The bread, which is fortified with anthocyanin, is digested at a slower rate than standard bread, said the researchers, who added it offered other health benefits such as high antioxidant content.
Anthocyanins are naturally occurring pigments in fruits, such as blueberries, as well as grains and vegetables such as black rice and purple sweet potatoes. The anthocyanin in the National University of Singapore (NUS) recipe uses anthocyanin extracted from black rice.
Scientific studies have shown anthocyanins are rich in antioxidant properties and can also inhibit digestive enzymes.
Knowledge anthocyanins is limited
"Despite their benefits, the knowledge of using anthocyanins as an ingredient in food products, particularly semi-solid products, is very limited,” said Professor Zhou Weibiao, director of the food science and technology programme at NUS.
“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."
Most breads contain a high amount of rapidly digestible starch giving them a high glycemic index that makes them unsuitable for diabetic patients, said the team, who published their research in the journal Food Chemistry last year.
Digestion rates lowered
They found digestion rates fell 12.8% when 1% of anthocyanin extract was added into bread dough and baked at an optimal temperature of 200 degrees Celsius for eight minutes. The digestion rate dropped to 20.5% when the recipe contained 4% of anthocyanin extract.
"Reducing the digestion rate of the bread will lead to a lower glycemic index and slower absorption of the bread's carbohydrates,” said Dr Sui Xiaonan, first author of the study. “This usually suggests a lower insulin demand and could potentially improve long-term blood glucose control."
Seeking industry partners
Prof Zhou added the team was keen to explore opportunities to work with industry partners to bring anthocyanin-fortified bread to market.
"Our results demonstrate it is feasible to create functional food products through anthocyanin fortification, using bread as an example,” he said. “We hope to conduct further studies to incorporate anthocyanins into other food items, such as biscuits.”
Earlier this month, this site reported that Meiert Grootes, chairman of Europe’s biggest supplier of speciality baking products, had acquired a stake in Malaysian-Australian biotech firm Holista Colltech, which has launched a formula to produce a clean-label white bread with a glycemic index of 53. Panatura GI uses Holista Colltech’s GI Lite formula containing extracts of okra, lentils, barley and fenugreek, and Veripan’s Pantura sourdough.
Source: Food Chemistry
Published online: www.sciencedirect.com/science/article/pii/S030881461501465X
‘Bread fortified with anthocyanin-rich extract from black rice as nutraceutical sources: Its quality attributes and in vitrodigestibility’
Authors: Xiaonan Sui, Yan Zhang, Weibiao Zhou