Dynamic interfacial tensions of dietary oils

For the characterisation of dietary oils various parameters are used. Although many applications in food technology, and also the process of fat digestion are controlled by interfacial properties, only very rarely interfacial properties are investigated. However, the interfacial tension and in particular its dynamics are very sensitive to the quality of an oil. We show that the short time dynamic interfacial tension is a very suitable property to classify oils and to follow their properties during a process like frying. The drop volume method as a simple methodology works well along the very powerful drop profile analysis tensiometry. The different dietary oils studied here show an interesting variety of dynamic interfacial tensions. We also propose a procedure that allows estimation of the amount of natural bio-surfactants present in the oil samples.

Graphical abstractDynamic interfacial tension of sunflower oil against water as original sample and after frying of 100 g and 10 times 100 g potatoes. Interfacial tensions are useful information to characterise the properties of dietary oils.Figure optionsDownload full-size imageDownload as PowerPoint slide