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...     

以大豆为主要原料制备新鲜豆乳干酪的工艺研究

豆乳干酪,是以豆乳取代牛乳的一种类似干酪的新型发酵豆制品。以大豆为主要原料,添加牛乳,采用牛乳干酪发酵剂发酵制备新鲜豆乳干酪,并对制备豆乳干酪的关键工艺参数进行研究,探讨发酵剂添加量对新鲜豆乳干酪在储藏14 d内的理化指标和质构特性的影响。结果表明,发酵剂添加量的不同对大豆干酪理化特性存在显著差异(p0.05)。随储藏时间的增加,豆乳干酪水分逐渐降低,pH缓慢下降,在相同接菌量条件下,不同储藏期内大豆干酪的硬度、弹性、咀嚼性逐渐降低。在接菌量不同时,豆乳干酪质构数值差异显著。试验结果显示,添加0.03%的发酵剂有利于新鲜豆乳干酪的制备。     

热烫拉伸融化过程对Mozzarella干酪品质、分子间作用力及微观结构的影响

Mozzarella干酪是目前我国进口量、消费量及大众接受度最高的干酪之一,因其在加热后能够融化拉丝,故在餐饮业中用途极为广泛。本实验通过测定并分析Mozzarella干酪在不同加工处理过程(新鲜凝块、热烫、热烫后拉伸、加热融化、融化后拉丝)中干酪的基本组分、质构、功能特性、分子间作用力、玻璃化转变温度(Tg)及微观结构的变化,研究热烫拉伸及加热融化过程对干酪品质特性的影响,并试图阐明干酪品质特性变化与分子间作用力变化的关系。结果表明,同未处理干酪凝块相比,热烫拉伸过程会造成脂肪损失30.1%,水分质量分数增加15.3%。热烫拉伸后干酪融化性下降,Mozzarella干酪样品同干酪凝块相比,融化性下降0.34 cm,拉丝长度无显著变化。热烫拉伸后,干酪Tg上升1℃,说明拉伸热处理导致干酪蛋白分子间作用力增加,蛋白分子运动性下降。蛋白疏水作用力及干酪蛋白溶解度测定结果表明疏水作用力无明显变化,分子间氢键作用力减少。扫描电子显微镜观察结果表明经热烫拉伸处理后干酪三维网络结构更加致密,同Tg变化及干酪溶解度测定结果一致。     

组合赋权法结合响应面分析法优化娟姗牛奶Mozzarella干酪制作工艺

以娟姗牛奶为原料乳,制作Mozzarella干酪,采用组合赋权法综合评价娟姗牛奶Mozzarella干酪的质量品质,并通过响应面分析法优化娟姗牛奶Mozzarella干酪的制作工艺。结果表明,Mozzarella干酪的色泽、风味、质构、特征结构的组合权重分别为0.052、0.427、0.351、0.170,质构指标中的硬度、弹性、凝聚性的组合权重分别为0.742、0.095、0.163,特征结构指标中的拉伸性、融化性、油脂析出性的组合权重分别为0.372、0.334、0.294。响应面分析法优化发现娟姗牛奶Mozzarella干酪的最佳工艺参数为:发酵剂添加量0.020%,拉伸温度76℃,拉伸时间3min,在此条件下娟姗牛奶Mozzarella干酪的理论综合值为15.97,实验验证综合值为15.99,模型拟合程度较高。     

不同乳酸菌对低脂Mozzarella干酪品质的影响

研究不同乳酸菌对低脂Mozzarella干酪品质的影响。采用无盐渍新工艺制作低脂Mozzarella干酪,经测定干酪的脂肪含量为9.85%。通过测定可溶性氮的指标、未融化干酪的质构特性、融化干酪的融化性和感官评定等对其进行研究。结果表明：低脂组的质构、融化性和风味均低于全脂组,但唾液链球菌嗜热亚种（ST）＋德氏乳杆菌保加利亚亚种（LB）＋干酪乳杆菌（LC）3 种乳酸菌组合制作的低脂Mozzarella干酪质构、融化性和风味等指标最接近全脂组。与生产Mozzarella干酪所用的传统乳酸菌组合（ST＋LB）相比,ST＋LB＋LC 3 种乳酸菌的组合,能有效地改善低脂Mozzarella干酪硬度大、融化性小、风味差的缺陷。     

黑豆豆乳添加量对Mozzarella奶酪成熟过程中品质的影响

在牛乳中添加不同的黑豆豆乳，研究不同的黑豆豆乳添加量对Mozzarella奶酪在成熟0 d、30 d、60 d、90 d时的水分活度、pH、质构、色泽、蛋白质降解等品质指标变化的影响。结果显示，随着黑豆豆乳添加量在2%～6%范围内的增大，奶酪的水分活度不断增大，pH不断降低，奶酪的硬度、弹性、粘附性、咀嚼性增加，奶酪的明亮度（L*值）下降，红度（a*值）和黄度（b*值）增加，而加入黑豆豆乳的奶酪在成熟过程中蛋白质降解与对照奶酪相似。综合各个指标，在牛乳中加入4%黑豆豆乳条件下制作的黑豆豆乳牛乳奶酪，既有独特的风味，同时奶酪具有较好的色度、质构、蛋白降解等指标特性。     

木瓜蛋白酶对Mozzarella干酪成熟过程中品质特性的影响

为研究木瓜蛋白酶对Mozzarella干酪成熟过程中品质特性的影响,对两组Mozzarella干酪在成熟过程中的质构、蛋白降解、融化性、油脂析出性、色度、风味物质等进行测定。结果表明:添加木瓜蛋白酶Mozzarella干酪的硬度、弹性、咀嚼性、内聚性均显著低于对照组Mozzarella干酪(P0.05),p H 4.6 SN/TN、12%TCA SN/TN、融化性在成熟24天后显著高于对照组Mozzarella干酪(P0.05),挥发性风味化合物的种类、部分挥发性物质的含量都较对照组Mozzarella干酪少。     

天然Mozzarella干酪和再制Mozzarella干酪理化特性和功能特性的比较

对天然Mozzarella干酪和再制Mozzarella干酪的理化特性（蛋白质、脂肪和水分质量分数及pH值）和功能 特性（质构特性、拉伸性、熔化性、油脂析出性和流变特性）进行分析。结果表明：天然Mozzarella干酪的蛋白质 量分数显著高于再制Mozzarella干酪,水分质量分数和pH值显著低于再制Mozzarella干酪,脂肪质量分数随干酪品 牌的不同存在差异;天然Mozzarella干酪的硬度、拉伸性、熔化性和油脂析出性都显著高于再制Mozzarella干酪;动 态温度扫描显示天然Mozzarella干酪和再制Mozzarella干酪的损耗角正切都随着温度的升高呈现先增加后降低的趋 势,天然Mozzarella干酪的损耗角正切在50～60 ℃时达到1,再制Mozzarella干酪的损耗角正切始终低于1。研究发 现天然Mozzarella干酪更适宜作为制作比萨、焗饭等需要焙烤食品的原料,再制Mozzarella干酪可以应用于三明治等 不需要焙烤的食品中。     

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。     

豆乳与牛乳比例对豆-乳内酯凝胶质构特性及微观结构的影响

用大豆和牛乳结合制作食品,可以合理平衡氨基酸的比例,使动物蛋白和植物蛋白组合,有利于膳食营养的均衡。以大豆乳、牛乳为混合原料,并以大豆乳、牛乳分别作为对照,以葡萄糖酸-δ-内酯(GDL)作凝固剂,探讨大豆乳与牛乳不同比例条件下,形成的豆-乳内酯凝胶的质构特性及微观结构的变化。结果表明:内酯豆乳与内酯牛乳在硬度、胶黏性、咀嚼性、脆性、黏性、弹性、内聚性方面差异显著。随着牛乳含量在混合物中的不断增加,当大豆乳和牛乳的比例达到1∶1前,大豆乳与牛乳的比例对豆-乳内酯凝胶的硬度、胶黏性、咀嚼性、脆性、黏性、弹性影响显著;当大豆乳和牛乳的比例达到1∶1后,差异不显著,而对其内聚性影响差异不显著。质构特性结合表面微观结构的测定结果表明:当牛乳添加量为30%时,豆-乳内酯凝胶质地较好,表面结构均匀,微观结构较好。     

热烫拉伸温度对Mozzarella干酪蛋白降解及质构特性的影响

不同的热烫拉伸温度对Mozzarella干酪的组织结构、凝块中微生物以及酶的活性有很重要的影响,进而会影响其成熟过程中蛋白质的降解以及最终品质的形成,该研究对不同热烫拉伸温度的Mozzarella干酪成熟过程中的蛋白降解及质构特性指标进行测定。结果表明,同一成熟期内,随着热烫温度（对照、70 ℃、90 ℃）的提高,干酪的pH 4.6可溶性氮（SN）显著下降（P＜0.05）,12%三氯乙酸-可溶性氮（TCA-SN）有所下降（P＞0.05）,而干酪的硬度、咀嚼性均显著增大（P＜0.05）,弹性增大而黏附性有所下降（P＞0.05）,融化性、油脂析出性均显著下降（P＜0.05）。因而采取70 ℃的热烫拉伸温度更有利于干酪成熟后形成良好的质构特性及充分的蛋白降解。     

USE OF FAT BLENDS IN CHEESE ANALOGS: INFLUENCE ON SENSORY AND INSTRUMENTAL TEXTURAL CHARACTERISTICS

Cheese analogs were prepared with the fat fraction composed of butterfat, soybean fat or soybean oil and their blends, in accordance with an experimental design of three components. The ten resulting formulations were subjected to a texture profile instrumental analysis and sensory analysis by a quantitative ranking test. Principal Component Analysis showed that the instrumental textural characteristics of hardness and adhesiveness were negatively correlated to cohesiveness and springiness, while the sensory texture characteristic of firmness was correlated negatively with elasticity and creaminess. Soybean fat confers hardness and adhesiveness to the cheese analogs, but decreases their cohesiveness and springiness, while the opposite effect is due to soybean oil and butterfat.     

超高压处理对干酪质构的影响

研究超高压(Ultra High Hydrostatic Pressure,HHP;200,600 MPa/10min)处理对5种市售干酪的硬度、黏着性、弹性、内聚性、咀嚼性和回复性6个功能特性的影响。结果显示,5种干酪在200 MPa处理时,其黏着性、弹性、内聚性、回复性差异不显著(P0.05),即较低压力处理对干酪的质构影响不大;超高压处理后,干酪的硬度和耐咀性分别降低31%,39%,且压力越大降低越显著(P0.05);高压处理后蓝纹、稀奶油干酪的内聚性分别增加了21%,15%;帕马森、切达干酪经超高压处理其各个性质基本无显著变化,而马索里拉、蓝纹、稀奶油干酪的各个功能性均有显著差异,说明超高压处理对干酪质构的影响与水分含量有关,即水分含量越高的干酪其质构受超高压处理变化越显著。     

Effect of camel chymosin on the texture,functionality, and sensory properties of low-moisture,part-skim Mozzarella cheese

The objective of this study was to compare the effect of coagulant (bovine calf chymosin, BCC, or camel chymosin, CC), on the functional and sensory properties and performance shelf-life of low-moisture, part-skim (LMPS) Mozzarella. Both chymosins were used at 2 levels [0.05 and 0.037 international milk clotting units (IMCU)/mL], and clotting temperature was varied to achieve similar gelation times for each treatment (as this also affects cheese properties). Functionality was assessed at various cheese ages using dynamic low-amplitude oscillatory rheology and performance of baked cheese on pizza. Cheese composition was not significantly different between treatments. The level of total calcium or insoluble (INSOL) calcium did not differ significantly among the cheeses initially or during ripening. Proteolysis in cheese made with BCC was higher than in cheeses made with CC. At 84 d of ripening, maximum loss tangent values were not significantly different in the cheeses, suggesting that these cheeses had similar melt characteristics. After 14 d of cheese ripening, the crossover temperature (loss tangent = 1 or melting temperature) was higher when CC was used as coagulant. This was due to lower proteolysis in the CC cheeses compared with those made with BCC because the pH and INSOL calcium levels were similar in all cheeses. Cheeses made with CC maintained higher hardness values over 84 d of ripening compared with BCC and maintained higher sensory firmness values and adhesiveness of mass scores during ripening. When melted on pizzas, cheese made with CC had lower blister quantity and the cheeses were firmer and chewier. Because the 2 types of cheeses had similar moisture contents, pH values, and INSOL Ca levels, differences in proteolysis were responsible for the firmer and chewier texture of CC cheeses. When cheese performance on baked pizza was analyzed, properties such as blister quantity, strand thickness, hardness, and chewiness were maintained for a longer ripening time than cheeses made with BCC, indicating that use of CC could help to extend the performance shelf-life of LMPS Mozzarella.     

Effect of Resistant Starch and Inulin on the Properties of Imitation Mozzarella Cheese

The effect of two fat replacers (inulin and resistant starch) on functional properties and microstructure of imitation Mozzarella cheeses was evaluated. Three groups of imitation Mozzarella cheeses were manufactured by adding 0, 2.4, 4.8, 7.2, 9.6, and 12% (w/w) inulin or resistant starch instead of the fat, respectively. Inclusion of the inulin up to 7.2% in cheese, fat content of it was significantly (p ≤ 0.05) decreased and the moisture and pH values of it were significantly (p ≤ 0.05) different. Inclusion of resistant starch up to 9.6% in cheese, fat content of it was significantly (p ≤ 0.01) decreased and the moisture and pH values of it were significantly (p ≤ 0.05) different. The physical properties of these cheeses were significantly different (p ≤ 0.05) among them. The textural properties were determined by instrumental texture pro?le. With increased levels of inulin or resistant starch from 2.4 to 12% (w/w), the hardness of the resultant imitation cheeses were significantly increased (p ≤ 0.05), while the cohesiveness and springiness decreased and the meltability and stretch ability had reduced (p ≤ 0.05), compared with the control, especially containing resistant starch stretch ability had reduced more. The microstructure of imitation Mozzarella cheese was observed by scanning electron microscopy. The scanning electron microscopy results indicated that interactions between casein and inulin or resistant starch in imitation cheeses accounted for variance properties of imitation cheese. It is concluded that inulin or resistant starch could be used to replace up to 7.2% of the fat in imitation cheese and that the preferred substitution was inulin.     

双蛋白切达干酪成熟过程中的质构和感官评价分析

在原料乳中添加质量分数为10%豆乳进行切达干酪加工,研究成熟过程中豆蛋白和筛选发酵剂对干酪质构及感官影响。结果表明,豆乳和发酵剂对干酪的基础理化指标有显著影响,从干酪质构分析结果可以看出,干酪在成熟期间,豆乳的添加对干酪的硬度、弹性、黏聚性和咀嚼性都有显著影响,干酪硬度和咀嚼度下降。应用发酵剂L.Lactis subsp.Cremoris QH27-1和L.Lactis subsp.LactisXZ3303生产双蛋白切达干酪可以提高干酪的质构特征和感官品质。     

THE INFLUENCE OF FAT, ACID, AND SALT ON THE PERCEPTION OF SELECTED TASTE AND TEXTURE ATTRIBUTES OF CHEESE ANALOGS: A SCALAR STUDY

Twelve cheese analogs varying in amounts of fat (10 17.5, and 25%), sodium chloride (0.5 and 2.0%), and citric acid (0.1 and 1.2%) were prepared to determine the influence of the three constituents on taste and texture perception, as well as on the rheological behavior of the analogs. Sourness, saltiness, springiness, firmness, cohesiveness, and adhesiveness were rated by trained judges on a graphic scale. The Instron Universal Testing Machine was used for the rheological studies. Increasing the salt content in the cheese analogs resulted in an increased saltiness and sourness intensity and a decreased pH. Increasing the acid or salt content caused a significant decrease in cohesiveness and springiness and an increase in firmness. A higher fat content resulted in a softer, less springy, more cohesive and adhesive cheese analog.     

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.