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Your search keyword '"Cheng, Yanfen"' showing total 13 results
Start Over Author "Cheng, Yanfen" Journal international journal of biological macromolecules
13 results on '"Cheng, Yanfen"'

11. Good hydrolysis activity on raffinose family oligosaccharides by a novel α-galactosidase from Tremella aurantialba

Author

Xu Lijing, Ming-chang Chang, Hexiang Wang, Dongxue Yang, Qiaoyi Zhang, Geng Xueran, Cheng Yanfen, and Jun-long Meng

Subjects
Hot Temperature, Dried fruit, Ion chromatography, Oligosaccharides, 02 engineering and technology, Biochemistry, Stachyose, Fungal Proteins, 03 medical and health sciences, chemistry.chemical_compound, Raffinose, Structural Biology, Enzyme Stability, Molecular Biology, 030304 developmental biology, 0303 health sciences, Chromatography, biology, Basidiomycota, Hydrolysis, Fast protein liquid chromatography, General Medicine, 021001 nanoscience & nanotechnology, biology.organism_classification, Enzyme assay, Thin-layer chromatography, chemistry, Metals, alpha-Galactosidase, biology.protein, Tremella aurantialba, 0210 nano-technology
Abstract

An α-galactosidase designated as TAG was purified from the dried fruit bodies of Tremella aurantialba with 182.5-fold purification. The purification procedure involved ion exchange chromatography on Q-sepharose, DEAE-Cellulose, and Mono Q and gel filtration by FPLC on Superdex 75. The purified α-galactosidase was a monomeric protein with a molecular mass of 88 kDa. The optimal pH of TAG was 5.0 and more than 60% of the original enzyme activity remained at pH 2.0 and 3.0. Its optimal temperature was 54 °C with good thermo-stability, 30.8% of the original activity was retained after exposure to a temperature of 70 °C for 1 h. The metal ions Hg2+, Cu2+, Fe3+ and Mg2+ strongly inhibited the enzyme activity. The enzyme activity was found to be inhibited by N-bromosuccinimide indicating that tryptophan was essential to the catalytic activity of α-galactosidase. The enzyme completely hydrolysed stachyose and partially hydrolysed raffinose to galactose at 50 °C within 6 h as detected by thin layer chromatography and the dinitrosalicylic acid method and the content of reducing sugar reached 4.36 mg/mL.

Published
2020

13. Characterization of free radical-mediated Pleurotus ostreatus polysaccharide-EGCG conjugates for chilled minced pork preservation.

Author

Niu, Xukai, Xu, Mengyan, Han, Xiaoyue, Han, Qianxi, Liu, Bo, Cheng, Yanfen, Yun, Shaojun, Cheng, Feier, Feng, Cuiping, and Cao, Jinling

Subjects
*FREE radical reactions, *PLEUROTUS ostreatus, *CONTACT angle, *POLYSACCHARIDES, *FREE radicals
Abstract

To improve the functions of Pleurotus ostreatus polysaccharide (POP), POP-EGCG conjugates were prepared using free radical graft polymerization reactions and were characterized using UV–vis, FT-IR, SEM, XRD, DSC, TG, particle size and potential, three-phase contact angle, and rheological tests; The antioxidant and antibacterial ability in vitro were detected. Moreover, effects of POP-EGCG on the quality of refrigerated minced pork were investigated. The results showed the optimal preparation conditions of POP-EGCG were 1 % POP, 1.3 % EGCG, 0.25 % Vc, 16 % concentration of H 2 O 2 , and reaction 17 h. The POP-EGCG showed the characteristic peak of EGCG and was a mesh honeycomb with rough and porous surface; It had higher crystallinity, increased particle size, but decreased thermal stability, solubility, and viscosity, and significantly enhanced antioxidant and antibacterial ability. The POP-EGCG effectively improved the sensory quality and inhibited lipid oxidation of chilled minced pork, and extended the shelf life of minced pork up to 9 days at 4 °C. Specifically, the TVB-N and TBARS of minced pork in the POP-EGCG group were respectively 14.93 mg/100 g and 0.9 mg MDA/kg, which were lower than the spoilage thresholds in the national standard. This study provides a theoretical basis for further development of natural antioxidants and antimicrobial agents. • POP-EGCG conjugates were prepared by a radical grafting reaction. • POP-EGCG increased crystallinity, but decreased thermal stability, solubility. • POP-EGCG have higher antioxidant activity and bacteriostatic ability in vitro. • POP-EGCG conjugates can delay the lipid oxidation of minced pork. [ABSTRACT FROM AUTHOR]

Published
2024
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