Stable isotope and trace metal compositions of Australian prawns as a guide to authenticity and wholesomeness

• The authors determined the isotopic compositions of prawn meat and chitin.
• Carbon and hydrogen isotopic composition distinguished between Australian and imported prawns.
• The authors determined the trace metal composition of prawn meat and heads.
• Arsenic, potassium and zinc concentrations distinguished between Australian and imported prawns.
• Some Australian samples contained high concentrations of arsenic which was present in a harmless form.

This research has explored the potential of stable isotope and trace metal profiles to distinguish Australian prawns from prawns imported from neighbouring Asian countries. Australian prawns were collected mostly from the Brisbane area. Strong differences in Australian vs. imported prawns were evident from both the isotope and trace element data, with the differences most likely occurring because imported prawns are typically reared in aquaculture facilities and frozen prior to sale in Australia. The aquaculture origins are characterised by comparatively; low δHVSMOW, δ13CVPDB values, low concentrations of arsenic, zinc and potassium, and high water contents (>80%). Relatively high arsenic and cadmium contents were found within Australian prawns, but the concentrations did not exceed local human health guidelines.