What are the types of Non enzymatic browning maillard reaction

Non enzymatic browning maillard reaction is the product of a non enzymatic and an enzymatic browning reaction. The reaction may be seen in temperatures below the boiling point of water or in the presence of reducing sugars such as glucose, fructose, or galactose. It is associated with many tastes in foods where sugars and amino acids are present.

Types of Non enzymatic browning maillard reaction

1. Defatted Maillard reaction

This is the reaction that occurs in early stages of processing where sugar is removed from the food. This is a major cause of nonenzymatic browning maillard reactions because it involves lipids and carbohydrates. Lipids begin to oxidize due to heat and oxygen which adds free radicals to the mixture. The oxidation adds dark brown color to food and a more desirable taste for many products. Both sugars and proteins can act as reducing sugars that react with free amino acids or other reducing sugars to produce substances with a wide variety of textures, flavours, and colours.

2. Intramolecular Maillard reaction

This is when two amino acids form an aldol condensation and then polymerize with other aldol condensates to form dark brown gels. A reducing sugar (such as fructose or glucose) is needed for the reaction and the products are usually found in the foods like cheeses, breads, cakes, or dried fruits.

3. Inverted Maillard reaction

This is the same as intramolecular maillard reaction but inversion occurs by heat which causes enolization. The products are found in bread crust, bread crust colour, instant noodle colour and Chinese noodles colour.

4. Strecker degradation

The Strecker degradation is a reaction between carbonyl compounds (aldehydes, ketones and carboxylic acids) and amines to produce a wide range of flavoured products. It is also called the Maillard-Strecker reaction or the browning reaction. It is responsible for most of the flavor in cooked meat, including beef, ham, pork, turkey and chicken.

Mechanism of this reaction

In addition to the above reactions, other reactions of this are occurring simultaneously. For example, nonenzymatic browning maillard reaction may occur near the surface of beef products and result in a dark color and bitter taste (some people like the taste). On the other hand, there is an enzymatic browning reaction which is responsible for a lighter colour (notably with pork) because it involves glycosidase which breaks down melanoidins.

Nonenzymatic browning maillard reaction also occurs in many vegetables and fruits during storage after harvesting. The browning reactions during storage are influenced by oxygen, temperature and light. The major reactions of this reaction include hydroxylation of the phenolic compound (such as chlorogenic acid), oxidation of the hydroxycinnamic acids and cleavage of pyruvate carboxylase. Nonenzymatic browning maillard reaction also occurs in bread crust when bread is exposed to reducing sugar present in the dough at high temperatures such as from steam during baking. This reaction is different from intramolecular maillard reaction because it produces an endothermic peak at increased temperature.

Applications of Non enzymatic browning maillard reaction

1. It is used to give a good colour, flavour and aroma to foods.

2. The color formed is important in regulation of food quality and food security. It is also used by law enforcement in detecting adulteration of products such as flour or baking powder.

3. It can be used to heat-process fruits and vegetables so that they are easily eaten by people with dentures. It is also used to produce additional aroma in food.

4. It is used to make artificial leather because it adds colour to the raw leather and gives an even texture.

5. It is also used in the production of soft drink sweeteners and alcoholic beverages as a colour enhancer.

6. The portion of foods that are exposed while they are being transported may deteriorate due to this reaction occurring during transportation, particularly when it is exposed to sunlight, especially if there are high levels of sugar present such as sugar cane or sugar beet juice (raw sugar), milk (raw milk), fruit juices (fresh fruit juices), or condiments (raw condiments).

7. The primary purpose of this reaction is to enhance flavor and sometimes colour, freshness and texture in foods produced. Applications vary by product type, but examples include natural tobacco flavouring; beer flavouring; flavours in confectionery products such as applesauce and chocolate; flavour enhancers in recipes for cakes, cookies, ice cream and pies; cocoa colouring; dried fruit colours; and colourants for the production of foodstuffs.

In conclusions, non enzymatic browning maillard reaction is a reaction that not only occurs in heat treated foods but also in foods that are stored and transported. This reactions play a vital role in the production of food quality, taste, aroma and flavoring.