9 Nippon Shokuhin Kagaku Kogaku Kaishi Vol. /,, No.0,,/+,/0 (,**/) 251 * * E#ects of Microbial Transglutaminase on Melting Point and Gel property of Gelatins Takahiko Soeda, Tomoko Kaneko*, Akiko Hokazono, Kumiko Tujimoto and Haruka Murakami Department of Environmental Chemistry, Faculty of Engineering, Kyushu Kyouritsu University, + 2 Jiyugaoka, Yahatanishi-Ku, Kitakyushu 2*1 2/2/ * Center of Research & Development, Ajinomoto, + + Suzuki-Cho, Kawasaki-Ku, Kawasaki-Shi, Kanagawa,+* 202+ Melting points of gelatin samples A, B, C and F increased by treatment with microbial transglutaminase (MTG). The increase of + in melting point by MTG was recognized by DSC measurment in case of sample C that showed the largest increase in melting point measured by the dropping ball method. On samples A, B and C of high bloom gelatin, gel strength increased in A and C, and crosslinkage increased in A, B and C by the MTG treatment. On the gelatin samples with di#erent bloom values, the gelatin A with a high bloom value showed high gel strength and crosslinkage ratio. On higher concentration of gelatin, the reaction proceeded rapidly, the gel strength became very high, and the ratio of crosslinkage also increased in dry basis. Gel strength increased with an increase in MTG concentration up to + u of MTG, and suddenly decreased +, hours after the reaction when used over / u of MTG and the amount of crosslinkage increased as the time proceeded. On the observation of gelatin gel by SEM, gel treated with MTG was constiluted of thick frames and contact network of protein. (Received Sep. +-,,**. ; Accepted Mar. ++,,**/) -* +, E.C.,.-.,.+- MTG Gln Lys -. MTG 2*1 2/2/ + 2 *,+* 202+ + + Corresponding auththor tsoe@kyukyo-u.ac.jp + MTG + mg +.*, A B C - D E F - 0 - / /* ph 1 MTG -*
252 /, 0,**/ 0 10 mm +** g /* *,. +*. eo(goglutamyl) lysine eo(goglutamyl) lysine eo(gogln) Lys Kumazawa 0. 0* HPLC OPA HPLC +** mol mol / JIS 1 mpa s., 0* g +* +1. mm, + mm s,* mm /,- g cm 1 mm 0 cm min - 0 2 / *... g,/ - 1 DSC 3 2 SEM +* +.*.. mpa s, +2/,,/ g,,.,/mpa s, + MTG * +,. 2,. A B C D E F,140,243,34, -*4* -,43,24.,34+,242,24/,241,24+,140,34* -+43,/42,/41,/4,,/4.,/40,04- A D : B E : C F :,/4*,-43,.43,/4*,.4.,/4/,.4,,04,,.4,,/40,,40,141 + DSC A: C B: C MTG+u.
11 : 253, MTG MTG : + u g, protein - A:MTG B:MTG +* u g, protein 22 +,+ g /.// 2/ ph /.2..- - -, MTG MTG +g / u/g, protein, u *,. + min + A, B, C F MTG * 0* A, C / B, D, E, F -* MTG DSC DSC C MTG+u *. DSC + *,-.0,,1./, *.1 mj mg,.,..01,2.2* *.2 mj mg + DSC MTG
254 /, 0,**/ 0 12. MTG MTG / MTG MTG -* - eo(gogln) Lys MTG Gln Glu ++ Gln MTG Gln a a +, MTG
13 : 255 0 MTG a a MTG + u A, B, C - eo (gogln) Lys, MTG A C C 2 B MTG C Gln B, MTG MTG SEM MTG MTG A - MTG MTG+u. A D MTG MTG a MTG a
256 /, 0,**/ 0 14,./ / MTG A, B, C / C / +, +- MTG MTG MTG 0 A MTG 2 MTG / u +* u C MTG + u MTG / u +, MTG A, B, C F MTG C DSC + A, B, C MTG A C A, B, C MTG MTG A + u / u +, SEM MTG + Ando, H., Umeda, M., Matsuura, A., Nonaka, M., Uchio, R., Tanaka, H. and Motoki, M., Purification and Characteristics of a novel Transglutaminase derived from microorganism, Agric. Biol. Chem, /-,,0+-,0+1 +323, 03 +* +-*+ +-*2 +33/ -.,.,/.,0+ +33/. Nonaka, M., Toiguchi, S., Kawajiri, H., Soeda, T. and Motoki, M., Change caused by microbial transglutaminase on physical properties of thermally induced soy protein gels, Food Hydrocollods, 2 (+), + 2 +33. / Folk, J.E. and Chung, S.I., Adv. Enzymol, -2, +// +31-0 Kumazawa, Y., Seguro, K., Takamura, M. and Motoki, M., Formation of e-(g-glutamyl) lysine cross-link in cured horse mackerel induced by drying, J. Food Sci., /2, +*20 +*23 33-1 K0/*- 2 +,1 / -,3 --. +310 3.+ +* 010 02+ +33. +*., 1.2/.3+ +33/ ++ Ward, A.G. and Courts, A., The Science and Technology of Gelatin +311 +, -.1.,-1,.1 +32. +- Soeda, T., E#ects of microbial transglutaminase for gelation of soy protein isolate during cold storage, Food Sci. Technol. Res., 3 (,), +0/ +03,**- +0 3 +- +1 - ++