© 2018 Can Caramelo

Watermelon & Feta Farro Salad

In the last post I left you in suspense. I started to tell you how our brain creates flavour y how flavour is predominantly retronasal smell (when volatile molecules from food in our mouth reach the olfactory bulb through the cavity between mouth and nose). So when these volatile smell molecules get to the olfactory bulb, a characteristic spatial firing pattern is elicited which is specific to each smell. These patterns are sent to the olfactory cortex where a smell object is formed and can be accessed in form of a memory. From there, the pathway of smell leads to the orbitofrontal cortex where the information from different sensory modalities (and even the motor system!) converges to form the perception of flavour. But I still had to answer why we salivate when only imagining food we like, why the smell of food makes us crave it sometimes and why, with a certain food, we might like the smell and maybe even the taste, but ultimately strongly reject it for its texture.

Let’s go with the first one. If we salivate or not when imagining certain food is related to how much we like this food, how much we’d like to eat it and how hungry we are. A monotonous diet can also increase our craving for something different and flavourful. The salivation produced by smelling or imagining something we’d like to eat, is a preparation for its actual consumption, we need saliva to lubricate the food and be able to swallow it. The salivary response to the smell or imagination of a certain food can be understood as classical conditioning – basically the same as Pavlov’s famous dog: first an association between the smell (or mental image) of a food and the process of eating is is created, then the salivary response can occur without the actual eating. But of course it’s not that simple. Because we salivate more if we smell something we really like for instance. And effectively, without any sensory exposure, just imagining a food we like, we often salivate, especially so if we have a vivid imagination (definitely my case).

When we smell something, a memory of that smell activates a memory of a flavour and when we smell something we very much want to eat, the neuronal circuits that are activated are the same as in a drug addiction and include structures like the hippocampus (related to memory), the insula, (a place where inputs from taste and smell are integrated, also involved in memories of flavour and emotional processing) and the caudate nucleus (part of the reward system, important also for sensory-motor integration).

Now, the mouthfeel of food. The tongue and mouth are represented extensively in our brain, providing evidence of their great importance. We have receptors localized on nerve tips that detect how a certain food feels in the cheeks, the tongue, the palate and even our teeth. French fries are usually well accepted when they are crunchy. And who likes a beer without gas or soggy lettuce? There are a few interactions between how a food feels in the mouth and the perception of its flavour. So, spiciness can reduce the perception of other flavours, sensitivity towards flavour molecules is highest with temperatures between 22-37ºC (70-100ºF), viscosity can reduce the perception of retronasal flavour and heat, by reducing viscosity, facilitates stimulation of the taste buds. When a texture is the way we like it and expect it to be, it usually goes quite unnoticed. If, on the contrary, we expect to take a bite of a crisp apple and it turns out to be really mealy, we’ll notice. The molecular cuisine takes advantage of the dissociation of expected texture and flavour to surprise us and draw the attention to the food that is consumed. In fact, the mouthfeel of food is so important that when food is pureed, the detection rate of which food it is turns out to be surprisingly low, only around 30-40%. In the orbitofrontal cortex where the multisensorial information that conforms our perception of flavour converges, there are neurons whose response to a flavour varies according to its viscosity and others sensitive to the fat content in food. But seemingly even cultural aspects influence our preferences for food textures. In the occidental part of the world, slimy gelatinous foods as can be mushrooms, have a bad reputation. The Japanese pay special attention to texture and sometimes favour it over taste. Also, when there is a strong aversion to consistency, it is often due to an association with something less than appealing. The texture of a mushroom for instance could be associated with a slug and this image can be so powerful that it makes it impossible to like the food. In this case, break the association through cognitive restructuring and replace it with something more appetizing can relieve us of the aversion.

I think I answered all the questions. If you have any doubts or if you’re wondering about how anything else works in the brain, let me know in the comments, and I’ll look into it. And now go ahead and make this refreshing salad recipe that combines crunchy watermelon and onion with chewy grains and crisp rocket.

Notes: If watermelon is not in season, it can be replaced with grapes or figs.

For 2 as a main or 4 as a side.

Ingredients

  • 1 cup farro (Or wheat berries, oat grains, pearl barley…), ideally soaked for a minimum of 1h or overnight
  • half watermelon
  • 1 red onion
  • 1 bunch arugula (rocket), organic if possible as it usually has elevated quantities of pesticides
  • 1 package feta cheese (180g/ 6oz)
  • a few sprigs of fresh mint or basil

For the vinaigrette:

  • 2 tablespoons extra virgin olive oil
  • 2 tablespoons balsamic vinegar
  • 1-2 teaspoons maple syrup or honey
  • 1 teaspoon dijon mustard
  • sea salt and freshly ground pepper

Directions
Put the soaked farro and 1 teaspoon salt to boil with 2 cups of water. Boil for 15-30min (depending on how long it has soaked), until you like the texture and drain any remaining water. You can wash it with cold water if you want to cool it quickly. Now cut the watermelon into mouth sized bites, the onion into thin slices, wash the rocket, chop the herbs and add it all to a big serving bowl, on top of the farro. Add all ingredients for the vinaigrette to a small bowl or a little jar and mix. Pour the vinaigrette over the salad and your’re ready to enjoy.

Post a Comment

Your email is never published nor shared.