102
resources for pectin. Deng et al. (2019) reported that ripeness of fruits had significant influence on the drying kinetics, which is related to the modification of physicochemical and pectic properties. The water-soluble pectin content increased as
ripening progressed, but the chelate- and sodium carbonate-soluble pectin contents
gradually declined (Deng et al. 2019).
Now, the most common raw materials for the production of pectin are the residues from the manufacture of fruit juices, including apple pomace and citrus fruits
(Alkorta et al. 1998; Blanco et al. 1999). The extraction of pectin is carried out by
acid hydrolysis at a pH range of 2–3 for 5 h at high temperature (70–100 °C). The
solid-to-liquid ratio is normally about 1:18. The pectin extract is separated from the
pomace using a hydraulic press or by centrifugation. The extract is filtered and
finally concentrated on a standard-setting strength. For powdered pectin preparation, the concentrated liquor is treated with organic solvents or certain metallic salts
to precipitate the polymers (Sakai et al. 1993).
Agro-industrial residues which are primarily composed of complex polysaccharides are also utilized to strengthen microbial growth for the production of industrially important pectinases. During the raw agriculture material processing for food,
a bulk quantity of agro-wastes is generated. Among these agro-residues, dried citrus
peel and orange bagasse contain large amounts of soluble carbohydrates, particularly fructose, glucose, sucrose, and pectin. Citrus peel is known as the major source
of pectinases in several industries instead of apple pomace. A significant quantity of
pectin in citrus peel urges us to use them as a substrate for microorganism to produce pectinolytic enzymes (Ahmed et al. 2016).
6.4 Pectinase Applications
6.4.1 Wine Industry
Wine is a word that evokes emotion in millions across the world. Red and white
wine are fermented drinks highly appreciated worldwide as they present a very
complex composition. They contain a number of specific compounds which are
polyphenols, anthocyanins, polysaccharides, and volatile compounds. In order to
achieve the best wine properties, efficient treatments must be very complex in all
wine production steps such as maceration and clarification. Within this context,
utilization of the enzymes in different steps of winemaking is crucial (Chandrasekaran
et al. 2015). Pectic enzymes are utilized in winemaking from different fruit materials. These enzymes are used at various stages of the winemaking process, especially
the crushing of fruits. Enzyme treatments during the crushing of fruits will increase
the yield of the juices and reduce the pressing time. In addition, enzyme treatment
helps to improve the color yield due to the extraction of pigments. Furthermore, the
addition of enzyme before or during fermentation helps to settle out undesirable
microbes with suspended particles. As a result, a better quality of wine is being
H. Suhaimi et al.
resources for pectin. Deng et al. (2019) reported that ripeness of fruits had significant influence on the drying kinetics, which is related to the modification of physicochemical and pectic properties. The water-soluble pectin content increased as
ripening progressed, but the chelate- and sodium carbonate-soluble pectin contents
gradually declined (Deng et al. 2019).
Now, the most common raw materials for the production of pectin are the residues from the manufacture of fruit juices, including apple pomace and citrus fruits
(Alkorta et al. 1998; Blanco et al. 1999). The extraction of pectin is carried out by
acid hydrolysis at a pH range of 2–3 for 5 h at high temperature (70–100 °C). The
solid-to-liquid ratio is normally about 1:18. The pectin extract is separated from the
pomace using a hydraulic press or by centrifugation. The extract is filtered and
finally concentrated on a standard-setting strength. For powdered pectin preparation, the concentrated liquor is treated with organic solvents or certain metallic salts
to precipitate the polymers (Sakai et al. 1993).
Agro-industrial residues which are primarily composed of complex polysaccharides are also utilized to strengthen microbial growth for the production of industrially important pectinases. During the raw agriculture material processing for food,
a bulk quantity of agro-wastes is generated. Among these agro-residues, dried citrus
peel and orange bagasse contain large amounts of soluble carbohydrates, particularly fructose, glucose, sucrose, and pectin. Citrus peel is known as the major source
of pectinases in several industries instead of apple pomace. A significant quantity of
pectin in citrus peel urges us to use them as a substrate for microorganism to produce pectinolytic enzymes (Ahmed et al. 2016).
6.4 Pectinase Applications
6.4.1 Wine Industry
Wine is a word that evokes emotion in millions across the world. Red and white
wine are fermented drinks highly appreciated worldwide as they present a very
complex composition. They contain a number of specific compounds which are
polyphenols, anthocyanins, polysaccharides, and volatile compounds. In order to
achieve the best wine properties, efficient treatments must be very complex in all
wine production steps such as maceration and clarification. Within this context,
utilization of the enzymes in different steps of winemaking is crucial (Chandrasekaran
et al. 2015). Pectic enzymes are utilized in winemaking from different fruit materials. These enzymes are used at various stages of the winemaking process, especially
the crushing of fruits. Enzyme treatments during the crushing of fruits will increase
the yield of the juices and reduce the pressing time. In addition, enzyme treatment
helps to improve the color yield due to the extraction of pigments. Furthermore, the
addition of enzyme before or during fermentation helps to settle out undesirable
microbes with suspended particles. As a result, a better quality of wine is being
H. Suhaimi et al.