ABSTRACT Objective: The purpose of this study was to investigate the effect and influencing factors of post-surgical radioactive iodine (RAI) therapy for patients with low- and intermediate-risk differentiated thyroid cancer (DTC). Subjects and methods: A retrospective analysis of 423 low- and intermediate-risk DTC patients admitted to the Department of Nuclear Medicine, Sichuan Provincial People’s Hospital from January 2005 to December 2020 was performed. All patients were treated with surgery, had a postoperative pathological diagnosis, and were treated with RAI, including 89 males and 334 females. Recurrence risk stratification: 143 cases were low-risk, and 280 cases were intermediate-risk. Results: The excellent response (ER) rate for low- and intermediate-risk were 93.7% and 78.2%, respectively (P < 0.05). There were significant differences in age, cumulative dose of [131I], and pretreatment stimulated-Tg (pre-Tg) levels between the low- and intermediate-risk groups (P < 0.05). There were significant differences in the cumulative dose of 131I and pre-Tg levels between ER and the non-ER group (P < 0.05). The area under the curve (AUC) values were 0.799 in the low-risk group, and 0.747 in the intermediate-risk group for the ROC curve by ER status of pre-Tg. The ER rate with RAI treatment decreased with an increase in pre-Tg levels. Conclusion: Pre-Tg was an important factor for RAI treatment decision-making and prognostic evaluation and differed between low-risk and intermediate-risk DTC. Aggressive RAI therapy was recommended for low-risk DTC with pre-Tg ≥ 20.0 ng/mL and in intermediate-risk group with pre-Tg ≥ 10.0 ng/mL.

Abstract The functional properties of wheat gluten protein isolated from nonfermented dough stored at -6 °C, -12 °C, -18 °C, -24 °C and -30 °C for 10 d, 20 d and 30 d were investigated. The solubility and water holding capacity of gluten protein decreased with decreasing frozen storage temperatures and increasing frozen storage time. The foamability of gluten protein was not affected by different frozen storage temperatures. However, the foamability of gluten protein decreased with extension of the frozen storage time. The storage modulus (G') and loss modulus (G") of gluten decreased with decreasing frozen storage temperatures. Meanwhile, the storage modulus (G') and loss modulus (G") of gluten increased with extension of the frozen storage time. When the frozen storage temperature of gluten was -12°C, the frozen water content was lower than that in gluten with other frozen storage temperatures. The water migration of gluten protein under different frozen storage temperatures and times was measured by low-field NMR. The microstructure of gluten protein was also observed under a scanning electron microscope. It was found that more serious damage to the gluten structure occurred with lower freezing temperatures and longer freezing times.

Abstract The aim of this work was to study the effect of zinc (Zn) gluconate-resistant potato starch type 2 (RS2) systems on hydration and rheological properties of wheat flour dough. Wheat flour, Zn with a content from 0.16 mg% to 0.32 mg% (flour basis), and enriched RS2 at levels of 10 g% to 30 g% (flour basis) were used. Hydration, rheological properties and microstructural characteristics of wheat flour dough were analyzed. The results showed that the dough stability time decreased with increasing RS2. When the RS2 content was less than 25 g%, the stability time was significantly higher than that of the control group. RS2 and Zn could improve the tensile strength and thermal stability of the dough but reduced the quality of protein and mechanical resistance of the dough. Zn could increase the hardness, adhesiveness and springiness of the dough, while RS2 had a negative effect on the springiness of the dough. The RS2-Zn system reduced the water absorption, moisture content and molecular mobility of the dough, and damaged the microstructure of the dough to varying degrees. The addition of RS2 (10 g%) and Zn (0.24 mg%) could render a dough with satisfactory rheological properties, hydration and microstructural characteristics.

Abstract This paper took fermented dough as the research object. The difference between the subfreezing temperature and other freezing temperatures for long-term storage of fermented dough was discussed. The fermented dough was quick-frozen at -30 °C for 1 h and then stored at -6 °C, -12 °C and -18 °C for 5 d, 10 d and 15 d. The results indicated that with decreasing freezing temperature, the content of bound water in the dough increased gradually so that the water in the dough could be better preserved and the storage time of the dough could be prolonged. Although low temperatures could have a better storage effect, too low temperature and prolonged freezing time would destroy the structure of the starch in the dough. The structure of the starch stored at the subfreezing temperature (-12 °C) was better than that stored at other temperatures. Compared with the common freezing temperature (-18 °C), the subfreezing temperature not only achieves a better storage effect but also reduces energy consumption.

Abstract This study investigated the effects of different storage temperatures on the structure and physicochemical properties of starch in frozen nonfermented dough. The results showed that the water activity and water loss rate of dough samples decreased with decreasing storage temperature. The density of hydrogen protons in the dough sample decreased as well. The freezable water content in dough increased with decreasing freezing temperature. The results showed that with decreasing freezing temperature, the formation and recrystallization of ice crystals in the process of freezing storage resulted in an increase in depressions and holes in wheat starch grains, internal and external damage to starch, and a gradual decrease in the relative crystallinity. The porous surface of starch particles and their loose molecular order structure promote the infiltration of water molecules into the interior of the starch particles. The combination of starch chain and water molecules makes the peak viscosity of starch in the dough gradually rise, but diminishes its stability when heated. Compared with the control group, the starch recovery value increased, and the starch enthalpy value increased gradually. The structure and physicochemical properties of starch in nonfermented dough stored at -12 °C and -18 °C were similar.

Abstract In this paper, frozen steamed bread was used as the object to study the effect of frozen storage on the protein characteristics in a steamed bread system by measuring the changes in water holding capacity, oil holding capacity, emulsifying capacity, soluble protein content, surface hydrophobicity, secondary structure and molecular weights of gluten proteins in frozen steamed bread. The results showed that with an extension of frozen storage time, the disulfide bond (S‒S) and total content of sulfydryl (-SH) decreased as a whole, and the molecular weights of steamed bread proteins were mainly distributed between 22 and 31 kDa, which were composed of a mixture of gliadin and low-molecular-weight glutenin subunits. With a decrease in frozen storage temperature, the soluble protein contents and protein water holding capacities of steamed bread first increased and then decreased, and the trend of the surface hydrophobicity was opposite. The frozen storage temperature had a significant effect on the protein properties of the steamed bread system. The changes in protein emulsification, oil holding capacity and soluble protein content were stable at -24 °C, which was suitable for long-term frozen storage.