Method for detecting content of ergothioneine in edible mushrooms

[0061] The preparation of embodiment 1 ergothioneine standard solution

[0062] Preparation of ergothioneine standard stock solution: Weigh 10 mg of ergothioneine standard substance (accurate to 0.0001 g), dissolve in water and dilute to 10 mL to obtain ergothioneine standard stock solution (1000 mg / L), and store at -18°C for future use.

[0063] In this embodiment, the storage time of the ergothioneine standard stock solution is determined. Because the solubility of the ergothioneine standard stock solution of 1000mg / L is very large, it cannot be measured directly on the machine, so it is diluted to 50mg / L in an appropriate amount at every turn, and its peak area is measured on the machine. Sampling and dilution was performed every 15 days, and the change of the peak area was observed. The results are shown in Table 1. As can be seen from Table 1, the mass concentration of ergothioneine is a standard stock solution of 1000mg / L, stored at -18°C, within 2 months, the peak

[0067] The chromatographic separation condition optimization of embodiment 2 ergothioneine

[0068] 1. Determination of detection wavelength. The ergothioneine standard working solution with a concentration of 10.0mg / L was scanned in the wavelength range of 200-400nm, and it was found that ergothioneine had a significant characteristic absorption peak at 262nm, so the detection wavelength was set to 262nm.

[0069] 2. Determination of the chromatographic column. The chromatographic columns used to detect ergothioneine in the prior art include C18 columns or hydrophilic columns. The present invention uses waters BEH C18 (recorded as No. 1 column), waters Atlantis T3 (recorded as No. 2 column), waters XBridgeBEH HILIC (recorded as No. 3 column) and Merck Zic HILIC (recorded as No. 4 column) four chromatographic columns Verify that ergothioneine has almost no retention on the No. 1 post and the No. 2 post, and the retention effect and separation effect on the No. 3 post and the

[0073] The drawing of the HPLC standard curve of embodiment 3 ergothioneine and determination of limit of detection, limit of quantification

[0074] Under the chromatographic condition finally determined in embodiment 2, ergothioneine standard working solution is introduced successively from low concentration to high concentration, draws standard curve by gained peak area and corresponding standard working solution concentration (mg / L), as figure 2 shown. The results showed that the concentration of ergothioneine had a good linear relationship with the peak area in the range of 1.00-50.0 mg / L (see Table 2).

[0075] Table 2 Regression equation and correlation coefficient of ergothioneine standard working solution

[0076]

[0077] Gained chromatogram (concentration of S / Nfigure 1 Among a), the limit of detection (LOD) is taken as 3 times of signal-to-noise ratio (S / N=3); the limit of quantification (LOQ) is obtained when the precision and accuracy of the actual samp