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

Effect of Gluten and Wheat Starch on the Frozen Storage Quality of Reconstituted Dough

The frozen preservation quality of dough cannot meet the requirements of industrial production of fresh and wet noodles. To investigate the effect of the main dough components (gluten protein and starch) on the quality of the frozen dough, dough restructuring with high gluten wheat flour (50%) and different proportions of gluten and wheat starch, and the water distribution, rheological properties, pasting characteristics, gel strength, microstructure and hydrogen bond strength were analyzed after freezing storage at 18 ℃ for 20 days, with 100% raw wheat flour as the control group. The results showed that the water in the frozen reconstituted dough gradually migrated from bound water to free water, and the elastic modulus decreased from 125900 Pa to 73020 Pa as the ratio of gluten to wheat starch decreased from 4:1 to 1:4, the pasting parameters increased, andgel hardness from 114.30 g to 181.39 g. Scanning electron microscope showed that the lower the ratio of gluten to wheat starch, the more unfavorable the uniformity of the gluten protein network structure. The hydrogen bond strength in the reconstituted dough was greater than that in the control group after adding gluten and wheat starch, and it continued to increase as the ratio of gluten to wheat starch decreased. When the ratio of gluten to wheat starch was 4:1, the elastic modulus of the reconstituted dough frozen for 20 days was 49.95% higher than that of the control group, which delayed the quality deterioration of the dough during the frozen storage. Reconstituting the dough with a certain ratio of starch to gluten can improve the viscoelasticity of the dough, which was beneficial to its cryopreservation quality

An oral colon-targeting controlled release system based on resistant starch acetate: Synthetization, characterization, and preparation of film-coating pellets

An oral colon-targeting controlled release system based on resistant starch acetate (RSA) as a film-coating material was developed. The RSA was successfully synthesized, and its digestion resistibility could be improved by increasing the degree of substitution (DS), which was favorable for the colon-targeting purpose. As a delivery carrier material, the characteristics of RSA were investigated by polarized light microscopy, FTIR spectroscopy, and X-ray diffraction. The results revealed a decrease of the crystallinity of RSA and a change of its crystalline structure from B + V hydrid type to V type. To evaluate the colon-targeting release performance, the RSA film-coated pellets loaded with different bioactive components were prepared by extrusion–spheronization and then by fluid bed coating. The effects of the DS, plasticizer content, and coating thickness of the RSA film and those of the content and molecular weight of the loaded bioactive component on the colon-targeting release performance of the resulting delivery system were investigated. By adjusting the DS, the coating thickness, and the plasticizer content of the RSA film, either the pellets loaded with a small molecular bioactive component such as 5-aminosalicylic acid or those with a macromolecular bioactive peptide or protein such as bovine serum albumin, hepatocyte growth-promoting factor, or insulin showed a desirable colon-targeting release performance. The release percentage was less than 12% in simulated upper gastrointestinal tract and went up to 70% over a period of 40 h in simulated colonic fluid. This suggests that the delivery system based on RSA film has an excellent colon-targeting release performance and the universality for a wide range of bioactive components

Extrusion processing and characterization of edible starch films with different amylose contents

Various edible starch films were prepared via extrusion, with a particular focus on the effects of the amylose content of starches from the same resource (corn) on film processibility and performances. Four corn starches with different amylose contents (4.3-77.4%) were used as model materials. The effects of various extrusion processing conditions, such as temperature, screw speed, feeding rate, and water content were systematically investigated. It was found that, while a higher amylose content increased the difficulty of extrusion processing, this could be overcome by increasing the processing temperature, moisture content, and equilibration time. On the other hand, mechanical testing, differential scanning calorimetry, dynamic mechanical analysis, and microscopy showed that films based on higher amylose starch had better mechanical and thermal properties. The reasons include not only the easy entanglement of long linear amylose chains, but also the retained granular structure in high-amylose films, which may act as self-reinforcement

Analysis of Starch Structure and Pasting Characteristics of Millet Thick Wine during Fermentation

Starch is the main substrate in millet thick wine (MTW). In order to control the fermentation process of MTW, it is critical to monitor changes in the starch structure and physicochemical characteristics during the fermentation of MTW. In the present study, the structural characteristics of MTW starch were analyzed by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and rapid viscosity analysis (RVA). The results of SEM and CLSM showed that large starch granules in MTW swelled, developed cavities, and ruptured or even vanished with the prolongation of the fermentation time, whereas the size and shape of small starch granules barely changed, only falling off the pomegranate-seed-like aggregates. With the increase in fermentation time, the relative crystallinity of starch in MTW gradually increased. In addition, the short-range ordered structures underwent complex changes. Changes in the starch morphology and ordered structure led to an increase in the peak viscosity time and the initial gelatinization temperature. The present results reveal the beneficial effect of fermentation on MTW processing and suggest its potential applications in other millet-based fermented products