Sensory properties determined by starch type in white sauces: effects of freeze/thaw and hydrocolloid addition.

The effect of 5 types of starch (rice, potato, waxy corn, corn, and modified waxy corn) on the sensory properties of white sauces was studied. A comparative study was also made of variations resulting from freezing/thawing and effect of replacing 0.15% starch with 2 nonstarchy hydrocolloids, xanthan gum (XG), or locust bean gum (LBG) in samples to be frozen. The sensory properties were studied through descriptive analysis by a panel of 10 trained judges. Principal components analysis and cluster analysis were used to group each of the samples according to the scores for consistency, resilience, graininess, thickness, heterogeneity, creaminess, and mouth coating, the sensory attributes which were chosen to define the sauces under study. Significant differences were found between the different starches employed: the rice and modified starches presented similar behavior to each other, as did the potato starch and corn starch, while the waxy starch sauce stood apart from the rest because of its resilience. The freeze/thaw cycle had the greatest effect on the corn-starch sauce, increasing its graininess and heterogeneity values owing to retrogradation. Adding XG or LBG to the sauces subjected to a period of freezing/thawing did not have a significant effect on the sensory attributes of the reheated sauces made with rice, potato, or waxy or modified starch, but lower graininess and heterogeneity values were observed in the sauce made with corn starch.