Combined effects of thermal processing and spice bioactive compounds on the reduction of aflatoxins in paprika

Abstract

Aflatoxins are potent mycotoxins frequently detected in paprika, posing significant food safety concerns. This study evaluated the effect of a Moroccan spice blend combined with thermal processing on aflatoxin reduction in naturally contaminated sweet paprika. The spice blend, composed of cumin, turmeric, ginger, black pepper, garlic, coriander, salt, and lemon juice, was applied to paprika samples subjected to different treatments, including heating at 180 °C for 20 min. Aflatoxins were extracted and quantified by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Thermal processing alone reduced total aflatoxins (ΣAFs) from 13.63 to 6.69 µg/kg (50.92%), while the spice blend alone reduced levels to 7.65 µg/kg (43.87%). The combined treatment achieved the greatest reduction, lowering ΣAFs to 4.92 µg/kg (63.90%). Two-way ANOVA revealed a significant interaction between thermal processing and the spice blend (F(1, 8) = 468.84, p < 0.001), indicating a statistically significant interaction that was characterized as sub-additive relative to the theoretical additive model. Tukey’s HSD test confirmed significant differences between treatments ( p < 0.001). The observed reduction may result from both thermal processing and the action of bioactive compounds present in the spices. These findings support the potential of combining traditional spice blend with thermal processing as a natural strategy to mitigate aflatoxin contamination in paprika.