Introduction
Soy is a basic food ingredient of traditional Asian diet used for thousands of years. They were introduced about a hundred years ago in Western countries. Soy foods are common nutritional solutions for vegetarians, due to their high-quality protein content and healthful fat. (1)
Soy is arguably one of the most controversial nutrition topics. It is a unique food that is widely studied for its estrogenic and anti-estrogenic effects on the body. Studies seem to present conflicting conclusions about soy, but this is largely due to the wide variation in how soy is studied. (2)
Soy is exalted as rich in nutrients and has been linked to health benefits, including lower blood sugar levels, improved heart health, fewer menopause symptoms, and protecting against certain cancers (prostate and breast).
On the other hand, soy is shunned by the others for the fear that it may cause breast cancer, hinder thyroid function or have feminizing effects on men, dementia, though these claims have not been substantiated.
Whether published in a popular press article or a well designed clinical study, debate about soy remains. (2)
What is Soy used for?
Soybeans were introduced about a hundred years ago in Western countries. They are an excellent source of high quality protein, which most other legumes lack, making the soybean and its food products a superior protein source for people following a strict vegetarian diet.This kind of protein is next only to the protein we get from animal foods.
Soybeans are healthful giving them numerous nutritional uses. They are a high protein plant food that people can prepare and eat in a variety of ways. People can eat them, drink them in milk alternative and take them in the form of supplements. (3)
Soy is a popular legume of Asian origin. It is a basic food ingredient of traditional Asian diet used for thousands of years. They undergo minimal processing of soybeans, to become foods such as natto, tofu, tempeh, miso, soy sauce, and soy milk, which are widely consumed in Asia, but they account for less than 10% of the soybeans used within the US. (4)
Most soybeans (90%) are processed into soybean meal (78%) and soybean oil (22%) through a solvent extraction method called “crushing”. Manufacturers may also use this soybean oil as an ingredient to make ecologically friendly fuel, as well as candles, crayons and engine lubricants. (4)
Majority of soybean meal is used in livestock feed as a source of protein, primarily within the poultry and swine industries. A minority is further processed into soy flours and protein concentrates which is widely applicable in the food industry. (3,4)
In short, Soybeans have been part of the human diet for more than ten thousand years. Nowadays soybeans have their fat and protein content separated to be used as animal feed or as a food ingredient. They are also used as an industrial ingredient. (4)
Processing of Soybean to Foods and other products/ uses
What are Soy Foods?
Soy foods are made from soybeans. The soybean is a legume named so because it grows in pods containing seeds (or “beans” as we call them).
It is worth mentioning that not all soy foods are equally nutritious or beneficial.
The less processed soy foods may contain more vitamins, minerals and beneficial compounds. Whereas the more the soy food is processed, the more salt, sugar, fat and unnecessary additives and fillers it may contain.
Minimally processed soy foods appear more effective at reducing blood sugar or cholesterol levels than processed soy based foods or supplements.
There are many types of soy foods. Some soy foods are produced through traditional methods which are further divided into two groups: 1) Fermented and 2) Unfermented.
Fermented soy foods include: Miso, natto, tempeh and soy sauce
Unfermented soy foods include: Soy milk, tofu, edamame, and soy nuts and sprouts.
Fermented soy foods are more beneficial than unfermented soy foods because fermentation has the capacity to improve nutritional and functional properties of the original product. Fermentation has been widely used to increase the bioavailability of nutrients and helps reduce the levels of anti-nutritional factors which can help improve your body’s ability to absorb the nutrients found in soy.
Other types of soy foods undergo modern processing techniques in large soybean-processing plants. Modern processing techniques have also allowed for the production of concentrated soy protein powders.
Summary
Soybeans are naturally rich in protein and contain all of the essential amino acids your body needs. Soy foods have been part of the traditional Asian diet for thousands of years. Among legumes, soybeans have high protein and fat contents. Nowadays, the fat and protein contents of soybean have been separated to be used as animal feed or as a food ingredient. They are also used as an industrial ingredient. (4)
Traditional soy foods can be fermented (miso, natto, tempeh, and soy sauce) or unfermented (whole soybeans, soy nuts and sprouts, soy milk and tofu). Modern soy foods include a variety of vegan meats and soy protein powders. (4)
References:-
- Soy, Soy Foods and Their Role in Vegetarian Diets – PubMed (nih.gov)
- Straight Talk About Soy | The Nutrition Source | Harvard T.H. Chan School of Public Health
- Soy: Types, benefits, and nutrition (medicalnewstoday.com)
- Is soy good or bad for you? – Examine
- Is Soy Bad for You, or Good? (healthline.com)
