engleski

Influence of the degree of starch damage on the amylographic evaluation of wheat flour

Degree of starch damage is an important parameter in the evaluation of the quality of flour but it is often ignored. A certain degree of starch damage has a favourable impact on the quality of baked goods, and any deviation from these values can have a negative impact on quality. The aim of this work was to explore the influence of the degree of starch damage on the amylographic evaluation of wheat flour using the Brabender Micro Visco-Amylo-Graph. Wheat grain sample with low amylolytic activity (Falling number – FN = 356 s) was subjected to sprouting to obtain wheat grain sample with high amylolytic activity (FN = 98 s). The kernels of these samples were milled in the laboratory mill Perten 3100 to obtain flour samples with small degree of starch damage (3.15%). The flours were re-milled in the kitchen mill (Phillips) during 5 minutes to get samples with higher starch damage degree (6.13%). The content of damaged starch was determined according to enzymatic method AACC 76-30A. Samples were analysed with Micro Visco-Amylo-Graph at constant heating rate of 7.5 °C/min. Based on the obtained results of research carried out in this paper, it can be concluded that, regardless the amylolytic activity, degree of starch damage have significant influence on the measured amylographic parameters. Increasing the degree of starch damage reduces the pasting temperature from 64.5 to 61.6 °C and 64.2 to 63.9 °C, significantly increase the peak viscosity from 129 to 191 Brabender Units (BU) and 623 to 660 BU, breakdown viscosity from 105 to 153 BU and 168 to 178 BU and setback from 27 to 46 BU and 533 to 534 BU for flour samples with high and low amylolytic activity, respectively. Those changes of amylographic parameters can be attributed to better water absorption and increased amylase leeching from starch granules which improves starch gelatinization. The results indicate the need for determining the degree of starch damage as a very important parameter for wheat flour evaluation.

Starch damage; Amylographic evaluation

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