NMR data processing
The section is the data processing of the experiment from milk extraction approach comparisons.
1, Topspin data export
Use convbin2asc in the command line and a file named "ascii-spec.txt" will be created under the following folder
**pdata\1\scii-spec.txt
2, Put all the txt file in one folder with sample names
Be sure to revise the sample names
The example data can be downloaded as follows
3, import the text file to matlab
Use the attached matlab code, and you can plot the overlay NMR spectra. Be sure only the spectrum txt files were in the folder, and sample names will be saved in a txt file (sample_names) for future applications
4, Smooth the average spectrum
Use the attached matlab code, and you can plot the overlay NMR spectra, only do this after the step 3. An example about smooth peaks are listed below. The method is based on the references with smooth method changes (Wang, Bo, Antoniette M. Maldonado-Devincci, and Lin Jiang. "Evaluating line-broadening factors on a reference spectrum as a bucketing method for NMR based metabolomics." Analytical biochemistry 606 (2020): 113872. )
5 Find peak range
Use the matlab code to find the peak range, the right picture is only to show the ideal situation
5 Convert NMR peaks to a table
Use the matlab code to find the peak intensity and save them to a table so that various types of calculations can be carried out
PCA study
Principal Component Analysis (PCA) can describe the overall distribution of all the peaks. For example, the 1.29 ppm showed difference in the spectrum cooperation also showed important in the PCA loading plot that contribute to the separation of the PCA score plot
