Corn starch xanthan gum interaction and its effect on the stability during storage of frozen gelatinized suspensions

FERRERO C.; MARTINO M.N. ; ZARITZKY N.

STARCH/STARKE

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 1994 vol. 46 p. 300 - 308

0038-9056

The knowledge of starch pastes behavior during frozen storage becomes necessary to understand more complex systems (e.g. sauces, dressings and desserts).The effect of sub-zero storage on the quality attributes of corn starch pastes (10% w/w) with and without xanthan gum (0.3% w/w) was analyzed.Pastes were frozen at different rates (0.3 to 270cm/h) and stored at -5, -10 and -20°C.Exudate production (syneresis) and rheological behavior were studied by means of capillary suction and rotational viscometry respectively.Ice recrystallization was analyzed by indirect microscopic observations using isothermal freeze fixation and amylopectin retrogradationby differential scanning calorimetry (DSC). Samples stored at -5OC (glass transition temperature) or higher temperatures were under the rubbery state evidenced by starch recrystallization. This state favored molecular mobility leading to deteriorative changes (likespongy structure formation related to amylose retrogradation). At lower storage temperatures (-10 and -20°C) under the glassy state,starch retrogradation was not detected and deteriorative changes can be related to ice recrystallization.The addition of xanthan gum minimized amylose retrogradation, syneresis and rheological changes, however, its presence did not prevent ice recrystallization nor amylopectin retrogradation.