Effect Of Blanching Temperature On Quality Of Mozzarella Cheese During Ripening

Mozzarella cheese is featured by its unique melting drawing function.It is commonly used as a pizza ingredient.In recent years,the consumption of this cheese has dramatically increased in our country.Different heating temperatures have different effects on the functional characteristics of Mozzarella cheese,which include the cheese’s physical and chemical composition,protein structure and final functional properties.In order to study the effect of high and low drawing temperature on the quality characteristics of Mozzarella cheese during the ripening process.In this paper,three experimental groups were selected,namely,the control group without hot ironing and the experimental group with the ironing temperature of 70 and 90 Celsius.Firstly,we were researched the changes of composition,microstructure and texture of Mozzarella cheese during the maturation process at different heating temperatures by chemical detection method.Then we were measured the cheese’s meltability,stretchability and color by the functional test method after the Mozzarella cheese is melted.Last we were studied the production of flavor substances during cheese ripening by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.The results showed that Mozzarella cheese’s moisture content decreases during maturity.And the moisture content of Mozzarella cheese decreases when the heating temperature increasesed during the cheese mature period(P<0.05).The SN in pH4.6 and in 12%TCA increase during the mature period.The SN in pH4.6 and 12%TCA are lower at the heating temperatures of 70 ℃ and 90 ℃ than control group(P<0.05).The heating treatment of the cheese makes the yellowness of the cheese relatively increased and the whiteness reduced(P<0.05).Protein network structure changed from loose to compact and the clot structure changed from irregular to near-parallel linear fibril structure under different heat extrusion treatments through the scanning electron microscopy.The initial number of living bacteria of high heating temperatures cheese in mature period were always less than control group.The hardness,elasticity and chewiness of cheese increased and adhesion became smaller,when the heating temperature was 70℃ and 90℃.The hardness and chewiness were significantly different in the same maturity period(P<0.05).As the heating temperature increased,the functional characteristics of the cheese changed.The cheese’s precipitation of the grease and the browency became large,but the meltability became small(P<0.05).The GC-MS mass spectra showed that the kinds of acids,alcohols,esters and the relative content of cheese,which appeared in the course of the treatment of 70 and 90 at 0 d,appeared more frequently than that control group.At 90 d,at the temperature of 70 and 90,the kinds of the acid substances reduced,and the types of the alkanes increased.In mature for 0 days,LC-MS spectra showed that the mature liquid,the content of peptides and small molecules dissolved incontrol group’s cheese are higher than those at 70 and 90 degrees of heating temperature of cheese.In mature period,70 and 90 degrees of heating temperature of cheese flavor and smell,texture pattern,organization,color and shape are better than control group(P<0.05).With the hydrolysis of protein,the best sensory evaluation of cheese is obtained at 3 kinds of hot pressing temperature in mature for 60 days.