Relations between Crack and Recipe and Quality of Doughnuts

Abstract

Crack is often observed during deep-frying at the inside, outside and/or upside of hard doughnuts and sometimes impairs the appearance. Experiments were carried out to know the effect of the proportion of ingredients and the preparation condition on the appearance of the doughnuts.
Multiple regression analysis showed that the increasing rate of the weight and volume of fried doughnuts were affected by sugar and butter content. The recipe without butter resulted in the doughnuts without outside crack. The more the sugar content was, the smaller the outside crack was. When the sugar and butter content was high, the upside crack was large. To leave the dough sample at 4°C before frying made the volume and the weight of the doughnut large and the upside crack small.
Panel members judged the doughnuts to be most preferable when the small crack at the upside was observed. We divided the sample doughnuts into two groups in terms of the ratings of the overall appearance, namely, preferable group and not preferable group. Then we ran a discriminant analysis. The recipes of the preferable group contained more sugar and egg and less butter than those of the other group.