Impact of infrared finishing on the mechanical and sensorial properties of wheat donuts

Infrared radiation may be used to simulate an immersion frying heat flux and create products with fried-like textures but lower fat contents. The objective of this study was to determine the process parameters needed to produce partially-fried, infrared-finished donuts comparable to fully-fried (control) donuts. A total of 8 different sets of infrared oven parameters (emitter height and belt speed) were tested. Instrumental analysis showed that all infrared-finished donuts had significantly (P≤ 0.05) lower fat content (25.6% to 30.6%) than the control (33.7%). Setting the infrared emitters in a height gradient from 70 to 50 mm or at a constant height of 60 mm above the belt produced donuts that were most instrumentally similar to the control. Infrared-finished donuts had comparable (P≤ 0.05) overall acceptance scores to the control, 5.28 to 5.85 versus 5.83, respectively. Infrared radiation may be used to finish-fry partially-fried donuts, yielding a product similar to a fully-fried donut but with significantly lower fat content. Practical Applications: The partial-frying, infrared-finishing process detailed in this article may be used for other deep-fried foods. It is likely that these foods will also have a lower fat content when prepared with this process than when they are deep-fried. This process provides a method of lowering the fat content of fried foods without changing the food formulation.