Molecular gastronomy (which amusingly, is almost a homonym with molecular astronomy), as popularised by Ferran Adrià and Heston Blumenthal, is an extremely interesting field. It’s interesting because, among other reasons, it shakes up your perception of food and how to cook it. A lot of hype and attention has been given by the media in recent years to “chemical additives” in food and the general vilification of so-called “E-numbers”. Of course, with everyone telling you that E-numbers are evil, you stop questioning it. But that’s a sweeping generalisation…
E-numbers are just food additives. Some are rather unpleasant or generally horrible synthetic chemicals, yes, but others are perfectly harmless. Actually Oxygen is E948. Just try cutting that one out of your diet. I’m sure most people don’t mind E1510 either, as that’s the number for ethanol. This little intro seems slightly superfluous, I’ll admit, but it seemed necessary given I’m about to list (complete with E numbers if there are any) a few of the more common molecular gastronomy reagents.
And yes, by reagents, I do mean ingredients.
- Lecithin (E322)
Used as an emulsifier, lecithin is a virtually non-toxic mix of surfactants (including fatty acids, glycerides, phospholipids and choline). It can also be totally metabolised, so it’s easy on the kidneys.
- Sodium Alginate (E401), Potassium Alginate (E402)
Another emulsifier with no discernible taste or odour. Alginate is a viscous copolymer gum made from the cell walls of brown algae. It’s used commonly as a thickener and is an essential reagent in ‘sphereification’.
- Sodium Citrates (E331)
Used as a ‘sour salt’ for tartness, acidity or both. It can also be used as an acidity regulator, a preservative, and is often used as an antacid.
Thickeners / Gelling Agents
- Agar (E406)
Most biologists will be familiar with agar. It’s an unbranched polysaccharide made from red seaweed, and makes a very good vegetarian gelatin substitute. It’s used as a clarifying agent, as well as a thickener for soups, jellies, ice creams and a japanese dessert called anmitsu.
- Carrageenan (E407)
Taking it’s name from a common type of irish seaweed, carrageenan is a sulphated polysaccharide also taken from red seaweed. It’s molecules can form a range of different gels in the presence of cations. Used as a thickener, stabiliser and clarifyer, it has pseudoplastic properties which make it easy to pump or pour, but allowing it to stiffen again afterwards. This tuff is used in everything from toothpaste to ice cream.
- Guar Gum/Guaran (E412)
Made from guar beans, this stuff acts as an emulsifier in the presence of calcium ions. It is a non-ionic hydrocolloid, which can act as a thickener and a binder for meats. Guar is especially good to use in ice creams and sorbets as it retards ice crystal growth.
Arrowroot powder can also be used as a thickener, creating a thin gel. It works as an excellent gluten-free substitute for cornstarch, but care should be taken to avoid overcooking it, which will cause it to liquify again. It’s a good idea to mix it into a cold liquid before adding it to the pan. Remove from heat as soon as it starts to thicken.
Arrowroot will also retard ice crystal growth.
- Pectin (E440)
A gelling agent that everyone should be familiar with. It’s found naturally in several types of fruit, and is the gelling agent used for jams and preserves. It’s also a stabiliser and a source of dietary fibre.
Sugars / Sweeteners
- Isomalt (E953)
Used as a natural sugar substitute, it’s not as sweet as sucrose and is lower in calories. Isomalt doesn’tpromote tooth decay and is less prone to crystallisation. As with a lot of sweeteners, excessive amounts may cause gastric distress.
The sweetest natural sugar, found in virtually every type or fruit. Treat exactly as regular sugar, except with a lower glycemic index (so it’s recommended for diabetics).
- Glucose (Dextrose)
The simplest (and most easily metabolisable) of all sugars. It’s not as sweet as sucrose and is useful because it melts and caramelises at only 150°C. Glucose can also be useful in making syrups because it inhibits the crystallisation of other sugars.
- Calcium Chloride (E509)
Useful in adding the flavour of salt, without adding sodium. It’s used mainly as a source for calcium ions or divalent cations (where required). It’s also essential in the process of sphereification.
Basically, it’s just cake icing. It’s used to make a number of things, including El Bulli’s croquant (2 parts fondant to 1 part each of glucose and isomalt).
- Glycerol (E422)
Glycerol (or glycerine) is a viscous sugar alcohol. It’s sweet tasting, has low toxicity (much lower than ethanol). It can be used to make glycerites – liquid extracts of herbs in glycerol. Glycerites extract sugars, enzymes, glucosides, bitter compounds, saponins and tannins. It’s main use is as a humectant.