## 4 Conclusions  
The present study explores the detailed impact of adding soybean protein isolate to high-gluten flour noodles. The addition of a 20% SPI enhanced the protein (30.69%) and moisture content (44.84%) of the noodles and reduced the carbohydrate content (23.06%). This increase in protein content may make noodles suitable for elderly people who are generally more susceptible to protein deficiency. The addition of SPI also altered the textural and sensory properties of the noodles. The control noodles were more acceptable in terms of flavor and taste. However, no statistically significant difference was observed between 5% SPI noodles and control noodles indicating that 5% SPI noodles were similar to control noodles in taste, flavor and overall acceptability. The addition of SPI not only increased the protein content of the noodles, but also categorized the noodles into the low-GI food with a GI of 48.63 for 20% SPI noodles. Synergistic risk factors such as hypertension and obesity are frequently present in people with diabetes, and they raise the risk of cardiovascular disease death rates. High GI is associated with an increased risk of cardiovascular disease events, and hence regulation of GI in patients with type 2 diabetes plays a crucial role; such regulation may also aid in lowering the risk of cardiovascular diseases. Considering the association of GI with diabetes and cardiovascular disease, the findings of the present study  
Figure 1: Blood glucose response curve of glucose, noodles, and 20% SPI noodles. According to the LSD (least significant difference) test, means followed by different letters at the same time are significantly different at \(p<0.05\).  
may serve as an impetus for regulating these factors in elderly people with the addition of SPI in noodles. Further, the quality of soy protein can also be improved by removing the anti-nutritional compounds and by breaking the protein into smaller peptides. Although soybean protein has been proven to be beneficial in various aspects, further investigation on the soy-protein-related allergies is needed. Moreover, an in-depth study is required to achieve better insights about the interactions between protein and components of different foods apart from noodles to produce various protein-rich foods without compromising the food quality in order to satisfy consumer expectations.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app13137772/s1](https://www.mdpi.com/article/10.3390/app13137772/s1)]([https://www.mdpi.com/article/10.3390/app13137772/s1](https://www.mdpi.com/article/10.3390/app13137772/s1)), Figure S1: IDDSI (International Dysphagia Diet Standardization Initiative, 2019) tests on control and 20% SPI noodles.  
Conceptualization, C.-Y.H. and C.-H.K.; methodology, J.-N.L. and S.-L.H.; software, J.-N.L.; validation, X.-Y.L.; formal analysis, Y.-C.L.; investigation, J.-N.L. and X.-Y.L.; resources, Y.-H.T.; data curation, C.-H.K.; writing--original draft preparation, P.N. and C.-H.K.; writing--review and editing, V.S., C.-Y.H. and C.-H.K.; supervision, C.-H.K. All authors have read and agreed to the published version of the manuscript.  
This work was supported by research funding grants provided by the National Science and Technology Council of Taiwan (NSTC 111-2221-E-992-005-MY3).  
Ethical review and approval were waived for this study as the current study falls in the \"Scope of human research cases exempted from review by the Ethical Review Board\" issued by the Ministry of Health and Welfare, Taiwan.  
Participant consent was waived because the current research involved no more than minimal risk to the participants, and no personal information of participants was disclosed.  
Data availability Statement: Data are contained within the article.  
Author P.N. thankfully acknowledges the National Science and Technology Council of Taiwan for providing the Post-Doctoral fellowship.  
The authors declare no conflict of interest.