Plant & Food Research’s laboratory test for digestibility of starch in foods is being made available to food manufacturers in early 2009.

“This new test puts New Zealand food manufacturers well ahead of the competition in their ability to measure and manipulate starch digestibility of foods. This test has been the workhorse of the Lifestyle Foods programme, and now it is being made available to the New Zealand food industry” said Dr Tim Lindley, business manager for the Lifestyle Foods programme.

The test was developed by Dr John Monro, of Plant & Food Research’s Palmerston North based Nutrition & Health Group, and measures the amount of rapidly digested starch, slowly digested starch, and resistant starch in a food sample.

The rapidly digested starch measurement enables calculation of glycaemic glucose equivalents, and hence glycaemic load, in a way that has significantly greater precision than using clinical measurements, and is much more affordable. The experience gained in doing well over a thousand of these tests to help Lifestyle Foods programme research teams identify new plant varieties, test new food ingredients, and develop new food structures with improved starch digestibility profiles, gives confidence that the test will be a useful tool for the food industry.

While rapidly digested starch is linked to the food’s glycaemic load, the slowly digested starch gives information about the ability of the food to deliver sustained energy supply for two hours after eating, and resistant starch indicates potential for gut health benefits.

The first industry application of the test will be to characterise the starch digestibility profiles of around 500 foods for assigning e-marks for rate of energy release. The test has also been used by the team working on the Aspire diet project, to develop a healthy muesli formulation and to compare the energy release properties of different types of breads.

Plant & Food Research (the New Zealand Institute for Plant & Food Research) began business on 1 December 2008, as the result of a merger between Crop & Food Research and HortResearch.