Changes on the quality of donuts using psyllium husk as powder and edible coatings

The aim of this study was to develop health functional donuts with reduced oil absorption using psyllium husk. Twenty-four donut samples were prepared using both methods of adding psyllium husk powder at 0∼10% to wheat flour with dough and applying a coating agent (4∼12 g/L) to the dough. The quality changes in the donuts were studied in terms of quality, oil absorption, antioxidant activity, and lipase inhibitory activities. The moisture content of the donuts increased with increasing addition of psyllium husk and concentration of coating agent. The oil absorption of the donut decreased compared to 14.76% of the control group. The hardness and chewiness of the donut changed significantly (P<0.05), and the color of the donut crumb became darker due to the unique color of the psyllium husk. The total polyphenol content increased from 0.36∼0.67 gallic acid equivalent mg/g (P<0.05). The total flavonoid content also increased from 0.23∼0.65 quercetin equivalent mg/g (P<0.05). The decrease in 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) IC50 and increase in inhibitory activity against porcine pancreatic lipase highlighted the enhancing functionality of donut by the addition of psyllium husk. Through this study, the possibility of the development of high-functional donut product was confirmed using psyllium husk.