Moisture and Microwave Effects on Selected Characteristics of Turkey Pectoral Muscles

The effect of added water and microwave heating on several characteristics of ground composites of pectoral muscles of eight USDA Grade A turkey toms was investigated. Samples (200 g) containing 0, 15, or 30 ml added water were prepared and heated in a Raytheon Mark IV Radarange (2450 MHz) for 0, 70, and 130 sec. Water added in the amounts of 15 or 30 ml represented 7 or 13% of the sample weight prior to heating.

Expressible moisture index and total moisture decreased with increased cooking times, whereas fat-free dry weight and initial and total cooking losses increased with cooking. Extractable fat and pH tended to increase when comparing raw and cooked samples.

Increasing the water levels in the samples resulted in decreased values for expressible moisture index and fat-free dry weight. Total moisture and initial and total cooking losses increased as the level of added water was increased. The effects of added water on extractable fat and pH were not consistent.

Expressible moisture index seemed to be the best measure of treatment effects since a greater percentage variation attributable to treatment was observed for this measurement than for the measurements of cooking losses and total moisture. Although water was lost during cooking, as indicated by total moisture values, it was possible to retain some added water. Cooking time contributed the greatest percentage variation, but added water also had significant effects on all the characteristics studied. The rate of microwave heating did not seem to be affected by the addition of water. This might be attributed to the maintenance of a constant water load within the oven.