30 May 2024
Eben van Tonder

Introduction

There are many options in soy processing. Mechanical, or chemical, low cost or high cost. On a very basic level, soy can be soaked overnight and cooked for a few hours and will likely be nutritious.  If we ignore for a moment legislation that has been implemented globally to enforce a minimum heat treatment process for soy to standardise the removal of anti-nutritional components, there is no reason why soy should not be consumed with minimal processing. Low-cost options exist to remove these pesky anti-nutritional factors.

Nobody can force me to heat treat my soy before consuming it provided that I grow it myself. In other words, the issue comes in when I want to sell it. In a country like Nigeria, they opted not to legislate heat treatment. You can use any of the far less expensive options provided that you, by analysis, prove that the anti-nutritional elements have been deactivated. You can use any method to achieve this. Their approach is sane!

How do we evaluate all the options in soy production in an environment where we have all the options on the table and are not forced into one direction determined by the government? Two general approaches to soy processing emerged. In this article, I outline and evaluate it.

Two approaches:

1. The direct utilization of soybeans through roasting, soaking or sprouting, and 

2. The extraction of oil with subsequent use of the soy cake.

Direct Utilization of Soybeans (low-cost option)

– Roasting: Heating soybeans to enhance flavour and digestibility, reducing anti-nutritional factors. The products can be consumed as snacks or milled for use in baking and meat products.  

– Sprouting, Soaking and  Boiling: Soybeans are soaked, or allowed to germinate, both of which will reduce or eliminate the anti-nutritional factors and then boiled. This process enhances nutritional value, improving protein quality and reducing anti-nutritional components. Sprouted, soaking and then boiled soybeans can be incorporated directly into meat analogues or extenders. For a detailed description of the sprouting method, see my article, “Enhancing Nutritional Value of Soybeans: Germination, Sprout Removal, and Drying“

Evaluation:  

a. Pros:
  – Low-cost processing.
  – Enhanced nutritional profile and digestibility.  

  b. Cons:
  – Labor-intensive additional processes for food production facilities.
  – Because of its labour-intensive nature, it makes scalability a nightmare! All production such as cooking will have to be just in time.
  – Limited product diversification.
If our only consideration was the lowest possible cost of sausage, no matter what, this would be the route to go.  The issue comes in if we suddenly have to go from a few hundred kg per day to tonnes per day.

Oil Extraction and Soy Cake Utilization

Option two is:

– Extrude the oil and further process the cake which is what remains following oil extraction.

– Byproducts from Soy Cake (I list the obvious ones – there are many more, but these will suffice to make my point)

  -> Lecithin: Widely used as an emulsifier in foods and pharmaceuticals.

  -> Soy Protein Concentrates (70% Protein): Applied in nutrition bars and snacks, meat analogues, and dairy alternatives. Highly functional as an alternative to Soy Isolates. Can be exported across Africa!

  -> Dietary Fibers: Huge application in food manufacturing. I must look into it but it should be very exportable.

  -> Pharmaceutical Products: Isoflavones are a very interesting option.

  -> Textured Vegetable Protein (TVP)

  -> Specialized Soy Flours: Utilized in gluten-free and high-protein baking.

In this option, more traditional byproducts are created. The market will tell you exactly what to produce.

Evaluation

Direct utilization, through roasting or sprouting and boiling, has a low-cost entry point for small-scale producers and makes sense as the cheapest option but not for a big operation. Headaches will grow exponentially as we grow. Labour-intensive and not suited for larger operations.

Oil extraction and focusing on the many byproducts from the soy cake – many high-value product options. Traditional functional endproducts with a wide range of applications in the industry. 

This approach has multiple revenue streams, not even to mention how it aligns with global trends towards plant-based nutrition. The initial investment and operational complexities are offset by the potential for higher profitability, product diversification, and market resilience.

Conclusion

Cheap options are available to incorporate soy into the manufacturing of a range of products, but consistency and scalability will remain huge challenges. Oil extraction and further processing of the soy cake is by far a better alternative offering consistency and scalability.