Submitted to: Journal of Food Quality
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/26/2007
Publication Date: 6/1/2007
Citation: Mohamed, A., Gordon, S.H. 2007. THERMAL AND SPECTRAL PROPERTIES OF TRANSGLUTAMINASE-CROSSLINKED WHEAT GLUTEN IN TRIS-HCI. Journal of Food Quality. 30(1):386-402. Interpretive Summary: With the increase in demand for wheat starch in the marketplace, vital wheat gluten, a by- product of wheat starch production, became available. This project was designed to enzymaticaly modify wheat gluten in-order for it to perform different functional properties. The modified gluten has stronger gelling and flow properties due to its higher molecular weight compared to the unmodified. The data generated by this project will benefit the wheat gluten enzymatic modification industry. Enzymatic modification of wheat gluten will help in expanding the utilization of low quality wheat.
Technical Abstract: Wheat gluten (10 g) was crosslinked (XL) using 10 units of transglutaminase (TG) in 2L 0.1 M TRIS-HCl, pH 7.5. The suspension was stirred for 24 hr at 40ºC and freeze-dried as-is or dialyzed and then freeze-dried. The XL material was tested using Modulated Differential Scanning Calorimetry (MDSC), where 25-30 mg was placed in a stainless steel pan and heated from 20 to 200ºC at 7ºC/min. The samples were subjected to three heating and cooling cycles. The MDSC data of the undialyzed sample showed two endothermic transitions during the first cycle and an exothermic followed by an endothermic transition on the second cycle. Further analysis showed that the two transitions of the first cycle are the melting of the TRIS. The first cycle of the dialyzed sample displayed two glass transition at 46.0ºC with 0.11 J/g/ºC and 130.0ºC with 0.29 J/g/ºC followed by an exothermic transition at 120.7ºC onset, 150.6ºC peak with 14.8 J/g 'H. The second cycle of the dialyzed material showed one broad glass transition at 97.3ºC and 0.495 J/g/ºC. FTIR spectra showed differences between crosslinked and uncrosslinked gluten and provided spectral evidence of molecular interaction between gluten and TRIS