Relation between adhesiveness and surface leachate rheological properties of cooked noodles: From the view of starch fine molecular structure

Adhesiveness is one of the important sensory properties of noodles. A better understanding of the molecular basis of the sensory property would allow for a more reasonable selection of wheat ingredients. In this study, the adhesiveness of cooked noodles made from reconstituted wheat flour was evaluated using a texture profile analyzer. The rheological properties of dissolved solids from the noodle surface were measured. The composition and structure of leachate, as well as multi-structure of native starch were analyzed. The correlation analysis showed that adhesiveness positively correlates with the loss modulus parameters [log K' (consistency coefficient) and Ea (activation energy)]. Increased content of leached starch can ascend the rheological parameters (log K' and Ea). In addition, more short amylose chains with 100-500 degree of polymerization (DP) in leached starch also induced the increase of log K' (p < 0.01) and Ea (p < 0.01). The fraction of short amylose chains in leached starch was negatively correlated with the content of long amylopectin chains ranged from 37 to 100 DP in native starch (p < 0.05), as well as the median diameter of particles (p < 0.01). Multi-level structures of native starch granules largely determine the composition and molecular structure of noodle leachate, consequently contrib-uting to surface rheological properties. It is thus proposed that wheat starch with more long amylopectin chains and large granules could be used to reduce noodle adhesiveness. Moreover, the rheological approach using noodle surface materials proposed here is useful to predict the noodle adhesiveness as an important sensory characteristic.