Guide for Selecting the Appropriate Specification and Model of Citric Acid

I. Core Classification Dimensions of Citric Acid Specifications (Basic Cognition)

1. Form and Water Content: Divided into monohydrate citric acid (C₆H₈O₇·H₂O) and anhydrous citric acid (C₆H₈O₇). Monohydrate citric acid contains 1 molecule of crystal water, with a low melting point (around 100℃), easy solubility and weak hygroscopicity; anhydrous citric acid contains no crystal water, has a higher melting point (around 153℃) and strong hygroscopicity, suitable for scenarios sensitive to moisture.

2. Purity Grade: Classified into food grade, pharmaceutical grade, industrial grade, and reagent grade (analytical reagent AR, chemical pure CP, etc.) according to application fields. The purity requirements from high to low are roughly: reagent grade > pharmaceutical grade > food grade > industrial grade, and the corresponding limit standards for impurities (such as heavy metals, sulfates, chlorides) are relaxed in turn.

3. Particle Size/Appearance: Common forms are powder and crystal (particle size can be divided into fine crystal, medium crystal and coarse crystal). Particle size affects dissolution rate and mixing uniformity; for example, powder has a fast dissolution rate, suitable for scenarios requiring rapid dispersion; crystal has good fluidity, suitable for metering and feeding.

4. Implementation Standards: There are clear national standards (GB) or industry standards in different fields. For example, food grade complies with GB 1886.235-2016, pharmaceutical grade complies with pharmacopoeia standards (ChP), and industrial grade complies with relevant chemical industry standards. Standards are the core basis for judging whether specifications are qualified.

II. Detailed Rules for Selecting Citric Acid Specifications and Models by Field

(I) Food Industry Field (Most Mainstream Application, Core Requirements: Safety, Qualified Purity, Adaptation to Processing Technology)

• Beverage Industry (Carbonated Drinks, Fruit Juices, Tea Drinks, etc.): Priority is given to food-grade monohydrate citric acid (fine crystal or powder form). Reason: Monohydrate citric acid has a fast dissolution rate, which can quickly adjust the pH value of beverages (inhibiting microbial growth and improving flavor stability), and has weak hygroscopicity, facilitating accurate measurement during storage and batching; for concentrated beverages or beverages that need long-term high-temperature storage, food-grade anhydrous citric acid can be selected to avoid the impact of moisture on product stability.