The Microscopic Structure of Crunchy and Crispy Jellyfish

The empirical world of gastronomy is full of fascinating transformations of food material. This applies to the types of dishes served in high-end restaurants as well as traditional preparations of food served around the globe. Whereas the impact of delicious food on everyday human wellbeing is indisputable, our scientific understanding of gastronomic phenomena is surprisingly limited.

Using tools from modern biophysics and -chemistry, we aim at gaining a better understanding of the (supra-) molecular behavior of the types of biological soft matter materials that food is, and at relating the molecular properties of food with our sensory experience while eating.

As an example, we have studied jellyfish - a food material mostly uncommon to the Western palate, but a delicacy in traditional Asian cuisine having a gastronomic history of more than a thousand years. It is eaten mainly for its interesting crunchy mouthfeel resulting from a month-long salt preservation using sodium chloride and alum. This preservation drastically changes the texture of the jellyfish from being gel-like to resembling that of pickled cucumbers.

We have used state-of-the-art two-photon microscopy and super-resolution STED microscopy to visualize the rearrangements in the filamentous network constituting the jellyfish mesoglea gel during the transformation from a soft gel to a crunchy texture. We further interpret our data in light of polyelectrolyte theory and a modified Flory-Higgins theory that describes ionic gel collapse in poor solvent to suggest an alternative preservation method. Using ethanol, we thus have created what can be classified as jellyfish chips that has a crispy texture and could be of potential gastronomic interest.