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排序方式: 共有1958条查询结果,搜索用时 15 毫秒
1.
该实验建立了基于分散固相萃取结合超高效液相色谱-串联质谱技术(UPLC-MS/MS)对啤酒中的茚嗪氟草胺及其3种代谢物残留量的测定方法。样品经乙腈提取后进行盐析分层,离心后乙腈层用C18固相萃取剂净化后,于电喷雾离子源正离子(ESI+)模式下采集碎片信息。结果表明,茚嗪氟草胺及其3种代谢物的基质曲线在1.0~50.0 μg/L的质量浓度内呈良好线性关系,相关系数(R2)均大于0.999,平均加标回收率为85.4%~98.1%,精密度试验结果的相对标准偏差(RSD)为2.29%~4.55%。方法检出限(LOD)和定量限(LOQ)分别为2.0 μg/kg和5.0 μg/kg。该方法快速高效,回收率、灵敏度高,重复性好,可有效测定啤酒中茚嗪氟草胺及其代谢物的残留量。  相似文献   
2.
A novel, simple, easy and cheap sample treatment strategy based on salting-out assisted liquid-liquid extraction for ochratoxin A (OTA) ultra-trace analysis in beer samples using ultra-high-performance liquid chromatography-tandem mass spectrometry determination was developed. The factors involved in the efficiency of pre-treatment were studied employing factorial design in the screening phase and the optimal conditions of the significant variables on the analytical response were evaluated using a central composite face-centred design. Consequently, the amount of salt ((NH4)2SO4), together with the volumes of sample, hydrophilic (acetone) and nonpolar (toluene) solvents, and times of vortexing and centrifugation were optimised. Under optimised conditions, the limits of detection and quantification were 0.02 µg l?1 and 0.08 µg l?1 respectively. OTA extraction recovery by SALLE was approximately 90% (0.2 µg l?1). Furthermore, the methodology was in agreement with EU Directive requirements and was successfully applied for analysis of beer samples.  相似文献   
3.
采用超声波辅助废啤酒酵母吸附分离蓝莓渣中的花色苷。以超声技术作为辅助手段,对其影响因素、吸附动力学、等温吸附特性和吸附机理进行研究,并采用高效液相色谱法分析吸附前后蓝莓渣中花色苷组分的变化。结果表明:超声条件下花色苷吸附量显著高于静置和振荡辅助条件下的(P0.05);废啤酒酵母对花色苷的吸附量随吸附时间的延长而增加,在120 min时达到平衡;花色苷吸附量随超声强度的增强、吸附温度的升高和花色苷初始质量浓度的增加而增加;废啤酒酵母对花色苷的吸附过程符合二级动力学模型,Temkin等温模型能较好地描述其吸附行为;傅里叶变换红外光谱分析发现废啤酒酵母表面的氨基、羟基和酰胺基团在吸附过程中起着关键作用;高效液相色谱分析表明废啤酒酵母对蓝莓渣中各种单体花色苷进行了不同程度的吸附。因此,超声波辅助废啤酒酵母对蓝莓渣花色苷具有较好的吸附效果。  相似文献   
4.
Several processes have been developed for producing alcohol-free beer while maintaining desirable sensory characteristics. One of the most popular thermal processes used is distillation, where not only ethanol but volatile aromatic components are partly or completely removed from the beer. Based on data from the literature and using the Aspen Plus simulator, this study evaluates and compares the aroma profiles of alcohol-free beers obtained by continuous vacuum distillation with different pressures and processes. Three processes were simulated at pressures of 60, 102, and 200 mbar. The first (Process A) was a standard continuous vacuum distillation, where the bottom product was an alcohol-free beer. In the second (Process B), the bottom product was blended with a standard beer that had not undergone any thermal process. In the third (Process C), part of the top stream was mixed with the bottom product. This study considered eight major compounds in beer: ethanol, propanol, isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol, ethyl acetate, diacetyl and isoamyl acetate. The three simulated pressure ranges showed similar results, indicating that reducing the pressure below 200 mbar did not improve separation. Further, vacuum distillation did not remove diacetyl from the beer. Processes B and C resulted in beer that was richer in flavour compounds. Furthermore, when these processes were compared to Process A, the concentration of esters was markedly higher. © 2019 The Institute of Brewing & Distilling  相似文献   
5.
比较调理啤酒鲈鱼片在不同贮藏条件下的品质变化   总被引:1,自引:0,他引:1  
为开发鲈鱼调理食品,解决其贮藏时间短的问题,以本实验室开发的调理啤酒鲈鱼片为对象,通过普通包装(对照组)、真空包装和气调包装,测定其在4℃和-3℃条件下贮藏过程中的菌落总数、挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、硫代巴比妥酸(thiobarbituric acid,TBA)值、p H值、电导率、汁液流失率,结合感官评价,探究不同包装方式的调理啤酒鲈鱼片在4℃和-3℃条件下的品质变化规律。结果表明:不同包装方式的调理啤酒鲈鱼片在4℃或-3℃贮藏过程的汁液流失率、TVB-N含量、TBA值、电导率和菌落总数均随贮藏时间的延长而呈增长趋势,-3℃贮藏过程增长较缓慢;p H值在贮藏初期降低而贮藏后期增高;感官评分呈降低趋势。综合各项指标变化规律,调理啤酒鲈鱼片采用气调和真空包装的货架期优于普通包装,采用气调包装优于真空包装,其货架期在4℃下可达12 d,比普通包装和真空包装分别延长8 d和4 d;货架期在-3℃下可达50 d,较普通包装和真空包装分别延长35、15 d。与4℃贮藏相比,气调包装调理啤酒鲈鱼片在-3℃条件下能明显保持产品的品质并延长货架期,可满足当前冰鲜流通和消费的需求,为调理啤酒鲈鱼片的开发提供技术依据。  相似文献   
6.
Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L−1), osmolality (mOsmol kg−1), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L−1 gallic acid), reducing and total sugars (%) and Na and K contents (mg L−1). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences.  相似文献   
7.
以10个进口和8个国产啤酒大麦品种及其相对应的麦芽为样本,采用高效液相色谱(HPLC)建立大麦和麦芽中14种多酚类物质的指纹图谱,并分别进行相似度分析、聚类分析(CA)和主成分分析(PCA)。结果表明,进口大麦样品的相似度(0.938~0.989)高于国产大麦样品(0.911~0.937),而进口大麦麦芽的相似度(0.892~0.967)普遍低于国产大麦麦芽的相似度(0.956~0.981);CA(判别距离<5)结果和PCA结果一致,8个国产大麦和1个进口大麦样品B2聚为一类,8个国产麦芽和3个进口麦芽样品M2、M3、M4聚为一类,说明通过大麦、麦芽多酚类物质的HPLC指纹图谱技术能基本区分国产和进口大麦品质的差异。  相似文献   
8.
采用气相色谱-质谱联用(GC-MS)技术和高效液相色谱(HPLC)法测定4种奶啤主要风味成分及有机酸,并结合各物质的香气活性值(OAV)进行主成分分析(PCA)和香气轮分析。结果表明,奶啤中共鉴定出58种风味成分,其中醇类11种、酯类23种、酸类6种、醛和酮7种、其他类物质共11种。其中天润奶啤中醇类物质相对含量较高,达到34.92%,酯类和酸类含量最低,分别为11.32%和28.41%,金河、西域春、海伦司奶啤中三种酯类和酸类含量最高,酯类含量分别为25.39%、23.61%、30.62%,酸类含量分别为43.62%、43.91%、40.59%。主要挥发性物质为乙醇、苯乙醇、乙酸苯乙酯、正癸酸。奶啤中含草酸、柠檬酸、苹果酸、富马酸和乳酸5种有机酸,柠檬酸含量最高,且柠檬酸和乳酸为主要呈香物质。  相似文献   
9.
该研究以大麦芽、小麦为主要原料,葡萄籽、百香果为主要辅料酿制啤酒,利用单因素试验考察混合主料(大麦芽、小麦与水)料液比、萨兹香型酒花添加量、混合辅料(葡萄籽、百香果与麦汁)料液比、初始pH值、酵母添加量和主发酵温度等因素对葡萄籽百香果啤酒感官评分的影响,并通过响应面优化葡萄籽百香果啤酒发酵工艺条件。结果表明,最优葡萄籽百香果啤酒发酵工艺条件为:大麦芽、小麦与水料液比1.0∶4.0(kg∶L),初始pH值5.0,萨兹香型酒花添加量0.6 g/L,百香果汁添加量80 g/L,葡萄籽、百香果与麦汁料液比2.0∶1.0(kg∶L),酵母添加量0.10%,主发酵温度21 ℃。在此优化发酵工艺条件下,葡萄籽百香果啤酒感官评分为88.44分,酿制的啤酒香气丰富有层次感,麦香突出,是一款理想的烈性啤酒。  相似文献   
10.
The burgeoning interest in archaic, traditional, and novel beer styles has coincided with a growing appreciation of the role of yeasts in determining beer character as well as a better understanding of the ecology and biogeography of yeasts. Multiple studies in recent years have highlighted the potential of wild Saccharomyces and non-Saccharomyces yeasts for production of beers with novel flavour profiles and other desirable properties. Yeasts isolated from spontaneously fermented beers as well as from other food systems (wine, bread, and kombucha) have shown promise for brewing application, and there is evidence that such cross-system transfers have occurred naturally in the past. We review here the available literature pertaining to the use of nonconventional yeasts in brewing, with a focus on the origins of these yeasts, including methods of isolation. Practical aspects of utilizing nondomesticated yeasts are discussed, and modern methods to facilitate discovery of yeasts with brewing potential are highlighted.  相似文献   
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