Screening Malaysian edible bird’s nests for structural adulterants and geographical origin using Mid-Infrared – Attenuated Total Reflectance (MIR-ATR) spectroscopy combined with chemometric analysis by Data-Driven – Soft Independent Modelling of Class Analogy (DD-SIMCA)

Abstract

Edible bird’s nest (EBN) is widely consumed in South-East Asia as a health food product. In recent years, the adulteration of EBN is quite common due to its high economic value and limited supplies of the natural authentic product. Authentication and traceability of EBN demands time-consuming sequential analytical measurements to confirm that the product quality meets technical and regulatory requirements. Mid Infrared spectroscopy combined with chemometric analysis by Data-Driven Soft Independent Modelling of Class Analogy (DD-SIMCA) was used in this study to screen Malaysian EBNs for structural adulterants and for confirmation of geographical origin. The samples used were authentic processed EBNs of different grades (2A, 3A, 4A and 5A) from the swiftlet species Aerodramus fuciphagus supplied by Ministry of Health, Malaysia. Similarly, adulterants commonly used in EBN namely agar, Karaya gum, bovine gelatin, fish skin, melamine and porcine gelatine were also characterized. Adulterant mixtures were prepared gravimetrically at concentrations of 1, 5 and 10%w/w by combining appropriate quantities of adulterants with individual authentic EBN samples. Samples were then analyzed by Mid-Infrared – Attenuated Total Reflectance (MIR-ATR) spectroscopy. All test samples are properly categorized as members of the target class. However, 61% of the tested adulterated EBNs were correctly classified as ‘alien’ or non-authentic samples. The sensitivity and specifity values for DD-SIMCA models applied to origin determination ranged from 90 to 100% for production regions from Kelantan, Perak and Malacca. MIR-ATR spectroscopy in combination with DD-SIMCA modelling has shown potential as a rapid screening technique to detect the presence adulterants and confirm the provenance of EBN produced in Malaysia. Further work is required to validate the approach with a larger set of authentic samples and for a wider range of adulterants including flavour enhancers and preservatives.