Physical Properties of Direct Acidified Mozzarella Cheese from Ultrafiltered Whole Milk Retentates

Retentates from ultrafiltration of pasteurized whole milk at three volume concentration ratios, 1.4:1, 1.7:1 and 2:1. were made into Mozzarella cheese by direct acidification with 10% glacial acetic acid.Excellent melting Mozzarella cheese was attained and increases in cheese yield were related directly to retentate concentration. Yield efficiency, based on casein recovery, was higher in retentate cheese than in controls. Cheese from ultrafiltered whole milk using low concentrated retentates generally showed improved physical properties over that of nonretentate control whole milks. Composition of direct acidified cheese from whole milk retentates when compared with federal standards of identity fitted those of low moisture Mozzarella rather than Mozzarella.     

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.     

Manufactore of Ras cheese from ultrafiltered milk supplemented with caseinates

Whole cow's milk was ultrafiltered (conc. Factor 5), sodium and calcium caseinate were added to the milk retentate at the rate of 0.5 and 0.75% (w/w) of the milk. Ras cheese was made from milk retentate supplemented with different levels of caseinate salts, as well as unsupplemented retentates, and compared with Ras cheese made by the traditional method. Retentate supplemented with 0.5% Na and Ca caseinate was suitable for Ras cheese-making with limited whey drainage, supplementation of retentate with 0.75% Ca caseinate gave defective cheese at the end of ripening, while Na caseinate increased soluble N and free fatty acids in the cheese. Organoleptic scoring showed that supplementation with Na caseinate enhanced cheese ripening.     

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.     

Production and Quality of Cheddar Cheese Manufactured from Whole Milk Concentrated By Reverse Osmosis

Pasteurized whole milk was concentrated by reverse osmosis (RO) on a pilot plant scale. The retentate was then used to produce cheddar cheese following the traditional method but using 50% less starter and 60% less rennet. The biochemical composition of the RO cheese was close to that of ordinary cheddar. The resulting non uniformity of the fresh curd as well as the granular texture of the cheese were probably due to the high lactose content of the retentate. Contamination of the milk from bacteria already present in the reverse osmosis system caused the high coliform level of the cheese.     

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.     

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.     

Influence of milk ultrafiltration on bacteriophages of lactic acid bacteria

Bacteriophages added to whole milk were partially concentrated during ultrafiltration. At 4:1 retentate, phage had concentrated 2.4:1. Thermal destruction at 54 degrees C followed first order kinetics up to 6% protein, whereafter it deviated. When allowed to grow in retentate in the presence of appropriate host, 3.5 generations of phage appeared after 12 h at 22 degrees C compared with four generations in skim milk. In the presence of phage, lactic acid bacteria population increased to only 10(7) cfu/ml compared with 3 X 10(9) in their absence. Retentate starter prepared in the presence of phage was as active as skim milk starter prepared in the presence of phage.     

Manufacture and quality of UF Ras cheese

Ras cheese was made by means of the traditional method from cow's milk and milk concentrated by ultrafiltration to concentration factors 2 and 5, and from diafiltered x5 retentate. The fresh cheese yield was determined and cheese was ripened for 3 months, changes in moisture, fat, nitrogen fractions, pH, acidity and ripening indices were followed periodically during the ripening period. The organoleptic properties of the cheese were also assessed. UF Milk retentate gave higher cheese yield depending on concentration factor. UF Ras cheese from high concentrated retentate was characterized by slow protein degradation, flavour development and hard texture. The composition and properties of UF Ras cheese from x2 retentate were close to that of traditional Ras cheese.     

Effects of standardization of whole milk with dry milk protein concentrate on the yield and ripening of reduced-fat cheddar cheese

Commercial milk protein concentrate (MPC) was used to standardize whole milk for reduced-fat Cheddar cheesemaking. Four replicate cheesemaking trials of three treatments (control, MPC1, and MPC2) were conducted. The control cheese (CC) was made from standardized milk (casein-to-fat ratio, C/F approximately 1.7) obtained by mixing skim milk and whole milk (WM); MPC1 and MPC2 cheeses were made from standardized milk (C/F approximately 1.8) obtained from mixing WM and MPC, except that commercial mesophilic starter was added at the rate of 1% to the CC and MPC1 and 2% to MPC2 vats. The addition of MPC doubled cheese yields and had insignificant effects on fat recoveries (approximately 94% in MPC1 and MPC2 vs. approximately 92% in CC) but increased significantly total solids recoveries (approximately 63% in CC vs. 63% in MPC1 and MPC2). Although minor differences were noted in the gross composition of the cheeses, both MPC1 and MPC2 cheeses had lower lactose contents (0.25 or 0.32%, respectively) than in CC (0.60%) 7 d post manufacture. Cheeses from all three treatments had approximately 10(9) cfu/g initial starter bacteria count. The nonstarter lactic acid bacteria (NSLAB) grew slowly in MPC1 and MPC2 cheeses during ripening compared to CC, and at the end of 6 mo of ripening, numbers of NSLAB in the CC were 1 to 2 log cycles higher than in MPC1 and MPC2 cheeses. Primary proteolysis, as noted by water-soluble N contents, was markedly slower in MPC1 and MPC2 cheeses compared to CC. The concentrations of total free amino acids were in decreasing order CC > MPC2 > MPC1 cheeses, suggesting slower secondary proteolysis in the MPC cheeses than in CC. Sensory analysis showed that MPC cheeses had lower brothy and bitter scores than CC. Increasing the amount of starter bacteria improved maturity in MPC cheese.     

Characterization of Nitrogen Fractions During Ripening of a Soft Cheese Made from Ultrafiltration Retentates

Nitrogen fractions of a soft cheese made from UF retentates were used to characterize the ripening of the cheese. Whole milk was fractionated, using UF and diafiltration to a retentate concentration factor of five times. Control and experimental soft, white cheeses were made from whole milk and UF retentate, respectively. Both cheeses were ripened at 8°C for 21 d and analyzed at 7-d intervals. Nitrogen fractions were separated and discontinuous PAGE was used to characterize total protein and whey protein. A ripening extension index related to rennet activity was determined based on the ratio of soluble N to total N. A ripening depth index related to starter peptidase activity was determined by the ratio nonprotein N/total N. Increases in ripening extension index and ripening depth were higher (48.45 and 18.56%, respectively) in UF cheese than in regular cheese (41.06 and 17.11%, respectively). The N fractions soluble in 20% sodium sulfate were composed mainly of bovine serum albumin, β-lactoglobulin A and B, and α-lactalbumin in fresh and ripened UF cheese. Whey protein N represented about 17 and .5% of total N in UF and regular cheese, respectively. No significant breakdown was detected in the whey protein N fraction in the UF 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.     

Effect of ultrafiltration,fat reduction and salting on textural properties of white brined cheese

The influence of ultrafiltration of whole and skim milk on rennetability in the course of white pickled cheese manufacturing was investigated. Concentrating factors of the milk were selected as 3x, 4x, 5x and 5.5x. The renneting properties of the unconcentrated milk and the retentates (skim and whole milk ultrafiltration retentates) were explained. The white cheese produced from unconcentrated whole milk via a traditional industrial method was compared with the white cheese produced by whole milk retentate (5.5-fold). The cheeses manufactured from retentate were salted using different methods, i.e. dry salting, brine salting and salt addition before renneting. The effect of salting method on the texture of UF-cheese was determined after three months storage. It was suggested that producing of white pickled cheese from whole milk retentate (full-concentrated) was more suitable than manufacturing from skim milk retentate and was than better the conventional method which uses unconcentrated milk, actually.     

Cathepsin D activity in quarg

Quarg cheese was produced from raw skim milk, pasteurised skim milk, raw skim milk with rennet added and ultrafiltrated raw skim milk. Quarg was also produced from raw skim milk with pepstatin added at curd cutting and from ultrafiltration retentate of raw milk with added pepstatin. No starter bacteria were used in this model system, with the reduction of pH being achieved by addition of glucono- δ-lactone. Yields ranged between 20.25 and 23.5%, with protein levels of 13.6–15.7%. Proteolysis occurred during storage of all experimental cheese samples for 3 m at 8°C. By immunoblotting using antibodies against bovine cathepsin D, immunoreactive procathepsin D was identified in all cheese samples. Presence of cathepsin D or procathepsin D-derived activity was confirmed by a specific enzyme assay in all samples, except those which contained pepstatin. Inhibition of cathepsin D-catalysed proteolysis by pepstatin was observed in chromatograms of water-soluble extracts analysed by reverse-phase HPLC. Peptides thought to be produced as a result of cathepsin D activity were observed in cheese made from both raw and pasteurised milk, suggesting that the activity at least partially survived pasteurisation.     

The behavior of selected microorganisms during the manufacture of high moisture Jack cheeses from ultrafiltered milk.

Whole milk was pasteurized and concentrated two times by ultrafiltration. Starter cultures, Lactococcus lactis ssp. cremoris and Lactococcus lactis ssp. lactis, were propagated in either reconstituted skim milk, two times UF retentate, or UF permeate, or a direct vat system was used for the starter culture. The cheese milk was simultaneously inoculated with starter culture and Pseudomonas fragi 4973, Staphylococcus aureus 196E, and Salmonella typhimurium var. Hillfarm. Control whole milk, UF control milk, inoculated whole milk, and inoculated UF milk were made into Monterey Jack cheese using traditional procedures. The process of cheese manufacture was followed by determination of pH, titratable acidity, and microbial population levels. The cheeses were stored for 6 mo and analyzed every month for percentage solids and microbial population levels. Generally, numbers of contaminant microbes increased at a similar rate during manufacture in all cheeses. During the 6-mo ripening period, bacterial starter culture population levels remained high, psychrotrophs declined slowly, Staphylococcus levels remained stable, and Salmonella populations decreased. No Staphylococcus enterotoxin was detected by reverse passive latex agglutination assay.     

An attempt to produce low fat cephalotyre (Ras) cheese of acceptable quality

Two trials were carried out to produce low fat Ras cheese with acceptable organoleptic properties. In the first trial, cheese milk containing 1%, 1·5% or 2% fat and including CMC or carrageenan at levels of 0·1% and 0·02%, respectively, was used in cheese making. Control cheese was also made from milk containing 4% fat. Cheese without added stabilizers and containing lower fat levels than the control cheese had a flat flavour and tough rubbery body throughout ripening. The addition of both stabilizers improved the body characteristics of low fat cheese but did not affect flavour development in cheeses made from 1% and 1·5% fat milk and only slightly enhanced flavour intensity in cheese made from 2% fat milk.In the second trial, cheese milk of 1% or 1·5% fat with added 0·02% carrageenan was used for the preparation of Ras cheese curd. The resultant curd was then mixed with 2% of a starter culture containing S. diacetylactis and L. casei with 10 ml of 0·05% MnCl₂ solution for each kilogram of curd or reduced glutathione at a level of 100 mg/kg curd. The additives enhanced flavour intensity, improved body characteristics and accelerated the formation of both soluble nitrogenous compounds and Free Volatile Fatty Acids.     

Influence of salt-to-moisture ratio on starter culture and calcium lactate crystal formation

The occurrence of l(+)-lactate crystals in hard cheeses continues to be an expense to the cheese industry. Salt tolerance of the starter culture and the salt-to-moisture ratio (S:M) in cheese dictate the final pH of cheese, which influences calcium lactate crystal (CLC) formation. This research investigates these interactions on the occurrence of CLC. A commercial starter was selected based on its sensitivity to salt, less than and greater than 4.0% S:M. Cheddar cheese was made by using either whole milk (3.25% protein, 3.85% fat) or whole milk supplemented with cream and ultrafiltered milk (4.50% protein, 5.30% fat). Calculated amounts of salt were added at milling (pH 5.40 ± 0.02) to obtain cheeses with less than 3.6% and greater than 4.5% S:M. Total and soluble calcium, total lactic acid, and pH were measured and the development of CLC was monitored in cheeses. All cheeses were vacuum packaged and gas flushed with nitrogen gas and aged at 7.2°C for 15 wk. Concentration of total lactic acid in high S:M cheeses ranged from 0.73 to 0.80 g/100 g of cheese, whereas that in low S:M cheeses ranged from 1.86 to 1.97 g/100 g of cheese at the end of 15 wk of aging because of the salt sensitivity of the starter culture. Concentrated milk cheeses with low and high S:M exhibited a 30 to 28% increase in total calcium (1,242 and 1,239 mg/100 g of cheese, respectively) compared with whole milk cheeses with low and high S:M (954 and 967 mg/100 g of cheese, respectively) throughout aging. Soluble calcium was 41 to 35% greater in low S:M cheeses (low-salt whole milk cheese and low-salt concentrated milk cheese; 496 and 524 mg/100 g of cheese, respectively) compared with high S:M cheeses (high-salt whole milk cheese and high-salt concentrated milk cheese; 351 and 387 mg/100 g of cheese, respectively). Because of the lower pH of the low S:M cheeses, CLC were observed in low S:M cheeses. However, the greatest intensity of CLC was observed in gas-flushed cheeses made with milk containing increased protein concentration because of the increased content of calcium available for CLC formation. These results show that the occurrence of CLC is dependent on cheese milk concentration and pH of the cheese, which can be influenced by S:M and cheese microflora.     

Manufacture of heat and acid coagulated cheese from ultrafiltered milk retentates

Ultrafiltration technology was used for the production of direct acidified cheese. Process parameters were optimized for cheese manufacture from whole milk retentates at 4:1 volume concentration ratio. Sensory evaluation indicated that cheese from ultrafiltration was preferred equally to traditional manufacture when the cheese was of similar composition, while citric acid was the preferred acidulent. An increase in cheese yield of 3.3% and an increase in yield on dry matter mass basis of 14.7% was achieved by use of ultrafiltration. Yield efficiencies based on protein, fat or total solids increased with retentate concentration.     

Ultrafiltration of Milk on French Farms and in the Making of a New Specialty Cheese Industry

Ultrafiltration and thermization of milk on dairy farms in France have been under study since 1979. More recently five dairy farms in Brittany have been routinely producing 2:1 whole milk retentate for Emmental and St. Paulin cheese making. The milk processed is ultrafiltered at 35°C and thermized at 72°C for 15 s in an Ultratherm unit. Cheese quality generally appears satisfactory.In Eastern France a new specialty cheese industry has been started utilizing 4.5:1 whole milk retentate produced by ultrafiltration conducted at 40°C. The specialty cheese attains its characteristic white surface from Penicillium album mold. It has a bland, nutty flavor and very soft, smooth texture. A surface bluing phenomenon occurs after 14 d.     

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.