Kraft gets into Glycemic Index Testing

The food giant has pioneered its own method for rapid tests to screen new food products.

By Joanna Cosgrove

Online Editor

Thanks to the Atkins diet fad, carbohydrates have gotten a bad rap. Truth is, not all carbs are the same and they can exert different effects on the body. Glycemic Index testing, or GI, typically analyzes carbs on a GI scale of 0 to 100, according to the extent to which they raise blood sugar (glucose) levels after eating. More companies are paying attention to the GI of their foods and beverages. A food with a high GI number raises blood glucose more than a food with a medium or low GI. High GI foods can rapidly fluctuate blood sugar levels, while low GI foods can produce a sustained blood sugar effect.

With the impact of GI in mind, Kraft Foods developed its own patent pending in vitro method to quickly predict the GI of foods in the R&D process. “Experts agree that minimizing post meal rises in blood glucose is better for your health,” commented Dr. Richard Black, Kraft’s vice president, Nutrition. In 1999, the World Health Organization (WHO) and Food and Agriculture Organization (FAO) recommended that people in industrialized countries base their diets on low-GI foods in order to prevent coronary heart disease, diabetes and obesity.

While Kraft’s method does not eliminate the need for in vivo GI testing, it serves as a valuable screening tool for new product formulations. The method, which includes chemical characterization of the food as well as the use of a sophisticated statistical model, produces results that are very tightly correlated with in vivo measures of GI.

Dr. Robert Magaletta, Kraft Foods fellow, Analytical Sciences, explained that the “glycemic index of a given food product is usually determined in vivo by monitoring the blood glucose level over a fixed period of time of a group of human subjects (usually about six or more individuals) who have ingested the food product; the blood glucose response for the food product is compared to that stimulated by ingestion of a control food of known glycemic index and the glycemic index is calculated from the blood glucose curves,” he said. “The glycemic index is defined as the incremental area under the blood glucose response curve of a 50-gram carbohydrate portion of the test food expressed as a percent of the response to the same amount of carbohydrate from the control food taken by the same subject.”

The Kraft GI test method was developed by Dr. Magaletta and Suzanne Dicataldo of Kraft Foods and is based on a comparison of in vitro enzyme digestion to human clinical GI results. “This method has been validated using a wide range of different sample types, including cookies, crackers, mixed meals, bars, fruits, juices, vegetables, beverages, trail mixes, dairy products, breads and pure sugars and starches,” commented Dr. Magaletta, who added that Kraft has already begun using the test internally. “Kraft does not plan to use these values on product labels at this time; this tool is being used to screen product variants for their GI values as an aid to product development,” he confirmed.

Kraft also agreed to license the technology to Homewood, IL-based Silliker, a company that provides agri-food manufacturers, restaurants and retailers with consulting, testing, auditing, research and training services that help assure agri-food safety and nutrition worldwide. According to the terms of the agreement, the test may be used for both Kraft and non-Kraft food testing. “Kraft will send products to Silliker for testing, but Silliker is also free to use the method to test samples for other companies as well,” affirmed Dr. Magaletta.

In turn, Silliker is excited to offer the technology to its own clients. Initially under the licensing agreement, Silliker will exclusively offer this method in North America at its Chicago Heights, IL, laboratory. At a future date, the offering may be expanded to include Silliker chemistry operations in Europe and Australia.

Silliker’s Pam Coleman, vice president of marketing, strongly recommended that this GI screen test be used to test existing or potential new products. “The value of it on existing products is to predict which ones may be eligible for a low GI claim,” she commented. “The value in the R&D world is to help determine which variable, out of potentially eight to 10, has the best GI score. However, before a product label is created, a full clinical trial should be performed to verify the GI.

“GI is determined through a clinical trial with human subjects,” she continued. “The test we're offering is a predictor or screen test. Before products go to market with a specific GI claim, a full clinical trial should be performed.”

Ms. Coleman added that the potential of the technology is far-reaching. “The technology can be used to test a wide range of products, including cookies, crackers, bars, fruits and vegetables, dairy products, and various beverages. Mixed meals can also be tested,” she said.

Given the rising obesity and diabetes rates here in the U.S. and abroad, getting a handle on a food or beverage’s GI can help formulators to create and direct consumers to choose sensible, low GI foods that are believed to “reduce the risk of developing type II diabetes, cardiovascular disease, colon cancer, breast cancer and other forms of cancer; help control type I and II diabetes, control hypoglycemia, control hypertension (and) help with weight loss,” said Ms. Coleman.