Sources of potassium permanganate consumption for food contact paper

In this study, potassium permanganate (KMnO 4 ) consumption on some key raw materials of food contact paper was analyzed, the content of lignin and total sugar in water simulant for KMnO4 consumption test was analyzed by GC–MS and UV–vis respectively, and the contribution to KMnO4 consumption of the paper samples from lignin and total sugar was investigated. The results have shown that cassava starch has the highest KMnO 4 consumption value among all the starches analyzed, and the KMnO 4 consumption of lignin was significantly greater than that of starches and glucose. KMnO 4 consumption of 15 different commercial paper samples and 10 different commercial fiber molding products were analyzed. The results indicated that KMnO 4 consumption of 12 commercial paper samples were exceeded the limit of 40 mg/kg set forth in GB 4806.8 national food safety standard for food contact paper and paper article. The contribution to the KMnO 4 consumption value of paper samples and fiber mold products from lignin and total sugar in water simulant was from 42% to 94% in most of the samples, lignin and total sugar were two main sources of KMnO 4 consumption in food contact paper. It is known that lignin and total sugar are nature materials and they are non-hazardous, which is not appropriate to set such control limit in the food safety standard, therefore, the limit of KMnO4 consumption for food contact paper and paperboard in GB4806.8-2016 should be revised.