| In this paper, properties of a novel recombinant lipase (Rhizopus chinensis lipase, RCL) and it's effects on bread and dough systems were studied. Mixolab, Texture Profile Analysis(TPA) and Differential Scanning Calorimeter (DSC) were all used to assess the RCL and two Nonozymes lipases (Lipopan F BG & Lipopan S BG) on thermomechanicalproperties of dough, baking properties and anti-staling properties of bread. And then contrast of dough stability, holding gas ability, dough emulsion properties, emulsion stability and rheological properties with or without RCL, try to explore the internal effects of RCL on dough systems. Finally compare the synergistic and substitution effects between RCL and chemical emulsifier (DATEM) for baking properties and anti-staling properties of bread. The enzymatic properties of RCL showed that RCL not only have triglyceride lipase activity, but also exhibited phospholipase activity. When showing triglyceride lipase activity, the optimal enzyme activity condition was at 45℃and pH 8.5, The activity of the enzyme was stable when the temperature was lower than 40℃, and the pH ranged within 7.0～9.0; But when it showed phospholipase activity, the optimal enzyme activity condition was at 50℃and pH 8.0, The activity of the enzyme was stable when the temperature was lower than 50℃, pH range within 6.0～9.0. On the comparison of RCL with lipopan FBG & SBG, We can see FBG showed the most phospholipase activity while SBG only have triglyceride lipase activity, Although RCL showed both triglyceride lipase activity and phospholipase activity, but triglyceride lipase activity is its main activity.Adopt Mixolab, TPA, Precision Colorimeter and DSC to analysis the thermomechanical properties of dough, baking properties and anti-staling properties of bread among RCL, FBG and SBG. The results of Mixolab showed that RCL(500U/kg) can make the dough stabilizing time and elasticity increase 12.18% and 33.33% respectively, the protein weakening speed reduce 35.50%, and also improve the dough thermal stability. When RCL was added to 1000U per kilogram flour, the volume increased to 24.63%, while hardness drop up to 29.74% and gumminess 32.35%, meanwhile significantly increased chewiness, springiness and whiteness of bread. From the measurement of hardness and enthalpy of bread, we can see RCL can also greatly reduce the speed of bread staling, so RCL has good anti-staling effect. Comparing RCL with lipopan FBG & SBG, We can see RCL is similar or better than FBG & SBG for improving the dough mechanical properties, bread baking characteristics and anti-staling effects.F3 Rheofermentometer, Dynamic Rheometry, RVA and DSC were used to explore the internal effects of RCL at dough system. F3 results show that RCL(1000U/kg) can make the dough stability increased 66.7%, holding gas ability increases 19.98%. Emulsion properties when added 1000U/kg RCL will raise to 10.82%, mainly because RCL hydrolysis lipids of dough to lysophospholipids and monoglyceride. And from dynamic rheological properties that we can see when added RCL to the dough, can improve viscoelastic properties of dough, and also dough was formed macromolecular substance, enhance gluten network structure. According to RVA and DSC, we can see the dough can formed in lipid-amylose complex, improve its anti-aging capability. Through analyzing the carotenoids content change during the dough fermentation time, we can also find that RCL has a good indirect oxidation effect.Based on the research of RCL can hydrolysis lipids to emulsifier, which give the possibility that use RCL to instead chemical emulsifier in bread making process. Through the comparison of RCL and DATEM, We can see that RCL is similar to emulsifier for improving bread baking characteristics and anti-staling effects. And from the synergistic effect between RCL & DATEM, we can see that synergistic effect is better than using DATEM alone, the results showed that the lipase can replace chemical agent 50%, and have a much valuable market patental.
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