乳酸

　　Main Application Areas

　　1. Food Industry (Core Field)

　　Acidulant: Used in beverages, jams, candies, etc., to impart a refreshing tart flavor with a smooth acidity (longer lasting than citric acid).

　　Preservative: Lowers the pH of food to inhibit microbial growth (e.g., preservation of bread and pastries).

　　Emulsifier/Thickener: Lactic acid esters (e.g., glyceryl monolactate) can improve food texture and are used in dairy and meat products.

　　Nutritional Fortification: Salts such as calcium lactate and ferrous lactate are used as calcium and iron supplements (high bioavailability).

　　2. Pharmaceuticals and Cosmetics

　　Pharmaceuticals:

　　Topical preparations (e.g., lactic acid ointment): Soften the stratum corneum, treat ichthyosis and chapped hands and feet;

　　Infusions/Injections: Regulate pH (maintain body fluid acid-base balance);

　　Disinfection and Preservation: Low concentrations of lactic acid can kill bacteria in the air or on instruments (e.g., fumigation disinfection in operating rooms).

　　Cosmetics:

　　Moisturizer: Binds with the skin's stratum corneum to lock in moisture (used in face creams, serums);

　　Exfoliation: Gently dissolves keratin protein to improve rough skin (suitable for sensitive skin).

　　3. Industrial Materials

　　Biodegradable Plastics: Lactic acid undergoes dehydration polymerization to produce polylactic acid (PLA), which has good biocompatibility and degradability (decomposes into CO₂ and water in the natural environment), serving as a substitute for traditional petroleum-based plastics (e.g., packaging materials, disposable tableware).

　　Textile/Leather: Used as a pH regulator, dyeing auxiliary, or to modify fibers through polymerization (e.g., anti-wrinkle fabrics).