Молекулярная гастрономия для креативных шеф-поваров (англ. язык) - страница 15

Молекулярная гастрономия для креативных шеф-поваров (англ. язык)

The large number of different molecules produced are responsible for the characteristic smells and

taste of the common caramel. When caramels are prepared in the presence of ingredients containing

proteins or amino acids (like cream or milk), in addition to caramelisation, the sugars will react with

amino acids from the proteins to produce an even greater variety of flavours and colours.

However, table sugar is often replaced by sugar substitutes, like aspartame. When this molecule is

heated, some of the aspartame molecules break down into an aspartic acid sugar unit and a

phenylalanine unit. These two sugars are not associated with this appreciated “caramel-taste” and

furthermore, aspartic acid has a slightly bitter taste.

Effect of acid

When a disaccharide such as sucrose is heated in the presence of acid, it will break down into its

component sugars. This is because the glycosidic bond that joins the two sugar units together is

broken down. Breaking a dissacharide up in this way is known as inversion, and has uses in the

kitchen, especially in making sweets because it reduces the amount of crystallisation.

Monosaccharides, by contrast, are little affected by pH because all the bonds in their structure are

very strong covalent bonds, which are not readily broken down in acid, and require very high

temperatures before they will start to break down.

Reactivity with proteins

Simple sugar molecules are also able to react with the subunits of proteins (called amino acids). When

an amino acid and a simple sugar meet, there is a rearrangement of atoms, and some atoms are

released (usually two hydrogen atoms and an oxygen atom, which forms a water molecule). New

molecules are formed from what remains. This simple reaction can produce many different new

molecules depending on which rearrangement has occurred. Furthermore, these newly formed

molecules can either break down to form other new compounds, or react further with each other to

produce other new molecules, or even react with other molecules if they are present (such as the fats)

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