namely to provide a source of walnut and walnut fat, would be successful.