Near-infrared technology measures beef fat better.

Shining invisible light on a hamburger patty could lead to a safer, faster and more environmentally-friendly way to determine how much saturated fat the burger holds. In the U.S., the FDA regulates the chemical-based fat analysis techniques widely used by the food industry to obtain the fat values for food labels. Health concerns over saturated fats have made this an important issue with consumers.

But the current analytical methods have drawbacks, such as disposal problems posed by chemicals used in the analysis. Now USDA/ARS scientists at the Quality Assurance Research Unit (Richard B. Russell Agricultural Research Center, Athens, GA 30605) are using a nonchemical alternative to do the job: near-infrared (NIR) spectroscopy. NIR light waves are just beyond the visible part of the light spectrum.

To further develop this technology, ARS scientists have entered into a cooperative research and development agreement with Foss North America (Eden Prairie, MN), an international supplier of automated rapid analysis tools for the food and agriculture industries. The NIR approach measures fat levels as low as 1%, well within FDA requirements. The approach takes less than 2 min. and uses no ether or other hazardous chemicals.

Current chemical methods take two days to yield results. First, technicians use petroleum ether to extract fat from a food sample. Then they inject a portion of the fat-ether solution into a gas chromatograph. It separates saturated from nonsaturated fats and calculates their percentages. The instrument burns the sample used for analysis, but most of the sample left from the extraction must be disposed of as hazardous waste.

Using NIR spectroscopy, a sample is exposed to NIR light waves. Saturated fat reflects the NIR wavelengths differently from other food components, including other fats. A software program measures the sample's absorbance, which is the light energy that passes through the sample. It then compares the data with information from samples with a known fat content.

ARS researchers are analyzing 300 beef samples to compare the speed, accuracy and convenience of NIR with traditional chemical analysis. ARS scientists and Foss plan to develop similar fat analysis techniques for chicken, sausage and pork. They will also compile a database containing protein and fat data on several meat items.

Further information. William Windham; phone: [phone]; fax: [phone]; email: [e-mail].