Enzyme application in food processing has become an industry standard. Endogenous enzymes are critical in food processing. Let us consider an example of each category of enzymes to discuss the enzyme application in fruits and vegetables processing.
Endogenous enzymes naturally exist in food and may affect the quality of the foods (either positively or negatively) by their actions. One of the most cognitive endoenzyme is pectin methyl esterase (PME), which is found in fruits and vegetables. It affects the quality of the final products (such as fruit juices) made from these fruits and vegetables.
Endogenous enzyme application in food processing
This enzyme is applied in texture modification of the thermo-processed fruits and vegetables. This is done by the manipulation of the enzyme using the temperature. For instance, under cold break tomato juice processing, PME rapidly hydrolyses the pectin esters to form methanol, which lowers the pH of the product.
Cold break processes
Cold break processing involves heating the tomato to 60°C to activate the PME. The activated enzyme depolymerizes pectin leading to loss of viscosity and cloudiness in the product. This facilitates separation of solid from liquid components of the juice making the process suitable for manufacturing juices such as tomato juice.
Hot break processes
Hot break processing on the other hand involves heat inactivation of the PME by heating the juice to 90°C. This results in preservation of the pectin, which promotes and stabilizes cloud and viscosity of the product. Hot break processing is utilized in manufacturing of pastes and gels, e.g. tomato paste.
Exogenous enzymes (exo-enzymes) are those enzymes that you add into the food to promote a desirable effect. An example of the exogenous enzyme is pectin esterase; a pectinase that cracks specific bonds in molecules of pectin.
Exogenous enzyme application in food processing
Pectinase (pectin esterase) is very useful in the manufacturing of fruits and vegetables; it breaks pectin. This results into modification of the texture of fruit juices. For this reason, you can use this enzyme in thinning of pastes/juice concentration and to clarify wines.
You may also add pectin esterase during processing to not only increase the yield of fruit juice concentrates but also to gelate the products. Gelation helps in texture modification and improvement of rheological properties of these products.