It used as an acidulant, pH controller, preservative, emulsifier, chelating agent, stabilizer, anti-caking agent, antioxidant and firming agent. Tartaric acid is able to chelate metal ions such as calcium and magnesium. Widely used as antioxidant in leather processing to soften leather and tanning leather. Used in the textile industry to soften and protect protein fibers and lighten complexions.