ENZYMES IN FOOD PROCESSING

Nupur AgarwalAmity Institute Of Food Technology, Noida, Uttar Pradesh ,Sector 125,India

A protein catalyst that speeds up a chemical reaction.

Lowers the activation energies of a substance

reactants

products

H

EA

T.S.

catalyst

Enzyme combines with a substrate to a form new products

Substrate- something that combines with the enzyme

enzyme

substrateproducts

pH Temperature Easily inactivated

(denatured) in presence of inhibitors (Lead Poisoning)

EFFECT OF PH

Enzymes are affected by changes in pH. The most favorable pH value - the point where the enzyme is most active - is known as the optimum pH.

Extremely high or low pH values generally result in complete loss of activity for most enzymes.

Like most chemical reactions, the rate of an enzyme-catalyzed reaction increases as the temperature is raised. A ten degree Centigrade rise in temperature will increase the activity of most enzymes by 50 to 100%.

Most animal enzymes rapidly become denatured at temperatures above 40°

If the amount of the enzyme is kept constant and the substrate concentration is then gradually increased, the reaction velocity will increase until it reaches a maximum. After this point, increases in substrate concentration will not increase the velocity

Names usually end in –ase. Usually named after substrates or

the chemical reaction lactose --- lactase

Cause food spoilage (rotting). Changes in flavor, color, texture

and nutritional properties. Can be inactivated by heat to

extend storage stability of foods. Used for fermentation

ON THE BASIS OF CHEMICAL REACTIONS CATALISED

Enzyme class Catalyzed reaction And Examples____________________________________________________Oxidreductases Oxidation-reduction reaction Dihydrogenases Oxidases Peroxidases OxigenasesH2O2 +.H2O2 = O2+2H2OTransferases Transfer of functional group Methyltransferases Glycosyltransferases Acyltransferase ATP +D GLUCOSE =ADP+D GLUCOSE 6 PHOSPHATEHydrolases Hydrolytic reactions esterases glycosidases peptidases

Lyases Group elimination (forming double bonds) Decarboxylases HydrolyasesMALATE =FUMARATE+H20Isomerases Isomerization reaction Racmaces L ALANINE =D ALANINE Ligases Bond formation coupled with a triphosphate cleavage DNA ligase

ENZYME SOURCE RELATIVE AMOUNTS

Polygalacturonase tomato 1.00

Pineapple 0.024

carrot o

grape o

Lipoxygenase soybeans 1.00

peas 0.35

wheat 0.02

peanuts 0.01

Peroxidase Green peas 1.00

spinach 0.32

ENZYMES USED IN STARCH INDUSTRY

1.Production of high fructose corn syrup and sweeteners.

FEEDSTOCK PRODUCT ENZYME(S)

STARCH CORN SYRUPS α-AMYLASES,PULLULANASE

GLUCOSE α-AMYLASE,GLUCOAMYLASE

FRUCTOSE а-AMYLASE,GLUCOAMYLASE,GLUCOISOMERASE

starchα-amylase dextrins glucoamylase glucose fructoseisomerase

ENZYMES USED IN MILK AND DAIRY PRODUCTS

ENZYMES FUNCTIONS

Chymosin Milk coagulation

Proteases Flavour improvement, decrease ripening time of cheeses

Lipases •Same as above

Sulphydryl oxidase

Remove cooked flavour

β-Galactosidase Lactose removal

Proteases Soyabean milk coagulation

ENZYMES IN BAKING

PURPOSE

Amylase Maximise fermentation purpose;prevent staling

Protease Improve handling and rheological properties

Glutamyl transferase Improve dough elasticity;retention of bread softness on storage

ENZYMES

ENZYMES IN BREWING

ENZYME PURPOSE

amylase(α and β)

Convert starch to maltose and dextrins

Proteases Hydrolyze proteins to amino acids;used by yeast to grow

Papain Chill proofing beer

Quality has been defined as degree of excellance which includes colour,texture,flavor and aroma

Three key enzymesresponsible for chemical alterations of pigments in fruits and vegetables areENZYME PURPOSE

Polyphenol oxidase Undesirable:-browning of apple,banana,potatoes.mushrooms.

Lipoxygenase Desirable:-bleaching and soyabean flours;formation of disulphide bonds in gluten during dough formationUndesirable:-development of off flavours and off aromas;damage vitamins andproteins ;oxidation of essential fatty acids

Textural factors include hand feel and mouth feel of firmness ,softness, juiciness, chewiness and grittiness .

ENZYME PURPOSE

Amylases(α,β) effect viscosity of starch based food like bread, ice cream etc

Proteases 1.Chymosin .Milk (curdling).2. gluten proteins of wheat bread dough (quality).3.Meat( tender and juicy).

Enzymes cause off flavors and off aromas in foods, particularly during storageENZYME PRODUCT

Lipoxygenase English green peas,grean beans, and corn

Cystine lyase Broccoli and cauliflower

naringin Grapefruit its juice(bitter taste)

Enzymes do have a role to play in nutritional quality of food.

ENZYME EFFECT

Lipoxygenase Decrease the amount of essential fatty acids in foods.Decrease carotenoids,Vit E,Vit C etc (due to free radicals produced during oxidation)

Polyphenol oxidase

Decrease available lysine content of proteins(browning)

World enzyme market

Detergents

Animal feed

Starch

Rennet

Textiles

Food

Diagnostics

Other