Quality of Canadian food-type soybeans 2015

Contact

Ning Wang
Program Manager, Pulse Research, Grain Research Laboratory
1404-303 Main Street
Winnipeg MB  R3C 3G8
Telephone: 204-983-2154 or
Toll-free 1-800-853-6705
Email: ning.wang@grainscanada.gc.ca

Introduction

This report presents the quality data for the 2015 harvest survey of Canadian food-type soybeans conducted by the Canadian Grain Commission. Soybean samples for food uses such as tofu, soymilk, miso and natto were submitted by soybean producers and processors from across Manitoba, Saskatchewan, Ontario and Quebec to the Canadian Grain Commission’s Grain Research Laboratory for analysis.

Harvest survey samples

The Canadian Grain Commission received a total of 85 food-type soybean samples including 4 from Manitoba, 2 from Saskatchewan, 56 from Ontario, and 23 from Quebec. The Canadian Grain Commission’s Industry Services graded all of the samples. Composite samples were prepared based on end-use (generic or natto) and province. Results from Manitoba and Saskatchewan were not included because of insufficient number of samples. All samples were tested for protein and oil content. Composite samples were analyzed for 100-seed weight, water absorption capacity, nitrogen solubility index (NSI), protein, oil, sugar and total isoflavones content. Due to insufficient natto-type samples, only results for generic food-type soybeans were included in this report. It is important to note that samples reported by grade do not necessarily represent the actual distribution of grade.

Quality of 2015 Canadian food-type soybeans

Protein and oil content

Protein content for 2015 Canadian food-type soybeans ranged from 37.7 g to 51.6 g per 100 g dry matter (Table 1). The mean protein content in 2015 was 41.9 g per 100 g dry matter, which was higher than the mean in 2014 (40.6 g per 100 g dry matter). The mean protein contents for Ontario and Quebec for 2015 were 41.2 and 43.6 g per 100 g dry matter, respectively.

Oil content for 2015 Canadian food-type soybeans varied from 17.3 g to 24.1 g per 100 g dry matter (Table 2). The mean oil content in 2015 was 21.5 g per 100 g dry matter, which was slightly higher than that for 2014. The mean oil content for Ontario in 2015 was 21.7 g per 100 g dry matter, which was higher than that for 2014. The mean oil content for Quebec in 2015 was 21.1 g per 100 g dry matter, which was higher than the mean for 2014.

Table 1 - Mean protein content for 2015 Canadian food-type soybeans by grade and provinceFootnote 1
Grade Protein content, g/100 g DM
2015 2014
Mean Range Mean
Ontario
Soybean, No. 1 Canada 40.8 38.1-43.6 40.6
Soybean, No. 2 Canada 41.4 37.7-45.5 40.2
All grades 41.2 37.7-45.5 40.6
Quebec
Soybean, No. 1 Canada NSFootnote 2 NS NS
Soybean, No. 2 Canada 43.6 39.8-51.6 44.0
All grades 43.6 39.8-51.6 44.0
Canada
Soybean, No. 1 Canada 40.8 38.1-43.6 40.6
Soybean, No. 2 Canada 42.3 37.7-51.6 40.7
All grades 41.9 37.7-51.6 40.6
Table 2 – Mean oil content for 2015 Canadian food-type soybeans by grade and provinceFootnote 3
Grade Oil content, g/100 g DM
2015 2014
Mean Range Mean
Ontario
Soybean, No. 1 Canada 21.8 20.5-24.1 21.4
Soybean, No. 2 Canada 21.6 18.9-23.6 21.0
All grades 21.7 18.9-24.1 21.1
Quebec
Soybean, No. 1 Canada NSFootnote 2 NS NS
Soybean, No. 2 Canada 21.1 17.3-22.4 19.9
All grades 21.1 17.3-22.4 19.9
Canada
Soybean, No. 1 Canada 21.8 20.5-24.1 21.4
Soybean, No. 2 Canada 21.4 17.3-23.6 21.0
All grades 21.5 17.3-24.1 21.1

Canadian generic food-type soybeans

Table 3 shows the quality data for 2015 Canadian generic food-type soybeans used for tofu, soymilk or miso. Mean 100-seed weight for 2015 generic food-type soybean was 19.6 g, which was higher than the mean for 2014 (17.5 g). Water absorption capacity was 1.22 g H2O per g seeds, which was higher than that for 2014. Seed size and water uptake capacity are important quality characteristics of food-type soybeans for the production of tofu, soymilk and miso.

The nitrogen solubility index, which indicates the percentage of water-soluble protein, was 81.5% for generic food-type soybeans in 2015 (Table 3), slightly lower than that for 2014 (82.8%). High nitrogen solubility index is preferred for soymilk and tofu production since soybeans with a high nitrogen solubility index tend to give a high protein recovery when processed into soymilk, which in turn leads to high recovery in the final tofu product.

The mean protein content for 2015 Canadian generic food-type soybean was 43.1 g per 100 g dry matter (Table 3), which was higher than the mean for 2014 (40.2 g per 100 g dry matter). The mean oil content for 2015 was 19.6 g per 100 g dry matter, which was slightly lower than the mean for 2014 (20.9 g per 100 g dry matter).

The mean sucrose content in 2015 generic food-type soybean was 57.4 g per kg dry matter, which was lower than the mean for 2014 (65.7 g per kg dry matter) (Table 3). The mean total oligosaccharides content for 2015 was 49.1 g per kg dry matter, which was higher than the mean for 2014 (44.3 g per kg dry matter).

The mean total isoflavones content for 2015 Canadian generic food-type soybean was 2345 mg per kg dry matter, which was lower than the mean for 2014 (Table 3). 

Table 3 – Quality data for 2015 Canadian generic food-type soybean compositesFootnote 4
Quality parameter 2015 2014
Physical characteristic
100-seed weight, g/100 seeds 19.6 17.5
Water absorption, g H2O/g seeds 1.22 1.17
Nitrogen solubility index (NSI), % 81.5 82.8
Chemical composition (g/100 g DM)
Protein content 43.1 40.2
Oil content 19.6 20.9
Sugar content (g/kg DM)
Sucrose 57.4 65.7
Raffinose 9.4 7.1
Stachyose 38.8 36.4
Verbascose 0.80 0.84
Total oligosaccharidesFootnote 5 49.1 44.3
Isoflavones (mg/kg DM)
Total isoflavonesFootnote 6 2345 3201

Footnotes

Footnote 1

Protein content (N x 6.25) is determined by near infrared measurement calibrated against the Combustion Nitrogen Analysis reference method.

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Footnote 2

NS = insufficient number of samples to generate a representative value.  

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Footnote 3

Oil content is determined by near infrared measurement calibrated against the ISO 10565:1992(E) reference method.

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Footnote 4

Soybean, No.1 Canada and No. 2 Canada combined.

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Footnote 5

Sum of raffinose, stachyose and verbascose.

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Footnote 6

Sum of isoflavone aglycones (daidzein, genistein and glycitein), glucosides, malonyl glucosides and acetyl glucosides.

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