February 18, 2016 Research Centre, Harrow, ON N0R 1G0
Soybean Quality Program
SOYMILK & TOFU ANALYSIS
Company: Secan
Seed Size (DM basis) 17.49
L 56.33 a 7.00 b 20.52 Whiteness Index -158.43
Moisture 8.4 Protein 42.9
Oil 21.7
Total Free Sugars 10.7
Sucrose 6.0
Stachyose 4.2
Water Uptake Factor (as-is) 2.27
Sample Weight 318.5
Dry Matter (DM) 291.6
Yield (Protein basis) 15.67 Protein 5.34
Oil 2.51
Total Free Sugars 1.29
Solids 10.18 pH 6.48 L 84.27 a 1.32 b 13.90 Whiteness Index -7.07 15.18 0.52 0.13 14.73 0.30 0.09
Composition on dry matter (DM) basis *
HunterLab Colour % % % % % % g/100 Seed Yield (DM basis) 6.72 Composition (w/v) Coagulant GDL CaSO % % % % 6.51 6.32 L/kg L/kg Total Carbohydrates 17.6 Total Isoflavones 1170 g/g bean
Water Uptake Factor (DM basis) 2.48 g/g bean
% µg/g g
g
Analyses were conducted following procedures in Mullin et al, 2001. Food Research International 34: 669-677 and using NIR calibrations provided by the manufacturer or developed at GPCRC. The data is provided without warranty, express or implied, of fitness for any particular purpose. Please refer to the accompanying pdf document 'Guide to Interpreting Tofu Results' for more information on the test.
Supported by:
Raw Bean
Physical Characteristics
Soymilk
Tofu
Sample Contains 125 g Dry Matter Protein Water : Protein Ratio 18:1
Daidzein 510 µg/g
Genistein 580 µg/g
11S:7S Protein Ratio 1.7
Refractive Index 10.70 ° Brix
Yield (kg tofu/kg)
Hardness, break, (N) Firmness (N/mm) Texture / Compression Protein basis DM Bean basis
Comments: Sc 3413N (2015 Crop) Variety: Lab ID: C151094 Specific Gravity 1.00 Protein Recovery 83.69 % 4.8 6.0 Whey Vol. (ml) HunterLab Colour Viscosity 6.92 cP 14.82 0.60 0.11 MgCl2 25.0 6.35 4 0.44 0.35 Springiness 0.43
Research Centre, Harrow, ON N0R 1G0 Soybean Quality Program
SOYMILK & TOFU ANALYSIS
Guide to Interpreting Results
Standard Test Parameters
The standard tofu test uses a sample of soybeans which contains 125 grams of protein. The appropriate sample weight is calculated after obtaining the NIR protein measurement. This means that the total sample weight used for a high protein soybean will be less than for a low protein soybean. Although both tests will contain the same amount of protein, the low protein sample will contain more fibre, oil and other seed constituents. This approach allows the soybeans to be compared on the basis of protein quality and results in soymilks with comparable protein contents ready for tofu gelation. It also reflects commercial practices of adjusting water ratios to the soybean protein content during tofu manufacture.
This laboratory process for making soymilk and tofu uses an 18:1 water to protein ratio (2250 ml water to 125 g protein). The water total includes the water present in the bean as received for analysis (‘as-is’); the water imbibed during soaking; and water added during grinding.
Tofu is prepared using either glucono-δ-lactone, calcium sulphate or magnesium chloride as the coagulant to reflect usage in various markets. The test results are presented individually. The method produces silken (non-pressed) tofu. Soybeans are soaked for 22h at 13˚C and then blended to a slurry in a commercial blender. The slurry is separated into soymilk and okara using a centrifugal commercial separator or juicer. The soymilk is cooked prior to addition of the coagulants in a round forming container. The resulting tofu cake is removed from the forming container prior to evaluation.
Physical Soybean Characteristics
Sample weight is the weight of soybeans ‘as-is’ required to obtain 125 g protein, and dry matter (DM)is the sample weight after adjusting to zero % moisture. Seed size is the weight of 100 seeds on a DM basis. Seed Weight at 13% moisture can be obtained by multiplying by 1.15.
Water uptake factor (WUF) is determined after soaking the beans for 22 h at 13o C in deionized water. WUF reported on an ‘as-is’ basis is determined by dividing the soaked bean weight by the raw bean sample weight. WUF reported on a DM basis is determined by dividing the soaked bean weight by the DM weight of the sample.
Soybean and Soymilk Composition
The compositions reported are determined by near infrared (NIR) spectroscopic analysis. All NIR analyses are predictive estimates based on calibrations provided by the manufacturer of the instruments and/or developed at GPCRC, Harrow. Moisture is the water content of the ‘as-is’ sample. All other
parameters are reported on a DM basis for raw beans and can be converted to 13% moisture basis by multiplying by 0.87. Soymilk composition is reported on the basis of soymilk volume.
Total free sugars includes all soluble sugars including glucose, sucrose, raffinose, stachyose and possibly trace amounts of other sugars found naturally in soybeans. Sucrose and stachyose are also reported individually because they represent the largest components of the free sugars. The stachyose value includes raffinose, a closely related sugar, present in much smaller quantities.
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Total Carbohydrates are determined by following a method used by the Miso Manufacturer’s Association in Japan. All of the free sugars plus all sugars bound up in cell walls and pectins are measured following acid hydrolysis of the soybean sample. This parameter is a direct and specific analysis and therefore it is not the same as ‘carbohydrate by difference’ described in proximate analysis.
Total isoflavones are reported as the sum of genistein, daidzein and glycitein, expressed as aglycone equivalents. Individual values for genisteIn and daidzein aglycone equivalents are also presented. The aglycone form is the isoflavone without any other attached molecule. In the raw soybean, isoflavones are present as the free (aglycone) form (daidzein, genistein and glycitein) and forms linked to glucose (diadzin, genistin and glycitin) or other larger, more complex molecules.
11S:7S Protein Ratio is reported as the total 11S subunits (acidic and basic) divided by the total 7S subunits as determined by calibrated electrophoresis and densitometric analysis. The 11S and 7S protein contents are associated with soy product properties such as gelation and emulsification.
Measurements of Soymilk Dry Matter Content:
Solids (%) is the dry matter determination for soymilk, obtained by NIR analysis.
Refractive index (˚Brix) of soymilk is determined using a refractometer and includes refractive compounds particularly sugars.
Specific gravity (g/ml) of soymilk is calculated by dividing the soymilk weight by the soymilk volume. These parameters are affected by the protein, oil, sugar and particulate contents and may not correlate exactly because of the variation in composition.
Soymilk Viscosity (cP) of soymilk is the resistance to flow or “thickness” of the soymilk and is measured using a Brookfield viscometer. The unit of measurement is centipoise (cP).
Soybean and Soymilk Colour
A HunterLab Labscan spectrocolourimeter is used to measure the colour of whole raw beans and soy milk. Colour measurements determined on the HunterLab Labscan are described in detail at
http://www.hunterlab.com. The following are very brief explanations of the measurements reported.
Hunter L,a,b Colour Scale
L measures lightness and ranges from 100 for perfect white to zero for black, approximately as the eye would evaluate it. The ‘a’ and ‘b’ values indicate the
colour of the product. The ‘a’ value measures redness when positive, grey when zero and greenness when negative. The ‘b’ value measures yellowness when positive, grey when zero and blueness when negative.
The HunterLab scale is a full colour descriptor which provides measurements of hue, saturation and intensity. It is used extensively for consumer products including a wide range of foods. Unlike wavelength based systems it is designed to approximate how the human eye perceives colour. For example red is perceived relative to green, and blue is perceived relative to yellow. The system also incorporates a measurement of lightness (L) because human colour perception of colour is highly affected by the lightness or darkness of the material.
Whiteness Index (W.I.)
The W.I. value is a single number index which indicates the closeness of the product to pure white and incorporates a measure of luminosity. Values can be either negative or positive. The more positive the value, the whiter the sample. Note that raw soybeans typically have a large negative value and the resulting soymilk may approach zero or become positive. There are many whiteness indices. Our instrument is now calibrated to the CIE Whiteness Index which is the current international standard. Note that although W.I. for whole raw soybeans is reported, this parameter is not typically relevant for such dark material.
Soymilk and Tofu Yields
Soymilk yield and tofu yield are reported on both a protein basis and on a soybean DM basis. This allows results to be compared on either a yield per kg of protein basis or on a yield per kg of raw soybean basis, respectively. Note that soymilk yield is measured in liters of soymilk and tofu is measured in kilograms of tofu. The tofu yield is measured after removal of any whey that is released.
Protein Recovery is calculated using the measured protein content of the soymilk and the total volume produced. This total recovered protein is expressed as a percentage of the total amount of protein present in the soybean sample used for the test.
Whey Volume released from the tofu is measured 30 minutes after the tofu is removed from the forming container. The protein gel of the tofu contracts over time causing liquid from within the gel to be released as whey. Tofu gels that are more stable release less whey. Samples with protein gels that contract significantly will release large volumes of whey very quickly. Whey volumes of less than 10 mls are normal.
Soymilk pH
Soymilk pH is measured by immersing a glass electrode in raw soymilk. It is a measure of the acidity or alkalinity of the soymilk.
Tofu Texture
The tofu texture is evaluated using an Instron Texture Measuring system. The purpose is to obtain objective instrument measurements that relate to characteristics such as bite and mouthfeel. The tests provide values of tofu firmness, hardness and springiness. The values will differ depending on the coagulant used. All of the tests are performed on cylinder shaped cores of tofu cut from the tofu cake and trimmed to a uniform size (2 cm diameter and 2 cm length). The springiness parameter obtained from the two-bite test is intended to distinguish between tofu with an strong gel structure and tofu that is simply solid but not springy. Both of these tofu types may result in similar firmness and hardness values but not be considered of equal texture quality.
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Please Note: Some soybean samples do not produce a stable, intact tofu cake after the addition of the coagulant. This may occur with one or all of the coagulants. The tofu may collapse after it is released from the forming container or it may release whey so quickly that the remaining tofu solids collapse. When this happens it is not possible to cut cohesive cores from the tofu cake and make any texture measurements.
The curve on the graph illustrates the increasing resistance of the tofu to the pressure being applied by the instrument. The slope of the dotted line at the point of inflection on the curve represents the value at which the tofu no longer resists the pressure and begins to deform. This value is the maximum
firmness. The maximum value reached before the tofu gel breaks measures the hardness of the tofu.
Compression firmness and hardness of the internal gel matrix of the tofu cake are measured by compressing a cylinder of tofu (2 cm diameter X 2 cm high cut from the interior of a tofu cake) between two plates. The sample is compressed a distance of 1 cm, or 50% of its original height. This test will cause the tofu to rupture or break.
The two-bite test uses the same system and tofu sample size as the compression firmness and hardness test, but it is conducted at a higher speed and involves two successive compressions on the same tofu sample. Springiness is measured as the height that the sample springs back after the first compression divided by the full distance of the first compression (distance B divided by distance A on the diagram).
Please Note: It is very important that the sample submitted for analyses is representative of the soybean lot. Variation in composition and functional characteristics can occur within a variety due to pre-harvest and post-pre-harvest conditions.
References
Mullin, W.J., Fregeau-Reid, J.A., Butler, M., Poysa, V., Woodrow, L., Jessop, D.B. and Raymond, D. 2001. An interlaboratory test of a procedure to assess soybean quality for soymilk and tofu production. Food Research International 34, 669-677.
Hunter Associates Laboratory, Inc. 1982. Hunter Labscan Spectrocolorimeter LS-5000 Instruction Manual. Reston, Virginia.
Compiled by Lorna Woodrow, Dale Anderson and Kathy Beaudoin, October 2015.
February 18, 2016 Research Centre, Harrow, ON N0R 1G0 Soybean Quality Program
MISO Preliminary Evaluation
Company: Secan
Seed Size (DM basis) 17.49
L 56.33 a 7.00 b 20.52 Whiteness Index -158.43 Moisture 8.4 Protein 42.9 Oil 21.7
Total Free Sugars 10.7
Sucrose 6.0
Stachyose 4.2
Water Uptake Factor (as-is) 2.27
% % based on DM % " % " % " % " g/100 Seed Total Carbohydrates 17.6 Total Isoflavones 1170 g/g bean Water Uptake Factor (DM basis) 2.48 g/g bean % based on DM µg/g "
Analyses were conducted following procedures in Mullin et al, 2001. Food Research International 34: 669-677 and using NIR calibrations provided by the manufacturer or developed at GPCRC. The data is provided without warranty, express or implied, of fitness for any particular purpose. Please refer to the accompanying pdf document 'Guide to Interpreting Tofu Results' for more information on the test.
Supported by:
Physical Characteristics
Composition
HunterLab Colour
Daidzein 510 µg/g " Genistein 580 µg/g " 11S:7S Protein Ratio 1.7 Sc 3413N (2015 Crop) Variety: Lab ID: C151094Whole Raw Bean
Ground Raw Bean
Y 31.73 x 0.41 y 0.40 84.53 0.67 21.24 -54.05 71.45 0.36 0.38
Greenhouse and Processing Crops Research Centre Food Processing Lab, Harrow, ON N0R 1G0
MISO PRIMARY EVALUATION
Guide to Interpreting Results
Physical Sample Characteristics
Seed size is the weight of 100 seeds on a dry matter (DM) basis. Seed Weight at 13% moisture can be obtained by multiplying by 1.1494
Water uptake factor (WUF) is determined after soaking the beans for 22 h at 13o C in tap water. WUF on an ‘as-is’ basis is determined by dividing the soaked bean weight by the raw bean sample weight as received for analysis (‘as-is’). WUF is reported on a DM basis is determined by dividing the soaked bean weight by the DM weight of the sample.
Product Colour
A HunterLab Labscan spectrocolourimeter is used to measure the colour of raw beans and ground beans. Colour measurements used on the HunterLab Labscan are described in detail at http://www.hunterlab.com. The following are very brief explanations of the measurements reported.
1. Hunter Lab Colour Scale
This scale is a full colour descriptor which provides measurements of hue, saturation and intensity.
From: http://www.hunterlab.com/appnotes/an08_9 1
L measures lightness and varies from 100 for perfect white to zero for black, approximately as the eye would evaluate it. The ‘a’ and ‘b’ values indicate the colour of the product. The ‘a’ value measures
redness when positive, grey when zero and greenness when negative. The ‘b’ value measures yellowness when positive, grey when zero and blueness when negative.
2. W.I. - Whiteness Index
The W.I. value is a single number index which indicates the closeness of the product to pure white and incorporates a measure of luminosity. Values can be either negative or positive. The more positive the
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value, the whiter the sample. There are many whiteness indices. Our instrument is now calibrated to the CIE Whiteness Index. Previously the ASTM WI E313 was used. The CIE W.I. is the current international standard. For darker products such as whole and ground soybean there are differences between the two standards. Note that although W.I. for raw soybeans is reported, this parameter is not typically relevant for such dark material and the other colour parameters can be of more significance.
3. Yxy CIE Chromaticity Coordinates
Yxy is another colour description system. The Y value correlates with lightness. The x and y values are two of three coordinates, and with a z value, add up to 1.0. Typically z is not reported since it can be easily calculated. For a detailed discussion of how this data may be used, please see HunterLab application notes ‘Yxy CIE Chromaticity Coordinates’ and ‘XYZ – CIE Tristimulus Values’ available at
http://www.hunterlab.com .
Composition
The compositions reported are determined by near infrared (NIR) spectroscopic analysis. All NIR analyses are predictive estimates based on calibrations provided by the manufacturer of the instruments and/or developed at GPCRC, Harrow. Moisture is the water content of the ‘as-is’ sample. All other parameters
are reported on a DM basis for raw beans.
Total free sugars includes all soluble sugars including glucose, sucrose, raffinose, stachyose and possibly trace amounts of other sugars found naturally in soybeans. Sucrose and stachyose are also reported individually because they represent the largest components of the free sugars. The stachyose value includes raffinose, a closely related sugar, present in smaller quantities.
Total Carbohydrates are based on a measurement used by the Miso Manufacturer’s Association in Japan.
It includes all of the free sugars plus all sugars bound up in cell walls and pectins. This is not equivalent to ‘carbohydrate by difference’ described in proximate analysis.
Isoflavones are reported as a total value representing the sum of genistein, daidzein and glycitein expressed as aglycone equivalents. Values for genisteIn aglycone equivalents and daidzein aglycone equivalents are also presented. In the raw soybean, these isoflavones are present as the free (aglycone) form (daidzein, genistein and glycitein) and linked to other molecules. These include diadzin, genistin and glycitin which are linked to glucose and other larger more complex forms. The analysis method enables us to present a total content based on the free genistein, daidzein and glycitein.
11S:7S Protein Ratio is reported as the total 11S subunits (acidic and basic) divided by the total 7S subunits as determined by calibrated electrophoresis and densitometric analysis.
Please Note: It is very important that the sample submitted for analyses is representative of the soybean lot. Variation in composition and functional characteristics can occur within a variety due to pre-harvest and post-harvest conditions.
References
Hunter Associates Laboratory, Inc. 1982. Hunter Labscan Spectrocolorimeter LS-5000 Instruction Manual. Reston, Virginia.
Compiled by Lorna Woodrow, Dale Anderson and Kathy Beaudoin, October 2012.
