Fayed A E, Farahat Azza M, Metwally A E, Emam M S Massoud And A O
Food Science Department, Faculty of Agriculture, Ain Shams University, Cairo, Egypt.
Acta Sci Pol Technol Aliment. 2014 Oct-Dec;13(4):359-373. doi: 10.17306/J.AFS.2014.4.3.
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.
软质脱脂乳干酪Kariesh是埃及最受欢迎的软质奶酪。过去,卡里什奶酪传统上是通过牛奶在重力作用下撇去乳脂层后的随机发酵生产的。最近,它的生产采用了几种制造工艺,如超滤(UF)-脱脂乳截留物、特定的细菌培养物、酶促凝固等。因此,需要进行生物学和营养评估。本研究旨在评估使用不同工艺(包括益生菌菌株)凝固的此类奶酪的特性,并重点关注一些化学和生物学属性。
Kariesh奶酪是通过对超滤浓缩的脱脂牛奶进行凝固而制成的,不进行乳清排放。凝固剂分别为3%的酸奶发酵剂(YC)、3%的益生菌发酵剂(ABT型)或2.5%的葡萄糖酸-δ-内酯(GDL),可单独添加或与凝乳酶(0.05ml/kg)混合使用,以实现酸-酶促凝固,与传统方法使用未浓缩牛奶制成的奶酪进行比较,传统方法中凝固剂分别为2%的YC或ABT,可单独添加或与凝乳酶(0.25ml/kg)混合使用。由于传统(C)工艺自然需要排放乳清,因此未使用GDL作为凝固剂。
所得结果表明,在Kariesh奶酪工业中应用超滤技术会使蛋白质、灰分和pH值显著增加。此外,通过YC、ABT或GDL与凝乳酶混合制成的超滤Kariesh奶酪的电泳图谱中,存在糖巨肽条带,而在传统工艺中,该条带通常会在乳清中丢失。此外,当大鼠食用超滤奶酪时,尤其是使用ABT凝固的奶酪,其食物摄入量(FI)、体重增加(BWG)、食物效率比(FER)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)、血液中的总钙以及离子钙和粪便中乳酸菌数量显著增加,而低密度脂蛋白(LDL)水平降低。使用ABT可提高Kariesh奶酪的干物质(DM)和灰分。此外,大鼠的FI、BWG、FER、TG、血液中的总钙以及离子钙和粪便中乳酸菌数量显著增加,而血液中的TC、HDL和LDL以及大鼠粪便中的大肠菌群数量显著下降。在Kariesh奶酪制造中,酶促与酸促凝固的结合显著提高了灰分和pH值。然而,奶酪的DM、蛋白质和可滴定酸度值降低。此外,大鼠的FI、BWG、FER、TC、HDL、LDL和粪便乳酸菌值降低。同时,大鼠的TG、总钙以及离子钙和粪便大肠菌群值增加。