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.     

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.     

Whole Milk Reverse Osmosis Retentates for Cheddar Cheese Manufacture: Cheese Composition and Yield

The impact of concentrating whole milk by reverse osmosis prior to Cheddar cheese making was studied. Heat treated, standardized, whole milk was reduced in volume by 0, 5, 10, 15, and 20% prior to Cheddar cheese manufacture. Milk solids at various milk volume reductions were 11.98, 12.88, 13.27, 14.17, and 15.05%, respectively. Permeates contained only traces of organic matter and would not create a significant by-product handling problem for a cheese plant. Solids content of the whey from cheese making increased with increasing milk concentration. Proximate compositions of reverse osmosis cheeses were comparable to control cheeses. Fat losses decreased, and fat retained in the cheese increased with increasing milk solids concentration. Improved fat recovery in the cheese was related to the amount of mechanical homogenization of milk fat during the concentration process. Actual, composition adjusted, and theoretical cheese yields were determined. Increased retention of whey solids and improved fat recovery gave cheese yield increases of 2 to 3% above expected theoretical yields at 20% milk volume reduction. Water removal from whole milk prior to Cheddar cheese manufacture gave increased productivity and cheese yield without requiring different cheese-making equipment or manufacturing procedures.     

Cheddar Cheese from Water Reconstituted Retentates

Reconstituted creamed retentates of ultrafiltration were converted to ripened cheese by Cheddar manufacturing principles. Initially, the fresh cheeses resembled normal Cheddar but during ripening were transformed into Gouda-Swiss types with pH rising rapidly from 5.2 to approximately 6.0.Cheese composition was affected by amount of full fat retentate in reconstituted mixtures. As total milk solids increased in reconstituted retentates, cheese moisture decreased and cheese volume rose to high yields. Cheese yield efficiency showed 1.21 to 1.32 kg cheese per kg total solids. Rennet curd of higher total solids retentates formed more rapidly than normal, and curds were harder. Whey from retentate reconstituted cheeses showed relatively low ash and fat even from cheeses made with high retentate. Soluble protein in 2-mo-old cheeses held at 10° C was lower in cheese from retentates of high solids.     

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.     

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.     

Application of Retentate Starter Produced from Ultrafiltered Milk to the Manufacture of Cheddar Cheese

Cheddar cheese was manufactured from whole milk and whole milk retentate using retentate starter made from milk ultrafiltered to 4:1 (vol/vol). One percent retentate starter added to whole milk and 2% starter to 1.7:1 whole milk retentate gave excellent quality cheese. Additionally, a 1% retentate starter added to whole milk gave approximately 3% more cheese. A 2% retentate starter added to 1.7:1 whole milk retentate gave 4% more cheese, reduced cheese making time over that required for control whole milk cheese, and made acid ripening of milk before renneting unnecessary. Starter concentrations above 1% in whole milk and above 2% in whole milk retentates produced some bitterness in the cheese.     

Process for Low-fat Cheese from Ultrafiltered Milk

Our objective was to optimize the process for making low-fat cheeses using liquid pre-cheeses obtained by ultrafiltration (UF). The study was conducted to examine the effects of using different proportions of cow, sheep, and goat milk in different compositions on the characteristics of cheeses, and to determine the effect of heating of the retentate on texture. Using ultrafiltered semi-skim milk (total protein content of retentate of 13–14%), cheeses with acceptable quality and reduced fat content were produced. Heating of the retentate produced by UF at 68–72°C, 20 s, improved cheese texture.     

Effect of Modified Manufacturing Parameters on the Quality of Cheddar Cheese made from Ultrafiltered (UF) Milk

Cheddar cheese was made from milk concentrated twofold by ultrafiltration (UF). Lowering the cooking and cheddaring temperature from 39°C to 35°C resulted in faster acid development, promoted more proteolysis, caused faster degradation of lactose, and contributed smoother body and texture to the cheese. Starter culture at 2% by weight of unconcentrated milk in combination with low cooking and cheddaring temperature reduced pH at faster rate and shortened the cheese making time by approximately 45 min, compared to cheese made using the traditional temperature (39°C). For the traditional temperature (39°C) of cooking and cheddaring, the addition of 0.2 mL/ kg rennet of unconcentrated milk produced the same rate of proteolysis in both control and cheese made from UF retentate. Composition (fat, protein, salt and moisture) and yield of the UF cheeses with modified temperature treatments were not significantly different from control.     

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.     

添加超滤牛乳的拉斯干酪特性

拉斯干酪添加有超滤牛乳制得,该牛乳中乳固形物质量分数分别为对照样(纯牛乳)的1.4、1.6和2.0倍,成熟3个月.拉斯干酪显示了比对照样更高的干酪得率,其水分、脂肪质量分数和pH值与对照样的相似,在成熟期均呈下降趋势,但氮质量分数等均呈上升趋势,且以牛乳中乳固形物质量分数提高到对照样的1.6倍时最高.结果表明,乳固形物质量分数为对照样1.6倍时牛乳制得的拉斯干酪其感官特性最佳.     

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.     

Nonfat Dairy Coffee Whitener Made from Ultrafiltered Skimmilk Retentates

Retentates of different protein concentrations obtained by ultrafiltration of skimmilk were freeze-dried and evaluated as nonfat dairy coffee whiteners. Blended in hot coffee the retentate whiteners containing added riboflavin gave a pH of 6.3–6.55, coffee whitening capacity comparable to a commercial nondairy coffee creamer, and acceptable dispersibility. The retentate nondairy whitener with optimum qualities contained 56% total protein, 0.5% fat, 31.0% carbohydrates, 1.92% calcium, and 27 mg sodium/100g.     

Behavior of Enteropathogenic Escherichia coli in Camembert Cheese Made From Ultrafiltered Milk

Skimmilk retentates from ultrafiltration (UF) were used in combination with concentrated cream (67% milk fat) to prepare a liquid precheese mixture that with the addition of rennet, lactic starter culture and a mold spore preparation of Penicillium candidum was transformed readily into Camembert cheese upon ripening. Yield increases from the retention of soluble milk protein, closer weight control tolerances for individual cheeses and reduction in rennet in comparison to the conventional Camembert process were observed. The behavior of enteropathogenic E. coli (ECC) serotypes was demonstrated in the Camembert cheese made from UF processes. Relationships were determined in UF Camembert as to microbial type and numbers used to inoculate the precheese, and as to site of survival and growth of different EEC serotypes. Differences which were observed in the physicochemical properties between conventional and UF cheesemilk mixtures predisposed the UF Camembert cheeses to greater E. coli survival and growth than in the Camembert cheeses made conventionally.     

Milk Plasmin Activity Influence on Cheddar Cheese Quality during Ripening

Up to six-fold increase in plasmin activity in milk did not significantly (p<0.05) affect the composition (moisture, protein, NaCl) of cheese, although a slight increase in moisture and decrease in protein content of the cheese was noted. Proteolysis in cheese increased with plasmin activity, resulting in improved flavor and overall quality of the cheese after 3 and 6 months ripening. Consistently, increasing the plasmin activity in milk about three-fold resulted in cheese of superior sensory quality.     

Calcium Bioavailability from Ripening Cheddar Cheese

Calcium bioavailability to rats was compared from CaCl₂ (28 mM), CaCO₃, fresh milk, milk adjusted to pH 5.35, and Cheddar cheese. The cheese was manufactured from pasteurized bovine milk and all doses were labeled extrinsically with ⁴⁵Ca and ⁴⁷Ca and administered orally to rats. One label (⁴⁵Ca) was added to milk before cheese manufacture and the other (⁴⁷Ca) was added to the cheese 24 h prior to dosing. Calcium bioavailability was determined by: 1) absorption measured by whole body counting, and 2) availability for bone metabolism assessed by bone radioactivity measurements. Calcium absorption averaged 76.8% and was not affected by length of ripening (p>0.05). Absorption from CaCl₂, CaCO₃, fresh milk, milk at pH 5.35, and the cheeses was similar. The two methods gave similar estimates of relative bioavailability. The ratio of ⁴⁷Ca absorption to ⁴⁵Ca absorption for any cheese sample was significantly greater than 1, indicating extrinsic labels added after processing may overestimate Ca absorption from cheese.     

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.     

豆奶,牛奶混合型干酪的研制

以豆奶和牛奶为原料，通过干酪制作条件的优化研究，得出了生产混合型干酪的重要工艺参数和技术要点。实验表明，用含有２０％豆浆的牛奶作为混合原料奶，消毒后加入２％的发酵剂和凝乳酶，经１－２月成熟，即可得到风味与纯牛奶干酪无显著差异的优质混合型干酪。