Determination of origin of edible bird's nest by stable isotopes and minerals analysis

Abstract

The EBN business is a highly profitable market as it is one of the widely consumed health foods in Chinese communities. Due to its high market value and profit margin, some parties are trying to exploit the industry by introducing counterfeit bird's nest, making false claims of its origin i.e. house-rearing versus cave-harvested, as well as providing misleading promotional description. Thus, traceability and authentication mechanisms should be implemented to protect our precious commodity. One such mechanism is the employability of stable isotope and mineral analysis, analyzed by elemental analyzer-isotope ratio mass spectrometer and inductively coupled plasma-optical emission spectrometer, respectively. A total of 30 pieces each of processed house nests and cave nests were obtained from different regions in Malaysia and Indonesia. ¡¹³N, d¹³C, Ca and Na were found significantly different (p<0.05) between EBN of different origins. As a first approximation, mineral contents and the natural abundance of C and N isotopes measurement of EBN provided information on the bird's diet and to a certain extent, the area where it inhabits (geographical proxy). Unsupervised pattern recognition techniques such as Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were then applied to investigate contributing environmental factors and identify key variables which influenced EBN origin discrimination. House nests and cave nests were successfully classified into different clusters using HCA. PCA demonstrated that Na, Ca and 813C were high loading variables in PC1 while PC2 was highly loaded by 815N, K and Mg. PC1 and PC2 which accounted for a total variation of 66.69% showed promising results with the EBN collected from house farms were discriminated from those harvested from caves. The use of stable isotopes and minerals profile combined with multivariate statistical analysis could be useful for authenticity assessment of EBN of unknown or suspect origin.