豆奶干酪制备的影响因素研究

通过对豆奶干酪生产因素的研究,发现豆乳添加量、混合乳杀菌温度、发酵剂添加量、混合酶比例和CaCl2添加量等因素对豆奶干酪的产率都有影响,从而确定最佳工艺参数.实验结果表明,为了提高豆奶干酪的产率,同时保证豆奶干酪的品质,豆乳添加量为10%;杀菌条件为80℃、15 s;发酵剂添加量为2.00%;调酸pH为5.8;谷氨酰胺转胺酶与凝乳酶比例为4∶1;CaCl2添加量为0.06%;热缩温度为40℃;干酪切割时间为120min,切割大小为10mm.     

干酪生产因素的研究

通过对干酪生产工艺的研究,发现杀菌条件、发酵剂添加量、混合酶比例和CaCl2添加量等因素对干酪电导率及品质都有影响,从而确定最佳工艺参数.实验结果表明:在干酪生产过程中,为了使产品的凝乳时间短、状态好,采用72℃、15s的杀菌条件;发酵剂添加量为1.50%;调酸pH为6.0;谷氨酰胺转胺酶与凝乳酶比例为3:1;CaCl2添加量为0.04%;干酪切割时间为100min,切割大小为10mm;堆积pH为5.20;干酪浸渍在20℃18%的食盐水中放置36h.     

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。     

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℃。     

几个影响新鲜软质干酪品质的因素研究

对影响新鲜软质干酪加工的主要因素进行了研究,通过研究新鲜软质干酪加工过程中发酵剂菌种配比、凝乳酶添加量、加热终温度,确定干酪的工艺流程及工艺参数。结果表明,原料乳中添加发酵剂(乳脂链球菌:嗜热链球菌)比例为8∶1,凝乳酶添加量为0.01 mL/100L牛乳,加热终温度为55℃为宜,可得到产率较高,口感良好的新鲜软质干酪。     

泡菜乳酸菌生产干酪工艺研究

对泡菜中乳酸菌进行了初步分离纯化,共筛选出4种菌株,对这4种菌株进一步进行了发酵性能研究和凝乳实验,选择出优良两种菌株,并应用于新鲜软质干酪的制作,采用L9(34)正交实验的方法,研究了不同发酵剂菌株添加比例、发酵温度、切割pH值对成品干酪滋味口感、色泽的影响,确定了该产品生产的最佳配方和工艺条件:菌种比为菌株8与菌株12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。     

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℃.     

工艺过程对干酪品质及产率的影响

探讨了干酪制作过程中工艺过程、发酵剂、凝乳酶及CaCl2的添加量等对干酪产率及品质的影响,从而确定最佳工艺参数。实验结果表明:在干酪生产过程中,为了使产品的凝乳时间短、状态好、产率高,采用72℃、15s的杀菌条件,发酵剂的添加量为1.2%,预酸pH为6.1,CaCl2添加量为0.015%,凝乳酶添加量为4g/L,干酪切割时间为100min,切割大小为5mm,干酪浸渍在6℃16%的食盐水中放置24h。     

夸克干酪工艺条件优化研究

为了获得适合中国人口味夸克干酪的最佳加工工艺和条件,以鲜乳为原料,经杀菌、冷却、接种、添加凝乳酶、凝块切割、排乳清、包装等工艺制作夸克干酪,主要通过L9(34)正交试验,发酵剂添加量、凝乳酶添加量、切割p H值和排乳清条件等4个关键工艺进行了优化,试图优选出适合中国人口味的夸克干酪制品最佳工艺条件。结果表明:当发酵剂添加量为3.5%、凝乳酶添加量为0.15%、切割p H为4.7和排乳清条件为2 400 r/min、20 min条件下制作夸克干酪时,可获得最佳感官品质的夸克干酪。当发酵剂添加量为4.0%、凝乳酶添加量为0.18%、分离p H为4.7和排乳清条件为3 600 r/min 20 min时,制作的夸克干酪出品率最高。     

保加利亚乳杆菌与嗜热链球菌发酵夸克的工艺条件优化

以脱脂乳为原料,保加利亚乳杆菌和嗜热链球菌混合发酵剂制备夸克。以乳清OD500nm值、夸克校正产率及感官品质为评定指标,对凝乳酶添加量、CaCl2添加量、发酵剂嗜热链球菌与保加利亚乳杆菌配比、切割pH值4个因素进行考察。在此基础上对夸克感官评分进行四因素两水平的正交试验。结果表明：在凝乳酶添加量0.015%、嗜热链球菌与保加利亚乳杆菌配比3:2、CaCl2添加量0.02%、切割pH值为4.5时,所得夸克的感官评分最高,具有浓郁的奶香味,酸味清爽无颗粒感。     

EFFECT OF THE USE OF DIFFERENT LACTIC STARTERS ON THE MICROBIOLOGICAL AND PHYSICOCHEMICAL CHARACTERISTICS OF NATURALLY BLACK TABLE OLIVES OF GEMLIK CULTIVAR

The effect of different lactic acid bacteria cultures on the physicochemical and microbiological characteristics of brined black olives of Gemlik cultivar at low fermentation temperature was studied. Fermentation was carried out according to the traditional Gemlik method with modifications like low salt concentration and lactic starter addition. The brines with 7% salt concentration were inoculated with lactic acid bacteria ( Lactobacillus brevis, Leuconostoc cremoris and L. paramesenteroides ), which were previously isolated from olive fruits at low temperatures and a commercial strain of Lb. plantarum. Fermentation procedures were carried out at controlled temperatures (between 10–12C). Lactic acid bacteria survival was accompanied by yeast development, no Pseudomonas and Enterobacter species were detected in all treatments during fermentation. The highest total titratable acidity, lowest pH and least yeast growth were determined at the brines and fermentation products, which were inoculated with L. cremoris.

PRACTICAL APPLICATIONS

The use of suitable starter cultures is necessary to improve the microbiological control of the naturally black table olive process, help to standardize the fermentation, increase the lactic acid yield and accordingly provide the production of olives with high quality. The requirements mentioned for starter cultures include a rapid and predominant growth, homofermentative metabolism, tolerance to salt, acid and polyphenols, and few growth factor requirements. Especially at the regions where olives were picked later when environmental temperatures are lower, the use of a starter culture that has the ability to grow at low temperatures may be necessary. Use of such starter cultures may help to increase acidification, to control some types of spoilage and to shorten the fermentation process.     

黑树莓夸克最佳工艺参数组合的灰色分析

以鲜牛乳和黑树莓果汁为主要原料,采用多目标灰色组合决策原理对黑树莓夸克生产中主要工艺参数CaCl2添加量、酶用量、切割pH值进行灰色分析.结果表明:黑树莓夸克主要工艺参数的最优组合为CaCl2添加量0.02％、酶用量40mg/L、切割pH值为4.6.     

发酵剂对双蛋白干酪理化特性及风味的影响

在牛乳和添加豆乳(质量分数10%)的牛乳中分别使用筛选发酵剂与商品发酵剂进行切达干酪生产,并对成熟干酪的理化成分、质地、风味成分和感官特性进行分析。结果表明,豆乳的添加对干酪的质地、风味和感官特性均无不良影响,而应用筛选发酵剂L. lactis subsp. cremoris QH27-1和L. lactis subsp. lactis XZ3303生产双蛋白切达干酪对干酪的品质有一定的改善作用,可将其应用于双蛋白干酪生产中。     

Influence of starter and nonstarter on the formation of biogenic amine in goat cheese during ripening

Two commercial starters were investigated for their potential ability to decarboxylate amino acids during goat cheese ripening. Two batches of goat cheese were produced with identical pasteurized milk but different starter cultures. One of them contained Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris and the other Lactococcus lactis subsp. lactis. The amine contents, microbial counts, proteolysis-related parameters, pH, total solids and salt content were studied in raw materials and cheeses. In raw materials, polyamines were the prevailing amines, whereas the main amines in cheeses were putrescine, tryptamine and, in particular, tyramine (94.59 mg/kg). Aerobic mesophilic microorganisms and Lactococcus counts increased throughout ripening, while Enterobacteriaceae were no longer detectable in cheese after 30 days of ripening. Amine concentration rose during cheese ripening in both batches. Moreover, the decarboxylase activity of microorganisms isolated from samples during cheese ripening was assayed and discussed.     

驼乳干酪的工艺优化及成熟期间的理化特性

研究了驼乳干酪最佳加工工艺及成熟期间理化和微生物指标的变化。确定了驼乳干酪的最佳工艺参数:发酵剂的添加量为0.006%,CaC12的添加量为0.03 g/L,pH值为6.1,凝乳酶的添加量为0.06 g/L,凝乳温度为35℃。驼乳干酪的干物质质量分数约为45%,随成熟时间的延长,驼乳干酪的蛋白质、脂肪、乳糖、水分,质量分数下降;硬度、咀嚼性升高,但黏着性和弹性降低;pH4.6-SN的质量分数、12%TCA-SN和5%PTA-SN的质量分数都有不同程度的上升;发酵剂乳酸菌数在逐渐降低,非发酵剂活菌数却在逐渐增高。     

发酵剂对牦牛乳硬质干酪蛋白降解和苦味关系的影响

用甘肃天祝新鲜牦牛乳为原料分别添加嗜温、嗜热和混合发酵剂制作硬质干酪,以pH 4.6-可溶性氮（soluble nitrogen,SN）、12%三氯乙酸氮（trichloroacrtic acid-N,TCA-N）、游离氨基酸（free amino acid,FAA）含量和疏水性肽/亲水性肽（S/Q）为蛋白水解度指标,研究3 种牦牛乳硬质干酪在6 个月内成熟过程中苦味和蛋白质降解之间的关系。结果表明：3 种干酪在成熟过程中pH 4.6-SN、12% TCA-N和FAA含量均呈上升趋势,苦味值与pH 4.6-SN、12% TCA-N和FAA含量成正相关,相关系数分别为0.400、0.412和0.458。3 种干酪成熟过程中S/Q的变化趋势和程度不同,嗜温发酵剂干酪中S/Q呈现降低趋势;嗜热和混合发酵剂干酪中S/Q均呈现先降低后增大的趋势,但在这两种干酪中S/Q的变化程度不同,嗜热发酵剂干酪在1～3 个月S/Q略有降低,在3～6 个月S/Q快速增大,而混合发酵剂干酪正好相反。S/Q与苦味值成极显著正相关（r=0.895）,S/Q可很好地反映干酪中苦味的强弱。而干酪中苦味强弱与蛋白质降解强弱密切相关,对蛋白降解程度越大的发酵剂制作的干酪越容易产生苦味,其中,嗜热发酵剂对干酪蛋白降解程度最大,混合发酵剂次之,嗜温发酵剂最小。     

Combined effects of concentrated thermophilic and mesophilic cultures and conditions of curd acidifications on the manufacture and quality of kasseri cheese

The effect offour process variables on the biological acidification of curd to be usedfor the manufacture of kasseri cheese was examined. The variables were (i) concentrated starter cultures: a thermophilic mixture of Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgar-icus compared with a blend of Lactococcus lactis subsp lactis, Lactococcus lactis subsp cremoris and Lactobacillus casei subsp casei, and (ii) acidification temperatures: 30 and 40° C for the thermophilic cultures and 20 and 30°C for the mesophiles. The use of concentrated starter cultures enabled the cheese to be made in one day as compared with three in the traditional system usually using raw milk and no culture. The mesophilic blend combined with a lower scalding temperature (35°C) gave a higher yield than the alternative culture, and the cheeses were higher in total solids, acidity andsalt; the same cheeses were also harder and less elastic. The use of mesophilic cultures and a low acidification temperature (20° C) is recommended.