https://dspace.ewha.ac.kr/handle/2015.oak/171890 2026-04-10T08:58:29Z 2026-04-10T08:58:29Z 김미경 박지훈 도한솔 https://dspace.ewha.ac.kr/handle/2015.oak/275109 2026-04-09T16:31:08Z 2026-01-01T00:00:00Z

Title: Physical, chemical, and structural properties of subcritical water-treated cellulose derived from Sargassum horneri Ewha Authors: 김미경; 박지훈; 도한솔 Abstract: To overcome the limitations of conventional nanocellulose – specifically cellulose nanocrystals and cellulose nanofibers – this study developed subcritical water-treated cellulose (SWT-C) using subcritical water treatment (SWT). In this work, SWT was applied to a solid residue obtained through conventional alkali and bleaching pretreatments to produce nanocellulose and the structural, physical, and chemical properties of SWT-C under various SWT conditions were evaluated. The yield of SWT-C decreased with increasing temperature and time, ranging from 9.54 ± 1.19% to 13.15 ± 1.27%. Entangled nanofibrillar networks were observed in SWT-C, with fiber diameters decreasing under harsher conditions. XRD analysis demonstrated that SWT enhanced crystallinity to 69.43 ± 2.61% (at 180 °C for 20 min). This value was higher than that of both the initial raw material (Sargassum horneri, 43.17 ± 1.07%) and the extracted micron-scale cellulose (57.25 ± 3.67%). FTIR spectra demonstrated enhanced peaks at 1430 and 898 cm−1, indicating removal of amorphous regions and improved molecular alignment. Colorimetric changes, attributed to 5-(Hydroxymethyl)furfural and furfural formation, included decreased L* and increased a* value as treatment conditions became harsher. Thermal analysis showed degradation and onset temperatures of 352.95 °C and 241.34 °C, respectively. Surface conductivity and polydispersity index (PDI) remained below 0.4 under optimal aqueous conditions: 160 °C for 60 min (0.1 wt%) and 160 °C for 40 min (0.2 wt%). These findings demonstrate that SWT significantly affects the physicochemical properties of SWT-C and highlight its potential as a sustainable material for food-related applications. © 2026

2026-01-01T00:00:00Z 김봉수 https://dspace.ewha.ac.kr/handle/2015.oak/274868 2026-03-30T16:31:09Z 2026-01-01T00:00:00Z

Title: Microbial Production and Industrial Applications of (S)-Equol for Precision Health and Functional Food Innovation Ewha Authors: 김봉수 Abstract: Equol is a nonsteroidal, microbiota-derived estrogenic metabolite of the soy isoflavone daidzein, known for its potent antioxidant, anti-inflammatory, and selective estrogenic receptor modulating activities. With enhanced bioavailability and tissue-specific hormonal effects, equol has been proposed as a candidate for managing hormone-related conditions such as menopausal symptoms, prostate health, and metabolic inflammation. However, endogenous equol production is limited to 25–60% of individuals, depending on the presence of specific gut microbial consortia. This review highlights recent advances in equol research, emphasizing its molecular mechanisms of action, population-specific clinical evidence, and translational potential in functional foods and nutraceuticals. Particular attention is given to microbial production strategies, including native and engineered equol-producing strains from human, animal, and food origins, as well as emerging heterologous expression systems. We further discuss challenges and opportunities in scalable fermentation, formulation stability, and regulatory approval that are critical for the industrial application of equol in precision health solutions. © 2026 American Chemical Society

2026-01-01T00:00:00Z 권오란 김유진 https://dspace.ewha.ac.kr/handle/2015.oak/274830 2026-03-30T16:31:05Z 2026-01-01T00:00:00Z

Title: Bi-dimensional health space mapping: machine learning analysis of population health dynamics in Korean and Dutch cohorts Ewha Authors: 권오란; 김유진 Abstract: Health spans a broad spectrum, encompassing various biological and lifestyle factors. The complexity of biological systems necessitates for integrating diverse factors into a unified biomarker. We constructed a health space model that highlights metabolism and oxidative stress as key indicators for tracking healthy aging and mapping health trajectories. To ensure cross-ethnic relevance, we used data from the Dutch Nutrition Questionnaires plus and Korean National Health and Nutrition Examination Survey (KNHANES) cohorts. Our approach combines machine learning with logistic regression, applying a least absolute shrinkage and selection operator penalty to propensity score-matched datasets. External validation using an independent KNHANES cohort showed strong performance (AUC = 0.959 for metabolic stress; 0.973 for oxidative stress), confirming model reliability. These findings support the health space model as a holistic tool for monitoring physiological stress. Our research advances personalized health monitoring and offers a foundation for precision nutrition strategies aimed at reducing chronic disease risk. © The Korean Society of Food Science and Technology 2025.

2026-01-01T00:00:00Z 김봉수 https://dspace.ewha.ac.kr/handle/2015.oak/274608 2026-03-23T16:30:03Z 2025-01-01T00:00:00Z

Title: Gut microbiome and metabolite signatures for predicting acute kidney transplant rejection: a prospective study Ewha Authors: 김봉수 Abstract: Acute rejection (AR) remains a significant challenge in kidney transplantation (KT) despite advances in immunosuppressive treatment. Recognizing the critical influence of the gut microbiome on modulating host immunity, we investigated the association between gut dysbiosis and AR in KT recipients. A total of 97 patients with KT were prospectively enrolled from two centers, and their samples were collected at multiple time points, such as pre-transplant (n = 97), three months (n = 66), and twelve months (n = 37) post-transplant. Microbial profiling was performed using 16S rRNA sequencing and fecal metabolomics was done via nuclear magnetic resonance spectroscopy. Thirty-three patients developed AR after KT, exhibiting reduced bacterial richness and diversity compared with KT recipients without AR. In addition, these patients had increased Escherichia-Shigella and decreased Phascolarctobacterium abundance. Pathway analysis identified 47 enriched pathways in AR patients, notably those involved in lipopolysaccharide biosynthesis and short-chain fatty acid metabolism. Consistent results were obtained from stool metabolomics, showing reduced propionate and lactate concentrations compared with patients without AR. Finally, combining pre-KT bacterial and fecal metabolite features with clinical parameters significantly improved AR prediction accuracy. Our results suggest that integrating clinical, microbial, and metabolomic data may provide a more holistic patient care regimen across both pre- and post-transplant phases.

2025-01-01T00:00:00Z