Analysis of Quality in Preprocessed Noodles during the Producing Process

In this study, the structure and physicochemical properties of the preprocessed noodles with different cooking times (0, 30, 60, 90, 120, 150 and 180 s), and their main components were studied to analyze the quality formation process of the preprocessed noodles. The results showed that the textural parameters of preprocessed noodles increased significantly compared to the fresh noodles (P<0.05), but the hardness decreased with the increasing in cooking time, and the changes were most obvious within 60 s. When the cooking time increased from 30 s to 180 s, the cooking loss rate increased by 2.90% while water absorption increased by 43.61%. Cooking resulted in the decrease in setback and breakdown viscosities for starch in noodles and a crystalline structure translation from A type to V type. With the extension of cooking time, the content of β-sheets structure for protein related to noodle rigidity decreased from 39.12% to 25.27%, while that of β-turns increased from 32.43% to 44.81%. The water in raw noodles mainly existed in the form of strong bound water (66.01%) and free water (18.70%). In addition, the preprocessed noodles went through the initial stage (30~60 s), the cooking stage (60~150 s) and the overcooking stage (150~180 s) in turn. The content of strongly bound water in fresh noodles was relatively high. During the cooking, the content of free water increased while the content of bound water decreased. Correlation analysis showed that the moisture content of preprocessed noodles was highly significantly (P<0.01) or significantly (P<0.05) correlated with hardness, P₂₁ and springiness, while hardness was positively (P<0.01) correlated with P₂₁. The results show that the textural characteristics can be predicted by moisture content and state in the production process of preprocessed noodles. The research provides basic data for the development of preprocessed noodles.