E#ect of Concentration of Soybean Powder on the Rheological Properties and the Network Structure of Soybean Curd Prepared from Powdered Soybean

1 Nippon Shokuhin Kagaku Kogaku Kaishi Vol. /., No.., +.- +/+ (,**1) 143 * ** *** * ** *** E#ect of Concentration of Soybean Powder on the Rheological Properties and the Network Structure of Soybean Curd Prepared from Powdered Soybean Miki Yoshimura, Shigehiro Naito*, Takao Nagano** and Katsuyoshi Nishinari*** School of Human Science and Environment, University of Hyogo, + + +, Shinzaike-Honcho, Himeji 01* **3, * National Food Research Institute,, + +,, Kan-nondai, Tukuba, Ibaraki -*/ 20., ** Faculty of Education, Ehime University, --Bunkyo-cho, Matsuyama, Ehime 13* 2/11 *** Faculty of Human Life Science, Osaka City University, - - +-2 Sugimoto, Sumiyoshi-ku, Osaka //2 2/2 The e#ect of the concentration of soybean powder (++ +1 (w/w)) on soybean curds prepared from powdered soybean in the presence of glucono-d-lactone (GDL) were studied by rheological measurement (compression test and dynamic viscoelastic measurement), measurement of amount of syneresis, observation of the network structure by confocal laser scanning microscopy (CLSM) and sensory evaluation of physical properties. Results of rheological measurements of soybean curd indicated that the rupture strain, rupture stress, rupture energy, storage modulus and loss modulus increased with increasing concentration of soybean powder. In the protein concentration range of... 0.3 (w/w), the storage modulus was proportional to,.- th power of protein concentration. The degree of syneresis of this soybean curd decreased with increasing concentration of soybean powders. CLSM data indicate that the network structure of the curd increased concurrently with the concentration of soybean powder. The network structure of the curd was well correlated with the results obtained from rheological measurements. As sensory evaluation indicated that the soybean curd with a higher concentration of soybean powder (+/ (w/ w) or +1 (w/w)) was observed to be harder, less moist and fuller bodied, it was judged preferable to the soybean curd with lower concentration (++ (w/w)). (Received Jul. 0,,**0 ; Accepted Jan. 3,,**1) Keywords : soybean powder, soybean curd, rheological property, network structure, palatability : + 1 01* **3, + + +, * -*/ 20.,, + +, ** 13* 2/11 - *** //2 2/2/ - - +-2 Corresponding author miki@shse.u-hyogo.ac.jp 2 +/ +0 +1 +2 +3 TGase

144 /..,**1. 2,* TGase,+ odo GDL,, GDL +,, Microtarac FRA, LEEDS & NORTHRUP 1*.* m 3* -+.,. m Table + +*/ /.1+ odo B,, +** g /** g HEIDON,/* rpm -* 3* 3* 3/, -*,* + ++ +- +/ +1 w w +** g 3*3 g, 103 g, 000 g, /22 g Table + Chemical composition of powdered soybean Component Water Protein Fat Total carbohydrate Dietary fiber (, w/w) 14-.*4- +14/,04/ +*40 +* ml GDL *.- w w GDL +* +* HN-+*. 22 3, -* -*,* + -* mm,* mm,* mm -* mm,/ mm,* mm +** g /** g +* +0, 3* 3* 3/, -*,* +.** g +* ml *.- w w +., g GDL +*,*, RE --*/.* mm +.* mm s 1* w w +* E E E E tan d,- -.* Hz, +** m *.**-- +* Byun,. No..,..* cm, Whatman

3 : 145, -* mm,,* mm,+.- cm, 3 cm B-,-. g +** g /** g HEIDON,/* rpm -* 3* 3* 3/, -*,* + ++ +- +/ +1 w w *.-202 g *.*+-, g GDL +* +* /** B - g MS+ IKA.* g / HN-+*. 2* -* -*,* +,***.* /.- nm +,2* + *,. ++ +, +- +/ +1 w w. +- 3 +* 2 / -*,+./ *.2 Hartky, p *.*/ Fisher SPSS +,.* for Windows, ++ +- +/ +1 w w. + Fig. + Fig., E E G G,, Table, ph... 0.3 w w ph /.. /.0 Fig. - G C G C n n,,/,0,.- Bikbov,1 1./ /2 w w / Kohyama,2 ++S GDL, 0 w w -.. Renkema,3 ph 1.0 b -./..0 /.* ph -.2 b -.* -.,,.2 -* sol fraction n

146 /..,**1. 4 Fig. + Rupture properties of soybean curds prepared from ++ +1 (w/w) powdered soybean and soybean milk Di#erent letters in the same column show significant di#erence (P *.*/), n +* +0 Fig., Dynamic viscoelasticity of soybean curds prepared from ++ +1 (w/w) powdered soybean curd and soybean milk Di#erent letters in the same column show significant di#erence (P *.*/), n +* +0 Table, Protein content and ph of soybean curds prepared from powdered soybean and soybean milk Soybean curds ++ (w/w), powdered soybean +- (w/w), powdered soybean +/ (w/w), powdered soybean +1 (w/w), powdered soybean Protein content (w/w).4. /4, 04* 043 ph /4. /4/ /40 /40 Soybean milk.41 /4...1 w w ph /.. ph +, w w ++ w w +- w w +0 +2 Fig. - Double logarithmic plot of storage modulus vs protein content for soybean curds prepared from ++ +1 (w/w) powdered soybean -+ 1

5 : 147 *..* *.//,./ 1./ kpa -, Fig.. Fig.. Syneresis of soybean curds prepared from ++ +1 (w/w) powdered soybean, Fig. / ++ w w +, w w +- w w +/ w w +1 w w -, Fig. 0 +, w w CLSM CLSM Fig. / Confocal laser scanning micrographs of soybean curds prepared from ++ +1 (w/w) powdered soybean

148 /..,**1. 6 Fig. 0 Confocal laser scanning micrographs of soybean curds prepared from +, (w/w) powdered soybean (A) and soybean milk (B) Fig. 1 Sensory evaluation of soybean curds prepared from ++ +1 (w/w) powdered soybean Asterisks show significant di#erence level by the F-test (p *.*+) - Fig. 1. p *.*+ p *.*+ ++ w w +/ w w +1 w w ++ w w, RMSE -- RMSE +0 +2,2 +3,/,*,. RMSE RMSE,* +3,- +3,, RMSE

7 : 149 Table -. r *.312 p *.*/ r *.32* p *.*+ r *.33. p *.*+ r *.330 p *.*+ r *.322 p *.*/ r *.322 p *.*/ r *.32, p *.*/ r *.3/. p *.*/ r *.32+ p *.*/ r *.310 p *.*/ r *.30. p *.*/ r *.3/- p *.*/ r *.31, p *.*/ r *.301 p *.*/ +0.* m,* m RMSE +.3 m,/ +.3 m.* +.3 m +* -. +*,/ m -/ -/ +. +/ w w +1 w w ++ w w ++ +1 w w +... 0.3 w w,.- ph, - +/ w w +1 w w. r *.3/

150 /..,**1. 8 Table - Pearson correlation coe$cients between sensory attributes and Rupture strain Rupture stress Rupture energy Storage modulus color hardness a springness hardness Rupture strain Rupture stress Rupture energy Storage modulus color hardness a springiness a hardness smoothness moisture body aftertaste Palatability of color Palatability of hardness Palatability of smoothness Palatability of body Overall palatability *430+* *430,* *4313* *4332** *4312* *4,30 *43*2 *42** *4332** *430+* *41,+ ** *4332** *403/ *433+** *433.** *433-** *433-** *4311** *432*** *4*,, *43,0 *422. *431.* *421- *403* *43/.* *431.* *4/+* *43.* *43,/ *4331** *4312* *433.** *4*./ *430.* *43,. *431+* *43*, *411* *43/1* *4310* *4.1/ *43/0* *43,1 *433+** *4330** *4+*2 *43/-* *423. *4320* *43,+ *41/. *431/* *4323* *4/.+ *431+* *43/+* *4322* *4,-- *43,1 *42-/ *4333** *43/+* *41-- *4330** ** *40.1 *4323* *432.* *4+/* *431,* *43*1 *432+* *43.. *42*2 *4310* *4322* *4/-- *432,* *43/.* *4*13 *4+03 *4,.0 *4./1 *4,+, *4-+3 *4,.1 *410, *4--. *4-33 *4301* *43*3 *43+. *43+* *43*2 *43,2 *4-0+ *43-2 *4210 ** Significant at + level * Significant at / level a : Force required to compress a sample with a teaspoon +,* -1. -2/ +31-, Saio, K., Tofu-relationships between texture and fine structure, Cereal Foods World,,., -., -/. (+313). - + -3,0,,03 +30/.,/ -21-3+ +312 /.,,/.,0+ +33/ 0 + pp,*1,++ +333 1 /, ++. ++3,**/ 2., -2/ -23 +323 3-3 -11-2. +320 +* ++ 23 3, +33. ++ Ishida, H., Uesugi, T., Hirai, K., Toda, T., Nakaya, H., Yokotsuka, K and Tsuji, K., Preventive e#ects of the plant isoflavones, daidzin and genistin, on bone loss in ovariectomized rats fed a calcium deficient diet, Biol. Pharm. Bull.,,+, +/3 +0, (+332). +,.0 -*- -+* +333 +- + pp /- 0+,*** +. /+ --.*,*** +/ +, /- 0+,**+ +0 0 1 +, +331 +1-0 01 1+ +332 +2,3 +0/ +1,,**- +3 ++.*.2, +333,*.,,/.,0+ +33/,+ /- -3.1,**0,, odo /+ ++/ +,,,**.,-,1,,1,-- +32*

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