114 Nippon Shokuhin Kagaku Kogaku Kaishi Vol. /,, No.-, ++.++3 (,**/) 20 * * A Comparison of Various Coagulants in Tofu-Forming Properties Yurie Mine, Kaori Murakami, Keiko Azuma, Shiho Yoshihara, Kimitoshi Fukunaga, Takashi Saeki and Etsuo Sawano* Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Yamaguchi University,,+0+, Tokiwadai, Ube 1//20++ * Sawa Sangyou Co., Ltd., +1*, Funaki, Kusunoki-cho, Asa-gun, Yamaguchi 1/1*,+0 We compared the behavior of five kinds of coagulants on gelation of soybean proteins on the basis of breaking stress of Tofu (soybean curd) prepared by using di#erent amounts of coagulant obtained by puncture and compression tests. The acid-type coagulant such as glucono-d-lactone (GDL) or L-ascorbic acid (LAA) requires a lower concentration, as compared with the salt-type coagulant such as calcium sulfate (CaSO.), Magnesium chloride (MgCl,), or a bittern, to form a Tofu gel of the largest breaking stress, beyond this concentration the gel was rapidly disaggregated. On the contrary, the maximum breaking stress of Tofu prepared by salt-type coagulant, CaSO., MgCl,, or bittern, slightly decreases with increasing coagulant concentration over a wide range. The behavior of CaCl, on heated soybean milk is intermediated between those of acid-type and another salt-type coagulants even though CaCl, belongs to a class of salt-type one. Based on the observations from the coagulability and texture of Tofu gel formed, the most suitable concentration, above which the poor taste develops, for each coagulant was determined. When the GDL-MgCl, mixtures were used as a coagulant, the behaviors of them were divided into three types depending on the range of compositions. The mixed coagulants of the composition between *.+2 and *.-1 mole fraction of MgCl, showed a synergistic e#ect of mixing acid-type coagulant with salt-type one, and the behaviors of which composed of either below *.+2 or over *.-1 mole fraction of MgCl, were identical with those of the individual coagulant, GDL or MgCl,, respectively. (Received Apr. 1,,**. ; Accepted Oct. +/,,**.) + CaSO. CaCl, MgCl, GDL +33* CaCl, 1//20++,+0+ * 1/1*,+0 +1* Corresponding author fukun@yamaguchi-u.ac.jp +, CaSO. - GDL CaSO.. GDL CaSO. / CaSO. 0 MgCl, CaCl, 1
21 : 115 2, PaNm, 3 +* + -* g,** ml /.3 g/+** ml, ph 0.2 / g/+** ml, ph 0.0 2/ L LAA GDL CaSO.,H,O MgCl,0H,O CaCl, GDL MgCl,, GDL, LAA -** ml,/* ml 2/ 2* 2* /* mm, /* mm, +** ml 1* ml 2/ +*, h CaSO., CaCl,, MgCl,, 2* 2* 1* ml 2/ +*, h GDL-MgCl, 2* *.0 wv GDL-MgCl, 2* 1* ml 2/ + +*, h - + METTLER PM0+** /* mm, /* mm, +** ml 1* ml.* mm,+ +2 mm, /* mm + mms -* mm + s ++ - - +* /-* + mms +* mm : 1*. 1/2/ 0 ; CaSO. : 3/31-1* / 1/ 2* 0 1, +, ; CaCl, : 0*, 1, +, ; MgCl, : 0*, 2/ 1 1, +, ; GDL : 2*, 1*. 1, +, ; : 3/ 31-1* 2* +- ; : 2* +.
116 /, -,**/ - 22 +/ 2* + /.3 g+** ml GDL GDL *., wv GDL *., wv, a b GDL *., wv - - ++ *.222 mpas,/ +0 3./ mpas,/ +1 *.+ wv GDL *., wv GDL 0 GDL GDL *.- wv,./.+*. m, Pa GDL.. GDL *.1 wv, / g+** ml *., wv GDL *., wv - *., wv GDL, : a b. *.- wv GDL GDL
23 : 117 / *., wv wv 0 *., wv mm +/ wv *., wv GDL / - +, ++s bo 1s 2* GDL, LAA H -O ph CaSO., CaCl,, MgCl,, +1 wv 0 1 GDL 0 1 *., wv mm -/.3 mm LAA,2.. mm GDL LAA GDL GDL LAA pk+..,/ pk, ++./1 +2 GDL LAA +2 CaSO., MgCl,, CaCl, CaSO.
118 /, -,**/ - 24 2 *.0 w v GDL-MgCl, CaCl, 3 0 1 / g+** ml CaCl,,-.- mm, LAA,2.. mm, GDL -/.3 mm, MgCl, -0.3 mm, CaSO. /2.+ mm, 01.* mm MgCl, Ca,.*+** mm,* Ca, CaCl,, CaSO. GDL,/-* mm +, 1S ++S SH,+ +,. / g +** ml GDL-MgCl, GDL MgCl, *.0 wv *.0 wv GDL-MgCl, 2 vs. MgCl, wt :mol *,* : *+2,*.* : +2-1.*+** : -1+** - : GDL ; : MgCl, ; : MgCl, 2 / g+** ml / GDL LAA -/.3 mm,2.. mm, CaSO., MgCl,,./ CaSO. /2.+ mm, MgCl, -0.3 mm 01.* mm CaCl, +,-.- mm GDL-MgCl, GDL, MgCl,, +, -. -3.+,.+1 +33, -3 /12/2/ +33, Tajiri, T., Physical properties of tofu produced using citrus fresh fruit juice and ume-zu as coagulation agent, Nippon Shokuhin Kogyo Gakkaishi,.*, 2+.2,- +33- Shen, C.F., De Man, L., Buzzell, R.I. and De Man, J.M., Yield and quality of tofu as a#ected by soybean and soymilk characteristics : Glucono-delta-lactone coagulant, J. Food Sci., /0, +*3++, +33+
25 : 119 / 0 1 2 3 +* ++ +, Kohyama, K., Sano, Y. and Doi, E., Rheological characteristic and gelation mechanism of tofu (soybean curd), J. Agric. Food Chem.,.-, +2*2+2+, +33/ Hou, H.J., Chang, K.C. and Shih, M.C., Yield and textural properties of soft tofu as a#ected by coagulation method, J. Food Sci., 0,, 2,.2,1 +331 Tezuka, M., Taira, H., Igarashi, Y., Yagasaki, K. and Ono, T., Properties of tofus and soymilks prepared from soybeans having di#erent subunits of glycinin, J. Agric. Food Chem.,.2, +++++++1,***.+ 3.,3/, +33..1 +,2+.3 +32/ -3 1+/1,+ +33, Usui, H., Local Agglomeration produced in the slurry during the strage of coal-water mixtures, Proceedings of - rd Japan-China Symp. on Coal & C+ Chemistry, p. -+-. +33* Tsai, S.-J., Lan, C.Y., Kao, C.S. and Chen, S.C., Studies on the yield and quality characteristics of tofu, J. Food Sci.,.0, +1-.+1.* +32+ +-./ -,,-,- +332 +..3 -/,**+ +/ 2 3,**+ +0 pp. 2/0 +310 +1 pp..+/ +310 +2 C C pp. 0 +33, +3.- +*++*, +33/,* Saio, K., Tofu-relationships between texture and fine structure, Cereal Foods World,,., -.,-./, -/*-/. +313,+ -3 /20/3/ +33, +0. 1 +0 +* +/