A research team from the Leibniz Institute for Food Systems Biology at the Technical University of Munich (LSB) has succeeded in automating an established method for the gentle and artifact-free isolation of volatile food ingredients. As the team’s current comparative study shows, automated solvent-assisted aroma evaporation (aSAFE) offers significant advantages over the manual process. It achieves higher yields on average and reduces the risk of contamination by non-volatile substances.
The optimized method is particularly important for odor analysis. Flavorings contribute significantly to the sensory profile of food and have a major impact on food enjoyment. Therefore, knowledge of the key odorants that shape food flavor is of interest both for analytical quality control and targeted product development in the food industry.
Extracting volatile compounds from food is anything but trivial
However, extracting volatile compounds from food is not so easy. Many known methods result in the loss of labile odorants as well as odor artifacts and are therefore unsuitable for odorant research. The manual SAFE technique, developed in 1999, made it possible for the first time to easily isolate even heat-labile odors from food without the formation of artifacts. “This is an important prerequisite for the use of further analytical methods to identify the key odorants,” says Philipp Schlumpberger, who participated in the study together with Christine Steubner. Both are currently working on their PhDs at LSB.
Today, manual SAFE is standard procedure in fragrance research worldwide. However, the research team saw the need for optimization in the ease of use, in the yield achieved and in reducing the risk of transfer of non-volatile material that could significantly interfere with subsequent analytical steps.
The valve is critical
“As we found, the problems are mainly related to the manual control of the valve on the drip funnel. So we replaced it with an electronically controlled pneumatic valve. To fully automate the SAFE apparatus, we further extended it with an automatic liquid nitrogen refill system, as well as an end point detection system and shutdowns,” explains Martin Steinhaus, head of the LSB Section and Working Group.
The team’s research shows that installing an automatic valve increased yields, especially for lipid-rich food extracts and fragrances with relatively high boiling points. In addition, operator errors that can lead to contamination of isolates with non-volatile substances in the manual version are avoided by the automated SAFE.
“In the meantime, the automated SAFE has replaced the manual option in our laboratories. Other academic and industrial research groups are already following our example,” says principal investigator Martin Steinhaus.