Proceedings of the 7 th Iniernatumal Workmg Conference on Stored-product Protection - Volume 2

Study on the factors effecting germinated and improving effect

Wang Ruolan1

Abstract It in China, in 1991 and 1996 the content of was very high over an extensive area in Henan The factors that influence Brabender maximum viscosity of Province. Germinated wheat has low flour production, the germinated and the improving methods were color of flour is gray and dark, the taste of the foods is studied in this paper. Using Response Surface Analysis sticky, the elasticity of IS not up to the standard, method, two factors quadratic regression equation of even the flour can not be processed into steamed , maximum viscosity was obtained. The orthogonal noodle, bread, and so on. It brought great damage in grain experiment showed that adding inhibitor to the flour was the and food production and also influenced the daily hfe of the important factor that influenced maximum viSCOSItyand the people. most effective method of improving qualities. At the same The Brabender maximum viscosity and falling number of time the optimum technological condition m the factors was high germinated wheat content were very low (often below obtained. At last adding the inhibitor to the germinated 200 B. U. or 200s) , the stabilization time of dough was very wheat flour, the regression equation between the maximum short and resistance extension was very weak. The viscosity and quantity of inhibitor added was obtained. Important reasons of damage on flour qualities are as follows: the extremely high a - amylase activity, excess molecules of starch were changed into hydrolysates, maximum VISCOSIty(M. V ) decreased and the taste was sticky. Other factors, such as increased protease activity Introduction and protem degradation, the constructions of protein and gluten were damaged, these caused the elasticity of gluten Wheat IS a kind of crops that have been cultivated and used weakness", so the different content of germinated wheat and widely. The output of wheat IS about half of the total gram germmation time that affect the M. V. was studied here. output in China every year. Wheat is the main kind of gram There are many methods of Improving the wheat's qualities, in many areas, and wheat flour IS also the raw matenal of such as heatmg, peeling and adding enzyme inhibitors, these many traditional foods. So the output and quality of wheat methods were researched by means of the orthogonal are very important m the national economy and are closely experiment m this paper and the optimum technological related to the people's dally life condition was obtained. Because of the application of advanced science and As a result of the high a - amylase and protease activity, technology to the agnculture , especially genetic engineering adding the inhibitor to the germinated wheat flour is the and biological engineering, the output of wheat has most effective improving method. At the same time, increased in the resent years, but the quality of wheat has investment of this method is low and operation is been the important question for scientists to study or convenient, this method IS welcomed in the practice. In diSCUSSIon. Especially when It was cloudy and rainy for days 1960's it is reported that phytate could inhibit a - amylase on end in the harvest seasons, the germinated wheat was and protease activity", adding inhibitors to germinated developed widely, the sprouting damage and the flour wheat flour to inhibit a-amylase activity" and improving the quality reduction were cntical. ThIS phenomenon was very flour qualities' had got good effects. Because phytate is common all over the world. In extremely abnormal years, liquid and It has high corrosiveness, its use IS inconvenient the extent of sprouting damage may be as high as 15 % of a and sometime Its application IS difficult m the practice. total production of about 25 million tons m Canada. Similar Meanwhile the regression equation IS obtained levels of sprouting damage have been experienced in Australia recently. In Europe, sprouting damage of cereals at relatively high levels occurs almost every year". So does Materials and Methods

Materials lZhengzhou Gram College, Zhengzhou 450052, Henan, China Wheat: new normal wheat, 13% moisture, M. V. is 570 1647 Proceedings of the 7th International Worktng Conference on Stored-product Protection - Volume 2

B.U. Cultivation of wheat germtnatwn: soak the normal Table 1. Germination time and germina ted wheat ratio whea t in the water for 3 hours at the room temperature, affected the M. V then spread out the wet wheat m the big dish, covered With No. Germinated time Ratio Max. VIscosity wet gauze and put them in the incubator at 25'C to cultivate (h) (%) (B. U.) gernunation. After different time, dry the germinated 1 24 5 460 wheat to the original moisture, mix the germmated wheat in 2 24 15 390 different quantities with the normal wheat, so as to obtain 3 24 25 300 the germinated wheat of. different germmation time and 5 425 content. ~ 36 Germinated wheat flour . mill the germmated wheat into 5 36 15 360 flour by Brabender experiment mill, called flour A, these 6 36 25 250 were the different germinated time and content. Flour B: 7 48 5 110 germinated wheat flour obtained from the null plant, 12.5% 8 48 15 38 moisture, M. V. was 20 B. U. only. 9 48 25 22 Instruments 10 36 15 365 11 36 15 355 Brabender Amylograph (with cooling water system), Brabender expenment mill, both made in Germany. y: M. V. (B. U. ) Methods ZI: germmation time (h), three levels: 24, 36 and 48. Zz: germinated wheat content (%), three levels: 5, 15 Brabender M. V. measurement: AACC method 22 -10. and 25. Peeling: the wheat was soaked in 3% salt solution for 20 If XI = (z I - 36) /12, then XI: - 1, 0 and 1; min. , then it was peeled by the small rice mill, the peeling Xz= (zz-15) /10, then Xz: -1, 0 and 1. time were 1, 2 and 3 nun. , resp. Used the central combination design: Heating: Spread the wheat on the piece of dry gauze, y = bo + b1Xl + bzxz + b12XIXZ + buXI + bzzx~ then put them m the incubator With fan for 6 min., the the plan of expenment and the results were shown m Table 2. temperatures were 90'C , 100'C, and 110'C , resp. Xl=XZ=X12=O; Additives XI' = X Z' = 6/11 = 0 . 545; y = 297.55 nX~ Phytic acid: 70% phytic acid agent, made m Shanghai Lu =2.xI - n XI = 6; Lzz =2.x~ - = 6; Z chemical reagent plant, China. L1'1' =2.xI' - n XI' =6- 11X 0.545 = 2.733 z Sodium phytate: 40 - 50% (edible grade), made in Lz'z' =2.x~, - n x~,=6 - 11 x 0.545 = 2.733 Orient Food Factory, Chengdu, SIchuan province, China. L12,IZ =2.xIz - n XIz = 4- 0= 4 z L1,z' =2.xl' XZ' - n Xl'XZ' =4- 11X 0.545 = 0.733 Results and Discussion LZ'I' = 0.733

others, LtJ =0 The relationship among the M. V., germination L1y = - 980 Lzy = - 423 L1Zy =72 time and the germinated wheat content L I' y = 1320 - 11 x 0 . 545 x 279.82 = - 355 .90 The M. V. of wheat mainly depends on the content and Lz'y= 1567 - 11xO.545x279.82 = -108.90 activity of a- amylase, while the a- amylase activity is then regular equation group: related to on the germination time and content, in order to 6b1 = -980 find the relationship among the M . V., time and content, 6bz = -423 the experiments were done and the results were shown in 4b12 = 72 Table 1. 2.733bll +0.733 bzz= -355.9 With germination time and content increasing the M. V. O. 733bll +2.733bzz = - 108.9 were decreased, when the time was 48h, content was 25%, the solutions: b, = -163.3, bz = -70.5, b12 = 18, M. V. was 22 B. U. only, so damaged the qualities of wheat bu= -128.8, bzz= -5.3, greatly. bo = 11 - b1Xl' - bzxz' In order to find the duality quadratic regression equation = 279.55 - (- 128.8) x 0 . 545 + 70.5 x 0 . 545 of M V. , germination time and content.Suppose: = 388.17

1648 Proceedings of the 7 th Iniernatumal Working Conference on Stored-product Protectwn - Volume 2

Table 2. Calculation of duality quadratic regression. yZ No Xl Xz Y XIXZ Xl' XZ' XlY XzY XlZY Xl' Y «c» 1 -1 -1 460 111-460 -460 460 460 460 211600 2 -1 0 390 0 10-390 0 0 390 0 152100 3 -1 1 300 -1 1 1 -300 300 -300 300 300 90000 4 0 -1 425 0010-425 0 0 425 180625 5 0 0 360 00000 0 0 0 129600 6 0 1 250 001 0 250 0 0 250 62500 7 1 -1 110 -1 1 1 110 -110 -110 110 110 12100 8 1 0380 10380 0 38 0 1444 9 1 1221112222 22 22 22 484 10 00000000 0 0 0 133225 11 000 00000 000 126025 ~ 0 0 3075 066 -980 -423 72 1320 1567 1099703

the regression equation: =237568.59 Y = 388.17 -163 .3XI -70 .5xz + 18xl Xz -128 .8xI - 5 .3x~ central experiments No.5, 10 and 11, z z 2 using Zl, Zz, taken the place of Xl' Xz: Qe = 360 + 365 + 355 - 3 x [(360 + 365 + 355) -:-3JZ= 50 y= -113.81 +48.95z1 -lO.86zz +0.15zlzZ -O.89zI -0.05z~ QL= Lyy- U- Qe= 2454 18 variance analysis and regression significance test: checked the tables: z Lyy = ~Yz - n"iF = 1099703 - 11 x 279. 55 Fo 05(2,2) = 19.00 F« 05(1,2)= 18.51 Fo 05(3,2)= 19.16 Lyy = 240072.77 Fo 01 (2,2) =99.00 Fo 01 (1,2) =98.50 Fo 01 (3,2) =99.17 bILly + bzLzy = -163.3 x ( - 980) + ( -70.5) x ( - 423) R = (U ~ Lyy)ll2 = (237568.59-:-240072.77)112 = 0.9948 = 189955.5 when a = 0.05, N, =5,Nz= 5, checkedthe table Fa = 5.05 l12 b12LlZy = 18 x 72 = 1296 R, = [5Fa-:-(5+5FJJ = [5x5.05~(5+5x5.05)Jll2 bnLI,y + b22Lz'y = ( -128.8) x ( - 355.9)+ ( - 5.3) x ( -108.9) = 0.9136 R R = 46417.09 because > a, SO regression is significance (Table 3) .

u = bILly + bzLzy + b12LlZy + buLI,y + bzzLz,y

Table 3. Variance analysis.

Vanance sources Sum square Degree of freedom Average sum square F Sigmficance

linear term 189855.50 2 94927.80 3797.10 ** mutual term 1296 1 1296 51.84 * quadratic term 46417.09 2 23208.55 928.34 * * residua 2454.18 3 818.06 32.72 * error 50 2 25 sum 40072.77 10

Depending on R (rn Table 5), the order of the factors Study on improving effects of different methods mfluenced the M. V. was: Except for germmation time and contents, improving Primary • Secondary methods and conditions also influenced the M. V , here used A DEC B

the orthogonal I experiment of 5 factors and 4 levels, The order of different methods was: D, E and C, addmg researched M. V. The factors and levels were in Table 4. the additive was the most effective improving method, when The additrve was phytate , addmg quantities were 0.1 ml, the M. V of flour was m 400 - 500 B. U., the good flour 0.3 ml and 0.5 ml m 300 ml of flour solution, these were qualities can be obtained, so the factor D should choose the concentration levell, 2 and 3 in Table 4 Usmg orthogonal level 3, here the average M. V. was 470.5 B. U.; the 5 table LI6(4 ), results and analysis were m Table 5 improving effects of factor E at levelland level 2 were 1649 Proceedings of the 7 th International Worktng Conference on Stored-product. Protectwn - Volume 2 almost equal, level 1 was more econormcal, so to chose level For convenient application in practice, taking sodium 1 was reasonable; Factor C should choose level 2, the phytate as enzyme inhibitor through changing the adding average M. V. was 475.5 B. U. The optimum technological quantities could observe the changing of the M. V., the condition of three methods was CzD3El. results were in Table 6.

Table 40 Factors and levels. Table 60 Inhibitor adding quantities and MV.

Factors Levels Flourt g) Inhibitorf g) M V. (B. U.) A: germmation time (h) 02436 48 50 0.30 95 B: germmated wheat content/ %) 5 15 25 35 50 0.40 160 C: Heating C'C ) 20 90 100 110 50 0.50 220 D: Additive (concentration levels) 0 1 2 3 50 0.60 270 50 0.70 340 E: peeling (nun) 0 1 2 3 50 0.80 460 50 0.90 610 Table 50 Results and analysis of orthogonal experiment.

No. A B C D( concentration E MV. The increasing of M. V. along with the content of (h) (%) C'C ) levels) (min) (B. U. ) Inhibitor quantities, in order to build the polynomial regression equation of them, 1 0 520 0 0 570 supposed: z was mhibitor quantities, 2 01590 1 1 680 y was (M V -;-100), 3025100 2 2 760 z 4 and y = Co + Clz + Czz + ~Z3 + C4Z 4 0 35 110 3 3 870 order: x = (z - 0.30) -;-0 . 1 + 1 ; 524 590 2 3 760 so, Xl =1, xz=2, x3=3, x4=4, xs=5, x6=6, x7=7; 6 24 15 20 3 2 750 supposed.: y = bo = bl 3(X)+ b4

Table 7. Calculation of polynomial regression. Z x Ch (e ) 'hex)

b, = LtY/St 0.809 0.091 0.158 -0.003 »i; 18.324 0.696 0.150 0.001 Y =3.079 A.t 1 1 1/6 7/12

Table 8. Vanance analysis.

Sources of sum square Sum square Degree Average F Significance hnear term 18.324 1 18.324 2819.1 ** quadratic term 0.696 1 0.696 107.08 ** cubic term 0.150 1 0.150 23.077 * quadruplet term 0.001 1 0.001 0.167 error 0.013 2 0.0065 sum 19.158 6

Sodium phytate can hydrolysize into phytate after adding water, so adding It into flour can obtain the satisfactory References improving effects. In addition, phytate inhibition effects also are related to 1. Cawley, R. Wand Mitchell, T. A. , 1968. Inhibition of pre-incubation time and pH m solution, when pre-incubation wheat ex- amylase by phytic acid. Journal of Science time was 1 h, pH was below 7, can obtain the good results". Food and Agnculture, 19, 106. 2. Fei Rongchang, 1997. Design and data Processing of Conclusion experiments. ed by Wuxi University of light industry. 3. Li Weili and Wang Ruolan, 1993. Utilization of physic The main factors that influenced M. V. of germmated wheat acid as ex- amylase inhibitor in improving flour quality of flour were germmation time and germinated wheat content germinated wheat. Journal of Zhengzhou Grain College. The duality quadratic regression equation of M. V. and 2,50. germmation time, content was: 4 S. S. Deshpande and Munir Cheryan, 1984. Effects of

Y = -113.81+48.95zI- 1O.86zz+0.15zIzz- 0.89zI phytic acid, Divalent cations, and their interactions on ex - 0.05z~ - amylase activity. Journal Food Science, 49, 516. In three improving methods (heating, adding mhibitor 5. U. ZaWIStoWSka, J. Langstaff and W. Bushuk. 1988. and peeling), adding inhibitor was the most effective Improvmg effect of a natural ex- amylase Inhibitor on the improving method and very convenient in practice. baking quality of wheat flour containing malted barley Adding sodium phytate can improve Brabender Maximum flour. Journal of Cereal Science, 8, 207. viSCOSItyof germinated wheat flour, and changing the adding 6. Wang Ruolan and Li Weih. 1992. Study on decreasing ex quantity can adjust M. V., the polynomial regression - amylase activity and improving the flour quality of equation between M. V. and the adding quantity was: germinated wheat. Journal of Zhengzhou Grain College, Y = -18.606 + 101. 879z - 18.998zz +1.580z3 2,43.

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