Quantitative assessment of protein fractions of Chinese wheat flours and their contribution to white salted noodle quality

Protein quantity and quality play a significant contribution to white salted noodle processing. The objective of this study was to determine the contribution of different protein fractions to 25 Chinese varieties on wheat based noodle quality. The results showed: the average ratio of monomeric protein, soluble glutenin and insoluble glutenin in Chinese Huanghuai winter wheat was 3.7:1.0:1.8. Compared with Canadian wheat varieties, the ratio was 4.4:1.0:2.0. The monomeric protein and insoluble glutenin were lower in the Chinese varieties, the soluble glutenin content was higher; while the dough character was lower than Canadian hard wheat, but most Chinese wheat can make good quality noodles. This may be the defining difference between noodle wheat and bread wheat. The monomeric protein content was significant positive correlated with fresh noodle maximum resistance, and high significant positive with extension distance and area. The soluble and insoluble glutenin were mainly responsible in fresh noodle maximum resistance, extension distance and using a texture analyzer, but were high negative correlated with fresh noodle sheet length (Table 2). For cooked noodles, the soluble glutenin content demonstrated a high significant positive relationship to cutting firmness, and a significant negative correlation to cooking loss. The insoluble glutenin content was high significant positive correlated with cooked noodle thickness, hardness and cutting firmness (Table 3). The results suggested that the monomeric protein is less important than that of the glutenin for fresh noodle resistance. The soluble glutenin content is the most important property for noodle wheat, and soluble glutenin content can be used in the early generations to identity Chinese noodle wheat. (c) 2006 Elsevier Ltd. All rights reserved.