Effect of A- and B-granules of wheat starch on Chinese noodle quality

Abstract

To investigate the effect of A- and B-type granules of wheat starch on noodle quality, the fractionation and reconstitution method was used to prepare noodles with five different ratios of A-to B-granules (100A-0B, 75A-25B, 50A-50B, 25A-75B, 0A-100B). The pasting and swelling properties of reconstituted flours and the microstructure of noodles observed under a confocal laser scanning microscope (CLSM) indicated that there were at least two aspects were responsible for the changes in noodle quality. First, the water distribution, texture and cooking quality of noodles were influenced by the different physicochemical properties of A- and B-granules; and second, the gluten structure in noodles was altered by the granule size distribution, which further led to a difference in noodle quality. In general, with increasing number of B-granules, the A22 (the proportion of less immobilized water) of raw noodles and the hardness, resilience and chewiness of cooked noodles increased first and then decreased, while the cooking loss, water absorption and protein loss showed the reverse trend. Raw noodle samples containing 50A-50B had the minimum T22 (less immobilized water) but the maximum A22 and, when cooked, had the greatest hardness, chewiness and resilience and the least cooking loss (6.6%) and water absorption (166.1%). These results have important implications for illustrating the mechanism by which A- and B-granules affect noodle quality and guide efforts to improve noodle quality and wheat breeding.