Chemical composition and authenticity of selected edible bird nest in Malaysia and Indonesia

This study was conducted to determine the authenticity of EBN and the compositional properties of unclean raw and clean EBN as well as to develop a rapid technique to determine the nitrite and nitrate content using sensor technology. The samples used were raw unclean and clean EBN from two major exporting countries: Malaysia (Langkawi and Perlis) and Indonesia (Java, Balikpapan and Kalimantan) from species Aerodramus fuciphagus and some common adulterants namely agar, starch, sodium alginate, carrageenan, egg white and pork skin. Functional groups identification study was employed using FTIR technique. In this study, both unclean and clean EBN gave similar pattern of FTIR spectra. The presence of similar compounds such as hydroxyl (OH), carboxyl (COOH), amines (NH), alkanes (C-C), alkynes (C≡C), carbonyl (C=O) and nitro (N=O) groups were identified. The spectra of pure adulterant were apparently different with pure EBN while the spectra of adulterated EBN samples with addition of the adulterants were quite similar from that of pure EBN but the compounds present were different. The fingerprint region of the spectra of pure and adulterated edible bird nest samples were quite similar at wavenumber <1500 cm -1 . The NH group was absent in all the adulterants except in pork skin and egg white. Pork skin has ester C=O stretch bond which was not present in EBN itself and in other adulterants. The C=O stretch is an ester vibration band of fatty acids at wavenumber 1745.1 cm-1. However, both EBN and adulterants have C=O stretch (amide) around 1670-1600 cm-1 for protein. Hence, FTIR can be used as a simple and rapid method to identify the authenticity of EBN and the non-halal component as adulterants. The largest component in EBN was protein with 22.4% to 32.7% respectively followed by carbohydrate ranging from 9% to 12%. Moisture (6.92% to 13.88%), ash (1.1% to 8.8%) and the lowest was fat content 0.01% to 0.07% respectively. Nitrite and nitrate in EBN was determined using sensor techniques using ISE electrode called E-tongue. This sensor technique is faster compared to the normal ion chromatography technique. Concentration of nitrite and nitrate in wastewater, unclean and clean EBN varies from 0.2 to 2.9 ppm which is lower than the standard set by China for export purposes. In this study, nitrite was less than 30 ppm and therefore safe for human consumption. The accuracy test carried out using Perlis EBN using sensor technique gave 100.2 to 100.8% recovery with RSD value less than 1% where as using ion chromatography gave 96.9 to 102.8% with RSD value 9 to 13%. Thus, sensor technique is highly sensitive and can be used as a standard method in determination of nitrite and nitrate in EBN samples as well as reduce the analysis time from 2 hour to 10 minutes. Mineral elements such as potassium and iron were high but lead content is low hence non-toxic.