Safety evaluation of the food enzyme endo-1,4-β-xylanase from a genetically modified Trichoderma reesei (strain DP-Nzd22)

Abstract

The food enzyme endo-1,4-β-xylanase (EC 3.2.1.8) is produced with a genetically modified Trichoderma reesei (strain DP-Nzd22) by DuPont. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and recombinant DNA. The endo-1,4-β-xylanase is intended to be used in distilled alcohol production, bakery and brewery. Residual amounts of total organic solids (TOS) are removed during the production of distilled alcohol, consequently dietary exposure was not calculated. For baking and brewing processes, based on the proposed maximum use levels, dietary exposure to the food enzyme–TOS was estimated to be up to 0.416 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rodents. The Panel identified a No Observed Adverse Effect Level of 1,000 mg TOS/kg bw per day. A comparison of the no observed adverse effect level with the dietary exposure results in a sufficiently high margin of exposure (at least 2,400). Similarity of the amino acid sequence to those of known allergens was searched and no matches were found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions upon dietary exposure to this food enzyme cannot be excluded, but the likelihood of such reactions to occur is considered to be low. Based on the data provided, the removal of TOS during the production of distilled alcohol and the derived margin of exposure for baking and brewing processes, the Panel concluded that this food enzyme does not raise safety concerns under the intended conditions of use.