Exploring the Science: What chemicals are in plant-based milk?

October 14, 2025 •

6 min read

According to a 2022 review, commercially available plant-based milks vary significantly in their chemical makeup and nutrient composition. Beyond the primary plant source and water, understanding what chemicals are in plant-based milk involves examining a range of added stabilizers, emulsifiers, oils, sugars, and fortified vitamins and minerals.

Quick Summary

This guide breaks down the chemical composition of plant-based milks, detailing common additives like gums and thickeners, as well as natural components and fortifications. Learn to identify key ingredients and understand their purpose and potential health effects.

Key Points

Natural vs. Added: Plant-based milks contain naturally occurring chemicals from their source ingredient and a variety of added substances.
Functional Additives: Gums like guar and xanthan, plus emulsifiers such as lecithin and controversial carrageenan, are added to improve texture, creaminess, and stability.
Nutrient Fortification: To enhance their nutritional value, many brands add synthetic vitamins (D, B12, A) and minerals (calcium) to match the profile of dairy milk.
Hidden Sugars and Oils: Many flavored or conventional plant milks contain added sugars (e.g., cane sugar) and refined vegetable oils to improve taste and texture.
Potential Contaminants: Trace levels of heavy metals, such as arsenic in rice milk, and pesticide residues can be present, though typically in low concentrations.
Check Bioavailability: The body's absorption of fortified nutrients, particularly calcium, can be influenced by the type of fortificant and the presence of antinutrients like phytates.
Label Reading is Key: For the healthiest choice, consumers should look for minimal, whole-food-based ingredients and consider organic or unsweetened varieties.

For millions, plant-based milk has become a staple, offering an alternative for those with lactose intolerance, dairy allergies, or ethical dietary preferences. However, the commercial varieties on grocery store shelves are often more complex than a simple blend of a plant and water. From natural compounds found in the source ingredients to a multitude of additives used for texture, shelf-life, and flavor, the chemical composition of plant-based milk is surprisingly diverse. Navigating these ingredient lists is crucial for anyone interested in healthy eating.

Understanding the Basic Components

Every plant-based milk starts with a core ingredient, such as a grain, nut, or legume, which contributes its own unique set of natural chemicals. The nutritional profile of the final product largely depends on this base, which is usually combined with a large proportion of filtered water.

Soy Milk

Derived from soybeans, this was one of the first popular dairy alternatives and is known for a nutritional profile that most closely resembles cow's milk, particularly its protein content. Naturally present chemicals include:

Proteins: Soy protein is considered a complete protein, containing all essential amino acids.
Isoflavones: These are a type of phytoestrogen naturally found in soybeans and have been linked to various health benefits.
Unsaturated Fats: Soy milk provides healthy mono- and polyunsaturated fatty acids.

Oat Milk

Known for its creamy texture and mild flavor, oat milk is made from whole oats and water. Its natural chemical components include:

Beta-glucans: This soluble fiber, inherent to oats, is beneficial for heart health and can help lower cholesterol.
Carbohydrates: Oats are high in carbohydrates, and during processing, enzymes often break down starches into simpler sugars like glucose and maltose, affecting the milk's sweetness and glycemic index.

Almond and Coconut Milk

These milks are typically lower in protein than soy or oat milk. Commercial versions are made from a small percentage of nuts or coconut cream mixed with water.

Fats: Coconut milk is higher in saturated fatty acids, while almond milk offers unsaturated fats.
Vitamins and Minerals: Almonds naturally provide vitamin E and magnesium, but commercial versions often fortify to enhance the nutrient profile.

The Role of Common Additives

To achieve the desired texture, flavor, and shelf-stability, manufacturers add a variety of chemical compounds that are absent in a homemade version.

Gums and Stabilizers: Ingredients like guar gum, xanthan gum, gellan gum, and locust bean gum are commonly added to prevent the separation of solids and liquids and to thicken the consistency. Some individuals may experience digestive issues like gas and bloating from consuming these gums.
Carrageenan: Derived from red seaweed, this controversial additive is used as a thickener and emulsifier. Animal studies have linked it to gastrointestinal inflammation, leading many consumers to avoid it.
Emulsifiers: Lecithin, often derived from soy or sunflower, helps create a smooth, creamy texture by preventing fat and water from separating. Mono- and diglycerides of fatty acids are also common.
Added Sugars: Many 'original' or flavored varieties contain added sweeteners like evaporated cane juice or cane sugar to improve taste. These are chemically similar to standard table sugar.
Refined Oils: Sunflower, canola, or palm oil may be added to increase the fat content and create a creamier mouthfeel. Some are high in omega-6 fatty acids and can be highly processed.
Acidity Regulators: Phosphates, such as dipotassium phosphate, are used to prevent curdling in coffee and provide stability. High phosphate intake can be a concern, especially for those with kidney issues.
Preservatives and Flavors: To extend shelf life, preservatives like potassium sorbate may be used. 'Natural flavors' can be complex and are not always derived from whole foods.

Fortification and Bioavailability

To make plant-based milks nutritionally competitive with dairy, manufacturers fortify them with synthetic versions of essential vitamins and minerals.

Calcium: Added as calcium carbonate or tricalcium phosphate. The bioavailability (how well the body can absorb it) can differ from natural dairy calcium and may be reduced by naturally occurring phytates in the plant base. Shaking the carton is important as calcium can settle.
Vitamins: Common fortifications include vitamins D, B12, B2, and A. Vitamin B12 is particularly important for vegans as it is primarily found in animal products.

Potential Contaminants

While modern food safety standards are high, some contaminants can appear in plant-based milks, often due to environmental factors or processing.

Heavy Metals: Trace amounts of heavy metals like arsenic, cadmium, and lead have been detected in certain plant milks. Rice milk is known to sometimes contain inorganic arsenic, making it unsuitable for children.
Pesticide Residues: Crops used for non-organic versions may be treated with pesticides. Organic options can reduce exposure to chemicals like glyphosate.
Processing Byproducts: Ultra-high-temperature (UHT) processing can create Maillard reaction products (MRPs), such as acrylamide, a potential concern with high intake.

Comparing Chemical Compositions in Plant-Based Milks

To make an informed choice, consider how different plant milk types vary in their chemical makeup. This comparison table highlights key distinctions among common varieties.


Feature	Soy Milk	Oat Milk	Almond Milk	Coconut Milk
Protein Content	Generally highest among plant milks, comparable to dairy.	Moderate, lower than soy but more than almond/rice.	Typically very low; often less than 1g per 100mL.	Generally low, though some protein can be added.
Added Sugars	Varies by brand. 'Original' versions often contain added sweeteners.	Can be high due to natural enzymes breaking down starch.	Often added to mask watery flavor; unsweetened versions exist.	Sweetened versions use sugar; some are naturally sweet.
Emulsifiers/Stabilizers	Very common, often including gums, lecithin, and carrageenan.	Common, using gums and sunflower oil for texture.	Uses gums and stabilizers to thicken and prevent separation.	Uses gums and stabilizers like gellan and carob bean gum.
Fortification	Often fortified with vitamins B12, D, and calcium.	Commonly fortified with calcium and vitamins.	Widely fortified with calcium, D, B12 to mimic dairy.	Fortified with calcium and vitamins.
Potential Contaminants	May contain higher levels of nickel and cadmium than other types.	Can contain pesticide residues unless organic.	Potential for trace heavy metals; pesticide use possible.	Lower pesticide profile but some arsenic possible.
Bioactives	Contains isoflavones, which are phytoestrogens.	Features beta-glucans, a heart-healthy soluble fiber.	Naturally contains vitamin E, a potent antioxidant.	Rich in fatty acids but low in other bioactives.

Making an Informed Choice

Ultimately, knowing the chemical composition of plant-based milks means being an informed consumer. The best approach is to examine ingredient lists closely. For those seeking the fewest added chemicals, look for products with short ingredient lists that primarily contain the plant source and water. Choosing organic can further minimize exposure to pesticide residues. For fortified nutrients, consider if the brand specifies the type of calcium salt used, and remember to shake the carton to ensure it doesn't settle at the bottom. While fortification can help, it's also important to get a wide array of nutrients from a balanced diet, rather than relying solely on a single fortified beverage. For more information on food additives, consult resources from organizations like the FDA.

Conclusion

While marketed as simple, wholesome alternatives, commercial plant-based milks contain a complex blend of natural and added chemicals. These substances serve functional purposes, such as improving texture and shelf-life, and providing fortification for key nutrients like calcium and vitamin B12. However, it is essential to be aware of additives like gums, carrageenan, and refined oils, which may cause health issues in some individuals. By understanding the natural components, added ingredients, and potential contaminants, consumers can make more informed choices about what chemicals are in plant-based milk and opt for the healthiest options for their needs.

Food and Drug Administration (FDA)

Frequently Asked Questions

Gums like guar, xanthan, and gellan are generally recognized as safe, but some people may experience digestive discomfort, gas, or bloating, especially with regular or high consumption.

Carrageenan is a controversial food additive linked to gastrointestinal inflammation and other health issues in animal studies. While approved for use, some choose to avoid it, particularly if they have a sensitive digestive system.

Trace amounts of inorganic arsenic can be found in some plant-based milks, especially rice milk, due to the way rice absorbs the element from soil. For this reason, rice milk is often not recommended for young children.

The bioavailability of fortified calcium can vary depending on the chemical salt used (e.g., calcium carbonate vs. tricalcium phosphate) and the presence of natural compounds like phytates. Shaking the carton is necessary to ensure the calcium doesn't settle.

No, while many 'original' or flavored varieties have added sweeteners like cane sugar, most brands offer unsweetened versions. It is best to check the nutritional information panel and ingredient list to confirm.

To avoid a long list of additives, look for brands with minimal, recognizable ingredients. Opting for unsweetened and organic versions can significantly reduce your intake of added sugars, refined oils, and pesticide residues.

Yes, organic plant-based milk is typically less processed and often lacks fortifications, added sugars, and synthetic flavors present in conventional versions. The sourcing of organic ingredients also minimizes exposure to pesticide residue.