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Microbial Transglutaminase (microbial + transglutaminase)
Selected AbstractsEffects of Microbial Transglutaminase on the Wheat Proteins of Bread and Croissant DoughJOURNAL OF FOOD SCIENCE, Issue 6 2001J.A. Gerrard ABSTRACT: Transglutaminase is a crosslinking enzyme that is finding increasing use in foods, yet the molecular changes responsible for its effects are not fully understood. Proteins were extracted from bread and croissant doughs that had been treated with transglutaminase and compared to those from control doughs by size exclusion high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. Transglutaminase increased the amount of protein extracted in the gliadin fraction in both bread and croissant doughs. In croissant doughs, a corresponding decrease in the protein extracted in the albumin to globulin fraction was seen. In each case, crosslinking of the high molecular weight glutenins was observed. The possible role of each of these changes on the functional properties of baked products is discussed. [source] Study of two different cold restructuring processes using two different qualities of hake (Merluccius capensis) muscle, with addition of microbial transglutaminaseJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2009Helena M Moreno Abstract BACKGROUND: Microbial transglutaminase (MTGase) can improve the mechanical and functional properties of restructured fish products without the need of thermal gelation. The present study seeks to determine whether, for different setting times, MTGase activity in restructured hake muscle made with pieces or with homogenised muscle can be affected by the quality of the protein in the raw materials. RESULTS: As regards mechanical properties, samples of both qualities subjected to the two different processes attained a suitable consistency after setting for 24 h at 5 °C. The quality of the protein in the sample is important when pieces are used for restructuring, but not when sample is homogenised. Also, there were strong correlations between residual MTGase activity up to 12 h and mechanical properties and electrophoretic band density. Water binding capacity (WBC) was not significantly altered by MTGase addition. CONCLUSION: The experimental combination of 10 g kg,1 of MTGase, 15 g kg,1 of sodium chloride and 7.5 g kg,1 of sodium caseinate was suitable for the production of minimally processed raw restructured fish products made with two different qualities of fish protein and two different restructuring processes. In the restructured products made with pieces, the protein quality significantly affected final properties, but in finely homogenised product the protein quality was less important. Copyright © 2009 Society of Chemical Industry [source] Effect of transglutaminase and carrageenan on restructured fish products containing dietary fibresINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 11 2007Carlos Cardoso Summary The inclusion of various levels of a microbial transglutaminase or a carrageenan additive to restructured hake products with or without dietary fibre (obtained from inner pea or chicory root) was studied. These experiments were aimed at producing technologically innovative restructured fish products with improved textural and colour properties. It was found that the addition of transglutaminase, up to 0.5% (w/w), favoured better textural properties, particularly, at 0.1% (w/w) level or above. On the other hand, restructured product with a dietary fibre content of 4% (w/w) and carrageenan addition, up to 2% (w/w), exhibited increased hardness. This can be particularly interesting for those products containing chicory root inulins as this fibre presented an adverse effect on hardness. Regarding colour, higher carrageenan contents caused a slight but significant colour change in the product, making it redder (for products containing Swelite and Fibruline) and more yellow (only concerning Swelite). [source] Gelatin-based biomimetic tissue adhesive.JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006Potential for retinal reattachment Abstract An adhesive that cures under moist/wet conditions could facilitate surgical procedures for retinal reattachment. We are investigating an adhesive that mimics the factor XIIIa-mediated crosslinking of fibrin that occurs in the late stages of the blood coagulation cascade. Specifically, we use gelatin as the structural protein (in place of fibrin), and crosslink gelatin using a calcium-independent microbial transglutaminase (in place of the calcium-dependent transglutaminase factor XIIIa). Injection of gelatin and microbial transglutaminase (mTG) into the vitreous cavity of Sprague Dawley white rats did not elicit structural or cellular damage to the retina as evidenced from histological evaluation 2 weeks post-injection. Qualitative in vitro studies indicate that the gelatin,mTG adhesive binds to bovine retinal tissue under wet conditions. Quantitative lap-shear tests were performed with more robust bovine tissue from the choroid and sclera. The lap-shear strength of the biomimetic gelatin,mTG adhesive was independent of tissue-type and ranged from 15 to 45 kPa, which is comparable to the values reported for other soft-tissue adhesives. These studies suggest that the mTG-crosslinked gelatin may provide a simple, safe, and effective adhesive for ophthalmic applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] DIFFERENT ARRANGEMENT OF ,-(,-GLUTAMYL)LYSINE CROSS-LINKING IN ALASKA POLLOCK (THERAGRA CHALCOGRAMMA) SURIMI PROTEINS BY STREPTOVERTICILLIUM AND ENDOGENOUS TRANSGLUTAMINASES DURING SUWARI PROCESSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2001KENJI SATO ABSTRACT The objective of the present study is to compare the protein cross-linking reaction in Alaska pollock surimi that is catalyzed by a commercially available microbial transglutaminase and by endogenous Alaska pollock transglutaminase. The endogenous transglutaminase was inhibited by EGTA and activated by CaCl2 The microbial transglutaminase was added to the salted surimi with and without EGTA and CaCl2. These surimi pastes were incubated at 25C up to 24 h followed by cooking at 90C. The resultant gels were fractionated into soluble and insoluble (aggregate) fractions by SDS-urea extraction. Compositional analysis revealed that the aggregate consisted predominantly of cross-linked myosin heavy chain. The distribution of ,-(,-glutamyl)lysine isopeptide in the soluble and aggregate fractions andpeptide mapping analyses of the aggregate fraction demonstrate that the formation of isopeptide cross-links in Alaska pollock surimi proteins during suwari process differs when catalyzed by the microbial transglutaminase and endogenous transglutaminase. [source] Effect of Ultra-high Temperature Treatment on the Enzymatic Cross-linking of Micellar Casein and Sodium Caseinate by TransglutaminaseJOURNAL OF FOOD SCIENCE, Issue 8 2004M.P. Bönisch ABSTRACT: It was found that ultra-high temperature (UHT) treatment of sodium caseinate and native whey protein-depleted micellar casein drastically increases the protein polymerization effect of an enzymatic treatment by microbial transglutaminase (TG). As a result the concentration of the isopeptide ,-(,-glutamyl)lysine was increased significantly in UHT-treated micellar casein solutions after TG incubation compared with the unheated casein solution. Sodium caseinate was more susceptible to the cross-linking reaction as compared with the native casein micelles. The results demonstrate that the protein structure significantly affects the TG cross-linking reaction. The effect of an UHT treatment was considered to be related to a better TG accessibility due to a more open casein micelle structure and to the inactivation of a TG inhibitor substance. The results demonstrate that an unidentified component in the natural milk serum inhibits the TG reaction. The thermal inactivation of a TG inhibitor is the dominant effect explaining the improved cross-linking of UHT-treated casein micelles as well as sodium caseinate. [source] Study of two different cold restructuring processes using two different qualities of hake (Merluccius capensis) muscle, with addition of microbial transglutaminaseJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2009Helena M Moreno Abstract BACKGROUND: Microbial transglutaminase (MTGase) can improve the mechanical and functional properties of restructured fish products without the need of thermal gelation. The present study seeks to determine whether, for different setting times, MTGase activity in restructured hake muscle made with pieces or with homogenised muscle can be affected by the quality of the protein in the raw materials. RESULTS: As regards mechanical properties, samples of both qualities subjected to the two different processes attained a suitable consistency after setting for 24 h at 5 °C. The quality of the protein in the sample is important when pieces are used for restructuring, but not when sample is homogenised. Also, there were strong correlations between residual MTGase activity up to 12 h and mechanical properties and electrophoretic band density. Water binding capacity (WBC) was not significantly altered by MTGase addition. CONCLUSION: The experimental combination of 10 g kg,1 of MTGase, 15 g kg,1 of sodium chloride and 7.5 g kg,1 of sodium caseinate was suitable for the production of minimally processed raw restructured fish products made with two different qualities of fish protein and two different restructuring processes. In the restructured products made with pieces, the protein quality significantly affected final properties, but in finely homogenised product the protein quality was less important. Copyright © 2009 Society of Chemical Industry [source] Low-salt restructured fish products using microbial transglutaminase as binding agentJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2002Simón J Téllez-Luis Abstract Low-salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20,g,kg,1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6,g,kg,1). The fish meat was massaged with the additives at <15,°C for 1,h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40,°C for 30,min followed by 90,°C for 15,min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4,N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS-PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low-salt restructured silver carp products with improved mechanical and good functional properties using 3,g,kg,1 MTGase and 10,g,kg,1 NaCl. © 2002 Society of Chemical Industry [source] Allergy assessment of foods or ingredients derived from biotechnology, gene-modified organisms, or novel foodsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2004Lars K. Poulsen Abstract The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein and a risk of sensitizing susceptible individuals. No single predictive test exists to perform a hazard assessment in relation to allergenic properties of newly expressed proteins in gene-modified organisms (GMOs). Instead, performance of a weighted risk analysis based on the decision tree approach has been suggested. The individual steps of this analysis comprise sequence homology to known allergens, specific or targeted serum screens for immunoglobulin E (IgE) cross-reactions to known allergens, digestability studies of the proteins in simulated gastric and/or intestinal fluids, and animal studies. These steps are discussed and five examples of risk evaluation of GMOs or novel foods are presented. These include ice-structuring protein derived from fish, microbial transglutaminase, GMO-soybeans, amylase and the Nangai nut. [source] Casein gelation under simultaneous action of transglutaminase and glucono-,-lactoneMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 3 2004Orquídea Menéndez Abstract Casein solutions (5% w/v) were treated with microbial transglutaminase (MTG) and glucono-,-lactone (GDL) under varying conditions in order to obtain gels. Storage modulus (G ,) and gelation time of the gels were measured by oscillation rheometry, while protein cross-linking was determined by gel permeation chromatography. The addition of only GDL to milk resulted in very weak gels, while MTG on its own was not able to create gel networks. Simultaneous action of both ingredients led to gels, the firmness of which was linearly related to the added amount of MTG, but passed through a maximum with rising GDL concentrations. Using chromatographical analysis, increasing G , values were interrelated with the formation of MTG-induced oligomers. The gelation time was directly proportional to the GDL concentration but not influenced by the addition of MTG within the studied range of concentration. [source] | ||||||||||