Safety evaluation of certain food additives - ipcs inchem

PHOSPHOLIPASE C EXPRESSED IN PICHIA PASTORIS 113
3.3 Assessment of dietary exposure based on individual dietary records
An estimate of dietary exposure to phospholipase C was made by the
Committee at the present meeting based on the Concise European Food
Consumption Database for the adult population (16–64 years of age), published by
the European Food Safety Authority (EFSA) in 2008 (European Food Safety
Authority, 2008). The European database compiles mean and high percentiles of
individual food consumption for 15 broad food categories from the majority of
European countries (n = 17). Mean and high levels of fat products (including
mayonnaise, dressings, béchamel and hollandaise sauces, low-fat dressings or
mayonnaise, goose fat and coconut extract) consumed by consumers only in
European Union (EU) member states were combined with the maximum use level
recommended by the petitioner of 1000 mg of the commercial enzyme preparation
(7% TOS) per kilogram of vegetable oil.
Thus, if it is assumed that the enzyme is not removed from the oil and if the
reported levels of fat products consumed by EU adult consumers are considered to
range from 21 to 59 g/day on average and from 51 to 150 g/day for high consumers
(95th percentile), dietary exposure to phospholipase C would be estimated to be
0.024–0.069 mg TOS/kg bw per day on average and 0.059–0.175 mg TOS/kg bw
per day for high consumers (95th percentile).
4. COMMENTS
4.1 Biochemical aspects
Phospholipase C from P. pastoris was tested for haemolytic activity using
phospholipase C from Clostridium perfringens as a positive control. No haemolytic
activity was detected.
Phospholipase C was also evaluated for potential allergenicity according to
the bioinformatics criteria recommended by the FAO/WHO Expert Consultation
(2001). The amino acid sequence of phospholipase C was compared with the amino
acid sequences of known allergens. No sequence homology that would suggest that
phospholipase C is an allergen was identified.
4.2 Toxicological data
Toxicological studies were performed with the phospholipase C enzyme
using a representative batch (PLC-16449-PD267B), which was produced according
to the procedure used for commercial production. The liquid enzyme concentrate
was lyophilized to produce the final, non-formulated test substance, with an average
activity of 315 U/mg (where a unit is defined as the quantity of the enzyme that
hydrolyses 1 μmol of phosphatidylcholine per minute at 37 °C and pH 7.3) and a
TOS value of 83.6% (w/w). Before being used in toxicological studies,
phospholipase C was analysed to demonstrate that it conformed to the General
Specifications and Considerations for Enzyme Preparations Used in Food
Processing (Annex 1, reference 184).