Biochemical composition of soybeans

Do you want to calculate the cost-effectiveness of soybean processing?

 

There are several aspects you need to understand:

• How many final products are you planning to get? What quality do you expect?
• What characteristics of raw material allow you to get the right final product?

 

First of all let’s figure out what does soybean consists of and how soy composition could be changed during its processing.

The biochemical composition of soybeans effects directly on the final products which are soybean oil cake and soybean oil.

 

Mechanical processing changes the properties of the product and outputsa certain amount of soy oil. But THE QUANTATY OF SUBSTANCES that are present in the product originally prior to its processing remains the same.

The only thing that could be changed is A MASS FRACTION of substances in the final product.

For example, you store 1000 kg of soy that contain 30% of protein; it literally means you have 300 kg of protein.

If you process these 1000 kg of soy in extruder and oil press, you’ll get several ready products with the total weigh of 1000 kg.

 

These products are:

• Soy oil cake
• Soy oil
• Soy hulls
• Evaporated moisture

From 1000 kg of soybeans you’ll get 720-780 kg of soy oil cake that contains 300 kg of protein.

If 1000 kg of soy contain 300 kg of protein it gives us 30%.

If 720 kg of soy oil cake contain 300 kg it’s logical to assume that it gives us 41.6%.

The biochemical composition of soybeans prior the processing:

• Protein: 30-40%
• Oil: 15-25%
• Fiber / soy hulls: 3-9%
• Moisture: 8-12%
• Other substances: up to 35%.
  (carbohydrates, sugar with minor proportion of protein, fat and fiber).

 

The moisture strongly influences the residual oil content in the oil cake.

If moisture of soybeans is 8% the residue oil in the oil cake is 7-8%.

If moisture of soybeans is 12% the residue oil in the oil cake is 12-13%.

Note: always try to keep soy moisture 8% as a result you’ll get 50 kg of soy oil per hour!

 

1 ton of soybeans consists of:

1 t of soy	100%	1000 kg
Protein	33%	330 kg
Oil	19%	190 kg
Fiber/hulls	5%	50 kg
Moisture	8%	80 kg
Other components	35%	350 kg

Soy processing:

 

Step 1. Removing the soy hulls using the dehulling mill. (from 1,000 kg of soy we get 50 kg of hulls).

The weight of all other substances remains the same but their mass fraction in the product increases.

• 1 t of soy                        100%          1000 kg – 50 kg = 950 kg
• Protein                           34.7%         330 kg
• Oil                                   20%            190 kg
• Fiber/hulls                    0%              50 kg – 50 kg = 0
• Moisture                        8.4%           80 kg
• Other components      36.8%         350 kg

 

Step 2. Extruding soy in the extruder.

During the extrusion process nearly 30 kg of moisture is removed from 950 kg of raw material.

Weight in kilograms of all other substances remains the same and their mass fraction in the product increases.

• Raw material                100%         920kg – 130 kg = 790 kg
• Protein                           35.8%        330 kg
• Oil                                   20,6%        190 kg
• Fiber/hulls                    0%             0 kg
• Moisture                        5.4%          80 kg – 30 kg = 50 kg
• Other components       38%          350 kg

 

Step 3. Mechanical soy extraction in the oil press also known as expeller or a screw-type press).

During the oil extraction process nearly 130 kg of oil is removed from 920 kg of raw material.

The final product is a press cake.

Weight in kilograms of all other substances remains the same and their mass fraction in the product increases.

• Raw material                 100%        920kg – 130 kg = 790 kg
• Protein                            41.7%       330 kg
• Oil                                    7,6%         190 kg – 130kg = 60 kg
• Fiber/hulls                     0%            0 kg
• Moisture                         6,3%         50 kg
• Other components       44,3%       350 kg

 

Step 4. Cooling the oil press down in the cooler.

During the cooling nearly 10 kg of moisture is removed from 790 kg of raw material.

Weight in kilograms of all other substances remains the same and their mass fraction in the product increases.

• Raw material                  100%        790kg – 10 kg = 790 kg
• Protein                             42.3%      330 kg
• Oil                                     7,6%         0 kg
• Fiber/hulls                      0%            0 kg
• Moisture                          5,1%          50 kg – 10 kg = 40 kg
• Other components        44,8%       350 kg

 

As a result from 1000 kg of soy (protein content 33%) you get:

• 50 kg of soybean hulls
• 130 kg of soybean oil
• 780 kg of soybean oil cake (protein content 42.3%)

 

Similarly, you can calculate the output and product characteristics based on your raw soybean characteristics.