食醋生产过程中铁、锌、铜的迁移变化

Change in Iron,Zinc,and Copper Concentrations during Vinegar Production

本文研究了食醋发酵过程中铁、锌、铜的产生途径及影响因素。采用原子吸收分光光度法对镇江香醋不同发酵阶段液相、固相中的铁、锌、铜含量变化进行分析。结果表明铁、锌、铜在发酵各阶段液相中主要以可溶态存在,沉淀的形成对Fe、Zn、Cu具有富集作用。随着发酵的进行,发酵设备、管道由于长期受醋酸、有机酸等的腐蚀使铁、锌、铜游离和在发酵生产过程中添加了含有铁、锌、铜的辅料,是醋醅中铁、锌、铜含量上升的主要因素。醋中铁主要来源于醋酸发酵和封醅陈酿阶段,在淋醋时铁浓度达到最高,59.69 mg/L。醋中的锌、铜主要来源于酒精发酵阶段,浓度分别达到18.12 mg/L和0.60 mg/L。由于醋醅对铁、锌、铜元素具有强吸附力,醋醅对醋液中的金属元素浓度具有一定的调控作用。通过本研究表明改进设备材质、采用合理的过滤措施及在发酵过程中使用金属离子吸附剂将是控制食醋中金属含量的有效措施。

Iron-, zinc- and copper-producing pathways and factors influencing vinegar fermentation were examined in this study. Iron, zinc, and copper content at different stages of fermentation during the production of Zhenjiang fragrant vinegar were analyzed using atomic absorption spectrometry. The results showed that these three minerals were mainly present in the soluble state in the liquid phase during various stages of fermentation and were enriched due to precipitate formation. The key factors that influenced the increase in the mineral content in vinegar fermentative substrates originated from corrosion of the fermentation equipment or pipes due to long-term exposure to acetic acid and organic acid, as well as from materials containing iron, zinc, and copper, which might be added during the fermentation process. Iron was introduced into the process mainly at the acetic acid fermentation stage and during sealing for maturation. Furthermore, iron concentration reached highest levels, of 59.69 mg/L at the leaching stage during vinegar production. In addition, alcohol fermentation was the main stage for enrichment of zinc and copper, where their concentrations in vinegar reached 18.12 mg/L and 0.60 mg/L, respectively. The fermentative substrates for vinegar had a strong ability to absorb elemental iron, zinc, and copper, thus contributing regulatory effects on the metal concentration in vinegar. The results indicate that the metal content during vinegar production could be controlled by improving the quality of equipment, optimizing filtering methods, or use of metal ion adsorbents.