低盐豇豆泡菜预处理工艺优化及贮藏特性分析

Optimized Pre-Treatment and Storage Properties of Low-Salt Pickled Cowpea

选择不同漂烫条件及护色液浓度优化豇豆护色保脆的工艺条件,采用中短波红外干燥技术对豇豆进行脱水干燥处理,研究干燥过程中不同辐射温度、辐射功率和辐射距离对豇豆干燥特性的影响,确定豇豆中短波红外干燥的工艺参数并探讨豇豆泡菜半干制品干燥水分临界点,并对豇豆半干制品贮藏期品质及泡制方式进行研究。结果显示,乳酸钙溶液(20 g/L)浸泡和热烫处理(90℃,1 min)能有效防止豇豆在贮藏期间的变色和软化问题;豇豆中短波红外干燥的工艺参数为辐射温度70℃、辐射功率900 W、辐射距离10 cm、辐射时间50 min,干燥水分临界点为70%;豇豆半干制品贮藏4周后,菌落总数为4.4×10~3 CFU/g,大肠菌群最可能数(most probable number,MPN)报告小于3 MPN/g,样品的微生物安全性良好;通过复水比可确定较适宜的复水条件为20℃处理3 h;综合泡制后品质指标得到豇豆半干制品的最适泡制方式为泡菜水发酵。

Changes in the hardness and color value of fresh cowpea were investigated under different blanching conditions and at different concentrations of browning inhibitor.Then medium-short wave infrared drying technology was used for partial dehydration processing of the pretreated material to determine the effects of radiation temperature,power and distance on the drying characteristics of cowpea.Furthermore,the quality change of pickled cowpea during storage was investigated and two fermentation methods were compared for improving the color and hardness.Results showed that the softening and browning of cowpea could be delayed by blanching at90℃for1min and soaking in20g/L calcium lactate solution.The infrared drying conditions were as follows:70℃,900W and radiation distance of10cm,50min.The critical moisture point of semi-dry cowpea was70%.After4weeks of storage,the total number of colonies was4.4×103CFU/g and the most probable number(MPN)of coliforms was under3MPN/g,indicating good microbiological quality.The optimal rehydration condition of semi-dry cowpeas was20℃and3h.Pickle brine was more suitable to obtain improved cowpea pickle quality.