Attrition reduction and quality improvement of coated puffed wheat by fluidised bed technology

Puffed wheat coated with sweet coverings is a ready-to-eat (RTE) breakfast cereal of popular consumption worldwide. Coating of puffed wheat is conventionally performed by tumbling, heating and syrup pouring, within a tumbling vessel. This tumbling process promotes attrition and causes uneven distributions of the coating syrup, with a consequent variability in quality of the final product. A fluidised bed processor, built with a top spraying nozzle, was tested as an alternative for coating of puffed wheat particulates with a sweet chocolate cover. The fluidised bed technique was compared with a tumbling method in which syrup was applied by spraying, as well as with a commercial sample. Crispness, colour, flavour and attrition resistance, were compared for the different coating techniques. No significant difference was perceived in colour, but the fluidised bed treated sample was considered crispy and more related to chocolate flavour than the commercial sample. In terms of attrition, the fluidised bed sample lost about 1% weight, while the tumbled-coated sample lost around 5% weight, and the commercial sample lost nearly 10% weight.