[boychef]

Hi everyone,

I was taught in sch to cook the tomato paste when cooking the brown sauce. Something to do with reducing the acidity?

Anyone here knw the real reason why we cook the tomato paste when doing the brown sauce.. thanks.

[deltadoc]

Because Escoffier and/or Careme said so?

doc

[Luc_H]

Hi Boychef,

I don't know if any science was covered in your classes but the main reasons to cook tomato paste would be:
To enhance the browning by cooking out the residual water from the pulp and breakdown the complex sugars in the paste. Broken down sugar become reducing sugars which react with proteins (and amino acids) to create browning (Maillard reaction) and browning typical meaty flavours.

This one is less known but... to release glutamates. Glutamic acid is an amino acid. One of 20 building blocks that make up proteins. Of the twenty aa, glutamic acid, in the presence of salt, becomes monosodium glutamate which is a very potent flavour enhancer (high in Umami). Tomatoes have high amounts of glutamate which probably explains why ketchup is a very popular condiment.

Cooked tomato paste has high amounts of reducing sugars and glutamate.
This combo will enhance the browning of the sauce, meaty taste and overall depth.

Luc H.

[boar_d_laze]

Before the chemistry lesson:

On its own, tomato paste has an offensive, raw taste with a somewhat bitter aftertaste (a result of sulfur derivatives). You need to cook it to get "the raw" off it. Heat makes for a particular kind of good flavor chemistry. However, in brown sauce a.k.a. sauce espagnole paste is not there for flavor -- at least not much. It's there to provide structure. If your espagnole tastes like a tomato sauce, than it's got too much tomato. The taste of tomato should be barely recognizable.

The right way to cook tomato sauce for an espagnole, as for most sauces which aren't going to grow up to be tomato sauce, is by creating something called a pincage in French. As far as I know it has no name in English. After the aromatics are nearly cooked, you push them aside to make a space in the pan, and add the tomato paste to the space. Let the paste sizzle long enough to form a fond on the bottom of the pan, then move the aromatics through the paste to coat, and cook until the color darkens. Et voila! Pincage! At that point, you remove the Gauloise from your Gallic lips, give a Gallic shrug, add flour to make a roux, stirring only in the clockwise direction, every stroke circumscribing a well deduced metric diameter.

With all due respect, AFAIK, Luc's description does not cover the chemistry as it is understood. What you're doing is not "enhancing" a Maillard reaction later, but creating one (or something very much like one) in the paste itself. Bitter, starchy, raw to sweet, deep and finished. "In tomato paste, for example, it was found that changes in aroma [and taste] caused by heating are primarily caused by the formation of dimethyl sulfide, methional, the furanones HD2F and HD3f, and the increase in [beta-]damascene and a substantial decrease in (Z)-3-hexenal and hexanal." [emphasis added] (Food Chemistry by Dieter-Blitz, et al). If you know your food chemistry you know that the furans and damascenes are your friends. IIRC, They are the product of a Maillard or Maillard type reaction, rather than an intermediate step.

Indeed, the raison d'etre of an espagnole is to infuse "browning" and structure into stock. That's why we cook the raw off tomato paste.

I hope everything, now she is clear. Eh, mon ami?
BDL

[boychef]

ah thanks everyone for the chemistry lessons. elementary, my dear watson.. hahas!!

[Luc_H]

It's always an occasion for me to learn more about food chemistry when BDL comments on my explanations. Cool stuff!

Just to state the obvious here (right BDL?)... sulphur containing chemicals are usually very potent smelling that is why they make excellent flavouring compounds. Methional for example is a derivative of methionine an amino acid found in tomatoes. Methional is produced by protein hydrolysis by reducing sugars which liberates the aa methionine then indeed through the Maillard reaction with another reducing sugar creating methional.

Almost all the sulphur found in tomato paste comes from only 2 amino acids (the only ones that contain sulphur anyway): Methionine and Cystine (or cystiene)
Tomato paste contains 4.3% proteins and 18.8% carbohydrates (sugars) meaning that 100g of paste has 4.3g of proteins.
In 4.3g of proteins 0.046g is methionine and 0.027g is cystine
but 2,11g (hmm 50%) is glutamic acid.
Ref: Nutrition Facts and Information for Tomato products, canned, paste, without salt added

Since there is much more sugar then proteins (4:1) in tomato paste then it will be more reactive with other (protein) foods then with itself. That was the point for using the term <enhancing>.

I reinstate, though, that glutamic acid hence glutamate is a major factor when using tomato paste in cooking. Like cheese many people cannot explain why food taste better when you add cheese, tomato paste, soya sauce.... all umami (glutamate) products (because it enhances flavour and make things taste better)

As for the Maillard reaction bit re-explained by BDL... whatever... (I didn't think I had to go in so much details)!!!

Luc H.

[boar_d_laze]

's Cool.

BDL