Rapid methods for determination of meat composition.

Rapid analytical procedures are needed to determine the total protein, moisture, and fat content of meat and poultry products. During the past 5 years, the U.S. Department of Agriculture (USDA) has been studying various methods involving instrumentation that test for these constituents either in combination or separately. The studies are initiated on request of the Department or the instrumentation manufacturer and are conducted at the manufacturers' facilities using 2 sets of samples preanalyzed by conventional means. One set, with values, is used for calibration purposes, the other set is tested as unknown samples. The resultant data are evaluated statistically vs the conventional test results. Most studies show the usefulness of these rapid tests for product quality control, but some fall short of regulatory requirements because of unacceptable bias or variability. Typical within-product standard deviations obtained in rapid methods instrumentation tests have ranged from 0.47 to 0.67 for percent total protein, 0.73 to 1.71 for moisture, and 0.41 to 1.14 for fat. For conventional methods, the acceptable USDA performance criteria for repeatability are standard deviations of less than 0.24 for protein, 0.46 for moisture, and 0.63 for fat. Improvements in instrumentation are being made and studies continue.