Method for identifying cubilose and adulterants thereof by utilizing feature tag peptide fragments

Abstract

The invention relates to an MRM qualitative detection method for cubilose and four common adulterants (pigskin, tremella, egg white and fish maw) thereof. According to the method, water solution containing 7M urea and 2M thiourea is used for extracting proteins in cubilose and common adulterants thereof; overnight enzyme digestion is carried out on the extracted proteins through trypsin; peptide fragments are analyzed by using a high-resolution tandem mass spectrum of an nL liquid chromatogram after being desalted; Proteinpilot 5.0 softawre is utilized to carry out library search authentication on data obtained by the high-resolution mass spectrum; high-response, miss cut-free and modification-free peptide fragments, the lengths of which are smaller than 25 amino acids, are selected to undergo Blast comparison on NCBI, so as to mine specific peptide fragments of the cubilose and common adulterants thereof; and SKYLINE software is utilized to construct MRM ion pairs for the cubilose andcommon adulterants thereof. The method is simple to operate, high in correctness and good in stability, and is capable of identifying the cubilose and common adulterants (one or several of pigskin, tremella, egg white and fish maw) thereof through one experiment, so as to provide technical support for maintaining normal market order of cubilose consumption.

Description

technical field [0001] The present invention relates to the application of proteomics technology based on mass spectrometry in the field of identifying the authenticity of bird's nest, mainly including the excavation of specific labeled peptides of bird's nest and its adulterants (pigskin, white fungus, egg white and fish maw) Development of multiple reaction monitoring (MRM) methods on quadrupole tandem mass spectrometry. Background technique [0002] Bird’s nest——a kind of nutritious food suitable for medicine and food unique to Southeast Asia. It is a swiftlet of different species in the Swiftletaceae (mainly Javan swiftlet and giant swiftlet) built in island caves with saliva. nest for breeding offspring. The reason why bird’s nest was eaten by humans was originally only as a food that could satisfy hunger, but with the continuous development of human civilization, bird’s nest’s unique medicinal effects such as nourishing yin and nourishing lungs, reducing phlegm and re...

AI Technical Summary

Problems solved by technology

The development of these methods has different focuses and limitations. For example, although the ELISA of sialoglycoprotein can judge the authenticity of bird’s nest from the change of sialoglycoprotein content, it cannot judge the identity of adulterants; Artificial synthesis makes the content of sialic acid in bird's nest no longer suitable as a feature for judging the authenticity of bird's nest; another example is that although infrared spectroscopy is non-destructive and fast, it requires high experience of testing personnel and is not easy to popularize, etc.

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