Cheddar Cheese from Ultrafiltered Whole Milk Retentates in Industrial Cheese Making

Transporting whole milk retentates of ultrafiltration to a distant large industrial Cheddar cheese making site resulted in 16 lots of Cheddar cheese from vats containing 2,546 to 16,360 kg of cheese milk. Whole milk retentates concentrated by ultrafiltration to 4.5:1 were added to cheese milks to give mixtures concentrated 1.2:1 and 1.3:1 with approximately 20 and 30% more protein and fat, respectively, than in unsupplemented control whole milks or unsupplemented commercial reference milks.Gross composition of Cheddar cheese made from commercial reference, control, and retentate-supplemented milk generally showed no major differences. Yield increased in cheese made from retentate-supplemented milk. Yield efficiency per kilogram total solids rose in retentate cheese over controls but not among commercial reference, control, and retentate lots based on per kilogram fat or total protein. Milk components were higher in wheys from retentate cheeses, but loss of components per kilogram cheese obtained generally showed lower values in whey from retentate cheese.General quality of retentate Cheddar cheese was equal to that of reference unsupplemented commercial cheese and higher than unsupplemented control Cheddar cheeses. It appears technically feasible to ultrafilter milk at one site, such as the farm, collecting station, or specialized center, and transport it to an industrial site for Cheddar cheese making.     

Low Moisture Mozzarella Cheese from Whole Milk Retentates of Ultrafiltration

Whole milk retentates, prepared by ultrafiltration of pasteurized milk to volume concentration ratios of 1.5:1, 1.75:1, and 2:1, were made into low moisture Mozzarella cheese using thermophilic bacterial cultures.Good melting properties, increased output per vat, and higher yield efficiency based on total solids were observed in retentate over control cheese. Optimum retentate volume concentration ratio was 1.75:1. Cheese from 2:1 volume concentration ratio retentates had desirable qualities but were firmer with greater whey fat losses than cheese from non-retentate controls or 1.5:1, and 1.75:1 volume concentration ratio retentates. Composition of cheese made from whole milk retentates using thermophilic starters complied with US federal standards of identity for low moisture Mozzarella cheese.     

Cottage Cheese from Ultrafiltered Skim Milk Retentates in Industrial Cheese Making

Ultrafiltered skim milk retentates were transported to a large industrial cottage cheese plant for milk supplementation leading to cottage cheese. The resulting industrial products were observed for composition, yields, whey component losses, and quality.Ten lots of small curd cottage cheese were made in vats containing up to 6593 kg skim milk. Retentate supplemented skim milks, concentrated approximately 10% (1.1:1) and 20% (1.2:1) in total protein, were very similar in initial composition to the controls. Mean cheese yield values from milks supplemented to 1.2:1 total protein were significantly higher than mean unsupplemented control milk values. Cheese yield efficiencies, per kilogram total solids, were also significantly higher in the retentate cheese but not when calculated per kilogram total protein.Total solids, total protein, and ash were higher in cottage cheese wheys from retentate supplemented cheese and were directly related to retentate supplementation concentration. Mean whey component loss per kilogram cheese exhibited significant decreases from milks of higher retentate supplementation. Retentate supplemented skim milk produced industrial cottage cheese of comparable quality to cheese made from unsupplemented control skim milks.     

Use of cold microfiltration retentates produced with polymeric membranes for standardization of milks for manufacture of pizza cheese

Pizza cheese was manufactured with milk (12.1% total solids, 3.1% casein, 3.1% fat) standardized with microfiltered (MF) and diafiltered retentates. Polymeric, spiral-wound MF membranes were used to process cold (<7°C) skim milk, and diafiltration of MF retentates resulted in at least 36% removal of serum protein on a true protein basis. Cheese milks were obtained by blending the MF retentate (16.4% total solids, 11.0% casein, 0.4% fat) with whole milk (12.1% total solids, 2.4% casein, 3.4% fat). Control cheese was made with part-skim milk (10.9% total solids, 2.4% casein, 2.4% fat). Initial trials with MF standardized milk resulted in cheese with approximately 2 to 3% lower moisture (45%) than control cheese (∼47 to 48%). Cheese-making procedures (cutting conditions) were then altered to obtain a similar moisture content in all cheeses by using a lower setting temperature, increasing the curd size, and lowering the wash water temperature during manufacture of the MF cheeses. Two types of MF standardized cheeses were produced, one with preacidification of milk to pH 6.4 (pH6.4MF) and another made from milk preacidified to pH 6.3 (pH6.3MF). Cheese functionality was assessed by dynamic low-amplitude oscillatory rheology, University of Wisconsin MeltProfiler, and performance on pizza. Nitrogen recoveries were significantly higher in MF standardized cheeses. Fat recoveries were higher in the pH6.3MF cheese than the control or pH6.4MF cheese. Moisture-adjusted cheese yield was significantly higher in the 2 MF-fortified cheeses compared with the control cheese. Maximum loss tangent (LT_max) values were not significantly different among the 3 cheeses, suggesting that these cheeses had similar meltability. The LT_max values increased during ripening. The temperature at which the LT_max was observed was highest in control cheese and was lower in the pH6.3MF cheese than in the pH6.4MF cheese. The temperature of the LT_max decreased with age for all 3 cheeses. Values of 12% trichloroacetic acid soluble nitrogen levels were similar in all cheeses. Performance on pizza was similar for all cheeses. The use of MF retentates derived with polymeric membranes was successful in increasing cheese yield, and cheese quality was similar in the control and MF standardized cheeses.     

Evaluation of Yield and Quality of Cheddar Cheese Manufactured from Milk with Added Whey Protein Concentrate

Cheddar cheese was produced from whole milk with blends of whey protein concentrates added. Two whey protein concentrate powders containing 35 or 55% protein were each reconstituted to a 15% (wt/wt) suspension and heat treated at 70°C for 15 min. Addition of the denatured whey protein concentrate suspension to the milk was at 5 or 10% by weight of the milk. Addition of reconstituted partially denatured whey protein concentrate increased cheese yields from 1.4 to 6.2% above those of the control on a 63% solids basis. The only significant (P<.05) increase in yield was from the 55% whey protein concentrate suspension at 10% replacement by weight of the milk. The correlation coefficient between percent denaturation in the whey protein concentrate and yield in this cheese was .62. Experimental cheese had decreased fat and total solids contents and increased total nitrogen, ash, and salt. Fat reduction varied from 4.3 to 18.2% below the control cheese, and total solids were from 1.7 to 8.9% below the control cheeses. Total nitrogen values of experimental cheese were from .73 to 5.64% above the control. Cheeses were evaluated organoleptically; more flavor defects were associated with increased whey protein concentrate in the experimental cheese. The most common criticism of the experimental cheese was an atypical (unclean) cheese flavor.     

Use of cold ultrafiltered retentates for standardization of milks for pizza cheese: Impact on yield and functionality

Pizza cheese was manufactured from two types of Ultrafiltration (UF)-fortified milks: high solids (UFHS; 15.2% TS) and medium solids (UFMS; 13.5%). Cheese milks were obtained by blending cold processed UF retentate with partially skimmed milk and UF (skim milk) retentate. Cheese functionality was assessed using oscillatory rheology and by baking on a pizza. Gels made from UF-fortified milks had similar clotting times and they clotted faster than control milk. Shear stress values of gels from UF-fortified milks were higher than control. Fat recoveries in the cheeses increased in the order UFHS<control<UFMS. Nitrogen recoveries were lower in control than UF-fortified cheeses. During heating loss tangent curves shifted higher during the first month of ripening and the temperature for the maximum loss tangent decreased. Crossover temperature also decreased during ripening. Trichloroacetic acid-soluble nitrogen levels were similar in all cheeses. Standardization of cheese milk with cold UF retentates increased yield without adversely affecting functionality.     

Standardization of milk using cold ultrafiltration retentates for the manufacture of parmesan cheese

The effects of using cold ultrafiltered (UF) retentates (both whole and skim milk) on the coagulation, yield, composition, and ripening of Parmesan cheese were investigated. Milks for cheese making were made by blending cold UF retentates with partially skimmed milk to obtain blends with 14.2% solids and a casein:fat ratio of 1.1. Cutting times, as selected by the cheese-maker, were approximately 15 and approximately 20 min for experimental and control milks, respectively. Storage modulus values at cutting were similar, but yield stress values were significantly higher in UF retentate standardized milks. Cheese yields were significantly higher in UF retentate standardized milks (approximately 12%) compared with control milk (cream removed) (approximately 7 to 8%). Significantly higher protein recoveries were obtained in cheeses manufactured using cold UF retentates. There were no differences in the pH and moisture contents of the cheeses prior to brining, and there was no residual lactose or galactose left in the cheeses. Using UF retentates resulted in a significant reduction in whey volume as well as a higher proportion of protein in the solids of the whey. Proteolysis, free fatty acids, and sensory properties of the cheeses were similar. The use of milk concentrated by cold UF is a promising way of improving the yield of Parmesan cheese without compromising cheese quality. The question remaining to be answered by the cheesemaker is whether it is economical to do so.     

Incorporation of Ultrafiltration Concentrated Whey Solids into Cheddar Cheese for Increased Yield

A process for incorporating whey solids into Cheddar cheese was evaluated. Whey was concentrated by ultrafiltration to between 9.8 and 20.3% solids (4.3 to 7.1% protein) and then heated at 75°C for 30 min. Return of this concentrate to cheese milk increased average yield 4.0% at constant cheese moisture. Cheese made by this procedure was lower in fat than control cheese and had a higher moisture content. Setting time was shorter, and acid development was faster. The pH was lower than that of the control cheese. Specific body, texture, and flavor characteristics were identified. Acid was the only flavor defect more prominent in experimental than in control cheese. None of the specific body or texture characteristics was significantly different.     

Yield and functionality of Cheddar cheese as influenced by homogenization of cream

Cheese milk was standardized (casein-to-fat ratio of 0.7) by blending 0.64% fat milk and 35% fat cream. Cream was homogenized at 0/0 MPa (CO), 3.5/3.5 MPa (H05), 6.9/3.5 MPa (H10) or 10.4/3.5 MPa (H15). Cream homogenization did not influence rennet-clotting time, but it increased rate of curd firming and increased curd firmness of cheese milk. Moisture and salt in moisture phase of cheese increased with homogenization. Moisture (37%) and salt (1.5%) adjusted yield increased 1.42, 3.44 and 3.85% in H05, H10 and H15, respectively, over CO. Homogenized treatment cheeses melted faster with age. Free oil in 1 week old cheeses was lowest in H10 and highest in H05 and increased in all treatments with age. Cheese hardness was not influenced by homogenization but decreased with age. Cheeses with homogenized cream had improved body and texture and flavor. Cream homogenized at 6.9/3.5 MPa was optimal for enhancing Cheddar cheese yield and functionality.     

Yield and Quality of Cheddar Cheese from High Somatic Cell Milk Supplemented with Retentate to Varying Concentrations or Directly Ultrafiltered

High somatic cell milk with a mean cell count of 2,235,000/ml was supplemented to 1.25:1 to 1.88:1 total protein with approximately 5.5:1 low somatic cell whole milk retentate of UF. Curd formation time of cheese milk decreased with increasing concentration of SCC. Supplemented milk concentrated to 1.65: 1 and 1.88:1 total protein displayed normal curd formation times: 34 and 31 min, respectively. Also, cheese made from these mixtures had normal moisture, whereas the remaining cheeses had higher than normal moisture. Supplementation to 1.65:1 and 1.88:1 total protein increased cheese yield by 9.67% and 11.38%, respectively, and produced excellent quality cheese after 2 mo at 10°C.Direct UF of high SCC milk to 1.84:1 total protein improved cheese quality and increased yield over control milk cheeses but not to the same high level attained with retentate supplementation.     

Alternative Test for Phosphorous in Cheese

A modified test for phosphorous in cheese based on quantitative precipitation, filtration, and indirect titration of milligram quantities of phosphorous is presented. The procedure was designed specifically for Cheddar cheese and was used to analyze a wide range of Cheddar samples including some with atypically high and low calcium and phosphorous. A modification of the procedure permitted measurement of total ash, calcium, and phosphorous in the same cheese sample. With reagent adjustments it is possible to test other cheese varieties as well as other dairy products.Average recovery of phosphorous from 10 replicate solutions containing known amounts of calcium and phosphorous was 99.1 ± .7%. Average recovery of phosphorous added to 10 replicate Cheddar cheese samples was 98.9 ± 1.5%. Ten Cheddar cheeses were analyzed in duplicate by the proposed method and by atomic emission. Results of the two methods differed by an average of .015% phosphorous, a significant difference, but the methods were strongly correlated (r =.94).Duplicate analyses by the proposed method were conducted on 54 Cheddar cheese samples ranging from .427 to .555% phosphorous. The average difference between duplicate measurements was .011 ± .009% phosphorous. The principle of the proposed test and modifications required for cheese analysis are discussed.     

Salt Diffusion in Cheddar Cheese

Salt changes in Cheddar cheese made intentionally with poor salt distribution and in model systems have been determined. Salt equilibrium was not attained within blocks of Cheddar cheese during 24 wk ripening. Diffusion of salt from milled salted curd into unsalted curd in a model system likewise was very slow with a steep salt gradient still existing after 56 d.In contrast, salt diffusion in 2 × 2 × 6-cm pieces of Cheddar curd was rapid with equilibration in about 48 h. Also, salt diffusion into unsalted discs (7.4 diameter by 2 cm thick) of curd from salted discs of curd was rapid.Brine salting of Cheddar cheese showed that the diffusion coefficient was directly related to moisture content and was consistent with those obtained in other cheeses.Reasons for a slow rate of salt equilibration in nonbrine-salted Cheddar cheese are proposed.     

Effect of Lecithin on Cheese Yield

Cheese manufactured from milk containing three types of lecithin with different acetone-insoluble concentrations were compared with control cheese. A randomized block design with four treatments (three lecithins and one control) was replicated six times in the manufacture of 24 vats of cheese. Commercial lecithins (.05%) were added to the cheese milk at the time of starter addition. Cheese was manufactured by a Colby procedure. Milk was assayed for total solids, fat, total nitrogen, noncasein nitrogen, and acid degree value. Cheese was assayed for solids, acid degree value, and fat. Whey was assayed for total nitrogen, fat, and acid degree value. Milk and cheese weights were to the nearest. 1 g. Wet cheese yield increased by an average of 1.9% for cheese containing lecithin. Adjusted whey fats decreased and cheese fat increased slightly (not significant) in lecithin-treated milk and whey surface fat appeared to decrease. No treatment effect was observed for whey total nitrogen or acid degree values of cheese. Whey acid degree values were greater for the STA-SOL UF^TM, suggesting that the carrier oil on the whey surface contained some free fatty acids. Apparently, the increased yield was largely due to increased moisture content with a small increase from the milk fat. The resulting increase in fat may be an economic advantage to cheese manufacturers.     

Impact of ropy and capsular exopolysaccharide-producing strains of Lactococcus lactis subsp. cremoris on reduced-fat Cheddar cheese production and whey composition

Cheddar cheese mixed starter cultures containing exopolysaccharide (EPS)-producing strains of Lactococcus lactis subsp. cremoris (Lac. cremoris) were characterized and used for the production of reduced-fat Cheddar cheese (15% fat). The effects of ropy and capsular strains and their combination on cheese production and physical characteristics as well as composition of the resultant whey samples were investigated and compared with the impact of adding 0.2% (w/v) of lecithin, as a thickening agent, to cheese milk. Control cheese was made using EPS-non-producing Lac. cremoris. Cheeses made with capsular or ropy strains or their combination retained 3.6–4.8% more moisture and resulted in 0.29–1.19 kg/100 kg higher yield than control cheese. Lecithin also increased the moisture retention and cheese yield by 1.4% and 0.37%, respectively, over the control cheese. Lecithin addition also substantially increased viscosity, total solid content and concentrating time by ultra-filtration (UF) of the whey produced. Compared with lecithin addition, the application of EPS-producing strains increased the viscosity of the resultant whey slightly, while decreasing whey total solids, and prolonging the time required to concentrate whey samples by UF. The amount of EPS expelled in whey ranged from 31 to 53 mg L⁻¹. Retention of EPS-producing strains in cheese curd was remarkably higher than that of non-producing strains. These results indicate the capacity of EPS-producing Lac. cremoris for enhanced moisture retention in reduced-fat Cheddar cheese; these strains would be a promising alternative to commercial stabilizers.     

Fermentation of Ultrafiltered Skim Milk Retentates with Mesophilic Lactic Cheese Starters

Acid production and its relation to pH changes by commercial, direct-set frozen concentrated lactic starters in skim milk and 2:1 skim milk retentates were studied. Retentates resisted pH change below pH 5.2 despite the production of large amounts of lactic acid by starter bacteria. Control skim milk required 6 h at 32°C to attain pH 4.6, but skim milk retentates incubated similarly could not be fermented to this pH even after 8.5 h. Doubling the starter inoculum in the retentate led to pH 4.6 in 7.5 h. Direct-set starter DS1, with more bacteria numbers than direct-set starter DS2, fermented skim milk and 2:1 skim milk retentate more rapidly.     

Identification of bioactive peptides in commercial Cheddar cheese

This study examined the presence of antimicrobial, antioxidant and antihypertensive peptides in three commercially available Australian Cheddar cheeses. Peptide extracts as well as fractionated peptide extracts were examined. Commercial cheese A peptides exhibited the greatest inhibition against Bacillus cereus and also commercial cheese A fractionated peptides greater than 10 kDa showed the highest inhibition against B. cereus. Commercial cheese A peptides also showed the highest inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH), a free radical used to measure antioxidant activity. All cheese fractionated peptides greater than 10 kDa demonstrated higher inhibition of DPPH after fractionation. Antihypertensive peptides were determined by inhibition of the angiotensin-converting enzyme (ACE). Overall, commercial cheese A had the lowest concentration required to inhibit ACE and commercial cheese A fractionated peptides lower than 5 kDa had the lowest inhibition after fractionation. These preliminary findings suggest that peptide extracts of three commercial Australian Cheddar cheeses exhibit antimicrobial, antihypertensive and antioxidant properties.     

The effect of fat content on the rheology,microstructure and heat-induced functional characteristics of Cheddar cheese

Cheddar cheeses with the different fat contents were made in triplicate and ripened at 4°C for 30 d and at 7°C for the remainder of the 180-d investigation period. The cheeses were designated: full-fat (FFC), 300 g kg⁻¹; reduced-fat (RFC), 219 g kg⁻¹; half-fat (HFC), 172 g kg⁻¹; and low-fat (LFC), 71.5 g kg⁻¹. A decrease in the fat content from 300 to ≤172 g kg⁻¹ resulted in significant (P<0.05) decreases in contents of moisture in non-fat substance and pH 4.6 soluble N (expressed as % total N), and increases in the contents of moisture, protein, intact casein and free amino acids. Reduction in fat content resulted in an increase in the volume fraction of the casein matrix and a decrease in the extent of fat globule clumping and coalescence. The mean values of fracture stress and firmness for the FFC were significantly lower than those of the RFC and HFC, which had similar values; the values for the LFC exceeded the limits of the test and were markedly higher than those of the other cheeses at all times. On baking the cheese, reduction in fat content resulted in significant increases in the mean melt time (time required for shred fusion) and apparent viscosity and a decrease in the mean flowability of the melted cheese. The stretchability of the FFC increased most rapidly and, at ∼15 and 30 d, attaining mean values which were significantly higher than those of the other cheeses. Thereafter the stretchability of the FFC decreased progressively to values that were significantly (i.e. at 150 d) or numerically (i.e., at 180 d) lower than those of the RFC and HFC. At ripening times ≥15 and ≤90 d, the stretchability of the LFC was significantly lower than that of the RFC, and significantly or numerically lower than the HFC.     

USE OF MILK CONCENTRATED BY ULTRAFILTRATION FOR MAKING HARD CHEESE,SOFT CHEESE AND YOGHURT*

Whole milk was concentrated by a factor of two by ultrafiltration. It was used directly for making Cheddar and Cheshire cheese, an unripened soft cheese of the Coulommier type, and yoghurt. The yields of hard cheese from the concentrated milk were the same as those from normal whole milk. The cheeses were acceptable though the flavour was milder than that of good quality Cheddar and Cheshire cheese. Medium fat soft cheeses were made from the concentrated milk. The yield of cheese was 41 per cent greater than that made from normal whole milk and the making time was half that of the normal process. The cheeses were consumed fresh or stored in deep freeze. For making yoghurt, the usual reinforcement with skim milk powder was not necessary as the concentrated milk had a high total solids content, nor was it necessary to homogenize the mix. The yoghurt contained 21 per cent total solids and was a very acceptable product.     

Effect of cream homogenization on textural characteristics of low-fat Iranian White cheese

The effects of cream homogenization of cheese making milk on textural and sensory characteristics of Iranian White cheese were studied. Cream was homogenized in a two-stage homogenizer at 6.0/2.5 or 9.0/2.5 MPa. Cheese samples were analyzed for rheological parameters (uniaxial compression and small amplitude oscillatory shear), meltability, microstructure, and sensory characteristics. Cream homogenization increased fat content leading to increased meltability. This effect increased as the homogenization pressure increased. The values of storage modulus, stress at fracture and Young's modulus of elasticity for cheeses from homogenized treatments were lower than those of unhomogenized cheese. Cream homogenization at 6.0/2.5 MPa effectively improved the textural, functional and sensory characteristics and enhanced the yield of low-fat Iranian White cheese. This cheese had the lowest values of storage modulus and stress at fracture, probably due to the high number of small, evenly dispersed fat globules in microstructure and especially its lower protein content. Cheeses with homogenized cream had improved texture, flavor and appearance.     

Vatless manufacturing of low-moisture part-skim mozzarella cheese from highly concentrated skim milk microfiltration retentates

Low-moisture, part-skim (LMPS) Mozzarella cheeses were made from concentration factor (CF) 6, 7, 8, and 9, pH 6.0 skim milk microfiltration (MF) retentates using a vatless cheese-making process. The compositional and proteolytic effects of cheese made from 4 CF retentates were evaluated as well as their functional properties (meltability and stretchability). Pasteurized skim milk was microfiltered using a 0.1-microm ceramic membrane at 50 degrees C to a retentate CF of 6, 7, 8, and 9. An appropriate amount of cream was added to achieve a constant casein:fat ratio in the 4 cheesemilks. The ratio of rennet to casein was also kept constant in the 4 cheesemilks. The compositional characteristics of the cheeses made from MF retentates did not vary with retentate CF and were within the legal range for LMPS Mozzarella cheese. The observed reduction in whey drained was greater than 90% in the cheese making from the 4 CF retentates studied. The development of proteolytic and functional characteristics was slower in the MF cheeses than in the commercial samples that were used for comparison due to the absence of starter culture, the lower level of rennet used, and the inhibition of cheese proteolysis due to the inhibitory effect of residual whey proteins retained in the MF retentates, particularly high molecular weight fractions.