Soybeans: A Versatile Legume Transforming from Ancient Staple to Global Favourite

By Tini Thangjam
Soybean or soyabean scientifically called Glycine max is a legume which is versatile and nutritionally rich. It originates from East Asia and its cultivation began even before written records existed. Its impact on the global level is humungous contributing to improvement in agriculture, nutrition, health and industries. Combining the rich history with its cultivation and the profound impact on health and nutrition, soybean has become a global phenomenon. Today we will shed light on the diverse applications soybean has to offer.
Soybean has a rich history specially in China. It became highly valued by East Asians for its nutrient profile and nitrogen fixing ability which enhances the fertility of soil. As agricultural practices began to spread, incorporation of soybeans in the daily diet of Asians rose and found its way into various culinary uses. In this day and age, different varieties of soybeans are cultivated all across the globe. Brazil, US, Argentina and China are leading countries in soybean production. As it has the ability of fixing nitrogen (replenishing soil with nitrogen), it plays a crucial role in crop rotation.
Let us uncover why it is renowned for its nutritional composition. Soybean has an exceptionally impressive nutritional profile. It is a complete protein source containing all the essential amino acids required by our body. This makes them an excellent source of proteins for a high protein diet and specially for vegetarians and vegans as a substitute for meats. The protein is relatively heat-stable storage protein which enables soybeans to be cooked in high temperatures. Although it contains high protein, it also contains high level of protease inhibitors which hinders digestion. The level of protease inhibitors can be reduced by cooking and are present in low levels in soy products such as tofu.
Additionally, it is rich in fiber, vitamins (B vitamins), minerals (iron, magnesium and calcium) and isoflavones. The phytochemical isoflavones are present in huge amounts in soybeans contributing to numerous health benefits. Studies suggest that it has anti-tumor, anti-menopausal osteoporosis and anti-aging properties. Moreover, they are reported to improve learning and memory skills, prevention and treatment of heart disease, diabetes and Kawasaki disease. All these health benefits stem from the phytoestrogen and antioxidant properties of isoflavones. However, due to phytoestrogen properties more study needs to be done involving the risks around it.
Soybeans have carved their ways into an extensive range of products. One of the most common uses of soybean is soybean oil, a versatile cooking oil having a high smoke point. Another popular product is tofu which is made from coagulating soy milk. Tofu is a staple in Asian cuisines and due to its subtle taste and ability to absorb flavours, it is a key ingredient in both sweet and savory dishes. Soy milk is a popular dairy milk substitute and serves as a foundation for most dairy-free products. It is made from soaking, grinding and boiling soybeans. Soy protein isolates (made from soybean meal that has been dehulled and defatted) and concentrates (defatted soy flour without water-soluble carbohydrates) are widely used in the food industry as key ingredients in meat alternatives, dairy substitutes and protein supplements.
Now if we delve into fermented soy products the first one that comes to mind is the soy sauce. It is the cornerstone for Asian cuisine, imagining Asian cuisine without it is impossible. Soy sauce is rich in taste and salty which adds depth and umami to various dishes. Tempeh which originates from Indonesia is also a fermented soy product. It has a nutty and firm texture often used in stir-fries, sandwiches and salads. Another similar product is natto which is originated from Japan. It is not firm but rather has a sticky texture. When talking about natto I always remember ‘hawaijar’ which is a popular fermented soy product of Manipur. It is quite similar to other fermented soy products such as douchi of China, choongkook jang of Korea and thua nao of Thailand. It is alkaline, has a sticky texture, is mucilaginous and slightly pungent like other fermented soy products. It offers lots of health benefits and in addition to that it contains probiotics which enhances our gut health. Unfortunately, its unhygienic production may lead to grave concerns for food safety. Its monitoring is definitely essential.
There are many controversies and challenges regarding soybeans. Its large-scale plantation usually leads to deforestation and habitat loss. There has been a debate going on about the effect of isoflavones on human hormones and questions about its risks specially if consumed in huge amounts. Although on the other hand, it provides myriad of health benefits ranging from high protein source to anti-tumor properties. Therefore, we should navigate through the controversies and challenges and explore the potential of this wonderful versatile legume.
(The writer has finished her Bachelors in Food Technology from College of Food Technology CAU, Lamphel, Manipur. The writer can be reached at tinithangjam@gmail.com)