title: Effects of microwave pretreatment and transglutaminase crosslinking on the gelation properties of soybean protein isolate and wheat gluten mixtures.
abstract: BACKGROUND
  The integration of soybean protein isolate (SPI) with wheat gluten (WG) crosslinked via microbial transglutaminase (MTGase) may enhance the formation of ϵ-(γ-glutamyl)lysine covalent bonds, because SPI is rich in lysine and WG contains more glutamine. Microwave pretreatment may accelerate enzymatic reactions. In this study, we aimed to elucidate the effects of microwave pretreatment on the gelation properties of SPI and WG crosslinked with MTGase.
  
  
  RESULTS
  Interestingly, the gel strength, water-holding capacity (WHC) and storage modulus (G') values of MTGase-induced SPI/WG gels were dramatically improved with increasing microwave power. Moreover, the MTGase crosslinking reaction promoted the formation of disulfide bonds, markedly reducing the free SH group and soluble protein content of gels. Fourier transform infrared spectroscopic analysis of SPI/WG gels showed that microwave pretreatment increased the proportion of α-helices and β-turns and decreased the proportion of β-sheets. Results from scanning electron microscopy indicated that the MTGase-induced SPI/WG gels had denser and more homogeneous microstructures after microwave pretreatment.
  
  
  CONCLUSIONS
  The effect of microwave pretreatment is useful in advancing gelation characters of MTGase-induced SPI/WG gels and provides the possibility for expanding the application of food protein. © 2015 Society of Chemical Industry.
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Qin
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Shui-Zhong
authors.initials: SZ
authors.lastname: Luo
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Xi-Yang
authors.initials: XY
authors.lastname: Zhong
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Shao-Tong
authors.initials: ST
authors.lastname: Jiang
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: School of Biotechnology and Food Engineering, Key Laboratory for Agricultural Products Processing of Anhui Province, Hefei University of Technology, Hefei, 230009, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Zhao
mesh_terms: D004151:Dipeptides / Q000737:chemistry; D005782:Gels; D005983:Glutens / Q000737:chemistry*; D008872:Microwaves; D030262:Soybean Proteins / Q000737:chemistry*; D011503:Transglutaminases / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004151:Dipeptides; D005782:Gels; D030262:Soybean Proteins; D014867:Water; C001299:epsilon-(gamma-glutamyl)-lysine; D005983:Glutens; D011503:Transglutaminases
keywords: gel properties; microbial transglutaminase; microwave; soybean protein isolate; wheat gluten