Influence of Lactobacillus casei LC2W on the proteolysis and aroma compounds of Cheddar cheese during ripening period

Cheddar cheeses were prepared with or without Lactobacillus casei LC2W for studying the survival of the probiotic bacteria and the influence of this strain on cheese proteolysis and aroma compounds of 180 days at 6 degrees C. Following ripening, the probiotic bacteria counts remained about 10(8) cfu/g. In addition, the water-soluble nitrogen (WSN)/total nitrogen (TN) and phosphotungstic acid soluble nitrogen 5% (PTA-SN)/TN had significant differences between cheeses with and without probiotic strain at the end of ripening. Analysis of aroma compounds showed that probiotic cheese had more aroma compounds than control cheese during the ripening period, and principal components analysis (PCA) showed that the aroma profile of the two types of Cheddar cheeses belonged to different areas at the beginning of ripening, but after 180 days of ripening they were in the same area. The study demonstrated that L. casei LC2W can be used as an adjunct culture into Cheddar cheese for making a functional food.