Investigating the Quality of Soymilk and Tofu made from Manitoba

Investigating the Quality of Soymilk and Tofu made
from Manitoba-Grown Food-Grade Soybeans
M.C. Reimer1, L.J. Malcolmson2 and S.D. Arntfield3; Departments of 1Human Nutritional Science and 3Food Science,
University of Manitoba and 2Canadian International Grains Institute
INTRODUCTION AND OBJECTIVES
For centuries soybeans have been an important food source in many parts of the world
(Liu, 1997). Soybeans are of particular importance to Asian countries, where they are
used to prepare traditional food products such as soymilk and tofu. In recent years the
popularity of soymilk and tofu has spread to North America where soy foods have gained
acceptance and are recognized as a healthy alternative to animal products. The
increased demand for food-grade soybeans has generated interest in growing soybeans
in Manitoba that are well-suited for soymilk and tofu production. Currently there is
insufficient data on the quality characteristics of Manitoba-grown food-grade soybeans.
Therefore, the objectives of this research are:
•To examine the effects of variety, growing location, and crop year on soymilk and tofu
yield and quality
•To evaluate the soymilk and tofu quality of Manitoba-grown food-grade soybeans
Table 1. Simple correlation coefficients between seed
characteristics and soymilk and tofu traits
Trait
Seed Size
Seed Protein
SOYMILK
Yield
Colour
0.71***
0.24
0.73***
0.31*
TOFU
Yield
Texture
Colour
0.76***
0.39**
0.65***
0.86***
0.31*
0.75***
*P < 0.05, ** P < 0.01, *** P < 0.001
Correlations are based on 48 observations
( 8 genotypes and 6 site-years).
Figure 1. Effect of genotype and site-year on seed
protein content
48
46
MATERIALS AND METHODS
42
40
38
36
34
GENOTYPE***
St. Adolphe06
Carman05
Morris06
Morris05
Rosebank06
Rosebank05
OAC 01-13
OAC 01-12
Dolly
OAC Erin
Jim
90A07
90A01
30
OAC Prudence
32
HAROVINTON (Ctrl)
Soybean Samples
•Eight non-GMO soybean varieties
•Two crop years
o 2005–three locations (Rosebank, Morris, Carman)
o 2006–three locations (Rosebank, Morris, St. Adolphe)
•Standard: Harovinton (Ontario)
Protein %
44
SITE-YEAR***
Red line indicates overall mean value *** P < 0.001
SOAKING
GRINDING
SOYBEAN SLURRY
EXTRACTION
HEATING
COAGULATION
COOLED/REFRIGERATED
TOFU
SOYMILK
Figure 2. Effect of genotype and site-year on soymilk
yields (gram of soymilk per gram of seed)
8.0
7.5
7.0
6.5
Yield (g/g)
WHOLE SOYBEANS
6.0
5.5
4.5
4.0
• Yield - gram of soymilk/gram of soybean seed
• Colour - Minolta Colorimeter
• Yield - gram of tofu/gram of soybean seed
• Colour - Minolta Colorimeter
• Texture - TA-XT2 Texturometer
GENOTYPE*
St. Adolphe06
Carman05
Morris06
Morris05
Rosebank06
Rosebank05
OAC 01-13
OAC 01-12
Dolly
OAC Erin
Jim
90A07
90A01
OAC Prudence
HAROVINTON (Ctrl)
3.0
ANALYSIS
SITE-YEAR***
Red line indicates overall mean value
* P < 0.05
*** P < 0.001
6.5
Yield (g/g)
6.0
5.5
5.0
4.5
4.0
GENOTYPE*
St. Adolphe06
Carman05
Morris06
Morris05
Rosebank06
Rosebank05
OAC 01-13
OAC 01-12
Dolly
OAC Erin
Jim
90A07
90A01
OAC Prudence
3.0
HAROVINTON (Ctrl)
3.5
SITE-YEAR***
Red line indicates overall mean value
* P < 0.05
*** P < 0.001
Figure 4. Effect of genotype and site-year on tofu
texture as measured by compression
Bhardwaj HL, Bhagsari AS, Joshi JM,
Rangappa M, Sapra VT, and Rao MSS. Yield and
quality of soymilk and tofu made from soybean
genotypes grown at four locations.
Crop Sci. 1999; 39:401-05.
Kim Y and Wicker L. Soybean cultivars
impact quality and function of soymilk and tofu.
J Sci Food Agric. 2005; 85:2514-18.
Liu K. Soybeans: Chemistry, Technology and
Utilization. USA:Chapman and Hall. 1999.
The financial support of Manitoba Pulse
Growers Association and The Agri-Food
Research and Development Initiative is
gratefully acknowledged. The assistance of
Bruce Brolley (Manitoba Agriculture, Food
and Rural Initiatives) for sample collection is
also acknowledged. Thanks to Dr. Gary Crow
(U of M, Animal Science), Elaine Sopiwnyk,
Kristina Pizzi, Anne-Sophie Bellido, and
Lee Huscroft (CIGI), John Antoniszyn
(Canadian Grain Commission), Dr. Lorna
Woodrow and Doug Jessop (AAFC, Harrow)
for their assistance.
7.0
6.5
6.0
Peak Force (N)
5.5
5.0
4.5
4.0
GENOTYPE*
Red line indicates overall mean value * P < 0.05
St. Adolphe06
Carman05
Morris06
Morris05
Rosebank06
Rosebank05
OAC 01-13
OAC 01-12
Dolly
OAC Erin
Jim
90A07
90A01
3.0
OAC Prudence
3.5
HAROVINTON (Ctrl)
•Seed size and protein had a significant positive
correlation with soymilk and tofu yield as well as tofu
colour and texture (Table 1).
•Genotype and site-year had significant effects on seed
protein (Figure 1), soymilk yield (Figure 2), tofu yield
(Figure 3), and tofu texture (Figure 4). However, site-year had
a stronger significant effect (P < 0.001) than genotype
(P < 0.05) on soymilk yield and tofu yield and texture.
•The eight Manitoba-grown food-grade soybean varieties
examined in this study had significantly lower protein content
than the Ontario-grown Harovinton standard (Figure 1).
However, some varieties produced tofu with a texture that
was not significantly different from that of tofu made from
Harovinton.
REFERENCES
Acknowledgements
Figure 3. Effect of genotype and site-year on tofu
yields (gram of tofu per gram of seed)
7.0
RESULTS
•Seed protein and seed size are major
determinants of soymilk yield, tofu yield
and tofu texture. These findings support the
general belief of processors and breeders that
large-seeded, high-protein soybeans produce
higher quality soymilk and tofu
(Bhardwaj et al., 1999).
•Both genotype and site-year significantly
affect soymilk and tofu quality with site-year
having the strongest influence.
•Although the protein quantity of Manitobagrown soybeans may be low, results from
tofu texture analysis indicate that the
protein quality may be high. High-protein
quality may be accounted for by an ideal ratio
of 11S/7S globulins, which is believed to have
a positive influence on soymilk and tofu quality
(Kim and Wicker, 2005). Further testing of the
11S/7S globulin ratio is required to determine
the protein quality of Manitoba-grown foodgrade soybeans.
5.0
3.5
ANALYSIS
CONCLUSIONS
SITE-YEAR***
*** P < 0.001
Canadian International Grains Institute
Institut international du Canada pour le grain