Applications of Pectinases
Over the years, pectinases have
been used in several conventional industrial processes, such as textile,
plant fiber processing, tea, coffee, oil extraction, treatment of industrial
wastewater, containing pectinacious material, etc. They have also been
reported to work on purification of viruses and in making of paper. They are
yet to be commercialized.
Fruit juice extraction
The largest industrial application of pectinases is in fruit juice extraction and clarification. Pectins contribute to fruit juice viscosity and turbidity. A mixture of pectinases and amylases is used to clarify fruit juices. It decreases filtration time up to 50%. Treatment of fruit pulps with pectinases also showed an increase in fruit juice volume from banana, grapes and apples. Pectinases in combination with other enzymes, viz., cellulases, arabinases and xylanases, have been used to increase the pressing efficiency of the fruits for juice extraction. Vacuum infusion of pectinases has a commercial application to soften the peel of citrus fruits for removal. This technique may expand in future to replace hand cutting for the production of canned segments. Infusion of free stone peaches with pectinmethylesterase and calcium results in four times firmer fruits. This may be applied to pickle processing where excessive softening may occur during fermentation and storage.
Pectinases have been
used in conjunction with amylases, lipases, cellulases and hemicellulases to
remove sizing agents from cotton in a safe and ecofriendly manner, replacing
toxic caustic soda used for the purpose earlier. Bioscouring is a novel
process for removal of noncellulosic impurities from the fiber with specific
enzymes. Pectinases have been used for this purpose without any negative
side effect on cellulose degradation.
of plant bast fibers
Bast fibers are the
soft fibers formed in groups outside the xylem, phloem or pericycle, e.g.
Ramie and sunn hemp. The fibers contain gum, which must be removed before
its use for textile making. The chemical degumming treatment is polluting,
toxic and non-biodegradable. Biotechnological degumming using pectinases in
combination with xylanases presents an ecofriendly and economic alternative
to the above problem.
Pectinases have been used in retting of flax to separate the fibers and eliminate pectins.
food processing industries release pectin, containing wastewaters as
by-product. Pretreatment of these wastewaters with pectinolytic enzymes
facilitates removal of pectinaceous material and renders it suitable for
decomposition by activated sludge treatment.
Pectinase treatment accelerates tea fermentation and also destroys the foam forming property of instant tea powders by destroying pectins. They are also used in coffee fermentation to remove mucilaginous coat from coffee beans.
Paper and pulp industry
Pectinases are used in
the enzyme cocktail, used for the production of animal feeds. This reduces
the feed viscosity, which increases absorption of nutrients, liberates
nutrients, either by hydrolysis of non-biodegradable fibers or by liberating
nutrients blocked by these fibers, and reduces the
Purification of plant viruses
Citrus oils such as
lemon oil can be extracted with pectinases. They destroy the emulsifying
properties of pectin, which interferes with the collection of oils from
citrus peel extracts.
of chromaticity and stability of red wines
Pectinolytic enzymes added to macerated fruits before the addition of wine yeast in the process of producing red wine resulted in improved visual characteristics (colour and turbidity) as compared to the untreated wines. Enzymatically treated red wines presented chromatic characteristics, which are considered better than the control wines. These wines also showed greater stability as compared to the control.
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Last update: 05-July-2007