- molecular gastronomy and the science of cooking
Audio & video
Films and Docu's
Aroma & taste
Reference & techniques
Last updated 2010-08-09
|Searing is not sealing
Many cookbooks still recommend that a piece meat should be seared at high temperature to seal the juices. This is one of the most widespread kitchen myths and can be traced back historically to the German chemist, Justus von Liebig, who was convinced that high temperatures would coagulate surface proteins in the meat and thus seal of the surface to prevent further loss of juice from the meat. In his book "The Curious Cook", Harold McGee approaches the problem scientifically. He weighs slices of beef before and after cooking and what he finds is that meat that has been seared in fact looses more of the original weight than meat which is cooked at a lower temperature. The reason for this is that as the meat is heated, the proteins coagulate and squeeze water out of the muscle.
Despite this fact, it is still recommended to sear a piece of meat at high temperature. But this has to do with taste. When the temperature rises above 110-120 °C, proteins and amino acids start to react with sugars present. This reaction is known as the Maillard reaction, named after the French chemist Louis-Camille Maillard. The Maillard reaction produces characteristic brown and golden colors plus a large number of taste and aroma molecules. To understand the importance of the Maillard reaction, just think of the huge difference between meat cooked in boiling water and meat cooked in a skillet at a temperature above 120 °C. The Maillard reaction is not limited to the cooking of meat. We also find products of the Maillard reaction in potato chips, bread crust, fried onions - to mention just a few. Even in vintage champagne, one can find products of the Maillard reaction. Despite the fact that the champagne is not heated to above 120 °C, storing it for several years compensates for this. Put simply, at lower temperatures, the Maillard reaction simply takes much longer. For vintage champagne, the Maillard reaction can take several years to develop the characteristic compounds.
Check out the book lists on molecular gastronomy and food chemistry.
Aroma, taste and flavor pairing
When we say that something tastes nice, what we are talking about has more to do with smell than with taste. It is estimated that 20% of a tasting experience comes from taste, that is from the tongue, whereas 80% comes from the smell or the aroma. Our tongue has about 9000 taste buds that are capable of detecting sweet, salt, sour and bitter (in order of increasing sensitivity). In comparison, we have around 5-10 million cells or receptors capable of detecting smell. There are about 1000 different smell receptors and they allow us to distinguish more than 10.000 different smells! This is possible because a specific volatile molecule can trigger more than one receptor. It is the combined response from these receptors that we perceive as a certain smell. The Nobel Prize in medicine for 2004 was awarded to Linda Buck and Richard Axel for their "discoveries of odorant receptors and the organization of the olfactory system".
Based on the fact that aroma of foods is so important for the way we perceive them, a hypothesis can be put forward: if the major volatile molecules of to foods are the same, they might taste (and smell) nice when eaten together. Heston Blumenthal has searched a commercial database with information on the contents of more than 7000 volatile molecules in several hundred different foods. Based on this, he has come up with a number of unusual combinations (from egullet.org and other sources). The links are to Heston Blumenthal's own recipes.
They all go surprisingly well together, and I guess the challenge for the cooks is to find a suitable way of presenting these dishes. I have only tried them in the simplest possible combinations
Remember to check out the books about aroma and taste.
Tags: molecular gastronomy, food science, popular science, cooking, food, chemistry, gastronomy, Heston Blumenthal, Fat Duck, flavor pairing, aroma, taste, Maillard