发酵剂对牦牛乳硬质干酪成熟过程中生物胺的影响

乳酸菌产生物胺的能力具有菌株特异性,因此,为了探究不同种类发酵剂对牦牛乳硬质干酪中生物胺形成的影响,该试验利用高效液相色谱对3种不同发酵剂制作的硬质干酪成熟过程中生物胺进行了测定和分析。结果表明,嗜热和嗜温发酵剂牦牛乳硬质干酪中检测出2-苯乙胺、腐胺、尸胺、组胺和酪胺,混合发酵剂干酪中检测出腐胺、2-苯乙胺、尸胺和酪胺。各生物胺之间呈现正相关性。3种不同发酵剂干酪在1～6个月成熟过程中,其各生物胺整体呈现增加趋势,嗜热、嗜温和混合发酵剂干酪中总生物胺最高含量分别为(448.3±9.6)、(456.8±58.4)、(293±24.5)mg/kg。组胺和酪胺是2种毒性相对高的生物胺,嗜热发酵剂干酪中组胺和嗜温发酵剂干酪中酪胺最高,其最高含量分别为(20.8±7.9)、(92.9±6.7)mg/kg,混合发酵干酪中未检测出组胺,酪胺含量次之,3种不同发酵剂干酪中组胺、酪胺含量均低于推荐安全剂量50 mg/kg和100 mg/kg。这为合理选择发酵剂和控制干酪中生物胺形成提供了依据。

Effect of starter cultures on the biogenic amines of hard cheese made from yak milk during the ripening

The capability of biogenic amine formation of lactic acid bacteria seems to be strain-dependent, therefore, the aim of this study was to evaluate the effect of different starter cultures(thermophilic, mesophilic and mixed thermophilic-mesophilic cultures) on the formation of biogenic amines in the hard cheese made from yak milk during the ripening using HPLC. Three treatments inoculated with different commercial starter cultures were prepared. The results indicated that 2-phenylethylamine, putrescine, cadaverine, histamine and tyramine were detected in the cheese made with the thermophilic and mesophilic culture. Putrescine, 2-phenylethylamine, cadaverine and tyramine were in the cheese made with mixed thermophilic-mesophilic culture. Positive Pearson correlations existed among biogenic amines. The concentrations of biogenic amines increased with the maturation of six months. The maximum contents of the total biogenic amine were(448.3±9.6),(456.8±58.4) and(293±24.5) mg/kg in these three groups of cheese. Histamine and tyramine have higher toxicity, and the histamine content in the cheese made with the thermophilic culture and the tyramine content in the cheese with mesophilic culture were the highest, and their maximum contents were(20.8±7.9) and(92.9±6.7) mg/kg, respectively. The tyramine content was low and histamine was not detected in the cheese made with the mixed thermophilic-mesophilic cultures. Their contents of biogenic amines in all samples analyzed was below recommended levels of 50 mg/kg for histamine and 100 mg/kg for tyramine. This research provides a theoretical basis for choosing proper starter culture and controlling the biogenic amines.