Activated carbon, as a substance with high adsorption capacity, plays an indispensable role in the food industry. Its application includes many aspects for example raw material purification, production processing, and wastewater treatment. Through the effect of physical adsorption and chemical adsorption, it achieves multiple goals including impurity removal, quality improvement, and so on.The following will provide a detailed description of the application of activated carbon in the food industry.
During the pre-treatment stage of food raw materials, the primary function of activated carbon is to remove pigments, odors, and so on from natural raw materials. Such as, in the sugar industry, the crude sugar liquid obtained from sugarcane or sugar beet pressing contains impurities such as melanoidins and caramel pigments. Traditional precipitation methods are difficult to completely remove these impurities, while activated carbon powder, with its developed microporous structure, can efficiently adsorb these macromolecular pigments while retaining the sweetness and nutritional value of sugar, making the finished white sugar reach the crystal-clear standard. Similarly, in juice processing, activated carbon powder can selectively adsorb phenolic oxidation products and bitter taste components in the juice, improving the clarity and enhancing the taste, especially in the industrial production of apple juice and grape juice, where activated carbon powder treatment has become a standardized process.
The refined purification in the production process is another important area of activated carbon application. In the refining of edible oil, pollutants for example free fatty acids, phospholipids, heavy metals, and so on in crude oil can affect the stability and safety of the oil. By adding food-grade powdered activated carbon and utilizing its surface rich functional groups to form hydrogen bonds or electrostatic attractions with the pollutants, the peroxide value and heavy metal content in the refined oil can be significantly reduced, making the refined oil meet national food safety standards. In the fermentation food industry, such as in the production of monosodium glutamate and citric acid, activated carbon powder is often used to remove fungal fragments, protein colloids, and metabolic by-products from the fermentation liquid, improving product purity. For example, in the production of monosodium glutamate, through activated carbon powder desaturation, the whiteness of glutamic acid sodium crystals can be increased to over 95%.
The treatment of food industry wastewater is a concentrated manifestation of the environmental protection value of activated carbon. The wastewater produced during food processing contains high concentrations of organic matter, oils, and color substances, and direct discharge would lead to water body eutrophication. Using coal-based column-shaped activated carbon as the filler for the biological filter, not only can it remove COD and BOD from the wastewater through physical adsorption, but its porous structure can also provide a substrate for microorganisms, forming an "adsorption-biodegradation" synergy, increasing the wastewater treatment efficiency by 30%-50%. For example, after the beer factory wastewater is treated by the activated carbon-biological membrane combined process, the COD removal rate can reach over 90%, and the effluent can be reused for park greening or equipment cleaning, achieving water resource recycling.
Furthermore, activated carbon also plays a hidden role in the safety guarantee of food contact materials. Residual solvents in plastic films used for food packaging and volatile organic compounds in printing inks may migrate and contaminate food. By adding activated carbon powder masterbatch during film production, these harmful substances can be adsorbed and solidified, reducing the risk of migration and ensuring the safety of food packaging.
From the deep purification of natural raw materials to the quality optimization of end products, from the compliance of production wastewater discharge to the safety protection of packaging materials, activated carbon, with its efficient, environmentally friendly, and low-cost advantages, becomes a key material for the sustainable development of the food industry. As food industry safety standards continue to improve, the research and application of modified activated carbon will further expand its potential in functional purification and provide technical support for the green upgrade of the food industry.