拉伸工艺对Mozzarella干酪品质的影响

选择不同的拉伸温度和拉伸时间,研究拉伸工艺对Mozzarella干酪组成、游离水分和功能特性的影响。结果表明,随着拉伸温度的升高和拉伸时间的延长,干酪的游离水分增加,脂肪和蛋白质质量分数下降,干酪产量下降。拉伸温度为60℃时,干酪的融化性最高,油脂析出性适中,拉伸性较好。延长拉伸时间,导致干酪产量下降,功能特性没有明显提升。本研究确定的最佳拉伸工艺:拉伸温度60℃,拉伸时间10min。     

不同工艺参数对Mozzarella干酪质构和功能特性的影响

采用三因素二次通用旋转组合设计,研究热缩温度、堆酿pH、拉伸温度等关键工艺参数对全脂Mozzarella干酪的质构特性(硬度、凝聚性、弹性)和功能特性(融化性和油脂析出性)的影响规律,结果表明提高热缩温度可增加干酪硬度及干酪的油脂析出性;提高拉伸温度也可增加干酪的油脂析出性;堆酿pH对干酪的弹性有较大影响,随着堆酿pH的降低,干酪的弹性增大,并与热烫拉伸温度之间有交互作用,即低的堆酿pH和高的拉伸温度时干酪的弹性大。     

原料乳中蛋白质与脂肪比例对 Mozzarella干酪品质的影响

采用3×3拉丁方试验设计,3个奶酪槽中原料乳的蛋白质与脂肪质量比分别为1∶1,1.2∶1,1.3∶1(通过添加脱脂干奶粉调整蛋白质含量)。研究蛋白质与脂肪比例对Mozzarella干酪的品质的影响。结果表明,随着原料乳中蛋白质脂肪比例的增加,干酪的含水量、油脂析出性显著降低(P<0.05),干酪的弹性显著升高(P<0.05),蛋白质与脂肪比例对Mozzarella干酪的蛋白质水解没有显著的影响。     

盐水腌制对于Mozzarella干酪成分及功能特性的影响

以盐水腌制工艺制作Mozzarella干酪,研究了腌制时不同的NaCl质量分数、成熟期以及不同的干酪部位对Mozzarella干酪的粗成分、功能特性及蛋白质水解的影响.结果表明,NaCl质量分数提高,游离油脂与可榨乳浆生成量减少.对蛋白质水解影响不显著;成熟期增加,游离油脂生成量与蛋白质水解程度都提高,可榨乳浆生成量降低;干酪外部的游离油脂生成量低于千酪中心游离油脂的生成量,但三者对粗成分的影响不明显.     

不同气调贮藏对Mozzarella干酪功能特性的影响

采用无盐渍新工艺制得部分脱脂Mozzarella干酪,以PVDC为包装材料,分别采用50%CO2和50%N2,75%CO2和25%N2,100%CO2对干酪进行气调包装,以真空包装为对照组(CK),在4℃下进行冷藏,对不同气调贮藏条件下的Mozzarella的理化指标以及功能特性进行了测定.结果表明:各气调组水分含量、pH值、硬度、弹性均显著高于时照组(P<0.05),各气调组干酪的pH值为4.6 SN和质量分数为12%的TCA SN均显著低于对照组(P<0.05),各气调组与对照组相比,凝聚性、融化性无变化.b值逐步下降.各气调组保持了干酪特有的功能特性,感官评分均高于时照组.质量分数为75%的CO2和质量分数25%的N2能有效地延长Mozzarella干酪贮藏期.     

热烫温度对哈罗米干酪理化性质的影响

探讨了不同的加热温度下对乳凝块理化性质以及成分含量的影响,以未经热烫的干酪凝块作为空白对照,分别测定了这五种干酪样品的pH值、水分质量分数、蛋白质质量分数、脂肪质量分数、油脂析出性、扫描电子显微镜、可榨乳清质量分数及质构特性。研究发现:随热烫温度升高,干酪的油脂析出性、硬度、脂肪含量等指标逐渐增大;热烫温度变化对样品的蛋白质、水分含量等指标影响不显著;扫描电镜观察发现随热烫温度升高,干酪结构致密性增加,此结果同干酪硬度随热烫温度变化相一致。综合评价80～90℃热烫工艺制得的哈罗米干酪质地较为坚硬,油脂易于析出,品质相对较好。     

非成熟Mozzarella干酪的品质研究

通过改进传统Mozzarella干酪的工艺,制备了非成熟Mozzarella干酪,使用质构测定仪、改良的Schreiber实验法、电子显微等方法分别测定了样品的TPA质构、融化性、油脂析出性、拉丝性和微观结构.结果表明,非成熟Mozzarella干酪的功能特性与传统Mozzarella干酪相比有所提高;微观结构显示成熟...     

模拟Mozzarella干酪工艺参数优化的研究

模拟Mozzarella干酪是一种类似天然干酪的产品。为使其品质更接近于天然Mozzarella干酪,研究了以干酪的质构、融化性、拉伸性和油脂析出性为指标,对生产工艺中的几个关键工艺参数进行优化。结果表明,融化温度、搅拌时间和搅拌速度对模拟Mozzarella干酪未融化时的物理特性和融化时的主要功能特性都有极显著性影响(P<0.01);融化温度为85℃,搅拌时间(加柠檬酸前)为5min,搅拌速度为250r/min时加工的模拟干酪的品质最接近于天然Mozzarella干酪。因此,在模拟Mozzarella干酪的加工工艺中选择融化温度85℃,搅拌时间5min,搅拌速度250r/min。     

不同体细胞原料乳对Mozzarella干酪特性的影响

以膜过滤(M)、低体细胞(LSCC)、高体细胞(HSCC)原料乳为原料加工Mozzarella 干酪,对其成分回收率及1 、15、30、45、60d 成熟期的蛋白降解、游离脂肪酸含量、油脂析出、融化性、质构及感官等特性进行分析。结果表明：体细胞数对成分回收率的影响不显著(P ＞ 0.05)。LSCC 组与HSCC 组干酪特性差异不显著,但是微滤处理对Mozzarella 干酪特性的影响显著。体细胞数＜ 600000cells/mL时该指标并不是影响Mozzarella干酪品质的重要因素。     

再制干酪乳化过程中理化、功能特性及微观结构的变化

以再制干酪为研究对象,探究再制干酪在不同乳化温度下（80℃和85℃）,从乳化开始到结束（5～30 min）,再制干酪功能特性（融化性、油脂析出性）、质构特性、流变学特性和微观结构的变化情况。结果表明,随着乳化时间延长,产品的融化性及油脂析出性呈下降趋势,乳化过程中85℃再制干酪的油脂析出性显著高于80℃再制干酪（P<0.05）。干酪的质构特性随着乳化时间的延长整体呈增大趋势,其中85℃干酪胶着性和咀嚼性显著增大（P<0.05）,85℃再制干酪的硬度、胶着性和咀嚼性均大于80℃。两种加工温度的干酪在相同乳化程度下干酪的储能模量（G’）均大于损耗模量（G”）,0.1～10 Hz内G’和G”都随频率的升高呈上升趋势。干酪的微观结构显示,乳化5～15 min时脂肪球数量大大减少且直径减小,分布更加均匀,蛋白质基质更加光滑,干酪结构更加致密;但乳化20～30 min时干酪的微观结构呈蜂窝状,即奶油化反应过度。因此,再制干酪加工过程中乳化时间短,奶油化反应不充分;再制干酪乳化时间过长会使质地发生不良变化。再制干酪乳化反应过程中,蛋白质-蛋白质和蛋白质-脂肪的相互作用增强,产品的功能特性...     

原辅料对再制马苏里拉干酪品质特性的影响

以天然马苏里拉干酪为目标,以干酪融化后特性(融化性、油脂析出率、拉伸性和褐变性)、感官、微观结构为指标,研究原辅料对再制马苏里拉干酪融化后品质特性的影响。结果表明:选择比例为1∶1(m/m,下同)的成熟度为3个月切达干酪和马苏里拉干酪,配合比例为1∶4色拉油和奶油进行再制马苏里拉干酪的制作,既保证了再制干酪所需的质构,同时也赋予产品特有的风味;添加量为1.3%的乳化盐和2.0%的柠檬酸能提供再制干酪所需的乳化性和合理的p H值,产品的加工特性最佳。     

Texture characteristics and pizza bake properties of low-fat Mozzarella cheese as influenced by pre-acidification with citric acid and use of encapsulated and ropy exopolysaccharide producing cultures

Low-fat Mozzarella cheeses containing 6% fat were made by pre-acidification of milk with citric acid to pH 6.1 and using encapsulated ropy or non-ropy exopolysaccharide (EPS) producing Streptococcus thermophilus. Moisture retention, changes in texture profile analysis (TPA), meltability and stretchability of cheese, and changes in colour, surface scorching and shred fusion were analysed after baking over 90 days (d). Control cheeses and those made from pre-acidified milk without EPS cultures had the lowest moisture content at 54.84% and 55.28%, respectively. Control cheeses were hardest and their meltability and stretchability were initially low. Hardness was reduced and the melt and stretch distances increased with time. When baked, control cheeses showed incomplete shred fusion. Pre-acidification reduced hardness and increased meltability. Capsular- and ropy-EPS were quantified at 30.42 and 30.55 mg g⁻¹ of cheese, respectively, and increased moisture retention in pre-acidified cheese to 56.67% and 56.21%, respectively. These cheeses were softer and exhibited lower springiness. Greater meltability was observed initially but became similar to control cheeses after 90 d of storage. When baked after 45 d of storage, cheeses containing EPS producing cultures showed improved shred fusion, meltability and a reduction in surface scorching.     

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。     

Improvement in melting and baking properties of low-fat Mozzarella cheese

Low-fat cheeses dehydrate too quickly when baked in a forced air convection oven, preventing proper melting on a pizza. To overcome this problem, low-fat Mozzarella cheese was developed in which fat is released onto the cheese surface during baking to prevent excessive dehydration. Low-fat Mozzarella cheese curd was made with target fat contents of 15, 30, 45, and 60 g/kg using direct acidification of the milk to pH 5.9 before renneting. The 4 portions of cheese curd were comminuted and then mixed with sufficient glucono-δ-lactone and melted butter (45, 30, 15, or 0 g/kg, respectively), then pressed into blocks to produce low-fat Mozzarella cheese with about 6% fat and pH 5.2. The cheeses were analyzed after 15, 30, 60, and 120 d of storage at 5°C for melting characteristics, texture, free oil content, dehydration performance, and stretch when baked on a pizza at 250°C for 6 min in a convection oven. Cheeses made with added butter had higher stretchability compared with the control cheese. Melting characteristics also improved in contrast to the control cheese, which remained in the form of shreds during baking and lacked proper melting. The cheeses made with added butter had higher free oil content, which correlated (R² ≥ 0.92) to the amount of butterfat added, and less hardness and gumminess compared with the control low fat cheese.     

Effect of frozen storage on physical properties of pasta filata and nonpasta filata Mozzarella cheeses

The effects of 1) ripening 2, 7, and 14 d at 7 degrees C before freezing; 2) tempering 7, and 14 d at 7 degrees C after freezing; and 3) frozen storage for 1 and 4 wk at -20 degrees C, on the meltability, stretchability, and microstructure of pasta filata and nonpasta filata Mozzarella cheeses were investigated. Cheeses were cut into 5 x 10 x 7-cm blocks and vacuum-sealed 1 d after manufacture. The results were compared to the corresponding results obtained with unfrozen control samples, aged at 7 degrees C between 2 and 21 d. The changes in physical properties of frozen-stored pasta filata and nonpasta filata Mozzarella cheeses were consistent with critical damage to the cheese microstructure as compared to the unfrozen control samples. Generally, aging before and tempering after freezing resulted in increased meltability of both frozen-stored pasta filata and nonpasta filata Mozzarella cheeses. The stretchability of frozen-stored pasta filata Mozzarella cheese increased during tempering, but that of nonpasta filata Mozzarella cheese decreased during aging and tempering. In most cases, one-week frozen stored pasta filata Mozzarella cheese had higher meltability and stretchability than 4-wk frozen-stored sample. For 1-wk frozen-stored nonpasta filata Mozzarella cheese, the meltability increased but stretchability decreased when it was frozen-stored for 4 wk.     

Effect of fat reduction on chemical composition, proteolysis, functionality, and yield of Mozzarella cheese

Mozzarella cheese was made from skim milk standardized with cream (unhomogenized, 40% milk fat) to achieve four different target fat percentages in the cheese (ca. 5, 10, 15, and 25%). No statistically significant differences were detected for cheese manufacturing time, stretching time, concentration of salt in the moisture phase, pH, or calcium as a percentage of the protein in the cheese between treatments. As the fat percentage was reduced, there was an increase in the moisture and protein content of the cheese. However, because the moisture did not replace the fat on an equal basis, there was a significant decrease in the moisture in the nonfat substance in the cheese as the fat percentage was reduced. This decrease in total filler volume (fat plus moisture) was associated with an increase in the hardness of the unmelted cheese. Whiteness and opacity of the unmelted cheese decreased as the fat content decreased. Pizza baking performance, meltability, and free oil release significantly decreased as the fat percentage decreased. The minimum amount of free oil release necessary to obtain proper functionality during pizza baking was between 0.22 and 2.52 g of fat/100 g of cheese. Actual cheese yield was about 30% lower for cheese containing 5% fat than for cheese with 25% fat. Maximizing fat recovery in the cheese becomes less important to maintain high cheese yield, and moisture control and the retention of solids in the water phase become more important as the fat content of the cheese is reduced.     

The effects of κ-casein polymorphism on the texture and functional properties of mozzarella cheese

The present study compared the texture and functional properties of mozzarella cheese made with milk containing different of genetic polymorphisms κ-casein (AA, AB, AE or BE). The genotype of κ-casein in the milk from individual Holstein cow was determined by pyrosequencing method. Full-fat Mozzarella cheese was made from pooled milk from 3 cows with the same κ-casein genotype and analysed 7 d after manufacture. The cheese made from type AB contained the highest level of fat and Ca/protein, and the lowest moisture content. The cheese made from type AB milk was harder and chewier than cheese made from type AE and BE milk. The cheese made from type AB and AA milk had higher stretchability but lower meltability and flowability than type AE and BE. In summary, the cheese made from type AB milk had different texture and functionality quality than that made from type AE or BE.     

乳化盐对再制马苏里拉乳酪品质的影响

乳化盐是再制乳酪的关键原料。通过测定烘焙功能性和流变性,研究乳化盐对再制马苏里拉乳酪品质的影响,结果表明,乳化盐对再制马苏里拉乳酪烘焙功能性有显著影响,随着型号为"JOHA PZ14"的复合磷酸盐添加比例的提高,再制马苏里拉乳酪融化性和油脂析出性增加,拉伸性先增加后降低,褐变性降低。选择型号为"JOHA PZ7":"JOHA PZ14"乳化盐=4:1时,再制马苏里拉乳酪烘焙功能性最接近天然马苏里拉乳酪。     

Low-fat mozzarella as influenced by microbial exopolysaccharides, preacidification, and whey protein concentrate

Low-fat Mozzarella cheeses containing 6% fat were made by preacidification of milk, preacidification combined with exopolysaccharide- (EPS-) producing starter, used independently or as a coculture with non-EPS starter, and preacidification combined with whey protein concentrate (WPC) and EPS. The impact of these treatments on moisture retention, changes in texture profile analysis, cheese melt, stretch, and on pizza bake performance were investigated over 45 d of storage at 4°C. Preacidified cheeses without EPS (control) had the lowest moisture content (53.75%). These cheeses were hardest and exhibited greatest springiness and chewiness. The meltability and stretchability of these cheeses increased most during the first 28 d of storage. The moisture content in cheeses increased to 55.08, 54.79, and 55.82% with EPS starter (containing 41.18 mg/g of EPS), coculturing (containing 28.61 mg/g of EPS), and WPC (containing 44.23 mg/g of EPS), respectively. Exopolysaccharide reduced hardness, springiness, and chewiness of low-fat cheeses made with preacidified milk in general and such cheeses exhibited an increase in cohesiveness and meltability. Although stretch distance was similar in all cheeses, those containing EPS were softer than the control. Cocultured cheeses exhibited the greatest meltability. Cheeses containing WPC were softest in general; however, hardness remained unchanged over 45 d. Cheeses made with WPC had the least increase in meltability over time. Incorporation of WPC did not reduce surface scorching or increase shred fusion of cheese shreds during pizza baking; however, there was an improvement in these properties between d 7 and 45. Coating of the cheese shreds with oil was necessary for adequate browning, melt, and flow characteristics in all cheese types.