Food Grade Citric Acid 101
Citric Acid (international code E330) is the most widely consumed natural fermented organic acidulant worldwide, naturally contained in the pulp of lemons, oranges and citrus fruits. Modern industrial mass production fully relies on the biological fermentation process of corn starch. Different from chemically synthesized acidic raw materials, the finished products of biological fermentation routes have been certified safe by global authoritative institutions, serving as an irreplaceable multi-functional basic raw material in food processing, pharmaceutical and daily chemical industries.
From the perspective of human metabolism logic, citric acid itself is the core intermediate product of the tricarboxylic acid cycle in human cells. The human body continuously synthesizes endogenous citric acid for energy conversion. Food-grade fermented citric acid can fully participate in metabolic decomposition after entering the human body without risk of accumulation and residue. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) lists it as a safe additive with no limited Acceptable Daily Intake (ADI). The US FDA and EU EFSA simultaneously recognize its general safety attribute, eliminating the misunderstanding of "chemical additives harming the body".
Domestic food-grade citric acid is divided into two mainstream specifications:
Monohydrate Citric Acid (molecular formula C₆H₈O₇·H₂O)
Its crystals contain fixed crystal water with stable moisture content controlled at 8.0%-9.0%, featuring mild water solubility and gentle acid release after dissolution.
Anhydrous Citric Acid (molecular formula C₆H₈O₇)
Refined by dehydration with zero free moisture, avoiding premature acid-base reactions and suitable for anhydrous formulas such as powder and effervescent products.
The supporting derivative Trisodium Citrate Dihydrate (E331), as the conjugate buffer salt of citric acid, can form a stable pH buffer system when mixed with citric acid to neutralize sharp sour taste, and simultaneously possess multiple functions of metal ion chelation, color protection and emulsification stabilization. The combination of the three covers the production demands of all categories of food.
The whole production process complies with GMP production standards for 100,000-class clean workshops, adopting non-GMO corn starch as the sole fermentation carbon source, inoculated with pure Aspergillus niger strains for sterile fermentation for 72 to 96 hours, completely isolated from heavy metals and industrial impurity pollution. The complete purification procedures include five major steps: plate-frame filtration to remove mycelium, calcium salt neutralization crude extraction, acidolysis impurity removal, activated carbon deep decolorization, and cation-anion exchange resin heavy metal removal. After concentrated crystallization, finished products are graded and screened to remove fine powder and agglomerated particles. The final food-grade packaging adopts food-contact PE inner film coated woven bags for sealing.
Each batch is delivered with a full set of quality inspection reports issued by CNAS-accredited laboratories, strictly complying with national standards GB 1886.235 (citric acid) and GB 1886.25 (sodium citrate). Test items include heavy metal limits of lead, arsenic, mercury, cadmium, sulfates, oxalates, light transmittance, moisture, total bacterial count, mold, yeast, Salmonella, Staphylococcus aureus pathogenic bacteria. All indicators must meet the standard before delivery.
In terms of compliance qualifications, the food-grade citric acid supplied by Rizhao Huikun Trading has complete sets of qualifications, including domestic food production license, third-party full-item COA test reports, Kosher certification, Halal certification, US FDA food contact approval, ISO22000 food safety management system certification. It can adapt to the audit and customs clearance requirements of domestic supermarket brands and food factories exporting to Europe, America, Southeast Asia, the Middle East, Latin America and other countries.
Storage requires a normal-temperature dry and ventilated warehouse with relative humidity controlled within 50%, stacking height no more than five layers to avoid heavy pressure damage and rain dampness. The sealed original package has a standard shelf life of 24 months, without caking, yellowing, acidity attenuation or impurity precipitation during the storage cycle.
In addition to the basic functions of acid adjustment and antisepsis, the core additional value of citric acid comes from metal chelation characteristics. It can capture trace iron and copper metal ions in raw materials and water, block metal-catalyzed oxidation reactions, delay fat rancidity and browning discoloration of fruit pulp, and greatly extend the food shelf life. After building a buffer system with sodium citrate, it can accurately lock the product pH range, avoid acidity fluctuation during high-temperature sterilization and long-term storage, and stabilize food taste, texture and forming structure. It is a core food ingredient to improve food stability at low cost.