Milk-clotting properties of plant rennets and their enzymatic, rheological and sensory role in cheese making: a Review

Plant rennets hold an important position amongst various coagulants used in cheese technology.
The selection of a suitable plant coagulant is important due to the increasing global demands of
cheese alongside reduced supply of calf rennet. Thus, a literature synthesis is presented to
investigate recent achievements on their functional properties and enzymatic role in cheese
making. Efforts have also been done to compare certain rheological and sensory properties of
final products, arising from some plant and animal based rennets. In fact, some coagulants such
as actinidin or dubiumin produce cheeses with sensory qualities similar to those produced by animal rennet. Others, like ginger, cucumisin or hieronymain proteases contribute to develop very different textures and flavors, due to excessive proteolytic activity and production of bitter peptides. For milk-clotting enzymes with high non-specific action, several improvement strategies have been developed to produce cheeses with sensory properties close to those of animal rennet. For example, the mixture of coagulants (cardosins/chymosin), the selection of appropriate milk or its ultrafiltration, as well as the increase of salting time of cheese during ripening could be efficient ways to improve texture and reduce bitterness. Concerning cheeses with high yield loss, the whey could be used for a traditional production of whey cheese. To conclude, the selection of appropriate plant rennet with high MCA/PA ratio and the optimization of all coagulation parameters play a central role in manufacturing cheese with superior rheological and sensory properties.