Determination of the geographical origin of Malaysian edible bird's nest by carbon, nitrogen and sulphur (CNS) stable isotopes

Abstract

The economic motivation for adulteration and mislabeling of origin is significant as edible bird's nest (EBN) rank amongst the world's most expensive animal products for food and traditional medicinal uses. The aim of this study is to determine the geographical origin of Malaysian Edible Bird's Nest by using bio element fingerprinting techniques using carbon, nitrogen and sulphur (CNS) isotopes in order to avoid product fraud, and to guarantee product quality and safety. The samples used were authentic processed EBNs from different states in Malaysia and supplied by Ministry of Health, Malaysia. The ground EBN samples were analyzed using Elemental Analyzer Isotope Ratio Mass Spectrometer (EA-IRMS) system. The EBN measured δ13C values cover a range of -26.99‰ to -23.80‰ and the δ15N values cover a range of 5.05‰ to 8.06‰. The carbon isotope values are typical of Calvin (C3) plant sources. The nitrogen isotope values show that the swifts feed on relatively small primary consumer insects. This is also evidenced by the substantial overlap of δ15N values from the different locations. From the analysis, a statistically significant correlation does exist between the δ13C and δ15N values for the EBNs. The EBN measured δ34S values covered a range of +1.9‰ to +14.3‰ with a mean value of +7.8‰. Higher δ34S values were observed for EBN produced in the state of Sarawak compared to the EBN produced in the other states of Kelantan, Malacca, Negeri Sembilan, Perak and Selangor. Stable carbon, nitrogen and sulphur isotope analysis of Malaysian EBNs has shown potential for distinguishing between the various states in which they are produced, based on preliminary data. Using additional stable isotope data such as that derived from hydrogen and/or oxygen and combining trace element profiling would likely improve the reliability of the determination of geographical origin and classification rates.