修饰发酵剂细胞促熟干酪的研究进展

修饰发酵剂细胞是采用各种物理、化学或基因修饰等方法使发酵剂(主要是乳酸菌)不能生长而不致产生过量的乳酸。同时在干酪中添加时细胞会完整存在，并能在成熟期间释放出活性胞内酶。修饰发酵剂的方法主要有热休克、冷休克、冷冻或喷雾干燥、溶菌酶处理、溶剂处理和基因修饰等。这些方法修饰乳酸菌(包括乳球菌，乳杆菌)与原发酵剂一并加入乳中，可加速干酪中的蛋白质降解和脂肪分解，缩短其成熟期，且增强风味(减少苦味)，在促熟干酪方面取得了较好的实验效果。综述了现有的修饰发酵剂细胞促熟干酪的方法，详述了热休克、冷休克这两种常用的方法，最后对修饰发酵剂细胞促熟干酪的应用前景作以展望。

THE DEVELOPMENT OF ATTENUATED STARTERS TO ACCELERATE RIPENING OF CHEESE

Attenuated statters are lactic acid bacteria unable to grow and to produce significant levels of lactic acid but still delivering active ripening enzymes during cheese ageing. The attenuation can be performed by several methods:heat-shocked,freezing-shocked,freeze- or spray-drying,lysozyme or solvents treatment.Attenuated starters can also be obtained by the selection of lactose-negative mutants. Whatever the method used,various attenuated lactococci and lactobacilli species have been prepared and added to the milk in parallel to the primary starter. They increased in most cases proteolysis and lipolysis,reducing ripening time and improving flavor(bitterness reduction). It had good effect on accelerated ripening of cheese. The aim of this review is to detail the various existing treatments,especially heat-shocked and freezing-shocked treatments. Lastly,the application future of attenuated starters to accelerated ripening is also discussed.