Additives and molecular gastronomy: a little clarification
A few years ago, there was a huge debate on molecular gastronomy. Some people looked suspiciously at those creative dishes and complained about the use of food additives. What a terrible term. If, instead, it was said that molecular chef used vitamins and natural extracts, the perception would have been drastically different. But scientists are not good at marketing, so the term "chemical additive" was used, which btw is the same employed by the food industry. Already the word "additive" is not very appealing, but adding "chemical" just gives the final blow.
For both science and common sense's sake, let's try to shed some light on additives. Specifically, we will see those employed by molecular chef.
Additives, in general.
What is a food additive? For convenience, I quote the definition reported on Health Canada's website:
"A food additive is any chemical substance that is added to food during preparation or storage and either becomes a part of the food or affects its characteristics for the purpose of achieving a particular technical effect."
Basically, it's a compound that doesn't take any part in the recipe, but gives the food a specific effect (e.g. color, texture...). For instance, sometimes yogurts are added with gelatin, whose role is just making them thicker. Preparation of yogurt does not require gelatin, which is just added to achieve a certain texture, maybe more appealing to consumers. In this case, gelatin acts as an additive.
What if I tell you that a lot of additives are "natural" (with natural I mean already existing in nature) substances? Would you see them under a different light? Check the list of additives reported on the FDA website: as you can read, certain vitamins as carotenoids are used as coloring agents. Do you know what is another term used for vitamins? Chemical compounds. Less reassuring, right? Still natural substances are chemical compounds, as the food we cook is made of atoms that, in turns, compose the molecules. When we cook, we just modify the chemical-physical structure of food. Molecular gastronomy tries to explain those facts.
Terminology is crucial, not just as a matter of clarity, but also for the emotional impact. Scientists might use scary technical terms (additive, chemical compound), while pro marketers know which words are appropriate (natural substance, if that's the case). Often, we mean the same thing, but the terminology we select might have a totally different impact on a general audience.
Be careful, if the term "chemical compound" shouldn't freak you out, the epithet "natural substance" is not synonymous of food safety. Just think about the toxins produced by certain species of mushrooms...
Let's try, thus, to make peace with chemistry that has the only fault of studying matter the and its reactivity.
Additives used in molecular gastronomy.
Let's be more specific and see which are the additives used in molecular gastronomy and why we shouldn't fear them.
Gelatin
We spoke about that in the gels' post. Gelatin is a protein (collagen) extracted from animal tissues. Thanks to its jellifying properties, gelatin is used to prepare panna cotta, puddings, aspics and so on...it is used as an additive to achieve a thick texture (see the yogurt example reported above). Maybe not everybody uses gelatin, but I believe no one would freak out in front of an indulgent panna cotta :)
Pectin
It's a polysaccaride present in the vegetable cell walls and has jellifying properties. When you make a jam, you simply extract pectin from the fruit. For a quicker result, you can add pectin in powder (surely, available at your grocery store) that allows a fast jellification of your jam. Pectin is also employed in the preparation of fruit pastes. Be careful though: pectins jellify in an acidic environment! If you mistake the pH, you might end up with a liquid mass that will never jellify.
Alginates
They are still polysaccarides, again with jellifying properties. Alginates are extracted from algae and they come in different forms commercially available. They are widely used by molecular chef for spherification, a technique that allows making little spheres, similar to caviar, starting from juices or liquids in general. I will talk about this technique in another post, stay tuned!
N2O, nitrous oxide
Used as propelling gas in whipping siphons, it is employed to make foams. N2O is present in the terrestrial atmosphere, in low percentage though. Thanks to its solubility in fats, it is employed as propelling gas in the spray whipped cream. N2O is also known as laughing gas. I got some N2O when I was in labor, but, honestly, I didn't laugh at all :P No worries, though: concentration of the gas in foams is too low to provoke that effect.
Liquid nitrogen
Not a real additive. It is employed for the preparation of a "molecular" ice cream. Thanks to the extremely low boiling point (about -195,82 ˚C), it allows a quick cooling of the liquid mixture without the formation of big ice crystals. The result is a soft ice cream and, paradoxically, not...frozen. Nitrogen is the most abundant gas of the terrestrial atmosphere (about 78%), we breath it every day. Handling liquid nitrogen requires extra care, but I won't be concerned on the final product.
Lecithin
It is contained in both egg yolk and soy, and finds a large employment as emulsifier. Lecithin is crucial for the preparation of light foams, which are usually made from juices (e.g. lemon juice) or other very low-fat liquids. Because of the low-lipid content, the whipping siphon can't be employed for the production of these types of foams. The juice is, thus, added with lecithin that, being an emulsifier, has both a hydrophilic (affinity for water) and a hydrophobic (affinity for fats) parts. The hydrophilic part binds the liquid, while the hydrophobic one the air, allowing the incorporation of air bubbles. Most of the lecithin is extracted from soy.
I hope that you found this article useful and that you can look molecular gastronomy with different eyes now :) I will dedicate future posts to the explanation of a few techniques used in molecular cuisine.