Using a pigment found in black and purple plant material including blueberries and black rice (anthocyanin), they were able to reduce the rate at which bread starch was broken down, meaning sugar was released into the blood over a longer period. This is beneficial to diabetics, who struggle to control blood sugar levels.
The team from the National University of Singapore (NUS) found the digestion rate of bread containing 1% pigment and baked at 200˚C was reduced by 12.8% and that upping the quantity of pigment to 4% slowed the rate even further by 20.5%.
Professor Zhou Weibiao, director of the food science and technology programme at the NUS faculty of science, said: “Despite their antioxidant capacity and associated health benefits, the knowledge of using anthocyanins as an ingredient in food products, particularly semi-solid products, is very limited. Hence, we wanted to explore the feasibility of fortifying anthocyanins into bread, to understand how it affects digestibility and its impact on the various quality attributes of bread.”
A previous study by the NUS in 2014 demonstrated that anthocyanin is relatively stable in baked goods, with up to 80% of its anti-oxidant capacity retained even when baked at 240˚C for 12 minutes.
Professor Weibiao said: “Our results demonstrate that it is indeed feasible to create functional food products through anthocyanin fortification, using bread as an example. We hope to conduct further studies to incorporate anthocyanins into other food items, such as biscuits. Our team is also keen to explore opportunities to work with industry partners to introduce the anthocyanin-fortified bread to the market.”