328
processing enzymes are used in starch processing, meat processing, dairy industry,
wine industry and in manufacture of pre-digested foods (Chaudhary et al. 2015).
The use of rennet in cheese manufacturing was among the earliest applications
of exogenous enzymes in food processing. In recent years, proteinases have found
additional applications in dairy technology, for example in acceleration of cheese
ripening, modification of functional properties and preparation of dietic products
(IDF 1990). Animal rennet (bovine chymosin) is conventionally used as a milkclotting agent in dairy industry for the manufacture of quality cheeses with good
flavour and texture. Rennin acts on the milk protein in two stages, by enzymatic and
by non-enzymatic action, resulting in coagulation of milk (Bhoopathy 1994).
Microbial coagulants are low-cost substitutes of rennet, since they are easily produced by fermentation. They have higher resistance to heat and stronger proteolytic
activity during cheese making and ripening (Jacob et al. 2011). Lipases in dairy
industry are used for flavour enhancement in cheese products (e.g. enzyme- modified
cheese flavour) and acceleration of cheese ripening and lipolysis of milk/vegetable
oil/fat to obtain specific flavours (Jooyandeh et al. 2009).
The supplementation of flour and dough with enzyme improvers (technical
enzymes) is a usual practice for flour standardization and also as baking aids.
Enzymes are usually added to modify dough rheology, gas retention and crumb
softness in bread manufacture, to modify dough rheology in the manufacture of
pastry and biscuits, to change product softness in cake making and to reduce acrylamide formation in bakery products (Cauvain and Young 2006). The enzymes most
frequently used in breadmaking are the α-amylases from different origins (Penella
et al. 2008). Amylases can degrade starch and produce small dextrins for the yeast
to act upon. Enzymes such as hemicellulases, xylanases, lipases and oxidases can
directly or indirectly improve the strength of the gluten network and so improve the
quality of the finished bread. The addition of certain types of pentosanases or xylanases at the correct dosage can improve dough machinability yielding more flexible,
easier-to-handle dough. The addition of functional lipases modifies the natural flour
lipids so they become better at stabilizing the dough. The addition of lipases has
been claimed to retard the rate of staling in baked products (Cauvain and Young
2006; Siswoyo et al. 1999). Lipoxygenases are also employed to improve mixing
tolerance and dough handling properties (Cumbee et al. 1997).
Enzymes are processing aids used worldwide for fruit processing, particularly
for the production of clear fruit juice and concentrate. Enzymes can increase the
yield of solid recovery during pulp washing, facilitate the production of highly concentrated citrus bases, improve essential oil recovery from peel, de bitter juice,
clarify lemon juice or increase the worth of waste products (Grassin and
Fauquembergue 1996). Pectinases are one of the important upcoming enzymes of
the commercial sector especially for fruit juice industry as prerequisites for obtaining well clarified and stable juices with higher yields (Lee et al. 2006; Sandri et al.
2011). Amylases are added together with pectinases at the start of the processing
season when apples contain starch. Vegetable juice processing therefore requires
S. Farooq et al.
processing enzymes are used in starch processing, meat processing, dairy industry,
wine industry and in manufacture of pre-digested foods (Chaudhary et al. 2015).
The use of rennet in cheese manufacturing was among the earliest applications
of exogenous enzymes in food processing. In recent years, proteinases have found
additional applications in dairy technology, for example in acceleration of cheese
ripening, modification of functional properties and preparation of dietic products
(IDF 1990). Animal rennet (bovine chymosin) is conventionally used as a milkclotting agent in dairy industry for the manufacture of quality cheeses with good
flavour and texture. Rennin acts on the milk protein in two stages, by enzymatic and
by non-enzymatic action, resulting in coagulation of milk (Bhoopathy 1994).
Microbial coagulants are low-cost substitutes of rennet, since they are easily produced by fermentation. They have higher resistance to heat and stronger proteolytic
activity during cheese making and ripening (Jacob et al. 2011). Lipases in dairy
industry are used for flavour enhancement in cheese products (e.g. enzyme- modified
cheese flavour) and acceleration of cheese ripening and lipolysis of milk/vegetable
oil/fat to obtain specific flavours (Jooyandeh et al. 2009).
The supplementation of flour and dough with enzyme improvers (technical
enzymes) is a usual practice for flour standardization and also as baking aids.
Enzymes are usually added to modify dough rheology, gas retention and crumb
softness in bread manufacture, to modify dough rheology in the manufacture of
pastry and biscuits, to change product softness in cake making and to reduce acrylamide formation in bakery products (Cauvain and Young 2006). The enzymes most
frequently used in breadmaking are the α-amylases from different origins (Penella
et al. 2008). Amylases can degrade starch and produce small dextrins for the yeast
to act upon. Enzymes such as hemicellulases, xylanases, lipases and oxidases can
directly or indirectly improve the strength of the gluten network and so improve the
quality of the finished bread. The addition of certain types of pentosanases or xylanases at the correct dosage can improve dough machinability yielding more flexible,
easier-to-handle dough. The addition of functional lipases modifies the natural flour
lipids so they become better at stabilizing the dough. The addition of lipases has
been claimed to retard the rate of staling in baked products (Cauvain and Young
2006; Siswoyo et al. 1999). Lipoxygenases are also employed to improve mixing
tolerance and dough handling properties (Cumbee et al. 1997).
Enzymes are processing aids used worldwide for fruit processing, particularly
for the production of clear fruit juice and concentrate. Enzymes can increase the
yield of solid recovery during pulp washing, facilitate the production of highly concentrated citrus bases, improve essential oil recovery from peel, de bitter juice,
clarify lemon juice or increase the worth of waste products (Grassin and
Fauquembergue 1996). Pectinases are one of the important upcoming enzymes of
the commercial sector especially for fruit juice industry as prerequisites for obtaining well clarified and stable juices with higher yields (Lee et al. 2006; Sandri et al.
2011). Amylases are added together with pectinases at the start of the processing
season when apples contain starch. Vegetable juice processing therefore requires
S. Farooq et al.