There are a number of different ways of analysing the fat content of different foodstuffs - the obvious candidates such as dairy products e.g. milk, cream and cheese and the more esoteric subjects like hot dogs and ketchup. Most systems involve the use of solvents and are based around Soxhlet extraction, invented by the admirably named Franz von Soxhlet in 1879.
Solvent-based systems can be time consuming and by definition are costly in reagents. Even systems that perform the different steps: hydrolysis, filtration, washing, in an enclosed system, which does allow for automatic hot hydrolysis fume removal and easier solvent extraction, still only handle around 36 samples per day. Now though sophisticated instruments exist that employ a totally different, solvent-free approach, which can analyse individual samples like dairy and, yes even hot dogs, in 2-3 minutes - as well as simpler oils and fats in seconds.
This approach has opened up new opportunities for Industrial and Research Food Analysis laboratories to become ‘greener’, save money in energy costs, as well as being more productive, by using a combination of microwave drying and Nuclear Magnetic Resonance Imaging.
The microwave drying stage, which also produces extremely accurate measurements of moisture content (0.1 – 99.99% moisture range) is incredibly finely controlled to ensure there is no overheating of the sample. NMR we tend to associate mostly with Magnetic Resonance Imaging for medicine and the amazing diagnostic images it can produce, but it also has a number of important applications in chemistry.
The complete removal of water from the sample by microwaves subsequently enables the pulsed energy of the NMR to produce a signal with minimal interference from water molecules. In this way microwave drying, together with the high performance NMR technology, can produce rapid, accurate results of fat content without the use of solvents.
Plus you don’t need a Ph.D. to operate the equipment. In fact, because this approach doesn’t require any costly or time-consuming calibration steps, and the equipment fits neatly on a bench top, you can simply obtain ‘custom methods’ and then any lab staff can be ready to analyses in hardly any time at all. The only thing that’s missing is a really good name for this approach, but on that score at least Soxhlet is going to take some beating.
To find out about the applications and products used take a look at http://www.fatanalysis.co.uk
To take a look at a product used to analyse fat and moisture in food go to http://www.youtube.com/