What is it?
Cellulase is a group of enzymes (EC 3.2.1.4 and related classes) that catalyse the breakdown of cellulose, the structural polysaccharide in plant cell walls. Commercial food-grade preparations are produced by controlled fermentation of fungi such as Trichoderma reesei (longibrachiatum), Aspergillus niger, or Penicillium species. The enzyme protein itself is present in trace amounts or completely inactivated in the final food product, as it is used in processing and typically denatured during heating.
What does it do?
Cellulase cleaves the beta-1,4-glycosidic bonds in cellulose chains, releasing shorter glucose oligomers and eventually glucose. In food processing, this softens plant cell walls, which improves juice yield when pressing fruits and vegetables, clarifies juice and wine by breaking down suspended plant cell debris, improves the extractability of colour and flavour compounds, and aids in bread dough conditioning by modifying the fibre fraction in wholegrain flours.
Where you will see it
Fruit and vegetable juice production (apple, pear, citrus, grape), wine making, beer brewing, wholegrain bread and bakery products, and plant-based food processing. Because cellulase is primarily a processing aid rather than a functional additive in the finished product, it often does not appear on the ingredient label. When it does appear, it is typically listed as 'cellulase' or simply 'enzyme' or 'enzymes'.
