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Tofu Characteristics Influenced by Soybean Crop Year and Location
T.C. Helms,
T.D. Cai,
K.C. Chang, and J.W.
Enz
Department of Plant Sciences, Department or Food
and Nutrition, Department of Cereal Science, and
Department of Soil Science
North Dakota State University
Abstract
Plant breeders and
tofu processors need to understand the influence of
environment on tofu quality and color. Our objective was
to determine the influence of locations within a year and
differences between years on tofu yield, quality, and
color. We evaluated two soybean (Glycine max (L). Merr.)
genotypes that were developed for the tofu specialty
market at four locations in 1993 and five locations in
1994. There were significant differences between years
for tofu yield, protein content, oil content, and color
averaged across genotypes. There were significant
differences among locations within each year for
soymilk solid content and
tofu yield, protein content, oil content, protein ratio
(11S/7S), firmness,and yellowness. Due to the influence
of environment, genotypes should only be compared for
tofu yield, quality, and color within the same
environment. Processors can use this information to
identify which locations produce the best quality tofu. This
article is only available online at http://www.ag.ndsu.nodak.edu/ndagres/ndagres.htm
Audience — Soybean breeders, soybean growers, soybean buyers, tofu producers
Keywords
Soybean (Glycine
max), tofu, crop year, location.
Introduction
Processors
that manufacture tofu from soybean (Glycine max (L.)
Merr.) desire both a high quality product and high tofu
yield. Firmness and whiteness are two important quality
attributes of tofu. However, little is known regarding
the effect of environment, genotype, and the interaction
of these factors on tofu quality.
Wang et al. (1983) reported that tofu made from a cultivar with a black hilum had a grey tinge and was less attractive than tofu made from other cultivars. The yields of fresh tofu differed among 10 cultivars due to differences in water content, but not dry product. They stated that "neither the size of the beans nor the amount of water absorbed by the beans was significantly associated with the yield and quality of tofu." They found that tofu produced from different cultivars varied in hardness and that cultivars high in protein content produced tofu high in protein content. Although differences among cultivars affected the texture and yield of tofu, they concluded that these differences were small.
Lim et al. (1990) reported that increased total solids of soymilk was associated with increased firmness of tofu. Firmness was not associated with protein content of tofu or soybean seed. Fresh tofu yield increased as the total solids content of soymilk increased. Soybean seed size was not associated with the yield of fresh tofu.
Smith et al. (1960) stated that tofu is typically 6% protein, 3.5% fat, 1.9% carbohydrates, 0.6% ash, and 88% water. They compared five soybean cultivars developed in Japan to 15 U.S. cultivars and one from India. Cultivars were not grown in the same environment and were not a composite of samples grown in different environments. Therefore, cultivar differences were confounded with the influence of the different environments in which the seed was produced. Japanese and U.S. cultivars had similar volume and water content. However, tofu produced from cultivars of Japanese origin were mostly a greyish white color, whereas tofu produced from cultivars of U.S. origin were light yellow. They stated that "the greyish white color is preferred in Japan and appears to be favored because of custom..." They concluded that "because uncomposited samples of soybean were used, observed differences may have been caused by climate and soil at the location of their growth." Tofu produced from two U.S. cultivars was equal in quality to tofu produced from Japanese cultivars.
Smith et al. (1960) stated that "yield of tofu varies with variety (location), but the general average yield from U.S. soybeans is about the same as from Japanese beans." However, due to the confounding of the influence of cultivar and environment, they were unable to determine whether environment influenced tofu quality and yield.
Murphy and Resurreccion (1984) reported that environment had a greater influence on glycinin concentration than genetic differences between two cultivars. Soybean protein is comprised primarily of glycinin and beta-conglycinin fractions. Glycinin is commonly considered the major component of the 11S sedimentation fraction and beta-conglycinin is the major component of the 7S fraction. Although genetic differences among cultivars for glycinin content were observed, they concluded that both glycinin and beta-conglycinin content were affected more by environment than genetic differences.
Tofu manufacturers desire high yield as well as firm, white tofu, but the influence of the growth environment on tofu firmness, color, and yield has not been evaluated. If differences among locations within a year affect tofu quality and yield, processors may decide to test soybean samples produced in different locations before purchasing the seed.
Plant breeders need to determine whether a relative or absolute standard should be used to evaluate experimental lines for tofu quality and yield. An absolute standard would be based on minimum tofu quality and yield of a genotype, without considering the environment in which the seed was produced. However, if environment affects tofu quality, breeders should compare new experimental genotypes to a standard cultivar grown in the same environment. Under these circumstances, breeders using an absolute standard might discard genotypes suitable for making high quality tofu. Our objective was to determine the influence of locations within a year and differences between years on tofu yield, quality, and color.
Materials and Methods
Two soybean
genotypes, 'Proto' (Orf et al., 1991) and M86-356 were
compared. Both are Maturity Group 0, high protein
genotypes developed at the University of Minnesota. They
were evaluated in a randomized complete block design with
three replicates per environment. Environments included:
1993 Northwood, ND; 1993 Hendrum, MN; 1993 Kragnes, MN;
1993 Dwight, ND; 1994 Northwood, ND; 1994 Hendrum, MN;
1994 Casselton, ND; 1994 Great Bend, ND; and 1994
Mantador, ND.
Each plot consisted of two 6.4-m long rows with 0.76 m between them and two adjacent plots. The center 4.6 m of each plot was harvested with a self-propelled combine. Tofu characteristics, protein, and oil content were evaluated on two replicates in the 1993 environments and three replicates in the 1994 environments.
Soybean (139 g) were soaked in tap water at room temperatures (20-22°C) for 8 hr. The soaked bean was ground with 625-ml water for 4 min at high speed in a blender (Model 908-2, Hamilton Beach Co., Washington, NC). After grinding, the slurry was filtered through a cheese cloth and squeezed by hand to obtain soymilk. The residue was mixed with water to produce an 8:1 water-to-bean ratio. The slurry was filtered again to recover soymilk solids. After adding 0.2 g antifoaming agent (Kaoh Co., Wakayama, Japan), the soymilk was heated to boiling and maintained for 5 min while stirring. When cooked milk was cooled to 85°C, modified nigari (a mixture of CaSO4•2H2O and natural nigari, Taiwan Salt Workers Co., Tainan, Taiwan) suspended in 15-ml water at 3% of raw bean weight or glucono-delta-lactone (Fujisawa Pharmaceutical Co., Osaka, Japan) at 0.5% of soymilk weight was added. The mixture was stirred at 150 rpm by a Caframo stirrer (Model R2R1, Wiarton, Ontario, Canada) for 30 sec. After standing for 10 min, the bean curd was cut into pieces with a scoop and transferred to a wooden mold (12.5 x 12.5 x 5.5 cm) for pressing. The bean curd was pressed sequentially at 8.7 g/cm2 for 10 min, 14.6 g/cm2 for 10 min and 20.4 g/cm2 for 15 min. After pressing, tofu samples were weighed and placed in cool water before performing textural and color analyses.
Tofu samples were freeze-dried. The crude protein, moisture, and crude oil contents of soybean and freeze-dried tofu were determined by near-infrared reflectance (NIR) (Infra-Alyzer 400, Technicon Instruments Corp., Elmhurt, IL). The NIR readings were calibrated with standard curves determined by AOAC Methods (1990).
The solid content of soymilk was determined as a degree of Brix using a refractometer (Auto Abbe, Model 10500, Buffalo, NY) at room temperature. Tofu yield is the fresh weight of tofu per weight of dry soybean seed. The color of fresh tofu was measured on a Hunter colorimeter (Model XL-23, Gardner Lab Inc., Bethesda, MD). The instrument was standardized with a standard white tile (L=91.94, a= -1.03, b=1.14).
Soybean were examined for storage protein mass distribution (7S and 11S) by sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) using a gradient gel of 8-16%, based on the procedure of Laemmli (1970). Samples were extracted on a magnetic stirrer with 0.05 M sodium phosphate buffer (1.2 g: 14 ml) at pH 7.5 for 90 min. The slurry was centrifuged at 1,960 x g for 10 min to remove residues. The protein concentration of supernatant was determined by the Biuret method and adjusted to 2 mg/ml with distilled water. An equal volume of SDS-sample buffer containing 10% of 2-mercaptoethanol was added to the protein solution. After boiling for 2 min, 40 microliters of the cooled solution containing 40 micrograms protein was loaded into the gel. Electrophoresis was performed in a BioRad Protean II chamber at 100 volts for 8 hr. The gel was stained with Coomassie Brilliant Blue R-250. The 7S and 11S proteins were quantified according to Wang and Chang (1995).
The firmness of tofu samples was measured using an Instron Universal Testing Machine (Model 1011, Instron Co., Canton, MA) equipped with a 5-kg load cell. A 5-cm diameter cylindrical plunger was used to compress the interior sample of tofu cake (1.5-cm height with 5-cm diameter). Four tofu cakes from each batch were compressed twice to 25% of original height at a crosshead speed of 20 mm/min. The recording chart speed was 20 mm/min. Firmness was measured from the highest point of the first compression cycle of the Texture Profile Analysis curves (Bourne, 1978).
Results and Discussion
There were
significant differences between years for grain yield,
tofu yield, protein content, and oil content (Table 1). Pooled across the two years,
there was a significant difference among locations within
each year for grain yield, protein content, oil content
and 11S/7S ratio.
Grain yield, tofu yield, protein content, and oil content were all greater in 1994 than in 1993 (Table 2). In 1993, the protein content of soybean grown at Kragnes, MN was lower than at Dwight, ND. This shows that protein content can vary with location within the same year. Processors can use this information to test the protein content of soybean grown in different locations to determine which location has produced the highest protein content. Oil content and 11S/7S ratio also differed among locations within each year. These results show that the effect of location within the same year can have a great influence on chemical constituents of soybean for both the amount of protein and type of protein fraction.
There was a genotype X location within-year interaction for protein content and 11S/7S ratio. The magnitude of the differences between Proto and M86-356 for 11S/7S ratio varied among locations within each year (Table 3). However, Proto was significantly greater than M86-356 only at the 1994 Casselton, ND location.
There were differences in redness and yellowness among years (Table 4). Tofu produced in 1993 was less red and more yellow than tofu produced in 1994 (Table 5). There were differences in tofu firmness and yellowness and soymilk Brix among locations within years (Table 4). In 1993, the firmest tofu was produced from soybean grown at Northwood, ND and Kragnes, MN (Table 5). Location within a year can have a large influence on tofu firmness. However, the soymilk was not closely associated with tofu firmness. In 1993 at Northwood, ND, the firmest tofu was produced with the highest soymilk Brix. However, in 1993 at Kragnes, MN, firm tofu was produced with a low soymilk Brix. Differences in yellowness among locations within 1993 were small. However, in 1994, there were large differences among locations for yellowness.
There was a significant genotype X location within-year interaction for whiteness (Table 4). M86-356 was significantly whiter than Proto only at the 1993 Hendrum, MN environment (Table 6). The genotype X location within year interaction for whiteness was primarily due to differences in magnitude rather than changes in rank.
Tofu produced from soybean grown in 1993 was less red and more yellow than tofu produced from soybean grown in 1994 (Table 5). In both 1993 and 1994, soybean grown at some locations within a year produced tofu that was less yellow than other locations within each of these years. Differences in the yellowness of tofu also depend on the year in which the soybean was grown. Processors can produce tofu that is less yellow by identifying soybean grown at specific locations within a year that produce less yellow tofu.
The cooler weather in 1993 compared to 1994 (Table 7) was associated with lower protein and oil content, decreased tofu yield, and lower grain yield (Table 2). On average, tofu from soybean produced in 1993 was less red and more yellow than soybean produced in 1994. Precipitation was above normal in both 1993 and 1994 at most locations (Table 8). Soil properties and soil fertility differed among locations (Table 9). The greatest association between tofu quality factors and environmental conditions appears to be due to the difference in temperature between 1993 and 1994. However, the unique combination of temperature, precipitation, soil fertility, and soil type associated with the different environments could not be replicated. Factors such as weather and soil were confounded at each environment and cannot be separated. If locations within years are considered a random effect, then averaged across locations within a year, the effect of years can be evaluated in this context.
Conclusions
Due to the
influence of environment, genotypes should only be
compared for tofu firmness, soymilk solid content, and
color when grown in the same environment. Processors can
benefit by evaluating the tofu quality of soybean grown
at different locations within a year and purchasing
soybean from those locations that produces the best
quality tofu. Rather than discard soybean genotypes based
on an absolute standard, tofu quality of experimental
lines should be compared to that of a known check
cultivar.
| Table 1. Analyses of variance for grain yield, tofu yield, protein content, oil content and 11S/7S ratio of two soybean genotypes. | ||||||
Mean squares |
||||||
| Source of variation |
df | Grain yield |
Tofu yield |
Protein content |
Oil content |
11S/7S ratio |
Year (Y) |
1 |
23.405** |
8.904** |
126.00* |
74.76** |
0.001 |
G*Y |
1 |
0.015 |
0.065 |
2.90 |
0.29 |
0.057 |
Location (L) within Y |
7 |
0.740** |
0.106 |
13.43** |
1.61** |
0.230** |
G*L(Y) |
7 |
0.053 |
0.044 |
5.40** |
0.15 |
0.068* |
Replicate (YL) |
13 |
0.134 |
0.086 |
0.88 |
0.34 |
0.027 |
Residual |
42 |
0.104 |
0.099 |
0.50 |
0.17 |
0.018 |
| *,** Significant at the 0.05 and 0.01 probability level, respectively. | ||||||
| Table 2. Mean grain yield, tofu yield, protein content, oil content, and 11S/7S sedimentation fraction ratio of nine environments, averaged across two genotypes. | ||||||
Year |
Location |
Grain |
Tofu
yield |
Protein |
Oil (%)a |
11S/7S |
1993 |
Northwood, ND |
1.69 |
3.94 |
36.5 |
15.4 |
1.40 |
1993 |
Hendrum, MN |
1.23 |
3.72 |
38.3 |
16.4 |
1.60 |
1993 |
Kragnes, MN |
0.63 |
3.63 |
40.8 |
16.5 |
2.10 |
1993 |
Dwight, ND |
1.10 |
4.15 |
42.4 |
15.0 |
1.90 |
1993 Average |
1.16 |
3.86 |
39.5 |
15.8 |
1.75 |
|
1994 |
Northwood, ND |
2.82 |
4.95 |
43.3 |
18.1 |
1.88 |
1994 |
Hendrum, MN |
2.30 |
4.74 |
42.7 |
18.9 |
1.72 |
1994 |
Casselton, ND |
2.59 |
4.80 |
42.4 |
18.8 |
1.46 |
1994 |
Mantador, ND |
2.84 |
4.84 |
43.0 |
19.3 |
1.90 |
1994 |
Great Bend, ND |
3.24 |
4.84 |
44.3 |
18.2 |
1.68 |
1994 Average |
2.75 |
4.82 |
43.1 |
18.7 |
1.73 |
|
LSD (0.05)b |
0.51 |
NSd |
1.3 |
0.8 |
0.24 |
|
LSD (0.05)c |
0.66 |
0.25 |
2.8 |
1.0 |
0.11 |
|
| aProtein
and oil content on a dry weight basis. bLeast significant difference among locations at the 0.05 probability level. cLeast significant difference among years at the 0.05 probability level. dNot significant at the 0.05 probability level. |
||||||
| Table 3. Mean 11S/7S protein ratio for two soybean genotypes evaluated at nine environments. | ||||
Year |
Location |
Proto |
M86-365 |
|
1993 |
Northwood, ND |
1.50 |
1.40 |
|
1993 |
Hendrum, MN |
1.72 |
1.60 |
|
1993 |
Kragnes, MN |
2.08 |
2.10 |
|
1993 |
Dwight, ND |
1.87 |
1.90 |
|
1994 |
Northwood, ND |
1.90 |
1.88 |
|
1994 |
Hendrum, MN |
1.76 |
1.72 |
|
1994 |
Casselton, ND |
1.88 |
1.46 |
|
1994 |
Mantador, ND |
1.96 |
1.90 |
|
1994 |
Great Bend, ND |
1.81 |
1.68 |
|
LSD (0.05)a |
0.28 |
|||
| aLeast significant difference between two genotypes within an environment. | ||||
| Table 4. Analyses of variance for tofu firmness, whiteness, redness, and yellowness and soymilk solid content of two soybean genotypes. | ||||||
Source of variation |
df |
----------------------- Mean squares ----------------------- |
||||
Tofu |
Soymilk |
----- Tofu Hunter color ----- |
||||
White |
Red |
Yellow |
||||
Genotypes (G) |
1 |
21222 |
0.389 |
4.42* |
0.18 |
0.06 |
Year (Y) |
1 |
1490874 |
0.046 |
1.54 |
1.10** |
37.85** |
G*Y |
1 |
106450 |
0.003 |
2.85 |
0.11 |
0.15 |
Location (L) within Y |
7 |
355094** |
0.311** |
0.53 |
0.07 |
0.72** |
G*L(Y) |
7 |
110750 |
0.080 |
0.65** |
0.04 |
0.32 |
Replicate (YL) |
13 |
39229 |
0.064 |
0.22 |
0.03 |
0.14 |
Residual |
42 |
110883 |
0.157 |
0.13 |
0.02 |
0.26 |
| *,** Significant at the 0.05 and 0.01 probability level, respectively. | ||||||
| Table 5. Mean tofu firmness, whiteness, redness, and yellowness and soymilk solid content of nine environments, averaged across two genotypes. | ||||||
Year |
Location |
Tofu |
Soymilk |
----- Tofu Hunter color ----- |
||
White |
Red |
Yellow |
||||
1993 |
Northwood, ND |
2480 |
8.13 |
85.7 |
-0.44 |
15.3 |
1993 |
Hendrum, MN |
1580 |
7.75 |
85.8 |
-0.39 |
15.8 |
1993 |
Kragnes, MN |
2260 |
7.55 |
84.7 |
-0.15 |
15.9 |
1993 |
Dwight, ND |
1660 |
7.83 |
85.4 |
-0.33 |
15.2 |
1993 Average |
2000 |
7.82 |
85.4 |
-0.33 |
15.6 |
|
1994 |
Northwood, ND |
1500 |
8.03 |
85.6 |
0.04 |
12.9 |
1994 |
Hendrum, MN |
1540 |
7.62 |
86.0 |
-0.02 |
13.4 |
1994 |
Casselton, ND |
1580 |
8.28 |
85.9 |
0.22 |
13.7 |
1994 |
Mantador, ND |
1630 |
7.87 |
85.9 |
-0.04 |
14.2 |
1994 |
Great Bend, ND |
1710 |
7.75 |
85.7 |
-0.08 |
13.7 |
1994 Average |
1590 |
7.91 |
85.8 |
0.03 |
13.6 |
|
LSD (0.05)b |
280 |
0.35 |
NSd |
NS |
0.5 |
|
LSD (0.05)c |
455 |
0.43 |
NS |
0.21 |
0.7 |
|
| aProtein
and oil content on a dry weight basis. bLeast significant difference among locations at the 0.05 probability level. cLeast significant difference among years at the 0.05 probability level. dNot significant at the 0.05 probability level. |
||||||
| Table 6. Mean whiteness (Hunter L-value) for two soybean genotypes evaluated at nine environments. | ||||
Year |
Location |
Proto |
M86-365 |
|
1993 |
Northwood, ND |
85.4 |
86.1 |
|
1993 |
Hendrum, MN |
84.3 |
87.3 |
|
1993 |
Kragnes, MN |
84.3 |
85.0 |
|
1993 |
Dwight, ND |
85.0 |
85.7 |
|
1994 |
Northwood, ND |
85.2 |
85.9 |
|
1994 |
Hendrum, MN |
86.1 |
85.8 |
|
1994 |
Casselton, ND |
85.8 |
86.0 |
|
1994 |
Mantador, ND |
85.7 |
86.0 |
|
1994 |
Great Bend, ND |
85.8 |
85.7 |
|
LSD (0.05)a |
0.07 |
|||
| aLeast significant difference between two genotypes within an environment. | ||||
| Table 7. Total monthly temperature departure from 1961-1990 average for nine environments. | ||||||||
Year |
Location |
------------------- Month ------------------- |
Season |
|||||
April |
May |
June |
July |
August |
Sept. |
|||
1993 |
Northwood |
-0.6 |
-0.9 |
-5.2 |
-6.2 |
-2.8 |
-5.0 |
-3.5 |
1993 |
Hendrum |
-0.5 |
-0.9 |
-3.7 |
-5.2 |
-0.2 |
-3.5 |
-2.3 |
1993 |
Kragnes |
-0.2 |
-0.3 |
-3.3 |
-5.1 |
-0.1 |
-3.3 |
-2.0 |
1993 |
Dwight |
-0.3 |
-0.2 |
-4.3 |
-4.7 |
-0.9 |
-3.2 |
-2.2 |
1994 |
Northwood |
-0.9 |
2.1 |
0.4 |
-4.4 |
-3.2 |
2.8 |
-0.5 |
1994 |
Hendrum |
0.5 |
2.9 |
1.8 |
-3.8 |
-2.7 |
3.0 |
0.3 |
1994 |
Casselton |
0.1 |
2.1 |
1.2 |
-4.4 |
-2.9 |
3.3 |
-0.1 |
1994 |
Mantador |
1.3 |
3.5 |
2.1 |
-4.2 |
-2.7 |
4.2 |
0.7 |
1994 |
Great Bend |
0.9 |
2.7 |
1.7 |
-3.9 |
-2.8 |
4.2 |
0.5 |
| Table 8. Total monthly precipitation (inches) departure from 1961-1990 average for nine environments. | ||||||||
Year |
Location |
---------------------Month --------------------- |
Season |
|||||
April |
May |
June |
July |
August |
Sept. |
|||
1993 |
Northwood |
-1.17 |
0.80 |
1.95 |
4.50 |
2.14 |
-1.93 |
6.30 |
1993 |
Hendrum |
-1.00 |
-0.48 |
2.31 |
1.93 |
-1.57 |
-1.79 |
-0.60 |
1993 |
Kragnes |
-0.70 |
0.76 |
3.23 |
7.37 |
-1.37 |
-1.35 |
7.94 |
1993 |
Dwight |
-0.03 |
1.30 |
2.02 |
1.84 |
-1.62 |
-1.31 |
2.21 |
1994 |
Northwood |
-0.67 |
0.54 |
1.81 |
1.37 |
-0.02 |
2.04 |
3.99 |
1994 |
Hendrum |
0.20 |
-0.53 |
3.21 |
3.96 |
2.03 |
3.32 |
12.19 |
1994 |
Casselton |
0.21 |
-0.10 |
-0.79 |
5.39 |
2.17 |
0.76 |
7.64 |
1994 |
Mantador |
0.38 |
-0.94 |
-2.38 |
3.40 |
-0.27 |
-0.95 |
-0.76 |
1994 |
Great Bend |
0.25 |
-0.89 |
-2.31 |
3.07 |
-0.24 |
-1.04 |
-1.15 |
| Table 9. Mean soil nitrogen (N), phosphorous (P), potassium (K), pH, exchange capacity (EC), organic matter (OM), and zinc (Zn) fertility for nine environments, averaged across three replicates per environment. | ||||||||
Year |
Location |
Na |
Pa |
Ka |
pH |
EC |
CM |
Zn |
1993 |
Northwood |
34 |
19 |
175 |
7.4 |
0.40 |
4.4 |
0.8 |
1993 |
Hendrum |
101 |
18 |
210 |
8.3 |
0.65 |
4.8 |
0.3 |
1993 |
Kragnes |
70 |
28 |
630 |
6.8 |
0.60 |
6.9 |
1.7 |
1993 |
Dwight |
29 |
10 |
90 |
8.2 |
0.45 |
2.5 |
0.5 |
1994 |
Northwood |
40 |
59 |
265 |
6.0 |
0.30 |
4.0 |
2.5 |
1994 |
Hendrum |
66 |
11 |
300 |
8.1 |
0.60 |
5.6 |
0.3 |
1994 |
Casselton |
42 |
24 |
220 |
7.5 |
0.40 |
4.1 |
0.5 |
1994 |
Mantador |
53 |
15 |
215 |
6.9 |
0.45 |
3.6 |
0.7 |
1994 |
Great Bend |
44 |
10 |
215 |
7.4 |
0.45 |
3.7 |
0.5 |
| a ppm | ||||||||
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Authors
T.C. Helms, Associate Professor
Deptartment of Plant Science
North Dakota State University
helms@badlands.nodak.eduT.D. Cai, Food Technologist II
Department of Food and Nutrition
North Dakota State University
tcai@plains.nodak.eduK.C. Chang, Professor
Departments of Food and Nutrition and Cereal Science
North Dakota State University
schang@plains.nodak.eduJ.W. Enz
Department of Soil Science
North Dakota State UniversityCorresponding author
T.C. Helms
Location where the research was
(primarily) done
Soybean Research and Utilization Lab
Department of Food and Nutrition
North Dakota State University, Fargo, North Dakota
Funding source of the project
USDA-CSREES
Great Plains International Trade Research Program
North Dakota Soybean Council
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