104
enzymes to improve the quality of the products and reduce the costing of production
(Chandrasekaran et al. 2015).
Pectinase enzyme is applied in the fruit juice industry to decrease the viscosity,
increase the yield and clarification of juice by liquefaction of pulps, and remove the
peels of the fruit. In this process, cell walls will be degraded by pectinases and
increase the yield of the juice. In addition, it helps in the maceration of vegetables
to produce pastes and purees (Garg et al. 2016). Clarification of fruit juice is one of
the crucial applications of acidic pectinase. Generally, the colloids are polysaccharides contained inside the fruit juice that contribute to the fouling problem during
the filtration process (Rai et al. 2004). Therefore, pectinases are utilized for pretreatment of juices to reduce the number of polysaccharides like pectin and starch.
Hence, the viscosity of the juice can be reduced and speed up the filtration process
and enhance the clarity of juice (Oumer 2017). This is due to the crushing of pectinrich fruit juice which stays linked to the fruit pulp in gelatinous structure and hinders the juice clarification process by pressing results in high viscosity juice. Thus,
the addition of pectinase will degrade the gel structures and enhance the juice concentration capacity (Pedrolli et al. 2009). The enzyme treatment can reduce viscosity up to 62%. Compared to undepectinized juice, after ultrafiltering of depectinized
apple juice, the permeate flux is much higher. The accretion of permeation rate
indicates the viscosity and total amount of pectin content is being reduced (Alvarez
et al. 1998). The addition of pectinase enhances the phenolic content being released
from the fruit skin. These phenolic contents contribute to antioxidant effects, conferring the health benefit to the host (Garg et al. 2016).
According to the studies, different fruit juice needs a different type of enzyme
treatment. For example, apples, berries, and grapes need an intense treatment with
a combination of pectinase and cellulases for complete clearance of haze, turbidity,
and viscosity. Fruit juices like orange and pineapple prefer mild pectinase treatment
for the extraction of juice as the main target is to have a high yield of juice but no
intense clarification as these juices are made for the consumer. Enzyme treatment
also improves visibility by preventing the darkening of juice as the unwanted haze
due to pectin fibers is removed. Hence, the color of the fruit juice can be preserved
(Singh 2018).
6.4.3 Coffee Processing
The fermentation of coffee using pectinolytic microorganism removes the mucilage
coat from the coffee beans (Oumer 2017). In general, mucilage from coffee beans
by natural fermentation is removed using water. However, the mucilage breakdown
is always not complete even after long hours of fermentation. If the coffee beans are
fermented for very long hours, stinker beans will be produced. Uncontrolled fermentation and incomplete mucilage removal contribute to the bad quality of coffee
(Oumer and Abate 2017). Therefore, pectinase enzyme can be used to enhance the
removal of mucilage coat from coffee beans.
H. Suhaimi et al.
enzymes to improve the quality of the products and reduce the costing of production
(Chandrasekaran et al. 2015).
Pectinase enzyme is applied in the fruit juice industry to decrease the viscosity,
increase the yield and clarification of juice by liquefaction of pulps, and remove the
peels of the fruit. In this process, cell walls will be degraded by pectinases and
increase the yield of the juice. In addition, it helps in the maceration of vegetables
to produce pastes and purees (Garg et al. 2016). Clarification of fruit juice is one of
the crucial applications of acidic pectinase. Generally, the colloids are polysaccharides contained inside the fruit juice that contribute to the fouling problem during
the filtration process (Rai et al. 2004). Therefore, pectinases are utilized for pretreatment of juices to reduce the number of polysaccharides like pectin and starch.
Hence, the viscosity of the juice can be reduced and speed up the filtration process
and enhance the clarity of juice (Oumer 2017). This is due to the crushing of pectinrich fruit juice which stays linked to the fruit pulp in gelatinous structure and hinders the juice clarification process by pressing results in high viscosity juice. Thus,
the addition of pectinase will degrade the gel structures and enhance the juice concentration capacity (Pedrolli et al. 2009). The enzyme treatment can reduce viscosity up to 62%. Compared to undepectinized juice, after ultrafiltering of depectinized
apple juice, the permeate flux is much higher. The accretion of permeation rate
indicates the viscosity and total amount of pectin content is being reduced (Alvarez
et al. 1998). The addition of pectinase enhances the phenolic content being released
from the fruit skin. These phenolic contents contribute to antioxidant effects, conferring the health benefit to the host (Garg et al. 2016).
According to the studies, different fruit juice needs a different type of enzyme
treatment. For example, apples, berries, and grapes need an intense treatment with
a combination of pectinase and cellulases for complete clearance of haze, turbidity,
and viscosity. Fruit juices like orange and pineapple prefer mild pectinase treatment
for the extraction of juice as the main target is to have a high yield of juice but no
intense clarification as these juices are made for the consumer. Enzyme treatment
also improves visibility by preventing the darkening of juice as the unwanted haze
due to pectin fibers is removed. Hence, the color of the fruit juice can be preserved
(Singh 2018).
6.4.3 Coffee Processing
The fermentation of coffee using pectinolytic microorganism removes the mucilage
coat from the coffee beans (Oumer 2017). In general, mucilage from coffee beans
by natural fermentation is removed using water. However, the mucilage breakdown
is always not complete even after long hours of fermentation. If the coffee beans are
fermented for very long hours, stinker beans will be produced. Uncontrolled fermentation and incomplete mucilage removal contribute to the bad quality of coffee
(Oumer and Abate 2017). Therefore, pectinase enzyme can be used to enhance the
removal of mucilage coat from coffee beans.
H. Suhaimi et al.