杀菌温度对莲藕汁色泽及化学成分的影响

Effects of Sterilization Temperature on Color and Chemical Compositions of Lotus Rhizome Juice

采用不同的杀菌温度对莲藕汁进行处理,研究其对色泽及相关化学物质含量的影响,并对两者进行相关性分析,确定色泽变化与物质种类及含量变化之间的关系。结果表明:用5种杀菌温度处理莲藕汁后,a^(*)、b^(*)、△E、A_(420nm)值均增大,还原糖及5-羟甲基糠醛含量均升高,抗坏血酸、总酚、苏氨酸、丝氨酸、蛋氨酸、组氨酸和脯氨酸含量均降低。相比于101,111℃和121℃杀菌,81℃和91℃杀菌对莲藕汁的颜色和化学物质影响较小。相关性分析表明:5-羟甲基糠醛、抗坏血酸和还原糖与色差△E和褐变度A_(420nm)均呈极显著相关关系,其中5-羟甲基糠醛与色差的相关性最强,系数达到0.940,说明5-羟甲基糠醛是引起莲藕汁杀菌前、后颜色变化的主要因素。

In this research,the effects of different sterilization temperatures on color and related chemical substances in lotus rhizome juice were studied,and the correlation between color parameters and chemical substances was analyzed to determine the relationship with them.The results showed that the values of a^(*),b^(*),△E and A_(420 nm)increased,the contents of reducing sugar and 5-hydroxymethylfurfural increased,and the contents of ascorbic acid,total phenol,threonine,serine,methionine,histidine and proline decreased.Compared with sterilization at 101,111 ℃ and 121 ℃,sterilization at 81 ℃ and 91 ℃ had little effect on the color and chemical substances of lotus rhizome juice.5-Hydroxymethylfurfural,ascorbic acid and reducing sugar were significantly correlated with △E and A_(420 nm),among which 5-hydroxymethylfurfural had the strongest correlation with △E,and the coefficient reached 0.940,indicating that 5-hydroxymethylfurfural was the main factor causing the color change of lotus rhizome juice before and after sterilization.5-Hydroxymethylfurfural was significantly related to ascorbic acid,reducing sugar,threonine and methionine.It could be inferred that the production of 5-hydroxymethylfurfural was mainly related to the oxidative decomposition of ascorbic acid and the Maillard reaction of threonine,methionine and reducing sugar.