小麦吸水特性及脉冲电场钝化脂肪酶的效果

Water absorption characteristics of wheat and inactivating effect of pulsed electric field on lipase

小麦全粉营养丰富,但储藏稳定性差,脂肪极易氧化。脉冲电场(PEF)是非热加工处理技术,对受试物料的品质影响小。为探究小麦的吸水动力学特性及脉冲电场钝化脂肪酶的效果,建立了10~50℃的吸水动力学Peleg方程M=M0+t/[-0.000 07T+0.007 1+(-0.000 1T+0.008 5)t],根据Arrhenius方程得出小麦的吸水活化能为11.891kJ·mol-1;在单因素试验的基础上,采用响应面分析法优化了PEF对脂肪酶的钝化条件:麦粒水分含量295 g·kg^-1、电场强度12.5 kV·cm-1、脉冲频率316 Hz、脉冲宽度4μs及处理时间315 s。在此条件下,小麦脂肪酶活性抑制率超过50%。

The whole wheat flour is nutritious but has poor storage stability and the fat is easily oxidized. Pulsed electric field(PEF) is a non-thermal processing technology that has little effect on the quality of the subjected materials. In this paper, the water absorption kinetics of wheat was investigated. The Peleg equation of wheat water absorption kinetics from 10 to 50 ℃ was established as M=M0+t/[-0.000 07T+0.007 1+(-0.000 1T+0.008 5)t]. The water absorption activation energy of wheat was calculated as 11.891 kJ·mol-1 according to Arrhenius equation. Response surface analysis methodology derived the optimal conditions for PEF to inactivate lipase exceeding 50% as 295 g·kg^-1 of the grain water content, 12.5 kV·cm-1 of the electric field strength, 316 Hz of the pulse frequency, 4 μs of the pulse width, and 5 min 15 s of the treatment time on basis of single factor experiments.