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Summary: In this study, a hybrid system was prepared by mixing rice starch (RS) with different mass fractions (0%–10% dry weight) of soy protein isolate (SPI) to investigate its retrogradation characteristics during storage. The results showed that the addition of SPI led to an increase in pasting temperature and a decrease in setback (SB) and aging rate (P < 0.05). When the level of SPI was increased to 10%, the pasting temperature reached a peak of 75.28°C, resulting in a decrease of 16.52% in regrowth rate and 51.61% in aging rate. The analysis of hardness and secondary structure indicated that the inclusion of SPI resulted in a less robust starch gel structure in comparison to RS, leading to a decrease in gel hardness and the short‐range ordered structure of starch. The pore structure of the starch gel was observed to be smaller and more uniform following the addition of SPI. The presence of SPI hindered the recrystallisation of starch granules, consequently leading to a delay in starch retrogradation. The results of this study have validated the positive effect of incorporating SPI on the anti‐aging properties of starch during storage. This serves as a foundational basis for enhancing the processing attributes of RS and the overall quality of starchy food products. [ABSTRACT FROM AUTHOR]

Summary: Rice bread is an essential component of a healthy diet. However, due to the poor processing properties of rice protein and starch, it is difficult to form an effective gel network structure, resulting in poor quality of rice breads. This research investigated the impacts of soy protein isolate (SPI) on the physicochemical properties of rice dough and the quality of rice bread. The results suggested that adding SPI could refine the thermal stability of mixtures and delay the aging of starch compared with pure rice flour, indicating that adding SPI reduced the amylose concentration and inhibited starch interaction in the mixed rice powder system. The rheology and SEM analysis of doughs showed that the appropriate addition of SPI increased the elasticity, and reached the highest fermentation height and gas retention coefficient at 9% SPI content, which increased by 115.38% and 8.39%, respectively. In contrast, excessive SPI led to protein aggregation and weakened the structural strength of the dough. When adding 9% SPI improved the hardness, chewiness and specific volume of rice bread, significantly reduced the brightness and baking loss rate, and refined the performance and quality of rice bread. This study confirms that SPI can be used as an improver for good gluten‐free bread (GFB) through its good functional properties and action on starch and provides some basis for further investigation of the interaction between SPI as an improver and rice starch. [ABSTRACT FROM AUTHOR]

Postmenopausal osteoporosis is one of the most common metabolic diseases in old women, and supplementing estrogen through bioactive substances is one of the important ways to improve menopausal syndrome. Some studies have confirmed that soybean isoflavone has estrogenic activity, and the main active component of soybean isoflavones is isoflavone aglycones. However, few studies have investigated the improvement effect of high-purity soy isoflavone aglycones on postmenopausal osteoporosis. Thus, the effect of different doses of high-purity soybeans isoflavone aglycone on the ovariectomized female osteoporosis rat model was evaluated by oral gavage. The rats were divided into seven experimental groups including SHAM, OVX, EE, SIHP, AFDP-L, AFDP-M, and AFDP-H, which was administered for 60 days from 30 days after ovariectomy. We collected blood from the abdominal aorta of rats on the 30th, 60th, and 90th days respectively, analyzed its serum biochemistry, and took out the femur for micro-CT imaging and bone microstructure parameter analysis. Results showed that the intervention effect of AFDP-H group on osteoporosis rats at 60 and 90 days was similar to that of EE group, and superior to the OVX group, SIHP group, AFDP-L group, AFDP-M group. The AFDP-H group inhibited the decrease in serum bone markers, bone density, trabeculae quantity, trabeculae thickness, and bone volume fraction, and increased the trabecular separation caused by ovariectomy, thereby significantly improving bone microstructure. It also prevented continuous weight gain and increased cholesterol levels in female rats. This study provided theoretical to application of soybean isoflavone aglycone in the intervention of osteoporosis. and confirmed that could replace chemical synthetic estrogen drugs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Yang, Ma, Li, Bian, Fu, Ren, Wang, Shi and Zhang.)