Application of Fourier Transform Infrared Spectroscopy on Edible Bird Nest Authenticity

In recent years, adulteration of edible bird nest (EBN) is quite common, due to the high economic value and limited supply of natural authentic EBN. The purity of EBN was determined using Fourier transform infrared (FTIR) spectroscopy. The compositional properties such as protein, carbohydrates, fat content, and moisture were determined. The samples used were unprocessed EBN and processed EBN of different grades (2A, 3A, 4A, 5A, and white biscuit) from the swiftlet species Aerodramus fuciphagus. In both the raw and processed EBN samples, the presence of similar compounds such as hydroxyl, carboxyl, carbonyl, aryl, amines, alkynes, and nitro groups was detected and both EBN samples showed similar shape of spectra. The spectra of the pure adulterants were different from that obtained in EBN samples. The spectra of adulterated EBN samples with addition of the adulterants were apparently different from that of processed EBN. The fingerprint region of the spectra of pure EBN and adulterated EBN samples was different at <1700 cm−1. Interestingly, only pork skin has ester C=O stretch bond and C=CH group which were not present in EBN itself and in other adulterants. Hence, the EBN samples could be proven authentic and labeled as halal products using FTIR technique. The highest component found in EBN samples was protein (58.3–63.9 %), followed by carbohydrate (11.3–12.9 %), moisture (7.0–9.34 %), and fat (0.05–0.09 %). The FTIR technique is a useful tool and rapid technique for the determination of purity of EBN as a deterrent to the commercial adulteration of EBN-based products.