腐乳生产后期发酵的化学变化

Chemistry Change During the Ageing of Beancurd Cheese

腐乳生产的后酵是腐乳特有风味形成、蛋白质降解的主要阶段 .实验结果表明 ,腐乳后酵过程中可溶性蛋白质及氨基酸含量的变化较直观地反映了腐乳的成熟情况 .当可溶性蛋白质含量达到w =18%～ 2 0 % (干基 ) ,氨基酸态氮含量达到w >0 .5%时腐乳已基本成熟 .另外对后酵期间的腐乳进行蛋白质凝胶电泳 ,发现后酵 4周后分子质量达到31× 10 3u以上的多肽都已经降解 ,5周后可溶性蛋白质以分子质量为 14× 10 3u的低分子多肽为主 .

Ageing of beancurd cheese is the main process of the protein hydrolysis and flavor development. The ageing conditions of beancurd cheese can be explained by the content change of the soluble protein and the amino acid in beancurd cheese during ageing process. When the mass fraction of soluble protein and amino acid come to 18% to 20%(dry) and more 0.5% respectively, the ageing is enough. By using SDS_PAGE, we find that after 4 weeks of ageing the peptide of molecular mass above 31×10 3 u are all hydrolysed. After 5 weeks a great deal of the soluble perotein are the 14×10 3 u peptide of molecular mass.