The Role of Natural Clays and Fining Agents in Food Processing and Health: Fruit Juice Clarification, Toxin Removal, and Safety Assessment

The food and health industries increasingly rely on natural mineral agents for processing efficiency and safety assurance. This paper reviews the efficacy of natural fining agents—specifically bentonite, sepiolite, and gelatin—in fruit juice clarification and mycotoxin decontamination, while also evaluating their safety profile for human consumption.

In the context of fruit juice processing, turbidity caused by polysaccharides, proteins, and polyphenols remains a primary quality concern. Research on Indian gooseberry (Phyllanthus emblica L.) juice demonstrates that a combined treatment of 1.5 mg/mL gelatin and 1 mg/mL bentonite significantly improves transmittance, vitamin C retention, and antioxidant activity compared to untreated samples, while effectively inhibiting microbial growth during 49 days of refrigerated storage. Similarly, in apple juice production, a combination of acid-activated sepiolite, gelatin, and silica gel achieved a 99.7% reduction in turbidity, outperforming single-agent treatments. However, the use of sodium-activated bentonites in apple juice must be carefully monitored, as studies indicate a correlation between higher sodium content in the activator and increased sodium release into the final juice product.

Regarding food safety, bentonite clays demonstrate significant potential in detoxifying contaminated milk. Aflatoxin M1 (AFM1), a potent carcinogen found in raw milk, poses severe public health risks. Experimental data utilizing specific bentonite variants (e.g., HAFR 3) reveals an adsorption efficiency of up to 98.5% for AFM1 in milk after 12 hours, with only minor alterations to the milk's nutritional composition, such as slight increases in fat and protein content alongside decreased lactose.

While the therapeutic and industrial benefits of clays are evident—ranging from antibacterial applications against MRSA to dental use—safety concerns persist regarding their direct consumption. Analysis of clay dietary supplements indicates that they may contain bioaccessible inorganic arsenic, ranging from 8% to 51%, posing potential chronic health risks. Consequently, while natural clays and fining agents offer superior performance in food stabilization and detoxification, their application requires rigorous toxicological screening for heavy metals and elemental leaching to ensure consumer safety.

Keywords: Fining agents, Bentonite, Sepiolite, Fruit Juice Clarification, Aflatoxin M1, Food Safety, Arsenic.