Effects of multi-frequency ultrasound pretreatment under low power density on the enzymolysis and the structure characterization of defatted wheat germ protein |
| |
| Institution: | 1. Technology Integration Base for Vegetable Dehydration Processing Ministry of Agriculture PR China, School of Food and Biological Engineering, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China;2. School of Food and Biological Engineering, Zhengzhou University of Light Industry, 5 Dongfeng Road, Zhengzhou, Henan 450002, China;3. Collaborative Innovation Center of Food Production and Safety, Henan Province, 5 Dongfeng Road, Zhengzhou, Henan 450002, China;4. Department of Agricultural and Food Engineering, University of Uyo, P.M.B 1017, Uyo 520001, Nigeria;5. Department of Biosystems Engineering and Soil Science, The University of Tennessee, 2506 E.J. Chapman Drive, Knoxville, TN 37996, USA;1. State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China;2. Department of Food Science and Technology, Faculty of Engineering and Technology, University of Gezira, P.O. Box 20, Wad Madani, Sudan;1. School of Food and Biological Engineering, Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, Jiangsu University, No.301 Xuefu Road, Zhenjiang 212013, China;2. Faculty of Agriculture, University of Zalingie, PO Box 6, Zalingie, Sudan;1. School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China;2. School of Food and Biological Engineering, Zhengzhou University of Light Industry, 5 Dongfeng Road, Zhengzhou, Henan 450002, China;3. Collaborative Innovation Center of Food Production and Safety, Henan Province, 5 Dongfeng Road, Zhengzhou, Henan 450002, China;4. Department of Agricultural and Food Engineering, University of Uyo, P.M.B 1017, Uyo 520003, Nigeria;1. School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China;2. Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, 301 Xuefu Road, Zhenjiang 212013, China;3. Department of Hospitality, School of Applied Science and Technology, Koforidua Polytechnic, P.O. Box 981, Koforidua, Ghana |
| |
| Abstract: | The effects of ultrasonic frequency mode, power density, pretreatment time and other parameters under low power density on the degree of hydrolysis (DH) of defatted wheat germ protein (DWGP) and angiotensin-I-converting enzyme (ACE) inhibitory activity of DWGP hydrolysate were studied in this research. Ultraviolet–visible (UV–Vis) spectra, free sulfhydryl (SH), disulfide bond (SS), surface hydrophobicity and hydrophobic protein content of ultrasound-pretreated protein and hydrophobic amino acid (HAA) content of alcalase-hydrolysate of DWGP were measured under optimized ultrasonic condition. The ultrasonic frequency mode with dual-fixed frequency combination of 28/40 kHz showed higher ACE inhibitory activity of DWGP hydrolysate compared with that of other ultrasound frequency modes and all the ultrasonic frequency combinations involving in 28 kHz showed higher ACE inhibitory activity. Under the dual-fixed frequency ultrasound mode of 28/40 kHz, ultrasonic power density of 60 W/L, pretreatment time of 70 min, temperature of 60°C and substrate concentration of 60 g/L, the ACE inhibitory activity of DWGP hydrolysate was the highest with its value of 74.75% (increased by 62.30% compared to control). However, all the ultrasonic pretreatment did not increase the DH of DWGP significantly (p > 0.05). The changes in UV–Vis spectra, SH and SS groups, surface hydrophobicity and hydrophobic protein content indicated that the structure of DWGP unfolded after ultrasound pretreatment. The HAA content of hydrolysate from the pretreated DWGP increased significantly (p < 0.05). The results proved that ultrasound pretreatment loosed the protein structure and exposed more HAA residues of protein to be attacked easily by alcalase. This resulted in the increase in the HAA content which related to the ACE inhibitory activity. |
| |
| Keywords: | Defatted wheat germ ACE inhibitory activity Ultrasonic pretreatment Frequency |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
