Abstract
Soft skimmed-milk cheese Kariesh is the most popular soft cheese in Egypt. In the past, Karish cheese was traditionally produced by the random fermentation of milk speared its cream layer by the gravity force. Recently, its production has been carried out by several manufacturing procedures using, ultrafiltration (UF) - skimmed milk retentate, certain bacterial cultures, enzymatic coagulation, etc. Therefore, the biological and nutritional evaluations are required. The present study was conducted to evaluate the properties of such cheese coagulated using different procedures involving probiotic strains with emphasis on some chemical and biological attributes.
Kariesh cheeses were manufactured without whey drainage from UF cow's skimmed milk concentrate coagulated either by 3% yoghurt bacterial starter culture (YC), 3% probiotic starter culture (ABT type) or 2.5% glucono delta lactone (GDL) added whether separately or incorporated with rennet (0.05ml/kg) to achieve the acidic-enzymatic coagulation in comparison with those made conventionally using unconcentrated milk coagulated either by 2% of YC or ABT added whether separately or incorporated with rennet (0.25 ml/kg). Due to the fact that whey is naturally needed to drain in the conventional (C) procedure, the use of GDL as coagulant was eliminated.
The obtained results indicated that the application of UF-technique in Kariesh cheese industry was associated with significant increments in the values of protein, ash and pH. Moreover, the electrophoretical patterns of UF-Kariesh cheese obtained with the incorporation between YC, ABT or GDL and rennet were distinguished with the presence of the band of glycomacropeptide, which is normally lost in the whey through the C-procedure. Furthermore, the food intake (FI), body weight gain (BWG), food efficiency ratio (FER),triglycerides (TG), total cholesterol (TC), high density lipoproteins (HDL), total, as well as ionized Ca of blood and the count of lactic acid bacteria of feces of rats were significantly heightened, while low density lipoprotein (LDL) level was lowered as they fed on UF-cheeses, especially when coagulated using ABT, those caused the strongest persistence against the rat colon tumor, which was induced by the injection with 1,2 di-methyl hydrazine. The use of ABT led to raise the dry matter (DM) and ash of Kariesh cheese. Also, the FI, BWG, FER, TG, total, as well as ionized Ca of blood and the count of lactic acid bacteria of feces of rats were significantly increased, while TC, HDL and LDL of blood, as well as coliform count of feces of rats were significantly declined. The incorporation of enzymatic with acidic coagulation in Kariesh cheese manufacture increased significantly the values of ash and pH. However, the cheese figures of DM, protein and titratable acidity were decreased. Also, the values of FI, BWG, FER, TC, HDL, LDL and feces LAB of rats were lowered. Whilst, the values of TG, total as well as ionized Ca and feces coliform of rats were increased.