卡拉胶/α-淀粉酶复合冻融稳定性对馒头的影响

Effects of Freeze-Thaw Stability of Carrageenan/α-Amylase Complex on Steamed Bread

摘要:

研究α-淀粉酶与λ-卡拉胶复合物在冻融循环过程中的酶活性及结构变化规律，并从面团的发酵性能以及馒头的孔隙分布、质构等方面分析复合物对冷冻面团特性和馒头品质的影响。结果表明：冻融3次后α-淀粉酶内源荧光猝灭，酶活下降到54%，形成的λ-卡拉胶/α-淀粉酶复合物可进一步降低酶活。添加α-淀粉酶能有效增大馒头比容，降低馒头硬度，增加弹性，但复合物对馒头质构的影响较小。添加α-淀粉酶与复合物后，馒头的气孔数量显著多于空白组，但孔洞数量和孔壁厚度均小于空白组，说明α-淀粉酶和复合物均能使馒头的内部结构更加细腻和稳定。综上结果，λ-卡拉胶/α-淀粉酶复合物对面团特性的促进作用不如单独添加α-淀粉酶，推测α-淀粉酶和λ-卡拉胶形成复合物后，多糖掩盖了α-淀粉酶的酶活性位点，削弱了酶对馒头品质的影响。

Abstract:

The changes in the enzyme activity and structure of α-amylase/λ-carrageenan complex during freeze-thawing were studied. The influences of complex on the properties of frozen dough and the steamed bread were analyzed through the fermentation performance, pore size distribution, and texture. The results showed that the fluorescence quenching was observed after three cycles of freeze-thaw and the α-amylase activity was significantly decreased to 54%. The formation of α-amylase/λ-carrageenan complex could further reduce the enzyme activity. The addition of α-amylase effectively changed the quality of steamed bread, such as increasing the specific volume, reducing the hardness, and improving the elasticity. But the complex of λ-carrageenan/α-amylase insignificantly affected the texture of steamed bread. The number of pores in steamed bread treated with α-amylase and complex was significantly higher than that in blank group, but pore wall became thicker, indicating that α-amylase and complex made the internal structure of steamed breads finer and more stable. In summary, α-amylase/λ-carrageenan complex did not improve the quality of steamed bread as well as the addition of α-amylase alone. The polysaccharide was speculated to mask the activity site of α-amylase and weaken the improvement effect on the quality of steamed bread after the formation of α-amylase and λ-carrageenan complex.