engleski

DETERMINATION OF AMIDATED PECTIN INFLUENCE ON THE DOUGH INITIAL FREEZING POINT BY DTA APPLICATION

Because of the water absorption ability hydrocolloids have been often used in backing industry for two reasons: the influence of the product freshens and the regulation of water content during freezing (reduction of water loss in the formed structure). In this investigation the influence of amidated pectin (PECTIN AMID AF 010-A) addition on content of unfreezable water in dough (flour-water-system) was cared out determining initial freezing points (Ti) by differential thermal analysis (DTA). Initial freezing points (Ti) of 10 modal solutions of pectin amid (w = 0.5 - 5%) and of dough samples with different pectin amid content (w = 0.5 - 5%, calculated on flour mass) were determined. For the dough preparing flour with the water content of 11.8%, ash content of 0.55% and with the water absorption of 57% was used. Relations between decrease of the initial freezing points Ti as a function of pectin amid content were calculated by linear regression. Coefficient of determination for the model solutions of pectin amid was R2 = 0.97 and for the dough samples was R2 = 0.98. The dough samples showed higher decrease of the initial freezing points (Ti = from - 0.85 to - 1.29 °C) than the samples of model solutions (Ti = from - 0.10 to - 0.27 °C). The influence of pectin amid on increasing of unfreezable water content was determined by comparison of initial freezing points of modal solutions and initial freezing points of dough samples depending on pectin amid content calculated on water content of samples.

dough; amidated pectin; initial freezing point; DTA

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