首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 78 毫秒
1.
本文研究了保鲜菌种对搅拌型酸奶的保鲜作用.保鲜菌种不参加酸奶的发酵过程,不影响酸奶的发酵时间及乳酸菌数量,并能显著抑制霉菌和酵母菌的滋生.在4℃冷藏的情况下,在酸奶中添加保鲜菌种能延长产品保质期,且不影响酸奶的感官特征;而在25℃常温贮藏条件下,保鲜菌种在较短时间内会迅速提高酸奶的酸度,严重影响产品品质.  相似文献   

2.
试验旨在研究发酵菌种对生物饲料及全混合日粮(TMR)霉菌生长的影响。试验1:0.1%的枯草芽孢杆菌、酿酒酵母菌及植物乳杆菌混合添加至基础日粮中,按照比例分为7组,对照组不添加菌种,将各组置于孟加拉红平板培养基上,测定霉菌生长区域占平板面积的百分比。结果显示：饲料经过发酵可有效抑制霉菌生长;含有植物乳酸菌发酵的生物饲料对霉菌抑制效果均较好,枯草芽孢杆菌和酿酒酵母菌共同发酵的饲料对霉菌的抑制效果最差。试验2：在TMR日粮中添加100 g/kg试验1中的生物饲料,测定各组TMR在室温(13℃)和高温(26℃)条件下的温度变化和霉菌生长情况。结果显示：常温试验中,添加植物乳酸菌发酵的生物饲料的TMR温度和霉菌总数显著低于对照组(P<0.05),添加枯草芽孢杆菌和酿酒酵母共同发酵的生物饲料的TMR温度最高;高温试验中,除枯草芽孢杆菌与酿酒酵母混合菌种组,其余各生物饲料发酵菌种处理组TMR温度和霉菌总数显著低于对照组(P<0.05)。研究表明,植物乳酸菌是主要抑制霉菌生长的菌种,加入酿酒酵母菌或枯草芽孢杆菌,抑制霉菌生长效果更佳;两菌发酵和三菌发酵中,枯草芽孢杆菌和酿酒酵母菌间具有拮抗...  相似文献   

3.
为给今后复合发酵添加剂的开发提供新的途径,研究了纤维素分解菌与乳酸菌复合发酵情况下二者数量均达到最优值的发酵剂量。采用响应曲面设计法,设计乳酸菌(LAB)和真菌的数量为响应值,求出响应值均为最大时的自变量值。自变量为同、异型发酵LAB和纤维素分解菌添加比例及添加剂量,其中同型[植物乳杆菌(Lactobacillus plantarum)+戊糖片球菌(Pediococcus acidilactici)]、异型[布氏乳杆菌(Lactobacillus buchneri)]发酵LAB的添加量均为1×105、3×105和5×105cfu·g~(-1)(即5、5.48、5.70 lg cfu·g~(-1)),纤维素分解菌的比例为黑曲霉(Aspergillus niger)∶绿色木霉菌(Trichoderma viride)∶枯草芽孢杆菌(Bacillus subtilis)=1∶1∶2、1∶2∶1和2∶1∶1,纤维素分解菌的添加剂量为0.1%、0.2%和0.3%。LAB和真菌的数量的测定采用传统菌种计数法计数。结果表明:建立的LAB和真菌数量的二次多项式模型显著性分别为P0.01和P=0.03,R2分别为0.95和0.74。其中同、异型发酵LAB的添加量及其交互作用对LAB数量的曲面效应影响显著(P0.05)。真菌的添加量以及同、异型发酵LAB的交互作用对真菌数量的曲面效应影响显著(P0.05)。最终优化结果为同型发酵LAB添加量为5×105cfu·g~(-1)(5.70 lg cfu·g~(-1)),异型发酵LAB添加量为4.7×105cfu·g~(-1)(5.67 lg cfu·g~(-1)),纤维素分解菌比例为2∶1∶1,添加量为0.3%。  相似文献   

4.
茶多酚对乳酸菌发酵及酸奶品质的影响   总被引：1，自引：0，他引：1  
为了研究茶多酚对乳酸菌及酸奶品质的影响,将鲜牛乳以每个样品100 m L为标准分装于玻璃瓶中,每16个玻璃瓶为一组,共9组,测定了酸奶的滴定酸度、持水力、质构、乳酸菌活菌数、感官评价等指标。结果表明:茶多酚对乳酸菌生长繁殖的影响呈抛物线形,茶多酚添加量低于0.30%时对乳酸菌有明显的促生长作用(P0.01),茶多酚添加量为0.20%时促生长作用达到最佳;同时对乳酸菌产酸有一定抑制作用,可延长酸奶的保质期;随着茶多酚添加量的增加,酸奶的持水力及质构的测定结果及感官评价均呈抛物线形变化,在茶多酚添加量为0.20%时各项指标达最优。说明当茶多酚添加量为0.20%时,茶多酚对乳酸菌发酵及酸奶品质影响的结果最佳。  相似文献   

5.
[目的]考察不同添加量银杏叶提取物对发酵乳贮藏期品质的影响。[方法]采用持水率、黏度、乳酸菌活菌数、抗氧化能力、感官评价方法测定不同添加量银杏叶提取物制备的发酵乳,并结合多元统计分析方法进行分析。[结果]银杏叶提取物对乳酸杆菌和链球菌的活力没有显著影响,为保证活菌数在1.0×107 CFU/g以上,建议该发酵乳最多冷藏9天。在酸奶中添加银杏叶提取物可提高其抗氧化特性。添加银杏叶提取物的酸奶样品与对照组在风味和口感方面存在差异,且添加量越大差异越明显。[结论]银杏叶提取物本身作为一种中成药,具有成为一种新的功能性酸奶成分的巨大潜力。  相似文献   

6.
[目的]对比自制酸奶与市售酸奶在贮藏期间的品质变化。[方法]通过乳酸菌活菌数、酸度、pH值等指标,先探究自制酸奶在发酵过程中的品质变化,后与市售酸奶进行对比研究。[结果]自制酸奶过程中,发酵开始3 h后,随着乳酸菌发酵产物乳酸的累积,酸度上升、pH值下降,乳酸菌活菌数大幅度上升。发酵开始7 h后,乳酸菌总数开始下降,酸度的增加趋势和pH的降低趋势都有所减缓。在贮藏阶段,随着贮藏时间的增长,各种酸奶品质变化基本相同,乳酸菌含量先升后降,pH值下降,酸度上升。在4℃贮藏条件下,品质变化小于25℃。[结论]冷藏处理下酸奶的品质下降更慢,在自制或者购买酸奶时应该尽可能选择冷藏处理,开盖后尽快饮用完。两种酸奶具有不同的特点,消费者可以根据需求进行选择。总之,本研究为酸奶的安全贮藏提供参考依据。  相似文献   

7.
试验旨在获取生物抑霉的优良菌株以及为质量安全青贮饲料生产提供高效菌剂。从青贮饲料、酸奶以及奶豆腐中分离纯化出乳酸菌和霉菌,并且通过双层平板法对具有抑制霉菌活性的乳酸菌菌株进行筛选,测定其上清液抑霉效果;采用蛋白酶处理和高温处理法分析乳酸菌抑霉的有效成分。结果表明:分离筛选的乳酸菌和霉菌经鉴定为植物乳杆菌和黄曲霉菌,且植物乳杆菌对黄曲霉菌的生长有明显抑制作用。蛋白酶处理对乳酸菌无细胞上清液的抑菌活性有不同影响,而加热处理并不改变其抑菌效果。研究表明,植物乳杆菌对黄曲霉菌生长有明显的抑制作用,推测其抑菌活性物质为蛋白质、肽类等,并且这些抑菌活性物质的热稳定性较高。  相似文献   

8.
酸奶是以乳与乳制品为原料,通过添加乳酸菌发酵而制成的一种发酵乳制品,含有丰富的蛋白质、脂肪、碳水化合物、矿物质以及多种维生素,营养价值很高。这种产品由于经乳酸菌发酵,牛奶中的乳糖大量分解成乳酸,具有抑制肠道中有害微生物,促进钙、磷消化吸收和预防多种疾病的作用,特别适宜于乳糖不适应症者饮用。目前,酸奶在我国大中城市普遍生产,消费量逐年上升,是发  相似文献   

9.
酸奶的营养价值和医疗保健作用   总被引：9，自引：0，他引：9  
酸奶是以牛乳或其它乳为主要原料,以乳酸菌或酵母发酵而制得的乳制品。酸奶多采用乳酸菌发酵,按工艺分为酸凝乳和搅拌型酸奶,其中搅拌型酸奶又包括调味酸奶和果浆酸奶等。普通酸奶通常以保加利亚乳杆菌和嗜热链球菌或乳酸链球菌作为发酵菌种。作为医疗用途的嗜酸菌乳、双歧杆菌乳等,则分别以嗜酸乳杆菌和双歧杆菌为主要发酵菌种。酸奶的发酵剂菌种不同,对酸奶的营养价值、医疗保健作用以及风味、状态、口感等均有决定性作用。一般而言,牛乳经过乳酸菌发酵制成酸奶后,其营养价值均有所提高,而且均具有一定的医疗保健和防病、治病作用…  相似文献   

10.
不同添加剂对青贮饲料有氧稳定性的影响   总被引：5，自引：0，他引：5  
二次发酵是饲料在青贮和取用过程中普遍存在的问题,并给畜牧业生产带来了严重的经济损失。化学及生物制剂能够有效地抑制青贮饲料中真菌的滋生,提高青贮饲料的有氧稳定性。从各类制剂的添加效果来看,化学制剂中的丙酸及其盐类的效果较好;而乳酸菌中异质发酵型乳酸菌的效果优于同质发酵型乳酸菌;丙酸菌虽然能有效地提高青贮饲料的有氧稳定性,但其在酸性环境下不适宜生长繁殖。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
Tropical Animal Health and Production -  相似文献   

15.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

16.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

17.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

18.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
  相似文献   

19.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

20.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号