When you look at the ingredient list of your favorite vegan fish alternative (yes, we are talking about Ordinary Seafood ;-)), or any other meat substitute, it is very likely that you will find soy, or to be precise soy protein concentrate, among them. But what is soy protein, why is it used so frequently and is it actually a good idea to consume soy? Today, we will have a closer look at this ingredient and answer all those questions. Let’s start with the basics: Soy protein concentrates are made from soybean (Glycine max), a legume that is grown mainly in the US, Brazil, and Argentina1 .
Soy is an interesting source of protein and fat, since it contains on average 36 % protein and 18 % oil. In 2021 the worldwide production of soy was about 371 million tons with about 20 % being used for direct food production (e.g. tofu, soymilk or oil), which has a very long tradition in Asia2. The remainder is used to produce defatted soybean meal. Nearly all the meal is used for animal feed, while only 2% goes into soy protein products for human consumption1. When we talk about soy protein, we mean three different products which are made from soy meal and categorized based on their final protein content in dry matter:
1. Soy flour (>50% protein)
2. Soy protein concentrates (>65% protein)
3. Soy protein isolates (>90%)
The production process of these different products is a topic for a complete blog post, so for today we will keep it short: The soybeans are dried, cracked and after removal of the hulls, processed into flakes which are then extracted to remove the oil. The remainder gets toasted and milled. The resulting soy flour has >50 % protein and can then be washed to remove soluble carbohydrates, resulting in a soy protein concentrate with even higher protein content. With further extraction and purification, the protein level can be increased to >90 %.
In our products, we use soy protein concentrates. But why is soy such an interesting ingredient? From a food technology standpoint, the main reason is its functionality: Soy proteins have the ability to form protein gels – which means, when treated in the right way, these ingredients can form structures that help to give vegan products a meat-like fibrous texture3. The other main aspect is protein quality, in terms of the amino acid composition. This might need a little bit of explanation. All animal and plant protein are made of the same building blocks, called amino acids. There are 20 different amino acids, and not all of them can be synthesized by our bodies, thus we need to ingest them via our diet. The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The quality of a given protein, e.g., soy protein, pea protein or pork protein is calculated based on the availability of these nine amino acids in the given protein and expressed as the DIAAS score (Digestible Indispensable Amino Acid Score). A score of 100 or higher means, that a protein is not limiting the supply of essential amino acids, even if the only protein you eat all day every day is just that one. Since this is a highly unrealistic scenario, a protein is considered a high-quality protein when its DIAAS score is between 75 and 1004. To give you a bit of an overview, here are some reference proteins and their DIAAS scores for individuals of 3 years and older.
Pork meat: 117 4
Soy protein isolate: 88 5
Whey: 85 4
Pea: 70 4
Potato: 100 4
With an average score of 88 soy is a high-quality source of protein. This combined with its advantageous technological properties, which e.g., potato protein is lacking, makes it very interesting to use soy in our products. Does this mean that soy is the perfect protein? Well at least not in the public perception: We hear a lot of critical questions around soy that we will try to answer below. Let's start with a very important and frequent question:
The answer is quite complex. For a deep dive, we recommend this excellent article here. For a good overview, continue reading: First, it should be considered that most of the soy produced worldwide is used to feed animals (76 %) and only 20% is used to make food6.
This fact alone tells us, that all problems related to soy are mainly connected to our appetite for animal products and only to a small amount directly to human consumption. This becomes even clearer if we consider the protein feed conversion efficiency. Sounds complicated? Yes, but in a nutshell, this number tells us what percentage of protein in the animal feed is actually converted into edible protein (e.g. in the meat that we eat). Want an example? For pork, this number is about 9 %, which means that over 90 % of the protein in the feed is not converted into edible protein – it’s simply lost7. For comparison: if you eat soy directly, 100 % of the soy protein is used for your food. Sounds much better than 9 % and implies that the land use for soy cultivation for animal feed is much larger not only because we eat so much meat, but also because it is so inefficient to raise animals for meat production. It’s much more efficient to use soy for our food. This also means that replacing meat with soy-based products will help to reduce the land use of soy cultivation.
Let’s circle back to the initial question. Is soy bad for the rainforest? Short answer, yes at least partially: Soy cultivation has been one of the reasons for deforestation e.g., in Brazil, where the soy production has increased from 0.27 million tons in 1961 to world leading 134 million tons in 20216. However, soy was by far not the main reason for deforestation. Yes, you are guessing right: The main reason was pasture beef, contributing to up to 72 % (1.86 million ha) of the yearly deforestation in Brazil in 2006, while deforestation for commercial crops, including soy, peaked to 18 % (or 747.000 ha) of the yearly deforestation in 2003. This is of course still a lot, but since then anti deforestation policies have helped to reduce this number to 7 % (87.000 ha). However, it must be said that these numbers represent only the direct effects of soy on deforestation. The land used for cultivation of soy is still increasing. It is likely that this is happening through the replacement of former pastureland by soy farms, while the pastureland moves into newly deforested areas. This implies that soy cultivation is still a significant driver of deforestation6. What now? Should I stop eating soy-based products? No. Just to remind you: More than three quarters of all that soy is consumed by inefficiently farmed animals and only about 2 % find their way into soy protein-based food, like Ordinary Seafood. We are convinced that moving away from an animal-based diet - and not avoiding soy - is key to stopping deforestation. Bluntly speaking: If we stop the ever-growing need for more and more animal feed and pastureland, we can stop deforestation, and have more than enough agricultural land left to grow the soy we need.
To assess the environmental impact of a certain product, we need to look at a Life Cycle Assessment (LCA) of that product – in our case soy protein. A LCA basically investigates the environmental impact of each step in the production of a compound. For soy, this would start with farming, harvesting, and continue with all the different steps of e.g., producing soy protein concentrate. This is quite granular and makes it difficult to have a general LCA for a product that is made by different manufacturers in different regions of the world, using different methods and energy sources (e.g., gas vs. solar). In the case of soy protein, we only found a single, comprehensive LCA for soy protein isolate produced by the manufacturer DuPont Nutrition & Health1. This LCA was done by DuPont inhouse experts, in compliance with standard methods – importantly the LCA was peer reviewed by external scientists. This makes the LCA quite reliable, although published by a soy protein manufacturer.
Let’s dive into the findings of the study. We will start with the CO2 emissions related to soy protein. In LCA, there are two types of analysis: consequential and attributional. Attributional means: How is the impact of the product we are looking at right now, in the current economic situation. Consequential means: How is the impact of the product when we consider shifting from one type of product to another. In our case the biggest substitution would happen in the vegetable oil sector, where soy oil would replace other vegetable oils like palm oil. Either way, the findings are quite clear: In consequential modelling 1 kg of soy protein causes about 2 kg CO2/per kg protein and in attributional modelling about 6 kg CO2/kg protein. Is this a lot? Decide for yourself. Here are a few examples for animal proteins from consequential modelling (attributional modeling in brackets):
Beef: 178 (184) kg CO2/kg protein 1
Pork: 24 (29) kg CO2/kg protein 1
Chicken: 17 (18) kg CO2/kg protein 1
But what about other environmental factors? Let's look at some numbers on water and land use: Blue water use: Beef: 1607 (1607) L water/kg protein Pork: 1855 (1855) L water /kg protein Chicken 629 (629) L water / kg protein Soy protein isolate: 38 (205) L Water/ kg protein Land use: Beef: 1311 (1310) m2 year/kg protein Pork: 59 (55) m2 year/kg protein Chicken: 33 (32) m2 year/kg protein Soy: 8 (6) m2 year/kg protein In summary, soy protein has a much lower environmental impact, as compared to animal protein. Of course, a diet based on unprocessed, regionally sourced vegetables will have an even smaller environmental footprint, but it's unlikely that passionate meat or fish eaters will be convinced by this alternative. Replacing animal protein with soy protein for delicious animal free seafood is thus in our opinion a good idea.
This may sound a bit crazy, but we get this question a lot. And we are here to answer it. The assumption that soy may cause feminization of male individuals is linked to the presence of isoflavones in soy. Isoflavones are molecules that resemble the human hormone estrogen (a sex hormone responsible for regulation of the female reproductive system), this is why isoflavones are also called phytoestrogens. It is important to understand that although similar in structure, isoflavones are not identical to estrogen and behave differently in your body. Although, isoflavones can bind the same receptors as estrogen (Erα and Erβ), they prefer binding to Erβ – whereas estrogen has equal affinity to both receptors. This might sound like a small difference, but it results in isoflavones having very different effects than estrogen8,9. Actually, isoflavone intake from soy consumption is correlated with quite a few health benefits, e.g. prevention of osteoporosis, certain cancers, and cardiovascular diseases8. Moreover, a meta-analysis including 38 individual studies on the effect of isoflavones clearly finds, that there is no evidence for male breasts caused by soy isoflavones9.
Our products contain soy from North America and Europe. Currently, about 50 % of the soy we use is from European production. We currently do not use soy that was sourced in South America.
We are convinced that the soy protein we use in our food products is a reasonable and sustainable choice and its advantages are clearly evident over its disadvantages. Especially when it comes to environmental impact, it should always be considered that the soy protein consumed in fish and meat alternatives replaces inefficiently produced animal protein with a much larger environmental impact.
1. Thrane, M., Paulsen, P. V, Orcutt, M. W. & Krieger, T. M. Chapter 2 - Soy Protein: Impacts, Production, and Applications. in Sustainable Protein Sources (eds. Nadathur, S. R., Wanasundara, J. P. D. & Scanlin, L.) 23–45 (Academic Press, 2017). doi:https://doi.org/10.1016/B978-0-12-802778-3.00002-0.
2. Ritchie, H. Is our appetite for soy driving deforestation in the Amazon? Our World in Data (2021).
3. Fasolin, L. H. et al. Emergent food proteins – Towards sustainability, health and innovation. Food Research International vol. 125 Preprint at https://doi.org/10.1016/j.foodres.2019.108586 (2019).
4. Herreman, L., Nommensen, P., Pennings, B. & Laus, M. C. Comprehensive overview of the quality of plant- And animal-sourced proteins based on the digestible indispensable amino acid score. Food Sci Nutr 8, 5379–5391 (2020).
5. van den Berg, L. A., Mes, J. J., Mensink, M. & Wanders, A. J. Protein quality of soy and the effect of processing: A quantitative review. Front Nutr 9, 1004754 (2022).
6. Ritchie, H. Is our appetite for soy driving deforestation in the Amazon? Our World in Data (2021).
7. Alexander, P., Brown, C., Arneth, A., Finnigan, J. & Rounsevell, M. D. A. Human appropriation of land for food: The role of diet. Global Environmental Change 41, 88–98 (2016).
8. Pabich, M. & Materska, M. Biological Effect of Soy Isoflavones in the Prevention of Civilization Diseases. Nutrients 11, 1660 (2019).
9. Reed, K. E., Camargo, J., Hamilton-Reeves, J., Kurzer, M. & Messina, M. Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated metaanalysis of clinical studies. Reproductive Toxicology 100, 60–67 (2021).