What is Tartaric Acid?
Tartaric acid is a white, crystalline organic acid that occurs naturally in many plants and fruits, including grapes, tamarind, bananas, and citrus. Its discovery is credited to Swedish chemist Carl Wilhelm Scheele in 1769, but forms of it had been observed much earlier by ancient civilizations. Commercially, it is often produced from byproducts of the winemaking process, such as lees and press cakes. This process involves converting the potassium bitartrate (a salt of tartaric acid) into calcium tartrate and then reacting it with sulfuric acid to yield tartaric acid. As an additive, it is designated with the E number E334 in Europe. The most common and naturally occurring form is the L-(+)-tartaric acid isomer.
The Role of Tartaric Acid in Food
Its unique chemical properties make tartaric acid a versatile and valuable ingredient in the food industry. It is not added for nutritional purposes but for its functional benefits.
Here are some of its primary uses:
- Acidulant and Flavor Enhancer: Tartaric acid provides a sharp, sour taste, making it a popular acidulant in candies, soft drinks, jams, and gelatin desserts, particularly those with grape or tamarind flavors.
- Leavening Agent: When combined with baking soda (sodium bicarbonate), it acts as a leavening agent in baking powder. The acid neutralizes the bitter sodium carbonate produced by the baking soda, helping dough rise and improving the final taste. The salt form, potassium bitartrate, is also known as cream of tartar.
- Preservative and Antioxidant: Its antimicrobial properties help extend the shelf life of food products. As an antioxidant, it prevents fat from becoming rancid and can inhibit oxidation reactions that lead to discoloration or off-flavors.
- Chelating Agent: Tartaric acid can bind to metal ions, which can otherwise catalyze undesirable reactions in food. This chelating action helps maintain product quality and flavor.
- Winemaking: It plays a crucial role in regulating the acidity of wine, which is vital for its taste, color, and chemical stability.
Is Tartaric Acid Really Safe to Eat?
Regulatory bodies worldwide have evaluated the safety of tartaric acid. The consensus is that it is safe for consumption in the quantities typically used in food products.
United States (FDA)
The FDA has affirmed tartaric acid as Generally Recognized As Safe (GRAS) for use as a direct food substance. This designation is for miscellaneous and general-purpose use under conditions of good manufacturing practices, meaning it's not a restricted additive.
European Union (EFSA)
In the EU, L(+)-tartaric acid (E334) is an approved food additive. The European Food Safety Authority (EFSA) re-evaluated it and established an acceptable daily intake (ADI) for tartrates, indicating a high level of safety when consumed within typical levels. However, it is noted that the additive is generally not permitted in infant and toddler foods in the EU, with exceptions for certain weaning foods. This is a precautionary measure due to developmental intolerance, not a sign of widespread danger.
Understanding the Risks of Overconsumption
While safe in food-grade amounts, high doses of tartaric acid can cause adverse effects. Consuming concentrated amounts can lead to gastrointestinal irritation, abdominal pain, nausea, and vomiting. The body metabolizes most ingested tartaric acid via intestinal bacteria, and the remaining 15-20% is rapidly excreted through the urine. The extremely high doses required for toxicity are not a risk with normal food consumption.
Note on pets: Tartaric acid is toxic to dogs, with cases of acute kidney injury reported after ingestion of cream of tartar or tamarind. Pet owners should be cautious about their dogs consuming large amounts of grapes or tamarind products, which contain high concentrations.
Tartaric Acid vs. Citric Acid: A Comparison
Both are organic acids used in the food industry, but they differ in origin and flavor profile.
| Feature | Tartaric Acid | Citric Acid |
|---|---|---|
| Primary Source | Grapes, tamarinds, and wine byproducts. | Citrus fruits like lemons, oranges, and limes. |
| Flavor Profile | Sharp, potent tartness, more intense than citric acid. | Milder, fruitier sourness. |
| Common Uses | Baking powder, candy, grape-flavored products, winemaking. | Soft drinks, jams, dairy products, dressings. |
| Form | Crystalline solid. | Crystalline solid. |
| Regulatory Status | Generally Recognized As Safe (GRAS). | Generally Recognized As Safe (GRAS). |
Conclusion: A Safe and Useful Additive
In summary, tartaric acid is a well-researched and widely-used food additive that is safe for human consumption within normal food quantities. Its GRAS status by the FDA and approval by EFSA for use as E334 highlight its low-risk profile. Derived primarily from grapes, it serves important functions as an acidulant, antioxidant, and leavening agent. While it is important to avoid excessive, concentrated doses, its controlled application in the food industry ensures that it is a safe component of a balanced diet. Concerns primarily relate to extreme overconsumption or, specifically, ingestion by dogs, for which it is toxic. For the average consumer, tartaric acid is simply a harmless ingredient that adds flavor and stability to many favorite foods. To learn more about food additives and regulations, the official FDA website is an excellent source of authoritative information, especially regarding the GRAS status of food substances.
