title: Microwave-assisted cross-linking of milk proteins induced by microbial transglutaminase.
abstract: We investigated the combined effects of microbial transglutaminase (MTGase, 7.0 units/mL) and microwave irradiation (MI) on the polymerization of milk proteins at 30 °C for 3 h. The addition of MTGase caused the milk proteins to become polymerized, which resulted in the formation of components with a higher molecular-weight (>130 kDa). SDS-PAGE analysis revealed reductions in the protein content of β-lactoglobulin (β-LG), αS-casein (αS-CN), κ-casein (κ-CN) and β-casein (β-CN) to 50.4 ± 2.9, 33.5 ± 3.0, 4.2 ± 0.5 and 1.2 ± 0.1%, respectively. The use of MTGase in conjunction MI with led to a 3-fold increase in the rate of milk protein polymerization, compared to a sample that contained MTGase but did not undergo MI. Results of two-dimensional gel electrophoresis (2-DE) indicated that κ-CN, β-CN, a fraction of serum albumin (SA), β-LG, α-lactalbumin (α-LA), αs1-casein (αs1-CN), and αs2-casein (αs2-CN) were polymerized in the milk, following incubation with MTGase and MI at 30 °C for 1 h. Based on this result, the combined use of MTGase and MI appears to be a better way to polymerize milk proteins.
authors.affiliation: Department of Food Science, Fu Jen Catholic University, Taipei 242, Taiwan.|Ph.D. Program in Nutrition &Food Science, Fu Jen Catholic University, Taipei 242, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Food Science, Fu Jen Catholic University, Taipei 242, Taiwan.|Ph.D. Program in Nutrition &Food Science, Fu Jen Catholic University, Taipei 242, Taiwan.
authors.forename: Jung-Feng
authors.initials: JF
authors.lastname: Hsieh
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D007768:Lactalbumin / Q000737:chemistry / Q000378:metabolism; D007782:Lactoglobulins / Q000737:chemistry / Q000378:metabolism; D008872:Microwaves; D008892:Milk / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry / Q000378:metabolism*; D058105:Polymerization; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology; D013997:Time Factors; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002364:Caseins; D007782:Lactoglobulins; D008894:Milk Proteins; D012709:Serum Albumin; D007768:Lactalbumin; D011503:Transglutaminases