瑞士奶酪生产工艺研究

以新鲜牛乳为主要原料,根据瑞士奶酪的生产工艺,采用L9(34)正交实验的方法,研究了不同切割尺寸、发酵剂添加比例、发酵剂添加量、发酵温度和切割pH对瑞士奶酪色泽、滋气味和组织状态的影响,确定了生产瑞士奶酪的最佳工艺条件为发酵剂添加量0.02%(质量分数),凝块切割尺寸0.6cm,切割pH6.60,发酵剂(唾液链球菌嗜热亚种∶瑞士乳杆菌∶谢氏丙酸杆菌)添加比例2∶2∶1,发酵温度37℃。      

瑞士的奶酪文化

提起瑞士食品,就不能不提起奶酪和巧克力。这就像说起中国的传统饮食文化,就不能就说到天津的狗不理包子和北京的全聚德烤鸭一样。奶酪生产在瑞士有着悠久的历史。它的发明应归功于瑞士独特的地理环境和瑞士先民的智慧。在瑞士的阿尔卑斯山上散落着星星点点的高山牧场。当年,瑞士的牧民们在山上的牧场放牧,一待就是半年以上。山上的食品非常匮乏,除了肉和杂粮就是牛奶。奶牛产下了鲜奶不可能一下子喝完,必须加工保存。于是,牧民们把鲜奶经过加热、脱脂、搅拌、挤压、储存翻面和烘干等多道工序,做成了可以长期保存的干奶酪。在瑞士,奶酪不仅…     

蓝纹奶酪生产工艺及质量控制

根据蓝纹奶酪的生产工艺,研究了主要工艺条件对蓝纹奶酪产品品质的影响,以及如何控制这些工艺环节上出现的质量问题。     

瑞士的奶酪文化

提起瑞士食品,就不能不提起奶酪和巧克力。这就像说起中国的传统饮食文化,就不能不说到天津的狗不理包子和北京的全聚德烤鸭一样。奶酪生产在瑞士有着悠久的历史。它的发明应归功于瑞士独特的地理环境和瑞士先民的智慧。在瑞士的阿尔卑斯山上,散落着星星点点的高山牧场。当年,瑞士的牧民们在山上的牧场放牧,一呆就是半年以上。山上的食品非常匮乏,除了肉和杂粮就     

阿胶奶酪的工艺研究

以发酵剂接种量、发酵时间、凝乳温度、阿胶添加量四个因素作三个水平的正交试验,通过准确测定阿胶奶酪中水分、脂类、蛋白质、干物质等的百分含量及产品的感官指标评分,得出阿胶奶酪的最佳生产工艺.阿胶奶酪的最佳工艺为发酵剂的添加量3%、发酵时间1 h、凝乳温度36℃、阿胶添加量1%.试验证实在奶酪中添加具有保健功能的阿胶可以生产出既具有奶酪的营养价值又具有阿胶的保健价值的新型保健奶酪--阿胶奶酪.     

苹果酒生产工艺的研究

以苹果为原料，经清洗、破碎、榨汁、发酵、澄清、调配、过滤等工序制成11度干型苹果酒，通过正交实验确定最适发酵条件为：接种量0．05％，发酵pH值3．5，发酵时间为12d，发酵温度为25℃。得到浅黄绿色、澄清透明、风味好、营养丰富的苹果酒。     

蒙古干酪生产工艺研究

以鲜牛乳为原料,根据蒙古干酪的生产工艺,采用L9(34)正交实验的方法,研究了不同灭菌条件、发酵剂添加量、捶捣切割pH值和热烫温度对蒙古干酪蛋白利用率、干酪品质的影响,确定了生产蒙古干酪的最佳工艺条件为63℃/1800 s的灭菌条件,发酵剂添加量为2.5%(体积分数),捶捣切割pH值为4.8,热烫温度为47℃.     

瑞士乳杆菌LH-G51冻干菌粉生产工艺研究

目的:对瑞士乳杆菌LH-G51菌粉生产工艺进行优化。方法:通过单因素及正交试验设计,确定适合LH-G51生长的发酵培养基、冻干保护剂配方及生产工艺。结果:发酵时间、碳氮源及微量元素添加量均对LH-G51生长有明显影响。最终确定LH-G51培养基碳氮源及微量元素为葡萄糖20 g/L、大豆蛋白胨10 g/L、酵母膏15 g/L、MgSO_4·7H_2O为250 mg/L、MnSO_4·H_2O为50 mg/L、发酵时间10 h、保护剂为B。结论:根据优化工艺,LH-G51冻干菌粉活菌数可达到4.21×10^(11)CFU/g。     

苦荞沙琪玛生产工艺研究

以苦荞粉、谷朊粉、高筋粉等为主要原料生产苦荞沙琪玛,通过单因素实验和正交实验,确定混合粉比例、发酵温度、发酵时间、油炸温度的最佳参数。实验结果表明,苦荞沙琪玛的最佳生产工艺条件为苦荞粉∶谷朊粉∶高筋粉(质量比)为20∶25∶55,醒发温度35℃,第一次及第二次醒发时间均为2h,油炸温度为160℃。      

松仁奶酪生产工艺及其感官评定研究

本实验探讨了松仁奶酪的生产工艺条件,分别对影响产品凝乳效果和感官品质的主要因素进行了研究.结果表明,最佳生产工艺条件为:松仁5%,发酵剂1%,凝乳酶0.008%,CaCl2 0.02%,凝乳pH5.5,凝乳温度40℃,凝乳时间28min,在此生产工艺条件下松仁奶酪凝乳细腻、凝块有弹性,风味与色泽均与纯牛乳干酪相似.     

夸克干酪传统工艺研究及优化

采用生产夸克干酪的传统方法,采用七因素二水平正交设计研究了发酵剂添加量、菌种比例(乳酸链球菌、乳脂链球菌与乳明串珠菌的质量比)、杀菌温度、凝乳温度、切割pH对夸克干酪品质的影响。结果表明:当发酵剂添加量为3%,菌种比例为1∶1∶2,发酵温度为35℃,杀菌温度为79℃,切割pH为4.7时,夸克干酪品质最佳。经验证,该工艺具有良好的可行性与稳定性,可用于实际生产。     

新鲜软质干酪加工工艺的研究

以鲜牛乳为原料,研究了新鲜软质干酪的制作工艺,采用L9(34)正交试验的方法,研究了不同发酵剂菌种添加比例、发酵温度、切割pH值对成品干酪滋味口感、色泽和涂抹性的影响,最终确定了该产品生产的最佳配方和工艺条件:菌种比为1:1(质量比),发酵剂添加量为3%(质量分数),发酵温度为37℃,切割pH值为4.6。     

添加具有抑真菌特性植物乳杆菌生产切达干酪工艺条件的研究

以两株具有抑制真菌活性的植物乳杆菌Lactobacillus plantarum ALAC-3、Lactobacillus plantarum ALAC-4为研究对象,分别与工业发酵剂复配生产切达干酪。通过研究传统发酵剂与具有抑真菌特性植物乳杆菌的不同菌株混合比例、接种量、培养温度、发酵时间因素的影响,采用单因素分析及正交实验,确定生产切达干酪的最佳工艺条件。并对添加植物乳杆菌生产的干酪的抑菌效果进行研究。结果表明,ALAC-3菌株发酵生产切达干酪的最佳工艺条件为:传统发酵剂与ALAC-3菌种混合比例4∶4∶2.5,接种量3%,培养温度35℃,发酵时间20 min;ALAC-4菌株发酵生产切达干酪的最佳工艺条件为:传统发酵剂与ALAC-4菌种混合比例4∶4∶0.5,接种量3%,培养温度37℃,发酵时间25 min。在此工艺条件下,制得的干酪质量良好。25℃的贮藏条件下,添加ALAC-3（ALAC-4）生产的干酪产品抑制真菌的效果良好。因此,可以将ALAC-3和ALAC-4作为生物防腐剂应用于切达干酪的生产中。      

Standardization of milk using cold ultrafiltration retentates for the manufacture of Swiss cheese: effect of altering coagulation conditions on yield and cheese quality

Fortification of cheesemilk with membrane retentates is often practiced by cheesemakers to increase yield. However, the higher casein (CN) content can alter coagulation characteristics, which may affect cheese yield and quality. The objective of this study was to evaluate the effect of using ultrafiltration (UF) retentates that were processed at low temperatures on the properties of Swiss cheese. Because of the faster clotting observed with fortified milks, we also investigated the effects of altering the coagulation conditions by reducing the renneting temperature (from 32.2 to 28.3°C) and allowing a longer renneting time before cutting (i.e., giving an extra 5 min). Milks with elevated total solids (TS; ∼13.4%) were made by blending whole milk retentates (26.5% TS, 7.7% CN, 11.5% fat) obtained by cold (<7°C) UF with part skim milk (11.4% TS, 2.5% CN, 2.6% fat) to obtain milk with CN:fat ratio of approximately 0.87. Control cheeses were made from part-skim milk (11.5% TS, 2.5% CN, 2.8% fat). Three types of UF fortified cheeses were manufactured by altering the renneting temperature and renneting time: high renneting temperature = 32.2°C (UFHT), low renneting temperature = 28.3°C (UFLT), and a low renneting temperature (28.3°C) plus longer cutting time (+5 min compared to UFLT; UFLTL). Cutting times, as selected by a Wisconsin licensed cheesemaker, were approximately 21, 31, 35, and 32 min for UFHT, UFLT, UFLTL, and control milks, respectively. Storage moduli of gels at cutting were lower for the UFHT and UFLT samples compared with UFLTL or control. Yield stress values of gels from the UF-fortified milks were higher than those of control milks, and decreasing the renneting temperature reduced the yield stress values. Increasing the cutting time for the gels made from the UF-fortified milks resulted in an increase in yield stress values. Yield strain values were significantly lower in gels made from control or UFLTL milks compared with gels made from UFHT or UFLT milks. Cheese composition did not differ except for fat content, which was lower in the control compared with the UF-fortified cheeses. No residual lactose or galactose remained in the cheeses after 2 mo of ripening. Fat recoveries were similar in control, UFHT, and UFLTL but lower in UFLT cheeses. Significantly higher N recoveries were obtained in the UF-fortified cheeses compared with control cheese. Because of higher fat and CN contents, cheese yield was significantly higher in UF-fortified cheeses (∼11.0 to 11.2%) compared with control cheese (∼8.5%). A significant reduction was observed in volume of whey produced from cheese made from UF-fortified milk and in these wheys, the protein was a higher proportion of the solids. During ripening, the pH values and 12% trichloroacetic acid-soluble N levels were similar for all cheeses. No differences were observed in the sensory properties of the cheeses. The use of UF retentates improved cheese yield with no significant effect on ripening or sensory quality. The faster coagulation and gel firming can be decreased by altering the renneting conditions.     

半硬质干酪加工工艺条件的研究

通过单因素试验和正交优化试验,研究发酵剂添加量、CaCl2添加量、凝乳酶添加量、凝乳温度和盐水浓度对半硬质干酪感官品质的影响,从而得出加工半硬质干酪的最佳工艺条件。结果表明,其最佳工艺参数为发酵剂添加量5%、CaCl2添加量0.02%、凝乳酶添加量3.0 g/100 L、凝乳温度36 ℃、盐水质量分数18%。此最佳工艺条件下得到干酪的感官评分最高为93.25分,干酪产率为10.37%,含盐量为0.74%,含水量为43.58%。香味浓郁、组织细腻、软硬适度、呈现乳白色且有光泽。     

筒纱上浆工艺应用及分析

毛纱中的一些高支纱或低支纱的单纱,有时因强力不好会影响上浆后络线和织布效率.上浆是一种有效的提高纱线强力的方法.文章主要讨论筒纱上浆工艺的应用,上浆率的测定及上浆后对络线和织布效率的提高.但并不是所有的纱线都适合上浆,通过多缸实验进行数据分析后总结出了一些注意事项.     

Effect of Holstein Friesian and Brown Swiss breeds on quality of milk and cheese

In Italy, more than 75% of milk is used for cheese making. For this reason, milk composition and coagulation traits and cheese quality represent the most important tools for the economic development of the dairy sector. In particular, cheese quality varies in relation to cheese-making technology and breed of cow. The aim of this study was to investigate the effect of 3 types of milk, originating from Holstein-Friesian (HF), Brown Swiss (BS), and mixed of both breeds, on vat milk characteristics, cheese yield, and quality in 3 different typical Italian cheese-making conditions (Casolet, Vezzena, and Grana Trentino). One hundred forty-four cows (66 HF and 78 BS) were involved, and a total of 24 vats of milk were evaluated. At maturity, 30, 21, and 16 wheels of Casolet, Vezzena, and Grana Trentino cheese were analyzed. Brown Swiss cows yielded 9% less milk per day than HF cows, but milk showed greater contents of protein, casein, titratable acidity, and better rennet coagulation time and curd firmness than HF milk. The chemical composition and cholesterol content of the 3 types of cheese were similar between breeds, whereas the cheese made with BS milk showed greater contents of monounsaturated and polyunsaturated fatty acids. Cheese made with BS milk had greater b* (yellow component) than HF. Cheese yield, recorded at different ripening times, demonstrated that BS milk yielded more cheese than HF. Mixed milk showed values, on average, intermediate to HF and BS milk characteristics, and this trend was confirmed in cheese yield at different ripening times.     

Application of infrared microspectroscopy and multivariate analysis for monitoring the effect of adjunct cultures during Swiss cheese ripening

Improved cheese flavor has been attributed to the addition of adjunct cultures, which provide certain key enzymes for proteolysis and affect the dynamics of starter and nonstarter cultures. Infrared microspectroscopy provides unique fingerprint-like spectra for cheese samples and allows for rapid monitoring of cheese composition during ripening. The objective was to use infrared microspectroscopy and multivariate analysis to evaluate the effect of adjunct cultures on Swiss cheeses during ripening. Swiss cheeses, manufactured using a commercial starter culture combination and 1 of 3 adjunct Lactobacillus spp., were evaluated at d 1, 6, 30, 60, and 90 of ripening. Cheese samples (approximately 20 g) were powdered with liquid nitrogen and homogenized using water and organic solvents, and the water-soluble components were separated. A 3-μL aliquot of the extract was applied onto a reflective microscope slide, vacuum-dried, and analyzed by infrared microspectroscopy. The infrared spectra (900 to 1,800 cm⁻¹) produced specific absorption profiles that allowed for discrimination among different cheese samples. Cheeses manufactured with adjunct cultures showed more uniform and consistent spectral profiles, leading to the formation of tight clusters by pattern-recognition analysis (soft independent modeling of class analogy) as compared with cheeses with no adjuncts, which exhibited more spectral variability among replicated samples. In addition, the soft independent modeling of class analogy discriminating power indicated that cheeses were differentiated predominantly based on the band at 1,122 cm⁻¹, which was associated with S-O vibrations. The greatest changes in the chemical profile of each cheese occurred between d 6 and 30 of warm-room ripening. The band at 1,412 cm⁻¹, which was associated with acidic AA, had the greatest contribution to differentiation, indicating substantial changes in levels of proteolysis during warm-room ripening in addition to propionic acid, acetic acid, and eye formation. A high-throughput infrared microspectroscopy technique was developed that can further the understanding of biochemical changes occurring during the ripening process and provide insight into the role of adjunct nonstarter lactic acid bacteria on the complex process of flavor development in cheeses.     

超滤技术在盐水奶酪中的应用研究

以新鲜牛乳为主要原料,结合盐水奶酪的生产工艺,研究了不同超滤膜孔径、操作参数对产品得率和通量的影响,根据实验结果确定最优超滤膜孔径10 nm,操作温度55℃,操作压力0.3 MPa,同时采用L9(33)正交实验方法,研究了不同灭菌方式、混合菌株、盐溶液质量分数对盐水奶酪色泽、滋气味和组织状态的影响,生产盐水奶酪最佳工艺条件是灭菌方式72℃,15 s,混合菌株(乳酸乳杆菌:乳酸乳球菌乳脂亚种)1:1,盐溶液质量分数为15%。