Browsing by Subject "factose"

The literature section of this Master's Thesis focuses on cheese making process from milk composition to cheese ripening. In addition, the thesis investigates the effect of lactose standardization on lactic acid fermentation, sensory characteristics of the cheese and what biochemical changes the standardization causes during cheese ripening. The aim of the experimental part was to investigate the effect of standardization of the lactose content of cheese milk and how it will affect the ripening and final quality of Swiss -type cheeses. The effect of lactose content of the cheese milk, protein fraction used, pre-ripening time and ripening temperature was studied using statistical design of experiments (DOE). 16 test batches were manufactured according to factorial screening design. Water, cream and protein fraction were used to standardize the lactose content of the cheese milk. In addition, two center point experiments were performed with third protein fraction. The fat and protein content, dry matter, moisture of non-fat substance, fat in dry mater, lactose, lactic acid, acetic acid, propionic acid, butyric acid and the level of volatile organic acids and titrated free amino acids of cheese were analyzed during manufacturing and ripening. The lactose and lactic acid content of the cheese milk can be lowered by standardization of the lactose concentration. If set too low however, it is no longer beneficial for the lactic and propionic acid fermentation processes or to the quality of the cheese, as flaws in the fermentation process will start to occur. With lower levels of lactose content, less lactic acid and more propionic acid will form in the cheese. Pre-ripening creates beneficial environment for propionic acids and that can prevent cracking of the cheese. Cheese that has been ripened for too long in temperatures too high will have flaws in the fermentation process. Moreover, the statistical centre point tests show that the standardization of the protein level in the cheese milk is best to be done by using protein fraction U. Fraction U gave best results on average in the sensory evaluation.