Alternative Methods for SO2 Determination in Food

As the global import and export of food continue to expand, ensuring product authenticity and nutritional precision becomes paramount. Consumer demands for comprehensive nutritional and ingredient information are escalating, prompting regulatory bodies like the US Food and Drug Administration (US FDA), Association of Official Analytical Collaboration (AOAC) International, ISO and others to evolve testing standards and methodologies while establishing maximum allowable thresholds for additives and contaminants. Sulfur dioxide (SO2) is a versatile food additive, serving as a preservative, antioxidant, and antimicrobial in products like dried fruits, wine, seafood, and processed foods. Its roles include extending shelf life by inhibiting microbial growth, preserving natural colors and flavors, and protecting vital vitamins. However, regulatory limits are imposed to ensure consumer safety and prevent overconsumption due to potential toxicity. The equilibrium between adhering to regulations while upholding food quality and health poses a challenge for food manufacturers. This necessitates accurate, efficient, and consistent methods and analyses. A pivotal aspect is the selection of a reliable reference method for SO2 determination. The optimized Monier Williams method is deemed the reference standard in accordance with the Association of Official Analytical Collaboration (AOAC) International 990.28. However, this method's drawbacks include its time-intensive nature (2+ hours per measurement), manual involvement, intricate sample preparation, and potential subjectivity during endpoint titration. This labor-intensive approach is problematic for high throughput laboratories and could lead to inconclusive outcomes. This abstract introduces and demonstrates two alternative methods, showcasing equivalent results that are achieved more efficiently and reproducibly. Validation against the AOAC 990.28 method underscores their reliability and suitability.