Structure, Meltability, and Firmness of Process Cheese Containing White Cheese
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Food Structure Volume 10 Number 3 Article 2 1991 Structure, Meltability, and Firmness of Process Cheese Containing White Cheese Miloslav Kalab H. Wayne Modler Marijana Caric Spasenija Milanovic Follow this and additional works at: https://digitalcommons.usu.edu/foodmicrostructure Part of the Food Science Commons Recommended Citation Kalab, Miloslav; Modler, H. Wayne; Caric, Marijana; and Milanovic, Spasenija (1991) "Structure, Meltability, and Firmness of Process Cheese Containing White Cheese," Food Structure: Vol. 10 : No. 3 , Article 2. Available at: https://digitalcommons.usu.edu/foodmicrostructure/vol10/iss3/2 This Article is brought to you for free and open access by the Western Dairy Center at DigitalCommons@USU. It has been accepted for inclusion in Food Structure by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. FOOD STRUCTURE, VoL 10 (1991), pp. 193-201 1046-705X/9 IS3.00+ .00 Scanning Microscopy International, Chicago (AMF O'Hare), IL 60666 USA STRUCTURE, \1ELTABILITY, AND FIRMNESS OF PROCESS CHEESE CONTAINING WHITE CHEESE Miloslav KalAb, H. Wayne Modler, Marijana Carie, and Spasenija MiJanoviC"' Food Research Centre, Agriculture Canada, Ollawa, Ontario, Canada KlA OC6 •Faculty of Technology. University of Novi Sad, Novi Sad, 21000 Yugoslavia Abstract lntroduction White cheese made by coagulating heated milk (90"C) Process cheese is made by heating and stirring blends with a 2.5% citric acid solution to pH 5.5 consists of casein of various natural cheeses and other ingredients in the particles having a characteristic core-and-shell ultrastruc presence of melting salts. Ripened cheeses form the major ture. The presence of this White cheese in process cheese part of the cheese blend [3] but a cultured ultrafiltered can be detected by transmission e lectron microscopy on the whole milk retentate was used as a major ingredient by basis of the core-and-shell ultrastructure which is stable Ernstrom eta/. in 1980 [7]. Since then, experimental results during cheese processing. White cheese additions may be have been reported by many authors. For example, Savel\o detected at levels equal to or higher than 8%. eta!. [21] found good melting properties of process cheese White cheese, which does not melt alone when heated, made with acid casein as well as rennet casein using appro increases meltability of the process cheese in which it is priate melting salts. Recently, Tamime et at. [22] processed present as an ingredient. Meltability in creases at all White cheese blends containing large proportions of a cheese base cheese concentrations examined (8, 16, and 33%) with prepared from a retentate obtain ed by ultrafiltration and trisodium phosphate used as the melting salt. With sodium diafiltration of reconstituted skim milk. One part of the citrate, there is a 14% increase in meltability at 8% White cheese base was used as obtained by coagulating the milk cheese. Meltability of process cheese containing 16% White with a bacterial starter culture and calf rennet and the cheese is about the same as the control process cheese, and other part was treated after coagulation by adding a pro meltability of process cheese containing 33% White cheese tease to increase proteolysis. Anhydrous milk fat was added is decreased by 20%. to the cheese blends to provide the desired fat content in Fi rmness of process cheese made with sodium citrate the fini shed product. Process cheese made from these increases as the proportion of White cheese is increased blends was of acceptable quali ty. from 8 to 33 % but decreases in process cheese made wi th Unripened cheeses such as White or Ricotta cheeses trisodium phosphate except at the highest White cheese made by coagulating hot milk with an acid [ 16] may also be concentrati on. used as ingredients in the process cheese blends. The use of these products in process cheese would be economically advantageous because (a) unripened cheese may be used directly from the manufacture without aging, (b) the yield is higher due to the recovery of both casein and whey pro teins, and (c) unripened cheeses have very low bacteri al counts at the time of manufacture. Initial paper received March II, 1991 Unripened cheese used in the process cheese blend Manuscript received July 18, 1991 may affect the texture and structure of the finished product. Direct inquiries to M. Kalab Being unable to melt on heating, White cheese is expected Telephone number: 613 995 3722 to decrease meltability of the process cheese in which it is Fax number: 613 995 3845 used. However, it would be difficult to detect unripened cheese by chemical analysis because there are only very small differences in qualitative chemical composition be tween process cheeses made from ripened cheese and pro cess cheeses in which White cheese has been used as an in gredient. One difference is the presence of K-casein in the form of a compl ex wi th ,8-lactoglobulin in White cheese, where it develops as a result of heating milk to 90°C before Key Words: Acidulation of milk, Casein micelles, Cheese coagulation. A possibility of detecting White cheese by prOcessing, Core-and-shell structure, Electron microscopy, electron microscopy has arisen from a finding that un Firmness, Meltability, Process cheese, TEM, Transmission ripened White cheese made by acid coagulation of hot milk electron microscopy, Whi te cheese. contains a characteristic ultrastructure. This ultrastructure, 193 M. Kalab, H. W. Modler, M. Carie, and S. Milanovic initially called the core-and-lining ultrastructure by Har walkar and KalAb [8] who studied it in milk gels obtained Table 1. Ingredient composition of process cheese blends from heated milk coagulated with glucono-0-lactone, is containing 8 and 33% White cheese characterized by casein particles having solid cores sur rounded by proteinaceous shells. There is a void space of Na citrate TSP SO to 80 nm in width, between the cores and the shells. The a· 33• a• 33• presence of the milk salt system and ,8-lactoglobutin was % % % % fo und to be essential for the full development of this ultra -----·-----------·-- ·----------··------------·---------------·-----·------ structure. The ultrastructure is found in several dairy prod Cheddar mild 34.8 26.3 34.2 25.9 ucts, e.g., Queso Blanco [13] and Paneer cheeses [12]. Re Cheddar medium 34.8 26.3 34.2 25.9 cently renamed [11], the core-and-shell ultrastructure has White cheese 7.9 33.9 7.8 33.3 been found very stable when exposed to various treatments Water** 10.6 1.6 12.8 3.9 such as frying in oil. An earlier finding of the core-and-shell Whey powder 6.6 6.6 6.5 6.5 ultrastructure in commercial process cheese [4] suggested Butter u u u u that White cheese was probably used as an ingredient in the Sodium chloride 1.0 1.0 1.0 1.0 manufacture of the process cheese. The objective of this Sorbic acid 0.2 0.2 0.2 0.2 study was to examine effects of White cheese on the struc Cheese colour 0.03 0.03 0.03 0.03 ture and textu re of process cheese, particularly the possi Na citrate 2.9 2.9 bility of detecting White cheese in process cheese and the Trisodium phosphate 2.2 2.2 sensitivity of such detection. Total 99.93 99.93 1 100.03 100.03 Materials and Methods * Percentage of White cheese present in the blend White cheese * * Including crystal water in the melting salts. White cheese was prepared in two different dairy es tablishments on laboratory and pilot plant scales. In both instances, th e preparation consisted of heating commercial Meltability of the process cheeses under study was milk, having a 3% fat content, at 90oC fer 10 min and co determined according to the method des ign ed by Olson and agulating the proteins using a 2.5% citric acid solution (45 Price [17] and slightly modified by Savello et at. [21]. Pro mL/L of milk). In one preparation, the citric acid solution cess cheese columns, 25 mm in diameter and 25 mm high, was dispersed in the milk through a spray nozzle [16] during weighing 15.0±0.1 g, were placed at rubber-stoppered ends the continuous production of White cheese and in the other of 250 mm long Pyrex glass tubes having 25 mm inner di preparation it was added in a thin stream from a can while ameter, and the opposite ends were closed with rubber the milk was mechanically stirred. The final pH of the co stoppers, each having a 3-rnm hole. The tubes were heated agulum was 5.5 in each case. The curd, consisting of casein in horizontal position for 50 min at l10°C. As the process and whey proteins, was drained overnight in perforated cheese samples melted, th e distance to which they spread, trays lined with cheese cloth. The White cheese used in this was measured in millimetres (mm) and used as a criterion study contained 18.2% protein, 17.3% fat, and 58.6% of meltability. moisture. Firmness was measured usi ng the Ottawa Texture Process cheese Meter [61 equipped with a cyli ndrical cell, 48 mm in diame Process cheese was made from blends of natural ter. Three wires, 0.4 mm in diameter, 139 mm total length, cheeses and three levels of White cheese: 8%, 16%, and we re driven at 177 mm/min through the cheese placed in 33%. One series of blends consisted of a 1:1 ratio of mild the cell and the resistance in grams was recorded on a and medium ripened Cheddar cheese diced in the form of chart; the data were converted into newtons (N).