Characterization of the frying process of fresh and blanched potato stripsusing response surface methodology

Characterization of the frying process of potato strips was carried out usi ng response surface methodology. Frying was performed on either fresh or bl anched strips following a conventional water treatment. The independent var iables of the process were frying temperature (between 170 degrees C and 20 0 degrees C) and frying time (between 4 min and 6 min). A central composite rotatable design was adapted to study the effects of the independent varia bles on different quality attributes of potato strips. Textural quality was measured by texture profile analysis, Volodkevich tests and multiple punct ure tests. Colour parameters and moisture and oil contents were also determ ined. The effect of frying time was more significant than the effect of fry ing temperature on the quality attributes, and when blanching was carried o ut before frying most attributes were independent of frying temperature. Fr ying of fresh strips at 185 degrees C for 4.5 min resulted in minimum optim al points for hardness 1, hardness 2. Volodkevich parameters and oil conten t and saddle points for colour parameters in approximately the same combina tion. For models fitted for most of the quality attributes of blanched frie d strips, r(2) was better and the lack of fit was not significant, although high-temperature short-time blanching before frying resulted in loss of fi rmness and discolouring, and increased the percentage of oil retained by th e strips, causing sensorial quality loss.