微波对槟榔干果杀菌效果及其品质的影响

以槟榔干果为材料,研究微波对槟榔干果杀菌效果及其品质的影响,采用单因素法和多因素正交法优化槟榔干果微波杀菌的工艺条件。结果表明,在微波频率2 450 MHz,微波功率为850 W,装载量为(9.5±0.01)kg/m2,微波处理75 s后,密实袋封口,常温贮藏180 d,处理组槟榔干果中菌落总数、霉菌数目和大肠菌群数均未检出,理化性质无显著影响。      

产聚γ-PGA菌株分离与产物鉴定

从豆酱中分离筛选一株产聚γ-PGA的菌株SK-3,依据菌落的外观形态、菌体镜下形态及其部分生理生化特性,初步鉴定菌株为枯草芽孢杆菌。该菌株固态发酵大豆所提产物经紫外光谱扫描、傅里叶红外光谱扫描,结果显示与聚γ-PGA标准品的图谱基本一致,说明产物归属于聚酰胺类化合物;所提产物水解后经纸上层析法检测,仅为单一氨基酸——谷氨酸,说明产物是谷氨酸聚合物。     

大麻沤麻液中细菌的分离和鉴定

为了解大麻沤麻液中细菌菌群构成,确立麻液分离菌的种属地位,本研究以大麻原茎沤麻液为菌种筛选的来源,利用传统可培养法分离得到24株细菌,并通过16S rDNA序列与细菌菌落形态、菌体的显微形态鉴定、生理生化鉴定相结合的方法对菌株进行鉴定,同时构建24株分离细菌与常规已知菌的系统发育树,初步确立菌株种属地位。研究结果表明：24株细菌共分11属,15种,其中主要以芽孢杆菌属居多,占25%,包括巨大芽孢杆菌（Bacillus megaterium）,蜡样芽孢杆菌（Bacillus cereus）,地衣芽孢杆菌（Bacillus licheniformis）和炭疽芽孢杆菌（Bacillus anthracis）。另有其他菌属,如宋内志贺菌（Shigella sonnei）,大肠埃希氏菌（Escherichia coli）,吉氏库特氏菌（Kurthia gibsoni-i）,肺炎克雷伯氏菌臭鼻亚种（Klebsiella pneumoniae subsp.）等。     

磁处理水对枯草芽孢杆菌生长的影响试验

采用分光光度法、平板菌落计数法,研究不同磁场强度的磁处理水对枯草芽孢杆菌生长的影响。结果表明,磁场强度为0.05 T磁处理水对枯草芽孢杆菌生长有一定促进作用(P＜0.01); 0.10﹑0.25 T的磁处理水对枯草芽孢杆菌的生长有非常明显的抑制作用(P＜0.01);0.08 T的磁处理水对枯草芽孢杆菌的生长没有影响(P＞0.05)。磁处理水对枯草芽孢杆菌的生长具有一定影响,其生长情况与磁场强度有关。     

茶叶企业实施茶叶良好操作规范的效果验证

验证在生产乌龙茶和绿茶的两家茶叶企业实施茶叶良好操作规范(Good Agricultural Practices of Tea,TeaGAP)的效果.结果表明:实施茶叶良好操作规范可以显著提高茶叶质量安全水平及员工福利待遇水平,并可产生良好的社会、经济及环境效益.实施TeaGAP后,两家企业茶叶中铅含量分别下降了9.6%和103.6%;包装后茶叶中菌落总数分别降低了135.7%和76%;其中一家公司的农药残留由实施前的可检出变为实施后的未检出.验证结果表明:茶叶企业实施TeaGAP取得初步成效.     

木香薷精油抑菌活性研究

木香薷是一种典型的芳香植物。为了探讨木香薷精油的抑菌活性,本试验采用抑菌圈法,选取了金黄色葡萄球菌(Staphylococcus aureus)、枯草芽孢杆菌(Bacillus subtilis)、黑曲霉(Aspergillus niger)、沙门氏菌(Salmonella)和大肠埃希氏菌(Escherichia coli)5个菌种作为研究对象,对木香薷精油的抑菌活性进行了研究。实验结果表明,木香薷植物精油对金黄色葡萄球菌抑制效果最为明显,大肠埃希氏菌和枯草芽孢杆菌,对木香薷精油中度敏感,沙门氏菌和黑曲霉对木香薷精油低度敏感。     

榴莲泥的超高压杀菌工艺研究

本研究探讨了超高压协同温热和2种抗菌肽(Nisin和?-聚赖氨酸)对榴莲泥的杀菌效果。结果发现,当低于400 MPa的超高压常温下处理5 min后,榴莲泥中菌落总数几乎没有下降;当超高压的处理压力上升到500MPa时,残留的菌落总数下降了3 log CFU/g;处理5 min后,随着时间的延长,菌落总数的残留量下降不再明显。当温度低于25℃时,温度对超高压处理的杀菌效果影响不大;当温度提高到45℃后,杀菌效率提高1.5 log CFU/g。Nisin和ε-聚赖氨酸的添加能提高超高压的杀菌效率,但?-聚赖氨酸对超高压杀菌效率的提高效果明显低于Nisin,并且?-聚赖氨酸对榴莲泥中芽孢的生长作用的抑制效果较差,而Nisin能较好地抑制榴莲泥中芽孢的生长繁殖。     

低盐风味麦辣酱发酵工艺研究

利用燕麦和黄豆原料,通过根霉Q303和米曲霉AS3.042微生物发酵,制备麦酱原醅,再与碎鲜辣椒混合,加入泡菜发酵液进行发酵,制备低盐风味麦辣酱。采用单因素和正交试验方法,对低盐风味麦辣酱的工艺参数进行了研究。结果表明：麦酱制醅的最佳条件为：根霉Q303、米曲霉AS3.042的接种量3‰、温度28℃、时间48 h;麦酱酱醅后熟温度45℃、后熟时间10 d、盐质量分数7%;低盐风味麦辣酱的最佳质量配比为麦酱∶碎鲜辣椒=1∶1、接种5%的泡菜发酵液、发酵温度为28℃、发酵时间5 d。     

两种干燥工艺——喷雾干燥和真空干燥所获得豆渣酱粉的比较研究

以豆渣酱为原料,采用喷雾干燥和真空干燥制备豆渣酱粉,确定最佳的工艺条件。相对于真空干燥豆渣酱粉,喷雾干燥豆渣酱粉的感官指标、理化指标更好,所以选择喷雾干燥制粉,优化后的喷雾干燥条件为:进口温度180℃,出口温度80℃。制得的豆渣酱粉口味良好、保存期长,具有一定的市场应用前景。     

崂山绿茶微生物污染情况及控制关键技术

本文以崂山绿茶为调查对象,对市售及加工等环节中崂山绿茶的菌落总数、霉菌总数及大肠菌群作了调查。结果发现,较为洁净的加工环境、按卫生要求分装的茶叶,菌落总数及霉菌总数较少,否则反之。在散装茶销售过程中防止水分含量增加,并保持较低的水分含量,对茶叶品质和控制微生物总量均有积极的作用。本文还对如何防止在加工及销售过程中的微生物污染提出了建议。     

Tillage effects,soil quality and production potential of kikuyu–ryegrass pastures in South Africa

Soil quality of tillage systems receives much attention worldwide, although few studies attempt to link soil quality to yield. Partial least‐squares regression analysis is a suitable method to construct predictive models around plural, highly collinear factors, such as soil quality and its effects on yield. This study aimed at identifying the soil quality properties which best model pasture herbage yield by relating soil quality indicators with variations in yield as a result of soil disturbance caused by tillage. The study was conducted on kikuyu (Pennisetum clandestinum) over‐sown with annual ryegrass (Lolium multiflorum) using different tillage methods. Tillage methods involved over‐sowing kikuyu with ryegrass using a minimum‐tillage seed drill, eradication of kikuyu with herbicide and ryegrass sown with a minimum‐tillage planter, shallow and deep disturbance, and a control. Most changes in soil quality indicators as a result of soil tillage were observed shortly after tillage and occurred mostly at the 0–100 mm soil layer. Few of these effects were still visible 420 d after tillage. Microbiological indicators changed most in response to the treatments, but unlike the chemical and physical indicators, microbiological indicators have no causal link to pasture production. The contribution of individual soil quality indicators to variance in pasture productivity could not be isolated and should thus be seen as complex processes which affect yield. Although mechanisms of how some soil quality indicators affect yield is clear, more research is required to determine mechanisms of how a combination of multiple soil quality indicators affects yield.     

施肥结构对茶园土壤氮素营养及茶叶产量品质的影响

通过设置施氮水平、有机肥与化肥配施比双因素田间试验,研究了不同施肥结构对茶园土壤有机质和氮素营养、春茶产量和品质的影响。结果表明,与不施肥处理相比,各种施肥处理均能有效提高茶园土壤有机质和全氮含量,且均在900βkg·hm^-2的施氮水平下75%有机肥+25%化肥处理效果最为显著;施肥可以显著提高春茶芽叶密度、百芽重等产量指标;有机肥比例高于25%的氮素处理能显著提高春茶的品质指标,有机肥比例50%以上时效果更好。     

HACCP原理在金观音乌龙茶生产中的应用

探讨了HACCP原理在金观音乌龙茶生产中的应用,通过对金观音乌龙茶生产过程的危害分析,确定了关键控制点、关键限值,建立监视系统和纠正措施,从而建立了金观音乌龙茶HACCP计划。为HACCP原理在茶叶加工中的应用提供参考。     

Relationship between F4 Individuals and F5 Lines in Cooking Quality of Rice

Abstract

The response of microarthropod populations to different combinations of conservations! agricultural practices was investigated in two field experiments. In the first experiment, cropping systems with combinations of tillage (conventional or reduced), biocide application (conventional or reduced), and fertilization (chemical or cattle manure compost) were compared. In the second experiment, five treatments including four fallow managements that received different levels of tillage, biocide, and organic matter input from vegetation were compared. The springtail (Collembola) population was higher with less tillage, less biocide application, and more organic matter input in both experiments, and these effects were additive; there was no specific combination of practices that has an interacting effect. The mite (Acari) population was also higher under most conservations! treatments, and a significant interaction effect between tillage and organic matter application was found. A large increase in the Acari population under the combination of reduced tillage and higher organic matter input suggested that beneficial effects of these practices on the Acari community could be increased by integrating these practices. There was no significant correlation between the microarthropod populations and plant cover or soil chemical/physical properties measured. Slight changes in soil environments caused by agricultural practices may affect microarthropod communities substantially even before the changes in soil properties become detectable.     

Classification and prediction of maize hardness-associated properties using multivariate statistical analyses

Maize kernel hardness and proximate constituents were evaluated by several methods. Proximate constituents and hardness-associated properties were significantly correlated, and their correlation coefficients were improved when moisture, protein, and oil contents were kept constant. Multivariate techniques were applied to create new sets of variables to characterize maize hardness. The principal component scores created by principal component analysis were subjected to cluster analysis and discriminant analysis. Three factors interpreted as representing physical and chemical properties were identified using factor analysis. A total of 248 maize samples were grouped into 7 and 10 subgroups by cluster analysis. Beale's pseudo F statistic and the plot of principal component scores showed that 10 clusters would be a better solution than 7 clusters. The groups resulting from cluster analysis seem to have unique physical and chemical properties showing the different order in values of hardness measurements. Thus, the grouping by cluster analysis according to hardness-associated physical and chemical properties improved the explanation of maize kernel hardness. The application of discriminant analysis to create a classification rule for hardness clusters revealed that new observations had an 87% correct classification into hardness clusters.     

连续不同施氮对小麦-玉米轮作农田土壤理化性状的影响

为明确施氮量对农田土壤理化形状的影响,以小麦-玉米轮作体系为研究对象,通过4年连续定位试验,比较了连续不同施氮处理对不同土层土壤理化指标的影响。结果表明,连续不同施氮处理对土壤有机质和全氮含量、碳氮比、土壤容重有显著影响,但对pH的影响较小。在0~30cm土层,土壤有机质和全氮含量随施氮量的增加而增加,当施氮量为240kg·hm~(-2)时,有机质含量增加速率最快,当施氮量为360kg·hm~(-2)时,土壤全氮含量最高。在30~60cm和60~90cm土层,不同施氮处理对土壤有机质、全氮含量的影响降低。综合土壤碳氮比和容重等指标,本区域推荐施氮量为240kg·hm~(-2)。     

六堡茶感官质量缺陷及其成因分析

分析六堡茶的感官质量缺陷和原因,指导产品质量的提高,让消费者辨别六堡茶感官质量的优劣.方法:通过对六堡茶的初制厂实地调查和分析、对精制厂生产进行长期观察和比较、对进行不同的六堡茶进行感官审评和理化分析、文献调研等方法进行研究和分析.结果:所有感官质量缺陷均有对应的一个或多个原因造成,或者一个原因导致多个质量缺陷.结论:...     

不同秸秆还田方式对棕壤磷素及玉米吸磷量的影响

通过田间试验,研究玉米秸秆直接还田、腐熟还田与化肥配施等处理对棕壤磷素、玉米吸磷量、玉米产量、磷肥利用率的影响。结果表明,除秸秆直接还田处理外,其他施肥处理均能显著提高土壤有效磷含量,且彼此间差异显著,以腐熟秸秆配施化肥处理最明显。各施肥处理均显著提高玉米吸磷量和玉米产量,以未腐熟秸秆配施化肥处理增产最明显。各处理的磷肥利用率从高到低依次为秸秆直接还田配施化肥处理秸秆腐熟还田配施化肥处理单施化肥处理。秸秆还田配施化肥提高了玉米产量,玉米吸磷量和磷肥利用率直接还田好于腐熟还田。     

广东高胡萝卜素甘薯品种广薯79的示范推广

结合固相萃取(SPE)-高效液相色谱技术,运用批量平衡法测定不同土壤对克百威的吸附-脱附量,拟合Freundich、Langmuir和DMM双模型方程,分析吸附-脱附量与土壤理化性质相关关系。实验表明,在高浓度时,土壤对克百威的吸附/脱附量与吸附平衡溶液中克百威的浓度呈良好线性关系,而低浓度时,克百威吸附-脱附量波动明显。实验结果拟合Freundich方程效果最佳,检验参数Kf和n值与受试土壤理化性质间呈相关关系。土壤中粘粒、有机质含量和阳离子交换量(CEC)对吸附量影响大,而在脱附行为中,CEC、砂粒、     

不同覆盖物对红壤旱坡地土壤环境和花生生长的影响

以种植花生的红壤旱坡地为对象,研究液态地膜覆盖(LFM)、塑料地膜覆盖(PFM)、稻草覆盖(SM)和无覆盖(NM)对土壤环境和花生生长效应的影响。结果表明:有覆盖物可以显著增加土壤含水量,调节土壤温度,加快花生光合作用,使花生干物质的分配更合理,且提高花生产量;不同覆盖物对土壤和花生生长等各项指标的综合效应不同,表现为稻草覆盖塑料地膜液态地膜无覆盖。