Have you looked in your shopping basket recently?
Written by: Bernd Schaefer
Hi, my name is Bernd Schaefer and I’m the technical specialist in Germany for Malvern’s separations products, which basically means I’m responsible for the Viscotek Gel Permeation/Size Exclusion Chromatography (GPC/SEC) systems.
Like many people I spent time last weekend shopping for food. With my work in mind at one point, it occurred to me during my culinary excursion to marvel at just how many food products contain polymers; natural polymers such as starches, carrageenans, alginates and of course proteins. As a technical specialist, I receive many of these sorts of samples each week for analysis. Since the molecular weights of the polymers are so closely tied to their physical properties, there is a much interest in their characterization.
I don’t normally go about linking my working life with the weekend shop! This time, though, I did find myself thinking about the effort that must have gone into formulating each of the products in my basket, and whether the lab work I’d done was eventually giving me a tastier ice cream that didn’t melt before I got home.
Carrageenans for example, are high molecular weight polysaccharides used as emulsifiers. Extracted from seaweed, this additive is widely used in; ice creams, milk shakes and desserts to increase viscosity; beer to improve clarity; and toothpaste to prevent components separating from one another.
Of course, additives with molecular weights below the limits specified by the FDA in its guidance for industry are considered toxic. However, we can be sure that where there are concerns the authorities tend to err on the side of caution. For example, the Joint FAO/WHO expert committee on food additives believes that, “based on the information available, it is inadvisable to use carrageenan … in infant formulas”. This is because, although the average carrageenan molecule weighs over 100,000 Da, the poligeenans which may result following exposure to high temperatures and acidity, have a molecular weight of less than 50,000 Da.
Digging out the data
For those interested in the connection between molecular weight and food analysis, please feel free to explore our online knowledge bank at: www.malvern.com Or, if you have anything you wish to ask me directly, please use the comment box below.