贮藏温度对青方腐乳生物胺和理化性质的影响

以市售的青方腐乳为原料，研究了开盖后贮藏在不同温度下其生物胺含量、水分活度（Aw）、pH值、氨基酸态氮的动态变化，探讨了生物胺与理化指标之间的相关性。结果显示，青方腐乳在不同温度下贮藏至15 d时总生物胺含量＞1 000 mg/kg，且组胺含量＞100 mg/kg，酪胺含量在贮藏至30 d时（除25 ℃第30天）＞100 mg/kg，均超过了相关标准推荐的限量值；在不同贮藏温度下，青方腐乳水分活度＞0.8，pH变化规律基本一致，在第15天达到最大，4 ℃贮藏时，氨基酸态氮含量随贮藏时间的延长而增大。相关性分析结果表明，理化指标的变化与生物胺存在一定的关系，pH与苯乙胺、尸胺、组胺和亚精胺呈极显著正相关（P＜0.01）。结果表明，为了食用安全，腐乳开盖后应尽量在15 d内食用完。

Effects of storage temperature on biogenic amines and physicochemical properties of grey sufu

Using commercial grey sufu as raw material, the dynamic changes of biogenic amines content, water activity (Aw), pH and amino nitrogen of grey sufu were studied under different temperatures after opening the lid, and the correlation between biogenic amines and physicochemical indexes was discussed. The results showed that when grey sufu was stored at different temperatures for 15 d, the total biogenic amine content was more than 1 000 mg/kg, and the histamine content was more than 100 mg/kg. When grey sufu was stored for 30 d (except for the 30th day of 25 ℃), the tyramine content was more than 100 mg/kg, which all exceeded the limit value recommended by relevant standards. At different storage temperatures, the Aw of grey sufu was higher than 0.8, the pH change rule was basically the same and reached the maximum on the 15 d. The content of amino acid nitrogen increased with the increase of storage time at 4 ℃. The results of correlation analysis showed that there was a certain relationship between the changes of physicochemical indexes and biogenic amines, and pH was positively correlated with phenylethylamine, cadaverine, histamine and spermidine (P＜0.01). The results showed that the sufu should be consumed within 15 d after opening the lid for food safety.