Fungal Genes and their Respective Enzymes in Industrial Food, Bio-based and Pharma Applications - Biotechnology of Fungal Genes - page 195

Triacylglycerol lipids are ubiquitous in plants and animals and are
therefore present in nearly all foods. In baking, triacylglycerol lipase is
applied as such, or in combination with some baking fat and results in
improved dough stability, crumb softness and shelf-life, particularly
relevant for tin bread production (Mutsaers 1997). In cheese processing,
various lipases, including fungal, are applied to accelerate cheese ripening
and flavour development (Fox and Law 1991). These lipases have
preference for short chain fatty acids. Fungal lipases are also applied in
transesterifi cation of oils and fats and in production of structured lipids
as ingredients in specifi c food products (Hayes 2004). The fungal lipases
applied in food industry are derived from A. niger, Rhizopus oryzae, Th.
lanuginosus, Rhizomucor miehei and Penicillium species. Most of these
enzymes are produced in the organism of origin, but some are overexpressed
in A. niger or A. oryzae.
The enzymes that degrade polar lipids are phospholipases and
galactolipases. These enzymes are applied in various foods. In bakery
phospho- and galactolipases are applied to replace synthetic emulsifi ers,
liberating fatty acids from the polar lipids present in fl our and resulting
in increased dough stability, loaf volume and improved crust appearance.
Actually, the enzymatic hydrolysis of one fatty acid from the polar
diglycerides of the wheat flour, such as digalactosyldiglyceride and
phosphatidylcholine, results in the in situ production of an analogue
of the synthetic emulsifi er, DATEM, being diacetyl tartaric acid ester of
monoglycerides. These polar monoglycerides stabilise the expanding gas
cells during proving of the dough, as these polar monoglycerides have
affi nity for the liquid lamella surrounding the gas cells (Poulsen and Soe
1997). Phospholipase is also applied for increasing the yield of mozzarella
production (Høler et al. 2006). The industrial application of phospholipase
Figure 2. Non-polar and polar lipid structures and enzymes able to hydrolyse these
lipids. A: triacylglycerol lipid; B: phospholipid; C: galactolipid; PLA1: phospholipase
A1; PLA2: phospholipase A2; PLC: phospholipase C; PLD: phospholipase D.