Product: Citric Acid Monohydrate (C₆H₈O₇·H₂O)

CAS No.: 5949-29-1
Hazard Class: Non-hazardous
UN No.: Non-regulated
Appearance: Colorless translucent crystals

Description: Citric acid monohydrate is produced through fungal fermentation (Aspergillus niger) of molasses or sucrose, serving as a natural organic acid with three carboxyl groups (pKa₁=3.1, pKa₂=4.8, pKa₃=6.4). As the most widely used food acidulant (E330), it provides tartness in beverages (0.5-1.5%), acts as antioxidant synergist in oils, and enables pH adjustment in pharmaceuticals (effervescent tablets). The monohydrate form loses crystalline water at 74°C, transitioning to anhydrous citric acid while maintaining identical functionality in chelating metal ions (Ca²⁺ binding capacity 250mg/g) and buffering systems (optimal pH 2.5-6.5).

Product: Citric Acid Anhydrous (C₆H₈O₇)

CAS No.: 77-92-9
Hazard Class: Non-hazardous
UN No.: Non-regulated
Appearance: White crystalline powder

Description: Citric acid anhydrous is produced by dehydrating citric acid monohydrate at 40-50°C under vacuum, serving as a versatile organic acid with three carboxyl groups (pKa₁=3.1, pKa₂=4.8, pKa₃=6.4). It is widely used as a natural preservative and acidulant (E330) in food/beverages (provides tartness without moisture), pharmaceutical excipient (effervescent formulations), and cleaning agent (chelates hard water ions). Compared to the monohydrate form, it offers higher stability in dry products (no water loss during storage) and faster dissolution rates (complete in <30 sec at 25°C).