Flow Properties, Firmness and Stability of Double Cream Cheese Containing Whey Protein Concentrate

As estimated on-line, the viscosity after cooling of double cream cheese curd containing heat-denatured WPC (DCC +) increased from 1.4 Pa.s to 1.7 Pa.s when cooled to the range of 45°C to 24°C, and then decreased from 1.7 Pa.s to 1.0 Pa.s when cooled from 24°C to 15°C. The viscosity of DCC^- (without heat-denatured WPC) increased from 1.5 Pa.s to 2.2 Pa.s at temperature shift from 40°C to 15.5°C. The firmness of stored DCC + and DCC^-, respectively, decreased from 15.1N to 6.5N when cooled to temperatures from 45°C to 15°C, and from 17.9N to 9.9N when cooled from 40°C to 15.5°C, as recorded by cone penetrometry. The structure of DCC+ cooled to 15°C collapsed after penetrometry, and DCC+ cooled to 20°C destabilized during shearing in coaxial cylinder rheometer. A new phase in DCC+ based on milk fat globules liberated by cluster disruption may be the cause of the structural and textural instability.     

超高压处理对再制奶油干酪质构、流变学特性及微观结构的影响

以低饱和脂肪酸的再制奶油干酪为研究对象,探究不同条件超高压处理(压力:150、300、450MPa;保压时间:10 min;保压温度:25℃)对再制奶油干酪质构、流变学特性及微观结构的影响.通过SPSS软件分析压力变化与干酪水分质量分数、水分活度、pH值及质构特性的相关性,通过质构分析仪测定干酪质构特性(涂抹性、硬度、...     

橄榄油对再制奶油干酪品质的影响

以奶油干酪为基料,研究不同比例橄榄油替代黄油在再制奶油干酪中的应用。测定干酪的质构、色度、油脂析出性及感官评定,并进行比较分析。实验结果表明,25%替代水平的干酪在质地和色度方面都与对照组无显著性差异(P>0.05);在油脂析出性和感官评分方面,添加25%橄榄油的干酪均优于对照组。综上,2 5%替代水平的干酪样品与对照组在各项指标上相似度最高,是最合适的替代比例。     

再制奶油奶酪生产新技术的研究

针对影响再制奶油奶酪质构特性、持水性、持油性和感官等品质的关键工艺,包括融熔温度、融熔时间、剪切速率、均质压力和冷却方式进行了研究。结果表明,融熔过程中的温度和时间对样品的各个性质有一定影响,且融熔过程中剪切速率的影响最显著,最佳的融熔条件为80℃,10 min,剪切速率900 r/min。不经均质的样品基本呈稠厚的液态,可流动。随着均质压力的提高,产品的硬度增加,当压力达到20 MPa时样品才达到硬度要求。本实验选择的两种冷却方式对样品的质构、感官和内部乳清析出没有显著影响,该工艺条件对产品品质总体影响不大。     

植物油脂替代动物油脂 在再制奶油干酪中的应用

以奶油干酪为基料,研究不同植物油脂替代动物油脂在再制奶油干酪中的应用。测定干酪样品的质构、色度、油脂析出性、融化性及感官评定,并进行比较分析。实验结果表明,添加橄榄油和小麦胚芽油的干酪硬度和涂抹性与对照组相近(P>0.05);添加橄榄油、小麦胚芽油、油茶籽油和米糠油的干酪粘聚力与对照组接近,减少了15.23%~26.68%;添加橄榄油和油茶籽油的干酪粘合性与对照组相差19.68%、33.16%,差异显著(P<0.05)。添加油茶籽油、橄榄油、米糠油、小麦胚芽油和亚麻籽油的干酪色度与对照组十分相近(P>0.05)。在油脂析出性上,添加玉米油、米糠油、橄榄油、油茶籽油和南瓜籽油的实验组品质均得到了改善。添加橄榄油、亚麻籽油的样品组在融化性能上与对照组差异不显著(P>0.05),仅减少了1.15%和1.85%。添加油茶籽油、橄榄油、小麦胚芽油的样品组受到认可,得分高于对照组。综上,橄榄油组与对照组在各项指标上相似度最高,是较好的替代油脂。     

不同酸化剂对再制奶油干酪品质的影响

以普通切达干酪和稀奶油为主要原料,研究以柠檬酸、乳酸、葡萄糖酸-δ-内酯(GDL)等为酸化剂,用直接酸化法制得的再制奶油干酪在品质上的变化。对制得的样品进行了质构分析、持水性测试、持油性测试和感官评定。实验结果表明,从质构角度来看,GDL和酒石酸制得样品的硬度值和涂抹性更接近天然奶油干酪,且差异不显著(p<0.05);从感官评价来看,GDL>柠檬酸>乳酸;所有酸化剂组内部乳清析出量普遍高于天然奶油干酪;6个酸化剂组中分别有4组的表面乳清析出和油脂析出与天然奶油干酪无显著性差异(p<0.05)。整体来看,GDL制得的样品与天然奶油干酪在各方面相似度最高,是最合适的酸化剂。     

Effect of pH on Microstructure and Characteristics of Cream Cheese

ABSTRACT:  This study evaluated the effect of pH on the microstructure of cream cheese and compared pH-induced changes in its microstructure with concomitant changes in cheese firmness and meltability. On 4 different days, experimental batches of cultured hot pack cream cheese were manufactured and analyzed for initial chemical composition. The cheeses were then sectioned into samples that were randomly assigned to 7 different treatment groups. Three groups were exposed to ammonia vapor for 1, 3, and 5 min to increase the pH; 3 groups were exposed to acetic acid vapor for 30, 60, and 90 min to decrease the pH; and 1 unexposed group served as the control. After equilibration at 4 °C, samples were analyzed for pH, firmness, meltability, and microstructure by scanning electron microscopy. The effects of experimental treatments on cheese pH, firmness, and meltability were analyzed by randomized complete block analysis of variance (ANOVA). Relationships between cheese pH and firmness and meltability were evaluated by regression. Experimental treatments significantly affected cheese pH, firmness, and meltability. Cheese firmness decreased and meltability increased with increasing pH from about pH 4.2 to 6.8. Cheese microstructure also changed dramatically over the same approximate pH range. Specifically, the volume of the protein network surrounding the fat droplets increased markedly with increasing pH, presumably due to casein swelling. These data support the hypothesis that protein-to-water interactions increased as the cheese pH increased, which gave rise to progressive swelling of the casein network, softer texture, and increased meltability.     

Effect of Cheese pH and Temperature on Serum Phase Characteristics of Cream Cheese During Storage

Three 13.6‐kg blocks of cultured cream cheese manufactured on different days were obtained from a commercial source within 2 wk of manufacture. Blocks were sectioned into samples that were randomly assigned to 3 treatments. A model system was used to change cheese pH. One group of samples was exposed to volatile ammonia to increase the pH to about 5.3. A 2nd group was exposed to volatile acetic acid to decrease the pH to about 4.5. A 3rd group served as a control (pH about 4.8). Samples from each pH treatment were vacuum‐packaged and randomly assigned to 1 of 2 storage temperatures: 4 °C and 20 °C. Samples were randomly chosen for analysis after 4, 8, 12, 16, 20, 24, and 28 d of storage and centrifuged at 12500 ±g for 75 min at 25 °C to obtain expressible serum (ES). The ES was analyzed for viscosity at 25 °C. Effects of pH treatment, storage time, and storage temperature were evaluated by analysis of variance (ANOVA) according to a split split‐plot design. The amount of ES increased significantly during storage and was affected by storage temperature and cheese pH. Significantly more ES was obtained at higher temperature and higher pH. Viscosity of ES decreased significantly during storage and was affected by storage temperature and cheese pH. Viscosity decreased more rapidly at higher temperature and higher pH. The data suggest that higher temperature and higher pH resulted in accelerated loss of stabilizer function during storage, possibly due to microbiological degradation of the stabilizer.     

Texture Evaluation of Ultrafiltered Teleme Cheese

The texture of traditional and ultrafiltered (UF) teleme cheeses was evaluated using instrumental and sensory texture profile analysis. The UF teleme was made from unheated or heat treated (75°C for 5 minutes) UF milk concentrate. Samples were tested after 2 and 4 mo ripening. Instron variables did not discriminate between the three teleme types but sensory attributes, assessed by a panel discriminated the samples. Weak correlations were obtained between sensory and mechanical variables. Redundancy ordination analysis indicated that textural behavior of each type teleme cheese was characterized by different attributes. Sensory springiness or brittleness, lumpiness and fat content characterized the majority of traditional teleme samples whereas adhesiveness, pH, water soluble and noncasein nitrogen characterized the heat-treated UF samples.     

奶油干酪生产关键工艺参数研究

为研究奶油干酪的关键工艺参数,通过奶油干酪制作工艺过程中氯化钙添加量、凝乳酶添加量、凝乳温度、脂肪添加量这些工艺参数的设计,以产率、蛋白质含量、脂肪含量、水分含量、感官品质为评价指标进行实验,通过正交优化分析试验得到最佳的工艺参数组合为凝乳酶添加量0.002g/mL、凝乳温度32℃、脂肪添加量12%、氯化钙添加量0.01g/mL。所得最佳工艺效果较好,可作为奶油干酪的实际生产工艺。     

Effect of substituting whey cream for sweet cream on the textural and rheological properties of cream cheese

In the manufacture of cream cheese, sweet cream and milk are blended to prepare the cream cheese mix, although other ingredients such as condensed skim milk and skim milk powder may also be included. Whey cream (WC) is an underutilized fat source, which has smaller fat droplets and slightly different chemical composition than sweet cream. This study investigated the rheological and textural properties of cream cheeses manufactured by substituting sweet cream with various levels of WC. Three different cream cheese mixes were prepared: control mix (CC; 0% WC), cream cheese mixes containing 25% WC (25WC; i.e., 75% sweet cream), and cream cheese mixes with 75% WC (75WC; i.e., 25% sweet cream). The CC, 25WC, and 75WC mixes were then used to manufacture cream cheeses. We also studied the effect of WC on the initial step in cream cheese manufacture (i.e., the acid gelation process monitored using dynamic small amplitude rheology). Acid gels were also prepared with added denatured whey proteins or membrane proteins/phospholipids (PL) to evaluate how these components affected gel properties. The rheological, textural, and sensory properties of cream cheeses were also measured. The WC samples had significantly higher levels of PL and insoluble protein compared with sweet cream. An increase in the level of WC reduced the rate of acid gel development, similar to the effect of whey phospholipid concentrate added to mixes. In cream cheese, an increase in the level of added WC resulted in significantly lower storage modulus values at temperatures <20°C. Texture results, obtained from instrumental and sensory analyses, showed that high level of WC resulted in significantly lower firmness or hardness values and higher stickiness compared with cream cheeses made with 25WC or CC cream cheeses. The softer, less elastic gels or cheeses resulting from the use of high levels of WC are likely due to the presence of components such as PL and proteins from the native milk fat globule membrane. The use of low levels of WC in cream cheese did not alter the texture, whereas high levels of WC could be used if manufacturers want to produce more spreadable products.     

Texture Changes During the Ripening of Port Salut Argentino Cheese in 2 Sampling Zones

ABSTRACT: Texture changes during ripening of Port Salut Argentino cheese for different sampling zones were studied. Compression relaxation tests were performed and results were analyzed using both Maxwellian and Peleg's models. Elastic equilibrium modulus obtained from the Maxwellian model decreased from 1.22 to 0.11 10⁴Pa during ripening. The constants derived from Peleg's model, k₁ and k₂, diminished with ripening time from 1.18 to 0.71 min and from 1.27 to 1.12, respectively. Asymptotic equilibrium modulus from Peleg's model decreased from 0.95 to 0.07 10⁴Pa during ripening. Rate parameters derived from a 1st order kinetics applied to both equilibrium moduli showed that the decrease was faster in the external zone (0.0846 d⁻¹) than in the central zone (0.0368 d⁻¹). The correlation between equilibrium moduli, salt concentration, moisture content, and maturation indexes was obtained with a determination coefficient of 0.76.     

Texture of Cheddar Cheese as Influenced by Fat Reduction

Cheddar cheeses with five different fat levels (34, 32, 27, 21, and 13 %) were manufactured in a randomized block design experiment and replicated four times. Cheeses were ripened for 4 months at 7°C. Microstructure was studied using Scanning Electron Microscopy (SEM). Texture characteristics (adhesiveness, cohesiveness, hardness, and springiness) were determined by Texture Profile Analysis (TPA) using the Instron Universal Testing Machine and a trained sensory panel. Scanning electron micrographs showed that the open-intricate microstructure of the cheeses was lost with a decrease in fat content. Hardness and springiness increased while adhesiveness and cohesiveness of the cheeses decreased with decreasing fat content. Texture attributes were influenced by the nature of the protein matrix that resulted due to fat removal.     

Instrumental and Expert Assessment of Mahon Cheese Texture

ABSTRACT: To improve Mahon cheese texture assessment, the relationship between instrumental and sensory measurements was sought. For that purpose 30 pieces of Mahon cheese from different batches and 2 different manufacturers were examined. Textural characteristics at different curing times were evaluated by uniaxial compression, puncture, and sensory analysis. Significant linear correlations were found between instrumental and sensory measurements. A logarithmic model (Weber-Fechner) fitted data better than a linear one. Only 1 factor was extracted when considering all the instrumental and sensory variables, thus indicating that both sets of measurements are related to the same phenomenon. The best predictors for Mahon cheese sensory attributes were found to be cheese moisture, deformability modulus, and slope in puncture.     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

Texture Assessment of French Cheeses

The texture of a variety of French cheeses was studied by examining their compositional and mechanical parameters. The data obtained were correlated to those derived from a panel assessment of the sensory textural attributes of the samples. Statistical treatment of the results employing cluster analysis, analysis of variance, and redundancy analysis revealed that the most influential objective variables to characterize the cheese texture are the dry matter content and the resistance to force compression at 10% deformation of the initial sample height. These variables were highly correlated with sensory attributes such as hardness, brittleness, cohesiveness, and adhesiveness.     

Texture and Microstructure of Block Type Processed Cheese with Formulated Emulsifying Salt Mixtures

Block-processed Ras cheese was produced with two salt mixtures: (1) Na-diphosphate+Na-polyphosphate+Na-tripolyphosphate in ratios 40 : 50 : 10, 30 : 40 : 30 & 30 : 30 : 40 and (2) Na-polyphosphate+Na-citrate+Na-orthophosphate+Na-diphosphate in ratios 50 : 20 : 20 : 10, 40 : 10 : 20 : 30 & 30 : 10 : 20 : 40. Commercial salts Joha SE and PZO were used for comparison, respectively. Texture profile analysis and microstructure (LM and TEM) of resultant cheeses were studied. Chewiness, gumminess, adhesiveness, and hardness showed a significant difference and the cheese samples exhibited higher values during storage. The values were highest in the samples stored at room temperature. Light microscopy photographs indicated different emulsification degree with various emulsifying salt mixtures. These observations were confirmed with the image analysis and TEM. Among the entire treatments, mixture (1) in ratio 30 : 40 : 30 and mixture (2) in ratio 40 : 10 : 20 : 30 gave the best and close texture to the commercial salts and can be recommended in the production of block processed cheese.