School of Science and Technology, Hong Kong Metropolitan University, Jockey Club Campus, 81 Chung Hau Street, Kowloon, Hong Kong, The People's Republic of China.
J AOAC Int. 2023 Jul 17;106(4):1003-1009. doi: 10.1093/jaoacint/qsad038.
Edible bird's nest (EBN) is one of the most valuable tonic Chinese foods, made from glutinous salivary secretion with highly concentrated mucin glycoprotein. For ease of consumption, manufacturers have marketed different ready-to-eat EBN products, in which the EBN content varies. This is the first study to analyze the EBN content in ready-to-eat beverages.
To determine the EBN content in ready-to-eat beverages by its active ingredient, N-acetylneuraminic acid (sialic acid).
Sialic acid in ready-to-eat beverages and raw EBN was extracted in sodium hydrogen sulfate solution, followed by derivatization using o-phenylenediamine dihydrochloride and determination using high-performance liquid chromatography (HPLC). Method precision, recovery of extraction, degradation of sialic acid due to cooking, and measurement uncertainty were evaluated.
The mean concentrations of raw EBN in different origins and colors ranged from 5.77 to 10.92%. Ten different brands of traditional ready-to-eat EBN beverages from the market were analyzed, in which estimated concentrations of EBN were diversified, ranging from 0.014 ± 0.010 to 0.66 ± 0.069% (w/w) (95% confidence level). The concentration of sialic acid was found to range from 11.4 to 527 mg/kg.
Based on the results, sialic acid content can provide a better estimation of the EBN content in traditional ready-to-eat beverages. Neither the selling price nor dried matter could be used as an indicator of the quality of the ready-to-eat EBN beverage among the samples obtained.
Sialic acid can be used as an indicator to estimate EBN content, where the sialic acid and EBN content in ready-to-eat beverages from the market were found to vary significantly.
燕窝是最有价值的中式滋补食品之一，由粘性唾液分泌物制成，富含高度浓缩的粘蛋白糖蛋白。为方便食用，制造商推出了不同的即食燕窝产品，其中燕窝的含量各不相同。这是首次分析即食饮料中燕窝含量的研究。
通过其活性成分 N-乙酰神经氨酸（唾液酸）来确定即食饮料中的燕窝含量。
采用硫酸氢钠溶液提取即食饮料和原燕窝中的唾液酸，然后用邻苯二胺二盐酸盐衍生化，高效液相色谱法（HPLC）测定。评估了方法精密度、提取回收率、烹饪导致的唾液酸降解以及测量不确定度。
不同产地和颜色的原燕窝的平均浓度范围为 5.77%至 10.92%。分析了市场上 10 种不同品牌的传统即食燕窝饮料，其中燕窝的估计浓度各不相同，范围为 0.014 ± 0.010%至 0.66 ± 0.069%（w/w）（95%置信水平）。唾液酸浓度范围为 11.4 至 527 mg/kg。
基于这些结果，唾液酸含量可以更好地估计传统即食饮料中的燕窝含量。在所获得的样品中，销售价格和干物质都不能作为即食燕窝饮料质量的指标。
唾液酸可以用作估计燕窝含量的指标，市场上即食饮料中的唾液酸和燕窝含量差异很大。
