Unfried Breaded Donut Coating via Steam Condensation
Solution Overview
Problem
Existing methods for producing breaded donuts without frying fail to achieve the desired crispness, uniformity, and visual appeal while also reducing fat content, as they either result in hard and dry textures or require retention of a final frying step.
Innovation Solution
A process involving a coating paste made from rice flour, cold water-soluble polysaccharides, cross-linked pea starch, and dextrin, pre-cooked in a steam oven at 190-210°C with 50% relative humidity, followed by freezing, to create donuts with reduced fat content and sensory characteristics similar to fried products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional frying is used to produce breaded donuts, then crispness and sensory characteristics are improved, but fat content increases and nutritional value deteriorates
Solution Approach 1:
The invention changes the cooking parameters from high-temperature frying to steam oven cooking at controlled temperatures (190-210°C) with specific humidity (50% relative humidity). This parameter change allows achieving crispness through steam condensation and coating dehydration without the harmful effects of frying oil absorption
Solution Approach 2:
The invention replaces the thermal-mechanical frying process with a steam-based thermal process. The steam oven system substitutes the oil immersion mechanism, using phase change of water (liquid to vapor to condensed liquid) to achieve the desired coating texture without fat infiltration
2Quantity of substance
If frying is eliminated to reduce fat content, then nutritional value is improved, but crispness and sensory characteristics deteriorate
Solution Approach 1:
The invention exploits the phase transition of water in the coating and substrate. Steam condensation on the coating surface provides localized heating and moisture transfer that dehydrates the coating, creating crispness. The freezing step also utilizes phase transition to lock in the coating structure before final heating
Solution Approach 2:
The invention uses a composite coating formulation combining rice flour (for crispness), modified starches (for adhesion and texture), cold water-soluble polysaccharides (for moisture control), and dextrin (for browning and structure). This composite material system achieves fried-like sensory characteristics through steam cooking without requiring actual frying
3Quantity of substance
If alternative cooking methods are used without frying, then fat content is reduced, but coating uniformity and visual appeal deteriorate
Solution Approach 1:
The invention applies a preliminary freezing step before the final heating. This preliminary action solidifies the coating, creating a stable structure that resists deformation during subsequent heating. It also pre-establishes the coating's physical properties to ensure uniform heat and moisture transfer, resulting in consistent appearance and texture
Solution Approach 2:
The cooking process uses periodic action with multiple heating stages. The first heating stage (steam oven) cooks the substrate and partially sets the coating. The second heating stage (higher temperature) achieves final browning and crisping. This periodic thermal treatment ensures uniform cooking and consistent visual appearance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process results in donuts with reduced fat content, crispiness, uniform coating, and visual appeal comparable to traditional fried donuts, while eliminating the need for a frying step, thereby addressing the technical challenges of organoleptic and visual quality.
Implementation Method 1
pre-cooking step is carried out in a steam oven, to obtain donuts
Implementation Method 2
pre-cooking step is carried out at a relative humidity of 50% and at a temperature between 190 and 210°C
Implementation Method 3
Freeze the donuts thus obtained
Data Source
AI summary
The present invention concerns a method for producing unfried breaded nugget-like products, comprising a step of preparing a particular coating paste, in particular from rice flour and modified starches, combined with a step of cooking in a steam oven. This method can be used in order to obtain nugget-like products that have the required crispness, uniformity and colour characteristics and a reduced fat content. The invention also concerns a nugget-like product likely to be obtained using the abovementioned method.