Agilent NMR platform tackles food authenticity and origins

The ProPulse 500 and 600 MHz NMR System comes standard with Agilent’s VnmrJ software.

NMR is used to study authenticity, adulteration, spoilage, origin, processing and process control, and uniformity of raw materials and products.

It also works to understand physical properties and changes such as water migration in materials or products over time, or aggregation of components in a matrix.

However, NMR spectroscopy is less sensitive than some other analytical methods, so is not normally used to analyze trace contaminants within mixtures, such as quantifying pesticides in food.

QA/QC solution​

David Russell, Agilent Technologies NMR applications scientist told FoodQualityNews.com that the technology brings important attributes to quality assurance/quality control (QA/QC) problems.  

“NMR requires little to no sample preparation before analysis, and it is holistic in that it interrogates practically every molecule in the sample.  This gives a complete sample profile and does not bias the experimental results toward only targeted compounds.​

“​The NMR experiment is inherently quantitative; all response factors for all molecules in a spectrum is 1.  NMR can accurately determine the absolute concentration of any component in the sample, even when the component is a complete unknown.  ​

“NMR does not require any separation of the sample into individual components, greatly simplifying the analytical process.” ​

NMR can be imported in to statistical programs like its Mass Profiler Professional (MPP) software alongside GC/MS or LC/MS data.

It is quantitative and non-destructive, which is well suited to mixture analyses and quantification on samples can often be done with one calibration.

Levels and speeds​

Russell said generalisations of levels and speeds of the system are “difficult​” as the answer depends on the type of work being performed.  

A QA/QC process control method might only require 60-90 seconds, sample-to-sample, for completion, he added.

“An untargeted authenticity or verification of origin study might require 10 or 15 minutes of data collection for some types of samples.  The type of hardware used to collect the data also has a significant impact.  ​

“NMR can be used to investigate components down to the very low micromolar range in typical food science samples.”​

He said that the two major bottlenecks to NMR use for food science are automation of data collection on the front end and data reduction on the back.

“Agilent's sophisticated software uses the linearity and reproducibility of our superior hardware to fully automate this task, returning both better and more reliable data than a human ever could.  ​

“The data reduction step has also been based on human interpretation and alignment of spectral data to some kind of purchased spectral library.”  ​

The firm recently released a method of data analysis (CRAFT) that converts the raw, time-based data directly into a spreadsheet.