title: Effects of multi-frequency power ultrasound on the enzymolysis and structural characteristics of corn gluten meal.
abstract: The aim of this study was to investigate the effect of multi-frequency power ultrasound (sweeping frequency and pulsed ultrasound (SFPU) and sequential dual frequency ultrasound (SDFU)) on the enzymolysis of corn gluten meal (CGM) and on the structures of the major protein fractions (zein, glutelin) of CGM. The results showed that multi-frequency power ultrasound pretreatments improved significantly (P<0.05) the degree of hydrolysis and conversion rate of CGM. The changes in UV-Vis spectra, fluorescence emission spectra, surface hydrophobicity (H0), and the content of SH and SS groups indicated unfolding of zein and glutelin by ultrasound. The circular dichroism analysis showed that both pretreatments decreased α-helix and increased β-sheet of glutelin. The SFPU pretreatment had little impact on the secondary structure of zein, while the SDFU increased the α-helix and decreased the β-sheet remarkably. Scanning electron microscope indicated that both pretreatments destroyed the microstructures of glutelin and CGM, reduced the particle size of zein despite that the SDFU induced aggregation was observed. In conclusion, multi-frequency power ultrasound pretreatment is an efficient method in protein proteolysis due to its sonochemistry effect on the molecular conformation as well as on the microstructure of protein.
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Jin
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, Zhenjiang, Jiangsu 212013, China. Electronic address: mhl@ujs.edu.cn.
authors.forename: Haile
authors.initials: H
authors.lastname: Ma
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Faulty of Agriculture, University of Zalingei, PO Box 6, Zalingei, Sudan.
authors.forename: Abu El-Gasim A
authors.initials: Ael-G
authors.lastname: Yagoub
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Department of Hospitality, School of Applied Science and Technology, Koforidua Polytechnic, P.O. Box 981, Koforidua, Ghana.
authors.forename: John
authors.initials: J
authors.lastname: Owusu
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, Zhenjiang, Jiangsu 212013, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Qu
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, Zhenjiang, Jiangsu 212013, China.
authors.forename: Ronghai
authors.initials: R
authors.lastname: He
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Jiangsu Provincial Key Laboratory for Physical Processing of Agricultural Products, Zhenjiang, Jiangsu 212013, China.
authors.forename: Cunshan
authors.initials: C
authors.lastname: Zhou
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville 37996, USA.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Ye
mesh_terms: D005591:Chemical Fractionation; D005983:Glutens / Q000737:chemistry*; D058767:Protein Unfolding; D000069453:Ultrasonic Waves; D003313:Zea mays / Q000737:chemistry*; D015028:Zein / Q000737:chemistry
chemical_list: D005983:Glutens; D015028:Zein
keywords: Circular dichroism; Glutelin; Molecular conformation; Multi-frequency power ultrasound; Scanning electron microscope; Zein