Quantification, Risk Assessment, and Mitigation of Cashew Allergen Cross-Contact in Shared Roasting Oil Systems

Allergen cross-contact in food production should be minimized to protect food-allergic consumers. Processing operations using shared cooking media, including shared roasting or frying oil, present multiple uncertainties related to allergen cross-contact. The quantity of allergen transferred to oil and subsequent products is unknown, and the effectiveness of oil cleaning methods on allergen removal has not been evaluated. In this study, bench-scale experiments were conducted to evaluate the amount of total cashew protein transferred to oil after frying (138 °C, 10 min or 168 °C, 3 min) and to products (peanuts and potato slices) subsequently fried in shared oil. After frying 15 batches of cashews (100 g/batch in 1 L of oil), 70-130 ppm total cashew protein was quantified in oil using targeted mass spectrometry. Peanuts or potato chips processed in oil after cashews were found to contain 23.0 and 193.5 ppm total cashew protein, respectively. Quantitative safety assessments indicated these concentrations could represent health risks to cashew-allergic individuals. Comparison of nine oil cleaning methods showed that 11-µm filters, 25-µm filters, and diatomaceous earth used with commercial filters were the most effective treatments in removing cashew protein residue. All three treatments could reduce cashew protein concentration from more than 200 ppm to less than 10 ppm. Risk reduction calculations demonstrated that with appropriate control measures, the risk associated with cashew allergen cross-contact in frying oil can be substantially mitigated. The data obtained in this study can help food manufacturers and foodservice providers design effective allergen controls to better protect food-allergic consumers.