**4. Soybean utilization and products**

### **4.1 Livestock feed**

Soybean is a valuable crop worldwide mainly because of soybean meal's nutritional efficacy as a food and feed ingredient. A high protein content, balanced essential amino acid profile, and the presence of other beneficial nutrients all contribute to its economic and nutritional value. Soybean meal constitutes 70% of seed value while only being roughly 35% of seed dry weight [108, 109]. Furthermore, in the United States, 97% of soybean meal is used for livestock feed [109]. This overwhelming usage rate as a livestock protein source is mainly due to the presence of essential amino acids. While some livestock require other amino acids, most livestock need nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine [110]. All nine of these amino acids are found in some quantity in soybean meal [111]. For this reason, soybean meal can maximize livestock production in cattle, swine, poultry, and aquaculture. Generally, soybean meal and other soy byproducts use are limited to a supplementary or finishing role for cattle due to feed ration complications from other seed components [110, 112, 113]. Soybean meal use is highly prevalent in monogastric livestock production such as swine and poultry and is increasing in popularity for aquaculture [114, 115]. However, soybean as feed has two main obstacles: methionine deficiency and trypsin inhibitor proteins. Albeit present in soybean, methionine content is deficient for livestock needs, is considered the first limiting amino acid for soybean meal and requires producers to supplement with synthetic methionine [116–120]. This has a variety of negative economic and environmental impacts, including increased cost and poor nitrogen-use efficiency [121, 122]. Trypsin inhibitor proteins are an antinutritional factor present in raw soybean that decreases feed efficiency and can harm the livestock. There are a variety of industrial processing methods used to overcome trypsin inhibitors in soybean such as thermal and infrared treatment [123]. In the future, soybean methionine deficiencies and trypsin inhibitor levels may both be solved via breeding and transgenic efforts.

### **4.2 Human food**

Soybean as human food exists to two different extents that are derived from geography and cultural tradition. Eastern hemisphere populations incorporate whole soybeans and processed soy foods into their lives on a daily basis, whereas Western hemisphere populations generally utilize processed soybeans as food ingredients. Eastern soy foods are divided into two main categories: fermented and non-fermented. Non-fermented soy foods include whole seed options such as whole dry soybeans, soy nuts, and edamame, processed items such as soy flour and soy milk, and vegetative soy sprouts [115, 124]. Soy milk in its simplest form is a water extract from soybean that when further processed can make tofu and tofu byproducts such as okara (soy pulp) and yuba (tofu skin). Fermented soy products include miso, soy sauce, tempeh, natto, and sufu, and each product has a specific bacterial species that enables proper fermentation. For example, natto is associated with Bacillus subtilis, and soy sauce is associated with Aspergillus sp. [115, 124]. Western cultures have assimilated many soy food products, and they are becoming more popular as consumers seek plant-based protein sources. However, the vast majority of soybeans in western diets consists of food ingredients made from soybean meal and soy oil. Soybean meal can be processed into ingredients such as soy flour, protein concentrates, and protein isolates that are used in bakery mixes, breakfast cereals, baby food, and exercise supplements [114]. Soybean oil is widely used in vegetable oil and margarine mixes for a variety of cooking purposes. The importance of traditional and innovative soy food uses has perpetuated because of the potential health benefits from soy consumption. Soy foods have been shown to play a role in chronic human disease prevention for conditions such as heart disease, osteoporosis, and cancer [125–127]. However, isoflavones, one of the most common seed components linked to disease prevention, is also negatively linked to hormonal health as a phytoestrogen. While large population subsets are concerned about isoflavones negatively impacting fertility, summarized data has shown inconsistent results [128–130]. As consumers continue to seek plant-based protein, soybeans will be the premier source for historically and culturally significant recipes as well as healthy, novel animal meat alternatives.

#### **4.3 Industrial uses**

Even though soybean is classified as an oilseed, soybean oil has historically been an afterthought for soybean producers and processors. When markets for soybean meal would falter, researchers and other stakeholders would turn to soybean oil for added value or seek alternative uses for meal components. Modern sustainability and industrial goals have stimulated soy-based product usage in a variety of fields, as summarized in **Table 3**. Soybean oil as biodiesel has experienced the largest

**37**

*Soybean Production, Versatility, and Improvement DOI: http://dx.doi.org/10.5772/intechopen.91778*

growth with United States consumers using over 2 billion gallons in 2017 [131]. Current biodiesel production methods can create soy-based fuel that perform nearly equal or equivalent to standard diesel fuels and have the potential to become a truly renewable resource when coupled with sustainable farming practices [132–134]. Constantly improving processing methods will continue to augment soybean seed component versatility and create new opportunities for soy-based products.

Soybean seed has many beneficial traits, such as high protein, oil, and soluble sugar content [135]. While soybean seed value is defined by these favorable qualities, past and present breeding attempts have sought further improvement. With regards to protein content, breeders have worked with soybean to increase total protein content as well as the amount of sulfur containing amino acids, methionine and cysteine [135]. Methionine and cysteine are of interest since the seed protein is naturally deficient, and these two amino acids can improve the nutritional value of soybean meal [135, 136]. However, some research indicates that total protein content is negatively correlated with other favorable seed qualities, including yield, oil content, and potentially methionine and cysteine content [137, 138]. So far, most

**5. Soybean seed composition improvement**

*Industrial uses for soybean products [114, 115].*

**5.1 Breeding efforts**

**Table 3.**


#### **Table 3.**

*Legume Crops - Prospects, Production and Uses*

breeding and transgenic efforts.

healthy, novel animal meat alternatives.

**4.3 Industrial uses**

**4.2 Human food**

soybean as feed has two main obstacles: methionine deficiency and trypsin inhibitor proteins. Albeit present in soybean, methionine content is deficient for livestock needs, is considered the first limiting amino acid for soybean meal and requires producers to supplement with synthetic methionine [116–120]. This has a variety of negative economic and environmental impacts, including increased cost and poor nitrogen-use efficiency [121, 122]. Trypsin inhibitor proteins are an antinutritional factor present in raw soybean that decreases feed efficiency and can harm the livestock. There are a variety of industrial processing methods used to overcome trypsin inhibitors in soybean such as thermal and infrared treatment [123]. In the future, soybean methionine deficiencies and trypsin inhibitor levels may both be solved via

Soybean as human food exists to two different extents that are derived from geography and cultural tradition. Eastern hemisphere populations incorporate whole soybeans and processed soy foods into their lives on a daily basis, whereas Western hemisphere populations generally utilize processed soybeans as food ingredients. Eastern soy foods are divided into two main categories: fermented and non-fermented. Non-fermented soy foods include whole seed options such as whole dry soybeans, soy nuts, and edamame, processed items such as soy flour and soy milk, and vegetative soy sprouts [115, 124]. Soy milk in its simplest form is a water extract from soybean that when further processed can make tofu and tofu byproducts such as okara (soy pulp) and yuba (tofu skin). Fermented soy products include miso, soy sauce, tempeh, natto, and sufu, and each product has a specific bacterial species that enables proper fermentation. For example, natto is associated with Bacillus subtilis, and soy sauce is associated with Aspergillus sp. [115, 124]. Western cultures have assimilated many soy food products, and they are becoming more popular as consumers seek plant-based protein sources. However, the vast majority of soybeans in western diets consists of food ingredients made from soybean meal and soy oil. Soybean meal can be processed into ingredients such as soy flour, protein concentrates, and protein isolates that are used in bakery mixes, breakfast cereals, baby food, and exercise supplements [114]. Soybean oil is widely used in vegetable oil and margarine mixes for a variety of cooking purposes. The importance of traditional and innovative soy food uses has perpetuated because of the potential health benefits from soy consumption. Soy foods have been shown to play a role in chronic human disease prevention for conditions such as heart disease, osteoporosis, and cancer [125–127]. However, isoflavones, one of the most common seed components linked to disease prevention, is also negatively linked to hormonal health as a phytoestrogen. While large population subsets are concerned about isoflavones negatively impacting fertility, summarized data has shown inconsistent results [128–130]. As consumers continue to seek plant-based protein, soybeans will be the premier source for historically and culturally significant recipes as well as

Even though soybean is classified as an oilseed, soybean oil has historically been an afterthought for soybean producers and processors. When markets for soybean meal would falter, researchers and other stakeholders would turn to soybean oil for added value or seek alternative uses for meal components. Modern sustainability and industrial goals have stimulated soy-based product usage in a variety of fields, as summarized in **Table 3**. Soybean oil as biodiesel has experienced the largest

**36**

*Industrial uses for soybean products [114, 115].*

growth with United States consumers using over 2 billion gallons in 2017 [131]. Current biodiesel production methods can create soy-based fuel that perform nearly equal or equivalent to standard diesel fuels and have the potential to become a truly renewable resource when coupled with sustainable farming practices [132–134]. Constantly improving processing methods will continue to augment soybean seed component versatility and create new opportunities for soy-based products.
