Application Summary of Food-Grade Silica in the Food Industry

1. Basic Information of Food-Grade Silica

1.1 Basic Properties

With a chemical formula of SiO₂, food-grade silica (also known as food-grade silica white) is a food additive approved for use under China’s GB 2760 National Food Safety Standard for the Use of Food Additives, classified as an "anti-caking agent" with the code 02.004. Its main component is amorphous silica, featuring non-toxicity, odorlessness, stable chemical properties (no reaction with acids, alkalis, oils, etc. in food), large specific surface area, and strong adsorption capacity.

1.2 Essential Mechanism of Action

It is related to its microscopic structure. The particle surface has a large number of micropores and hydroxyl groups, forming strong adsorption capacity and spatial barrier effect, thereby exerting multiple functions.

2. Overview of GB 2760 National Food Safety Standard for the Use of Food Additives

2.1 Standard Development History

It originally originated from China’s internal national standards in the 1970s. The standard number was determined in 1981, and the current version is the 2011 edition. On December 31, 2014, the National Health and Family Planning Commission issued the GB 2760-2014 edition, which was implemented on May 24 to replace the 2011 edition.

2.2 Revision Entity

Led by the National Food Safety Risk Assessment Center, the drafting group was composed of multiple industry associations and institutions, including the China National Food Industry Association and the China Bakery Food Industry Association.

2.3 Revision Background

5.After the implementation of the 2011 edition of the standard, international organizations and relevant Chinese authorities conducted the latest evaluations on new food additives such as aluminum-containing food additives, requiring adjustments to some standard provisions.

6.The Food Safety Law stipulates that the use of food additives must not only ensure safety but also emphasize technological necessity. The technological necessity of some additives needs to be re-examined and discussed.

2.4 Major Revision Contents

7.Integrating Additive Announcements: Incorporating food additive-related announcements approved by the National Health and Family Planning Commission into the standard to solve the problem that the coexistence of announcements and standards is unfavorable for use and inquiry.

8.Adjusting the Scope of Additive Management: Referring to practices in other countries, the content related to nutrient supplements was removed from the GB 2760 standard, as most countries do not manage nutrient supplements, spices, processing aids, etc. as food additives.

3. Core Functions of Food-Grade Silica

3.1 Anti-Caking Function (Most Important Function)

9.Problem Scenarios: Powdered or granular food raw materials such as salt, sugar, and milk powder are prone to particle agglomeration and caking due to changes in environmental humidity and temperature, as well as storage pressure, affecting usability (e.g., caked milk powder is difficult to dissolve) and sensory experience.

10.Mechanism of Action: First, spatial barrier—tiny particles are uniformly dispersed on the surface of food particles, forming a "physical barrier" to prevent particle adhesion. Second, moisture adsorption—using a high specific surface area to adsorb trace free moisture in food, reducing the surface humidity of particles and avoiding crystal bridging caused by moisture (e.g., salt caking due to dissolution and recrystallization from moisture).

11.Application Case: Salt without anti-caking agents tends to form hard lumps after 1-2 months of storage; adding 0.1%-0.5% food-grade silica can keep it loose for a long time.

3.2 Flow-Promoting Function

12.Problem Scenarios: During the production process of powdered foods or raw materials such as flour, coffee powder, and vitamin powder (e.g., mixing, conveying, filling), poor fluidity easily leads to "bridging" (blockage of equipment pipelines) and uneven filling volume, affecting production efficiency and product quality stability.

13.Mechanism of Action: It adheres to the surface of powder particles, reducing friction and adhesion between particles, lowering "cohesiveness," and improving fluidity to ensure smooth production (e.g., the weight error of each bag of products can be controlled within ±2% during filling).

3.3 Adsorption and Carrier Functions

14.Adsorption Function: It can adsorb odors, oils, and trace harmful substances in food (e.g., adding a small amount to fried foods to adsorb excess oil, and adsorbing raw material odors in health products). It can also stabilize volatile components such as flavors and fragrances, reducing their loss during processing and storage.

15.Carrier Function: For liquid or trace solid food additives (e.g., liquid flavors, vitamins, pigments), it uses high adsorption capacity to uniformly load them into its micropores, converting them into stable powders for easy mixing with other food raw materials (e.g., after adsorbing liquid flavors, it can be easily added to biscuit powder to avoid local excessive concentration of flavors).

4. Specific Application Fields of Food-Grade Silica

5. Safety Instructions for Food-Grade Silica

1.Authoritative Evaluation Conclusion: Its safety has been evaluated by many authoritative institutions worldwide, including China’s National Health Commission, the U.S. FDA, and the European Union’s EFSA, confirming its non-toxicity and non-irritation.

2.Human Metabolism Characteristics: It has stable chemical properties; after oral administration, it is not absorbed by the human body and is excreted with feces, without accumulation in the body.

3.Usage Limit Regulations: China’s GB 2760 stipulates that the maximum usage amount in "cocoa products, chocolate and chocolate products (including cocoa butter substitute chocolate and its products)" is 1.5 g/kg, and it can be used "as needed" in other foods (added in appropriate amounts according to production needs to ensure safety), following the principle of "not exceeding the necessary minimum amount."

4.Production and Purity Requirements: It must be produced through compliant processes such as the fumed method and precipitation method, without heavy metals such as lead and arsenic and harmful impurities, and must meet the requirements of GB 1886.246 National Food Safety Standard for Food Additive - Silica, with a silica content of ≥99.0%.

In conclusion, food-grade silica is an indispensable "functional additive" in the food industry. It can effectively solve problems such as food agglomeration and poor fluidity, improve production efficiency and product stability, and has extremely high safety when used in compliance with regulations.