Optimization of osmotic dehydration of cauliflower.

Osmotic dehydration of cauliflower as influenced by temperature (40-90
C), salt concentration (5-25%), ratio of brine to material (2-4, w/w) and time
(5-180 min), was studied through central composite rotatable design (CCRD)
under response surface methodology. Responses of weight loss (%) and salt
pickup (%) were fitted to polynomials of second degree requiring 6 and 7 terms,
respectively, with multiple correlation coefficients of 0,97 and 0.98. The fitted
functions were optimized for maximum weight loss and with 4% salt pickup using
a flexible polyhedron search method. Out of four such optimum sets one was
selected based on the actual weight losses in the verification experiments with
larger batch sizes, color and appearance, texture and rehydration properties of
the dried materials. The optimum conditions required the material to be
processed at 8OC for 5 min in 2 times (w/w) of 12% brine. The selected optimum
as well as two other optimum sets also inactivated polyphenol oxidase which
causes enzymatic browning.