Soy

Soy refers to both the soybean plant and the various protein-rich foods and products derived from its beans. Soybeans are highly adaptable and can be transformed into a wide range of culinary and industrial products. They are a high-protein vegetable that serves as a dietary staple for many, as well as a critical ingredient in numerous industrial applications such as biodiesel and plastics[1].

In terms of food and beverages, soy is commonly used in a variety of products. It is a key ingredient in soy milk, which can be used as a substitute for dairy milk in recipes, and is also used to make imitation dairy products like soy yogurt, soy cream, and soy-based cheese analogues. Soy is also found in tofu, which can be used in dishes like stir-fries, soups, salads, and as a pasta replacement. Other soy products include soy flour, soy concentrates, and soy isolates, which are used in meat, sausages, baked goods, flour tortillas, desserts, and pasta products to enhance functional properties such as adhesion, elasticity, and emulsification. Additionally, soy is used in soy sauce, soy curls, and textured soy protein, which are incorporated into various foods like meat alternatives, breakfast cereals, beverages, and bakery items[2][3][4].

The process of creating products from soybeans involves several intricate steps. Initially, the soybeans undergo a thorough cleaning process to remove impurities such as metals, stones, and other debris. This is followed by a dehulling process, where the soybean hulls are removed to increase the protein content of the final meal product and to enhance the efficiency of the subsequent solvent extraction. There are different methods for dehulling, including hot, warm, and cold dehulling, each involving various stages of conditioning, drying, and cracking the soybeans to facilitate hull removal[1][2].

After dehulling, the soybeans are cracked and flaked into thin layers to rupture the cells containing the soybean oil. The flakes are then subjected to solvent extraction, typically using hexane, to extract the oil. The solvent is subsequently removed from both the flakes and the oil through desolventizing processes involving heat, steam, and distillation. The desolventized flakes are then dried and ground into soybean meal, a high-protein product. The extracted soybean oil can be further refined through processes such as degumming, neutralizing, bleaching, and deodorizing to produce an edible oil. Additionally, soybean oil can be used to produce biodiesel and various oleochemicals[3][2].

The safety profile for human consumption of soy, in the context of food and beverages, is generally favorable but with some caveats. Except for individuals with soy allergies, soy is considered a safe food. However, it can cause digestive upsets such as constipation, diarrhea, and other mild stomach and intestinal side effects. Soy may also alter thyroid function in people deficient in iodine. For women who have had breast cancer or are at risk, consuming soy foods is considered safe, although the safety of soy isoflavone supplements in these cases is uncertain. During pregnancy, consuming soy in amounts greater than those commonly found in foods may be unsafe due to the estrogen-like substances it contains, and its safety during breastfeeding is also unclear. Additionally, individuals with kidney failure or a history of kidney stones should be cautious about consuming large amounts of soy due to its phytoestrogen and oxalate content[1][2].

Regarding potential contamination risks, soy can be subject to several hazards. Heavy metal contamination is a concern, although studies have shown that the concentrations of metals like cadmium, copper, lead, and zinc in soybeans are generally within safe limits set by health organizations. However, ongoing monitoring is recommended due to potential environmental and agricultural factors that could increase metal contamination[3]. The use of heavy pesticides in soybean cultivation is another risk, though specific data on pesticide residues in soy products is not detailed in the available sources. Pathogen risks, such as Sudden Death Syndrome (SDS) in soybean fields, are more related to crop management and do not directly impact human consumption safety, but poor agricultural practices could potentially lead to other contaminants. Cross-contamination with allergens is also a significant risk, especially in foods processed in facilities that handle multiple ingredients, highlighting the need for careful food preparation and labeling for individuals with soy allergies[4][5].