Toxicological studies on Polyporus pinsitus laccase expressed by Aspergillus oryzae intended for use in food

The laccase used in the study was produced by submerged fermentation ofAspergillus oryzae,containing a gene originating fromPolyporus pinsitus.Laccase is to be employed as a processing aid in the juice industry to make a clear and stable juice. The enzyme was subject to a series of toxicological tests to document its safety in use. It was not mutagenic in theSalmonella typhimurium reverse mutation assay, and it did not cause chromosomal aberrations in cultured human lymphocytes. No evidence of inhalation toxicity or skin and eye irritation was found. Oral administration to rat of up to 10mlkg-1 b.w.day-1 (equivalent to a total organic solids dosage of 676mgkg-1 b.w.day-1 or a laccase dosage of 2601 LACUkg-1 b.w.day-1) for 13 weeks did not cause any adverse effect. The maximum recommended dosage of laccase used for juice applications is 50 LACUl-1 juice.