Abstract:

The effects of lipase, acidic protease and flavor protease on shortening ripening period of fermented mutton sausage were investigated. The optimal combination of enzymes was determined by using three-factor quadratic rotational composite design. Physicochemical index and sensory index of fermented mutton sausage with added exogenous enzymes were measured. The optimal amounts of three enzymes were found to be: 0.0022% lipase, 0.0011% acidic protease and 0.0027% flavor protease. On the 14th day of ripening, the contents of free fatty acids and non-protein nitrogen in the protease-treated group was 1.437% and 0.647%, respectively, which had no significant difference with those of the control group on the 35th day (P＞0.05). Throughout the whole ripening period, TVB-N and thiobarbituric acid (TBA) exhibited no significant difference between the protease-treated group and the control group (P＞0.05). In addition, similar sensory quality was observed in the proteasetreated group on the 21st day and the control group on the 35th day. Therefore, addition of exogenous enzymes can reduce the required ripening period of fermented mutton sausage by 40%.

Key words: exogenous enzyme, fermented mutton sausage, non-protein nitrogen (NPN), free fatty acid (FFA)