Optimisation of high temperature puffing of potato cubes using response surface methodology

One cubic centimetre potato cubes were blanched, sulfited, dried initially for between 40 and 80 min in air at 90°C in a cabinet drier, puffed in a high temperature fluidised bed and then dried for up to 180 min in a cabinet drier. The final moisture content was 0.05 dwb. The resulting product was optimised using response surface methodology, in terms of volume and colour (L*, a* and b* values) of the dry product, as well as rehydration ratio and texture of the rehydrated product. The operating conditions resulting in the optimised product were found to be blanching for 6 min in water at 100°C, dipping in 400 ppm sodium metabisulfite solution for 10 min, initially drying for 40 min and puffing in air at 200°C for 40 s, followed by final drying to a moisture content of 0.05 dwb.