Chemical characteristics of low-fat wheyless cream cheese ...

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Khadijeh Poursharif et al Euro. J. Exp. Bio., 2012, 2 (3):690-694 ______________________________________________________________________________ The terms and definitions used to describe fat replacers vary among authors and are often confusing and misunderstood. Fat replacers chemically resemble to fats, proteins, or carbohydrates and are generally categorized into two groups: fat substitutes and fat mimetics. Fat substitutes are macromolecules that physically and chemically resemble to triglycerides(conventional fats and oils) and ,often, referred to as lipid- or fat-based fat replacers. Fat substitutes are either chemically synthesized or derived from conventional fats and oils by enzymatic modification. Fat mimetics are substances that imitate organoleptic or physical properties of triglycerides. Fat mimetics, often called protein- or carbohydrate- based fat replacers, are common food constituents, e.g., starch and cellulose, but may be chemically or physically modified to mimic the function of fat. Fat mimetics generally adsorb a substantial amount of water [3]. In recent years, many studies related to low fat Mozzarella or Cheddar cheeses have been published [4-8]. However, other cheeses with higher levels of consumption, such as low fat soft cheeses, have received much less attention. Whey produced from cheese making (including cream cheese), as a by- product, limits productivity. Whey has few uses and results in the loss of valuable proteins for the cheese product. The production of whey can also create additional costs for waste treatment, even though whey contains food grade ingredients which have been separated from milk. The inability of whey proteins to be retained in cheese is an important factor contributing to a lake of efficiency in the production of cheese, including reduction in overall yield and increased costs [9].Although whey has sometimes been further processed to obtain food ingredients, the acid whey generated cream cheese product cannot normally be utilized in this manner. It would be desirable, therefore, to provide a process for making cream cheese in which whey is retained in the final product [10]. Wheyless cream cheese is a soft cheese containing more than about 65 percent moisture with a high whey protein/casein ratio (e.g., about 60/40 or higher) and with desirable firmness which does not involve whey separation [10]. The most recent definition says that probiotics are live microorganisms administered in amounts that positively affect the health of the host [11, 12].In addition to the probiotic approach of directly introducing live bacteria to the colon through dietary supplementation, another approach to increase the number of beneficial bacteria, such as bifidobacteria, in the intestinal microbiota is through the use of prebiotics. Prebiotics are non-digestible dietary components that pass through to the colon and selectively stimulate the proliferation and/ or activity of populations of desirable bacteria in situ [13]. Inulin is a linear β (2 1)-linked fructose polymer that occurs in garlic, asparagus root, Jerusalem artichoke, dahlia tubers or chicory root [14]. It is a carbohydrate- based fat replacer. Fresh cream cheese is a cheese obtained from the homogenization of a fresh cheese base with further ingredients, including gums and hydrocolloids, salt and other spices. This cheese is a versatile food that permits addition of other ingredients, including fibres like inulin. It has a spreadable structure, and is used as a spread on bread, in sandwiches and as a salad dressing. It is an unripened cheese, stored at refrigeration temperatures, and the shelf life is rather limited [15]. The incorporation of inulin, as a partial fat replacer, specifically in wheyless cream cheese, has not been previously reported. Therefore, the objective of this study was to examine the effect of level of inulin incorporation on the chemical properties (pH, fat, dry matter, moisture and salt) of wheyless cream cheese. For this purpose, the wheyless cream cheese with different contents of inulin was produced and investigated. MATERIALS AND METHODS 2.1 Additives The following additives are involved in the production of wheyless cream cheese: • Two stabilizers: locust been gum (LBG, Robertet, The Netherlands) and carrageenan (CL220, Danisco, Denmark). • Dairy proteins consisted of skim milk powder (SMP, Iran), whey protein concentrate (WPC, Progel, Netherlands) and sodium caseinate (EM7, Netherlands), to provide an aqueous dairy protein blend. • Inulin (Frutafit TEX, SENSUS, Netherlands) . • Coagulant (Standard rennet, Chy-Max, Chr, Hansen Inc., Denmark: 183 International MilkClotting Units (IMCU)/mL (International Dairy Federation, 1997)) . Pelagia Research Library 691
Khadijeh Poursharif et al Euro. J. Exp. Bio., 2012, 2 (3):690-694 ______________________________________________________________________________ 2.2 Starter culture Mesophilic starter culture, contained Lactococcus lactis subsp. Cremoris, Lactococcus lactis subsp. Lactis, Lactococcus lactis subsp. biovar diacetylactis and Leuconostoc mesenteroides subsp. Cremoris, was obtained from Chr.Hansen, Denmark. 2.3 Cheese making Cream cheese was made according to the wheyless cream cheese process [10]. Wheyless cream cheese was produced from fresh bovine milk. The milk was first standardized t0 the fat content of about 10-12% for low fat cream cheese and 24-28% for high fat cream cheese ,which was kept as control. Then milk was heated at 60 ৹C and mixed powders skim milk powder(2%w/w), whey protein concentrate(0.5%w/w),locust bean gum (0.01%w/w), carrageenan,(0.7%w/w),sodium caseinate (5%w/w) and inulin [0%w/w (control or treatment CI,0 ), 8%w/w (treatment CI,8), 10%w/w (treatment CI,10) and 12%w/w (treatment CI,12). Then was heated at 70 ৹C and homogenized at about 200 bar and pasteurized at 80 ৹C for 20 min and cooled to 22 ৹C. The pasteurized milk was inoculated with a mesophilic culture at 22 ৹C and incubated at this temperature until the pH reached a value of ~ 4.7. Starter was used at the rate of 1% w/w. After 20 min, rennet was diluted 30 fold with cold water and then added, at concentration of 4.5 IMCU/kg of milk , to milk. The curd was heated, after coagulation, and added salt (0.8w/w). At this point, The mass was then agitated very gently. The mixture cooked at 40-60 ৹C and homogenized at about 20-70 bar. The samples were then hot packed at 70 ৹C into 100-g plastic cups and cooled to the storage temperature, 4 ৹C. 2.4 Chemical analysis The fat content of cream cheeses was determined by Gerber method [16].The pH of cheese samples was measured with a digital pH meter (Mettler Toledo PH meter, model S20-k, Switzerland).Cheese was analyzed for moisture content by vacuum-oven method [17].Salt content was determined according to the Iran standard methods. All analyses were conducted after one day of storage at 4 ৹C. 2.4 Statistical analysis Each treatment was performed in three replications. All data are presented as the Mean ± Standard Deviation (SD). After verifying normality of variables, ANOVA analysis followed by Duncan post-hoc test for multiple comparisons were done at significant level of 0.05 (p
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