谷氨酰胺转胺酶在奶酪制作中的应用

通过Box- Behnken设计和响应面法研究谷氨酰胺转胺酶(transglutaminase,TG)添加量、作用温度和作用时间对奶酪的凝胶硬度、弹性以及产率的影响,各自建立相应的回归模型。在试验选定的因素水平范围内,随着TG添加量的增加和作用温度的升高,奶酪的产率、硬度均增加,弹性先降低后增加。而作用时间对产率和硬度的影响较小,弹性随作用时间的延长先降低后增加。利用软件进行寻优分析,得到最佳工艺条件为TG添加量0.59g/100mL、作用温度45℃、作用时间22.88min,此时奶酪产率理论最大值为12.27%。在此条件下经过验证实验得到奶酪实际产率为11.93%,与理论预测值接近。     

Use of low concentration factor ultrafiltration retentates in reduced-fat Minas Frescal cheese manufacture: effect on yield and sensory properties

The yield and sensory properties of reduced-fat Minas Frescal cheese made from low concentration factor (CF) retentates were studied. Three different CFs were tested (1.2, 1.5 and 1.8). The chemical compositions of the milk, retentate, whey and cheese were determined, as well as the cheese yield. The cheese moisture content decreased with increasing CF. The cheese yield was significantly dependent on the CF in the same direction as the moisture content. Despite compositional differences among the samples, only the cheese made with a CF of 1.8 presented low sensorial acceptance. CF 1.2 was found to be the optimum value for reduced-fat Minas Frescal cheese manufacture in the CF range studied.     

Assessing the yield,microstructure, and texture properties of miniature Chihuahua-type cheese manufactured with a phospholipase A1 and exopolysaccharide-producing bacteria

Chihuahua cheese or Mennonite cheese is one of the most popular and consumed cheeses in Mexico and by the Hispanic community in the United States. According to local producers the yield of Chihuahua cheese ranges from 9 to 9.5 kg of cheese from 100 kg of milk. Cheese yield is a crucial determinant of profitability in cheese-manufacturing plants; therefore, different methods have been developed to increase it. In this work, a miniature Chihuahua-type cheese model was used to assess the effect of a phospholipase A₁ (PL-A₁) and exopolysaccharide (EPS)-producing bacteria (separately and in combination) on the yield, microstructure, and texture of cheese. Four different cheeses were manufactured: cheese made with PL-A₁, cheese made with EPS-producing bacteria, cheese with both PL-A₁ and EPS-producing bacteria, and a cheese control without PL-A₁ or EPS-producing bacteria. The compositional analysis of cheese was carried out using methods of AOAC International (Washington, DC). The actual yield and moisture-adjusted yield were calculated for all cheese treatments. Texture profile analyses of cheeses were performed using a texture analyzer. Micrographs were obtained by electron scanning microscopy. Fifty panelists carried out sensorial analysis using ranking tests. Incorporation of EPS-producing bacteria in the manufacture of cheese increased the moisture content and water activity. In contrast, the addition of PL-A₁ did not increase fat retention or cheese yield. The use of EPS alone improved the cheese yield by increasing water and fat retention, but also caused a negative effect on the texture and flavor of Chihuahua cheese. The use of EPS-producing bacteria in combination with PL-A₁ improved the cheese yield and increased the moisture and fat content. The cheeses with the best flavor and texture were those manufactured with PL-A₁ and the cheeses manufactured with the combination of PL-A1 and EPS-producing culture.     

An empirical method for prediction of cheese yield

Theoretical cheese yield can be estimated from the milk fat and casein or protein content of milk using classical formulae, such as the VanSlyke formula. These equations are reliable predictors of theoretical or actual yield based on accurately measured milk fat and casein content. Many cheese makers desire to base payment for milk to dairy farmers on the yield of cheese. In small factories, however, accurate measurement of fat and casein content of milk by either chemical methods or infrared milk analysis is too time consuming and expensive. Therefore, an empirical test to predict cheese yield was developed which uses simple equipment (i.e., clinical centrifuge, analytical balance, and forced air oven) to carry out a miniature cheese making, followed by a gravimetric measurement of dry weight yield. A linear regression of calculated theoretical versus dry weight yields for milks of known fat and casein content was calculated. A regression equation of y = 1.275x + 1.528, where y is theoretical yield and x is measured dry solids yield (r2 = 0.981), for Cheddar cheese was developed using milks with a range of theoretical yield from 7 to 11.8%. The standard deviation of the difference (SDD) between theoretical cheese yield and dry solids yield was 0.194 and the coefficient of variation (SDD/mean x 100) was 1.95% upon cross validation. For cheeses without a well-established theoretical cheese yield equation, the measured dry weight yields could be directly correlated to the observed yields in the factory; this would more accurately reflect the expected yield performance. Payments for milk based on these measurements would more accurately reflect quality and composition of the milk and the actual average recovery of fat and casein achieved under practical cheese making conditions.     

Effect of lecithin addition on the yield and quality of soft cheeses

The effect of lecithin added at levels of 0.025 %, 0.050 % and 0.075 % to cheese milk used in manufacture of Domiati and Kareish cheese on yield, weight losses and quality of cheese was studied. Addition of lecithin increased cheese yield and decreased weight losses during pickling. The bacterial content of all cheeses treated with lecithin was higher than that of control cheese when fresh and during pickling. Cheese made with added lecithin showed higher moisture, salt, fat, and acidity than control cheese. The total nitrogen percentage was almost the same in all treatments. The levels of both soluble nitrogen and total volatile fatty acids in cheese containing lecithin were higher than in the control cheese. No marked differences were evaluated for flavour, body and texture of fresh cheese made from milk with or without lecithin, while during pickling the organoleptic properties of cheese containing lecithin were improved.     

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.     

Cheese yield,cheesemaking efficiency,and daily production of 6 breeds of goats

Little is known about the complex process of cheesemaking at the individual level of dairy goats because of the difficulties of producing a high number of model cheeses. The objectives of this work were (1) to study the cheesemaking ability of goat milk; (2) to investigate the variability of cheesemaking-related traits among different farms; (3) to assess the effects of stage of lactation and parity; and (4) to compare 6 breeds of goat (Saanen and Camosciata delle Alpi for the Alpine type; Murciano-Granadina, Maltese, Sarda and Sarda Primitiva for the Mediterranean type) for their cheesemaking ability. For each goat (n = 560) we studied (1) 8 milk quality traits (fat, protein, total solids, casein, lactose, pH, somatic cell score, and bacterial count); (2) 4 milk nutrient recovery traits (fat, protein, total solids, and energy) in curd; (3) 3 actual cheese yield traits (fresh cheese, cheese solids, and cheese water); (4) 2 theoretical cheese yield values (fresh cheese and cheese solids) and the related cheesemaking efficiencies; and (5) daily milk yield and 3 daily cheese yield traits (fresh cheese, cheese solids, and water retained in the curd). With respect to individual animal factors, farm was not particularly important for recovery traits or actual and theoretical cheese yield and estimates of efficiency, whereas it highly influenced daily productions. Parity of goats influenced daily cheese production, whereas DIM slightly affected recovery as well as percent and daily cheese yield traits. Breed was the most important source of variation for almost all cheesemaking traits. Compared with those of Alpine type, the 4 Mediterranean breeds had, on average, lower daily milk and cheese productions, greater actual and theoretical cheese yield, and higher recovery of nutrients in the curd. Among Alpine type, Camosciata delle Alpi was characterized by greater nutrients recovery than Saanen. Within the 4 Mediterranean types, the 3 Italians produced much less milk per day, with much more fat and protein and greater recovery traits than the Murciano-Granadina, resulting in greater actual cheese yield. Within the Italian breeds, milk from Sarda and Sarda Primitiva was characterized by lower daily yields, higher protein and fat content, and greater recoveries of nutrients than Maltese goats. These results confirmed the potential of goat milk for cheese production and could be useful to give new possibilities and direction in breeding programs.     

Effect of minor milk proteins in chymosin separated whey and casein fractions on cheese yield as determined by proteomics and multivariate data analysis

The objective of this work was to find regressions between minor milk proteins or protein fragments in the casein or sweet whey fraction and cheese yield because the effect of major milk proteins was evaluated in a previous study. Proteomic methods involving 2-dimensional gel electrophoresis and mass spectrometry in combination with multivariate data analysis were used to study the effect of variations in milk protein composition in chymosin separated whey and casein fractions on cheese yield. By mass spectrometry, a range of proteins significant for the cheese yield was identified. Among others, a C-terminal fragment of β-casein had a positive effect on the cheese yield expressed as grams of cheese per 100 g of milk, whereas several other minor fragments of β-, α_s1-, and α_s2-casein had positive effects on the transfer of protein from milk to cheese. However, the individual effect of each identified protein was relatively low. Therefore, further studies of the relations between different proteins/peptides in the rennet casein or sweet whey fractions and cheese yield are needed for advanced understanding and prediction of cheese yield.     

乳酸菌胞外多糖对低脂Mozzarella奶酪质构、微观结构等品质的影响

目的 研究乳酸菌胞外多糖对低脂Mozzarella奶酪质构等品质特性的影响。方法 在脱除50%乳脂肪的原料中加入0.5%乳酸菌胞外多糖制作低脂Mozzarella奶酪, 同时以全脂Mozzarella奶酪和低脂Mozzarella奶酪为对照, 对Mozzarella奶酪成熟过程中的硬度、弹性、胶黏性、咀嚼性、融化性、油脂析出性、微观结构及感官评分等指标进行分析。结果 0.5%乳酸菌胞外多糖提高了低脂Mozzarella奶酪的水分含量、出品率, 改善了低脂Mozzarella奶酪致密的结构, 形成了类似全脂Mozzarella奶酪疏松、光滑的组织结构, 降低了低脂Mozzarella奶酪的硬度、胶黏性和咀嚼性, 提高了弹性、融化化性和油脂析出, 成熟90 d加入多糖低脂Mozzarella奶酪的滋味和气味、组织状态、色泽接近全脂Mozzarella奶酪。结论 乳酸菌胞外多糖可以提高低脂Mozzarella奶酪的水分含量和出品率, 改善低脂Mozzarella奶酪的组织结构和质构特性。     

Effects of breed,farm intensiveness,and cow productivity level on cheese-making ability predicted using infrared spectral data at the population level

Fourier-transform infrared (FTIR) spectra collected during milk recording schemes at population level can be used for predicting novel traits of interest for farm management, cows' genetic improvement, and milk payment systems. The aims of this study were as follows. (1) To predict cheese yield traits using FTIR spectra from routine milk recordings exploiting previously developed calibration equations. (2) To compare the predicted cheese-making abilities of different dairy and dual-purpose breeds. (3) To analyze the effects of herds' level of intensiveness (HL) and of the cow's level of productivity (CL). (4) To compare the patterns of predicted cheese yields with the patterns of milk composition in different breeds to discern the drivers of cheese-making efficiency. The major sources of variation of FTIR predictions of cheese yield ability (fresh cheese or cheese solids produced per unit milk) of individual milk samples were studied on 115,819 cows of 4 breeds (2 specialized dairy breeds, Holstein and Brown Swiss, and 2 dual-purpose breeds, Simmental and Alpine Grey) from 6,430 herds and exploiting 1,759,706 FTIR test-day spectra collected over 7 yr of milk sampling. Calibration equations used were previously developed on 1,264 individual laboratory model cheese procedures (cross-validation R² 0.85 and 0.95 for fresh and solids cheese yields, respectively). The linear model used for statistical analysis included the effects of parity, lactation stage, year of calving, month of sampling, HL, CL, breed of cow, and the interactions breed × HL and breed × CL. The HL and CL stratifications (5 classes each) were based on average daily secretion of milk net energy per cow. All effects were highly significant. The major conclusions were as follows. (1) The FTIR-based prediction of cheese yield of milk goes beyond the knowledge of fat and protein content, partially explaining differences in cheese-making ability in different cows, breeds and herds. (2) Differences in cheese yields of different breeds are only partially explained by milk fat and protein composition, and less productive breeds are characterized by a higher milk nutrient content as well as a higher recovery of nutrients in the cheese. (3) High-intensive herds not only produce much more milk, but the milk has a higher nutrient content and a higher cheese yield, whereas within herds, compared with less productive cows, the more productive cows have a much greater milk yield, milk with a greater content of fat but not of protein, and a moderate improvement in cheese yield, differing little from expectations based on milk composition. Finally, (4) the effects of HL and CL on milk quality and cheese-making ability are similar but not identical in different breeds, the less productive ones having some advantage in terms of cheese-making ability. We can obtain FTIR-based prediction of cheese yield from individual milk samples retrospectively at population level, which seems to go beyond the simple knowledge of milk composition, incorporating information on nutrient retention ability in cheese, with possible advantages for management of farms, genetic improvement of dairy cows, and milk payment systems.     

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.     

Effect of Carrageenan on Physicochemical and Functional Properties of Low‐Fat Colby Cheese

The effect of carrageenan (κ‐carrageenan, ι‐carrageenan, and λ‐carrageenan) on the physiochemical and functional properties of low‐fat Colby cheese during ripening was investigated. Protein, fat, and moisture contents; the soluble fractions of the total nitrogen at pH 4.6; protein and fat recovery; and the actual yield and dry matter yield (DM yield) were monitored. Hardness, springiness, and the storage modulus were also evaluated to assess the functional properties of the cheese. Moreover, the behavior of water in the samples was investigated to ascertain the underlying mechanisms. The results indicated that 0.15 g/kg κ‐carrageenan had no significant effect on the actual yield and DM yield, and physiochemical and functional properties of low‐fat Colby cheese. The protein content increased in the low‐fat cheese and low‐fat cheese containing κ‐carrageenan, and the moisture in the nonfat substance (MNFS) decreased in both samples, which contributed to the harder texture. The addition of 0.3 g/kg ι‐carrageenan and 0.3 g/kg λ‐carrageenan improved the textural and rheological properties of low‐fat cheese by 2 ways: one is increasing the content of bound and expressible moisture due to their high water absorption capacity and the other is interfering with casein crosslinking, thereby further increasing MNFS and the actual yield.     

The use of Fourier-transform infrared spectroscopy to predict cheese yield and nutrient recovery or whey loss traits from unprocessed bovine milk samples

Cheese yield is an important technological trait in the dairy industry in many countries. The aim of this study was to evaluate the effectiveness of Fourier-transform infrared (FTIR) spectral analysis of fresh unprocessed milk samples for predicting cheese yield and nutrient recovery traits. A total of 1,264 model cheeses were obtained from 1,500-mL milk samples collected from individual Brown Swiss cows. Individual measurements of 7 new cheese yield-related traits were obtained from the laboratory cheese-making procedure, including the fresh cheese yield, total solid cheese yield, and the water retained in curd, all as a percentage of the processed milk, and nutrient recovery (fat, protein, total solids, and energy) in the curd as a percentage of the same nutrient contained in the milk. All individual milk samples were analyzed using a MilkoScan FT6000 over the spectral range from 5,000 to 900 wavenumber × cm⁻¹. Two spectral acquisitions were carried out for each sample and the results were averaged before data analysis. Different chemometric models were fitted and compared with the aim of improving the accuracy of the calibration equations for predicting these traits. The most accurate predictions were obtained for total solid cheese yield and fresh cheese yield, which exhibited coefficients of determination between the predicted and measured values in cross-validation (1-VR) of 0.95 and 0.83, respectively. A less favorable result was obtained for water retained in curd (1-VR = 0.65). Promising results were obtained for recovered protein (1-VR = 0.81), total solids (1-VR = 0.86), and energy (1-VR = 0.76), whereas recovered fat exhibited a low accuracy (1-VR = 0.41). As FTIR spectroscopy is a rapid, cheap, high-throughput technique that is already used to collect standard milk recording data, these FTIR calibrations for cheese yield and nutrient recovery highlight additional potential applications of the technique in the dairy industry, especially for monitoring cheese-making processes and milk payment systems. In addition, the prediction models can be used to provide breeding organizations with information on new phenotypes for cheese yield and milk nutrient recovery, potentially allowing these traits to be enhanced through selection.     

Evaluation of mathematical equations to predict the theoretical yield of Chilean Gouda cheese

This study was performed to obtain an adequate tool for predicting the yield of Chilean Gouda cheese. The theoretical yields were calculated by applying equations derived from technical references to industrial cheese production and were compared with their own actual yields, thus selecting those equations showing the best correlation with the actual yield.
The manufacturing and ripening of the cheese were controlled through the chemical composition of milk, whey and cheese, and the weight of the product before and after ripening was recorded.
The actual and theoretical yield values derived from each formula were compared using the mean yield graphs. Furthermore, the global concordance coefficient ( W ) of Kendall and Smith was also applied, showing the lack of significant discrepancy between actual and theoretical yield values [ P  > 0.01 ( W  = 27; W ≥  18.48)] for either 3- or 30-day cheeses. Out of the 11 formulae used to measure the yield of cheese, six showing a good correlation between the yields were selected through the comparison of error sums and Pearson correlation analysis. However, two formulae showed the best yield results for practical use.     

Effect of denatured whey protein concentrate and its fractions on cheese composition and rheological properties

The objectives of this study were (1) to assess the effect of a denatured whey protein concentrate (DWPC) and its fractions on cheese yield, composition, and rheological properties, and (2) to separate the direct effect of the DWPC or its fractions on cheese rheological properties from the effect of a concomitant increase in cheese moisture. Semihard cheeses were produced at a laboratory scale, and mechanical properties were characterized by dynamic rheometry. Centrifugation was used to induce a moisture gradient in cheese to separate the direct contribution of the DWPC from the contribution of moisture to cheese mechanical properties. Cheese yield increased and complex modulus (G*) decreased when the DWPC was substituted for milk proteins in milk. For cheeses with the same moisture content, the substitution of denatured whey proteins for milk proteins had no direct effect on rheological parameters. The DWPC was fractionated to evaluate the contribution of its different components (sedimentable aggregates, soluble component, and diffusible component) to cheese yield, composition, and rheological properties. The sedimentable aggregates were primarily responsible for the increase in cheese yield when DWPC was added. Overall, moisture content explained to a large extent the variation in cheese rheological properties depending on the DWPC fraction. However, when the effect of moisture was removed, the addition of the DWPC sedimentable fraction to milk increased cheese complex modulus. Whey protein aggregates were hypothesized to act as active fillers that physically interact with the casein matrix and confer rigidity after pressing.     

Effects of starter level, draining time and aging on the physicochemical, organoleptic and rheological properties of feta cheese

Feta cheese was made from ewe's milk using three different levels of starter (0.20, 0.50 and 0.75%) and two draining times (6 and 20 h). Cheese made with addition of 0.75% starter had a lower pH and moisture content than the cheeses made with 0.20 and 0.50% starter. With the increase in starter level there was also an increase in cheese fat content, although the fat in dry matter remained almost constant. The lower level of starter resulted in cheese with lower protein content, while other cheese components were not significantly affected by the starter levels used. The yield of cheese made with addition of 0.75% starter was significantly lower than the yield of cheeses made with the other levels. Also, the yield of cheeses made with 6 h drainage was greater than the yield of cheeses made with 20 h drainage. In general, the organoleptic and rheological properties of cheeses were not affected by the three levels of starter used for feta cheese manufacture.     

Impact of low concentration factor microfiltration on milk component recovery and Cheddar cheese yield

The effect of microfiltration (MF) on the composition of Cheddar cheese, fat, crude protein (CP), calcium, total solids recovery, and Cheddar cheese yield efficiency (i.e., composition adjusted yield divided by theoretical yield) was determined. Raw skim milk was microfiltered twofold using a 0.1-microm ceramic membrane at 50 degrees C. Four vats of cheese were made in one day using milk at lx, 1.26x, 1.51x, and 1.82x concentration factor (CF). An appropriate amount of cream was added to achieve a constant casein (CN)-to-fat ratio across treatments. Cheese manufacture was repeated on four different days using a randomized complete block design. The composition of the cheese was affected by MF. Moisture content of the cheese decreased with increasing MF CF. Standardization of milk to a constant CN-to-fat ratio did not eliminate the effect of MF on cheese moisture content. Fat recovery in cheese was not changed by MF. Separation of cream prior to MF, followed by the recombination of skim or MF retentate with cream resulted in lower fat recovery in cheese for control and all treatments and higher fat loss in whey when compared to previous yield experiments, when control Cheddar cheese was made from unseparated milk. Crude protein, calcium, and total solids recovery in cheese increased with increasing MF CF, due to partial removal of these components prior to cheese making. Calcium and calcium as a percentage of protein increased in the cheese, suggesting an increase in calcium retention in the cheese with increasing CF. While the actual and composition adjusted cheese yields increased with increasing MF CF, as expected, there was no effect of MF CF on cheese yield efficiency.     

Effect of milk pasteurization and acidification method on the chemical composition and microstructure of a Mexican pasta filata cheese

Four Mexican pasta filata cheese variations were prepared using raw milk and starter culture (RMSC), raw milk and acetic acid (RMAA), pasteurized milk and starter culture (PMSC), and pasteurized milk and acetic acid (PMAA). Chemical composition, yield and microstructure were evaluated. Scanning electron micrographs of the cheese variations were evaluated by lacunarity analysis. PMSC and PMAA cheeses had higher protein, moisture and yield, but lower calcium content than RMSC and RMAA cheeses. The manufacturing conditions and refrigerated storage produced structural differences in the cheese variations, which displayed different heterogeneity patterns arising from spatial distribution of their components as determined by lacunarity analysis. Raw and pasteurized milk cheese variations showed an opposite lacunarity pattern trend during storage time.     

Fresh cheese from camel milk coagulated with Camifloc

Camel milk was processed into cheese using Camifloc and calcium chloride. Two types of cheeses were produced from camel milk, using Camifloc (CF cheese) and CaC_l2 in addition to Camifloc (CFCC cheese). The study revealed the usefulness of Camifloc in coagulation of camel milk. The time of coagulation was found to be about 2–3 h, and the yield of CFCC cheese was found to be higher than the CF cheese, while a shelf life of 4 days was obtained for both cheeses. Both cheeses showed nonsignificant variations in compositional content except for the percentages of protein and ash, which showed significant differences at P < 0.001 and P < 0.05. Sensory evaluation by taste panellists was conducted to determine the acceptability of cheeses during the storage periods. Differences were found between the CF cheese and the CFCC cheese in saltiness and overall acceptability, and higher mean scores were recorded for the CF cheese than the CFCC cheese. The study recommends the use of Camifloc in making cheese from camel milk; and if CaCl₂ is added, it can improve the cheese yield. However, we suggest that the rate of salting should be reduced, and further drying and storage of the cheese should be done.     

Association Between Somatic Cell Count of Milk and Cheese-Yielding Capacity

During 1 yr, 42 Holstein cows were selected to provide monthly individual milk samples with SCC, which ranged from less than 100,000 to more than 1,000,000/ml of milk. Milk was analyzed for fat, protein, lactose, casein, and SCC and was used for laboratory-scale cheese making. Data obtained from the milk input and the cheese output were used to determine actual, moisture-adjusted, Van Slyke's theoretical yields, and efficiency of yield. Least squares analyses of data which adjusted for the effect of milk composition indicated that SCC in milk were inversely related to moisture-adjusted yield and efficiency of yield. An increase of SCC from 100,000 to 500,000/ml was associated with a decrease of approximately 5.0 and 11.0% in adjusted yield and efficiency of yield, respectively. A further increase of SCC to 1,000,000/ml resulted in an overall decrease of 8.7 and 13% in adjusted yield and efficiency of yield, respectively.