Adding about one-quarter teaspoon of a fibre-rich component of oats boosts the nutritional value of low-fat yoghurt without noticeably affecting the taste or texture of this increasingly popular dairy food.
That’s the conclusion of research carried out by the Agricultural Research Service in the USA.
Oat fibre is of interest to foodmakers and nutritionists alike. Studies with volunteers have shown that it can lower serum cholesterol, which may help improve heart health.
Researchers experimented with adding fibre-containing oat beta-glucan to what’s known in the dairy industry as “low-fat yoghurt mix.” It is made up of low-fat milk and a selection of common, safe-to-eat bacteria that ferment the milk. Best known bacteria include Lactobacillus acidophilus or various Bifidobacterium species.
The intent of the research was to see how much fibre could be added without altering key qualities of yoghurt, including texture, viscosity, colour, pH, and fermentation time.
In experiments at the ARS National Center for Agricultural Utilization Research in Peoria, Illinois, the research team added 0.1, 0.2, 0.3, 0.4, or 0.5 percent purified oat beta-glucan—a light, fine-textured, whitish powder—to low-fat yoghurt mix and compared the results to yoghurt mix with no oat fibre.
In the oat beta-glucan work, the team determined that up to 0.3 percent highly purified (95 percent pure) oat beta-glucan, which translates to 0.3 grams of beta-glucan per 100 grams of yoghurt mix, could be added without significantly altering key yoghurt qualities. But adding 0.4 percent or higher changed the yoghurt’s colour, contributed to unwanted hardening, and slowed fermentation.
The 0.3-percent level of fortification totals out at 0.75 grams of fibre per 8-ounce serving of yoghurt.
