Enzymes from yeast adjuncts in proteolysis during cheddar cheese ripening

Abstract

A great deal of research in cheese technology is devoted towards the manipulation of glycolysis, lipolysis and proteolysis in order to accelerate ripening times or to improve flavour. There is increasing evidence that certain yeast species contribute to flavour and texture development during ripening of certain cheeses, including Cheddar cheese. The addition of yeast cultures as adjunct cultures may accelerate ripening, or lead to a faster development of flavour and taste. This is brought about by an increase in primary proteolysis of the caseins as well as the break down of amino acids into flavour compounds. The respective enzymes involved seem to be proteases with plasmin or plasmin activator activity, and glutamate dehydrogenase. This research reports on the inclusion of yeasts as adjuncts in the processing of Cheddar cheese. Yeasts that expressed both enzyme activities were added as single adjuncts, while combinations of yeasts with singular enzyme activity were employed. Changes during ripening were monitored by sensory and biochemical analyses. The latter includes proteolysis, lipolysis and enzyme activity.