牛肉香气成分的分析及其香精的开发

本文介绍了牛肉挥发性成分的提取方法、牛肉香气成分组成以及牛肉香精的开发.常用的分析方法有气相色谱-质谱联用技术(GC-MS)和气相色谱-嗅觉检测技术(GC-0).采用甲硫醇、呋喃硫醇、吡嗪、反-2,4-壬二烯醛和呋喃酮等主要的牛肉香气成分香原料,可以调配出香气逼真的炖牛肉香精.     

基于分子感官科学的烟用香精关键香气活性成分分析

采用同时蒸馏萃取结合气相色谱-质谱联用技术分析烟用香精中的挥发性成分,利用气相色谱-质谱-嗅觉检测器联用技术结合香气提取稀释分析确定其香气活性成分,同时对香气活性成分进行定量分析并计算其香气活性值,通过香气重组实验与缺失实验确定烟用香精的关键性香气活性成分.结果表明:在烟用香精中共鉴定出54种挥发性成分,其中有22种香...     

反应型牛肉香精中香味化合物的鉴定

采用动态顶空制样（DHS）结合气相色谱-嗅闻-质谱联用技术（GC-O-MS）对牛肉香精的香气成分进行分析,并运用动态顶空稀释分析（DHDA）确定其关键香味化合物。2-甲基-3-呋喃硫醇、2-糠硫醇、壬醛、辛醛、3-甲硫基丙醛、4-羟基-2,5-二甲基-3（2H）-呋喃酮、反,反-2,4-癸二烯醛这7种对牛肉香气具有重要作用的化合物在牛肉香精中均被检测到。1-辛烯-3-酮（蘑菇味）、2-甲基-3-呋喃硫醇（肉香、维生素）和2-糠硫醇（烤香、肉香）、糠醛（甜香、烤地瓜香）这四种化合物是牛肉香精中最关键的香味化合物,其在牛肉香气的形成中也具有重要作用。     

4种市售不同香型肉味香精挥发性风味成分的比较

采用顶空固相微萃取-气相色谱-质谱联用法对市售的鸡肉、牛肉、猪肉和羊肉香精的挥发性风味成分进行了分析,并对其中的主要成分及含量进行了比较,探讨了4种不同香型的肉味香精挥发性风味的差异.研究结果表明,在4种肉味香精中共鉴定出80种挥发性成分,主要为醇、醛、酮、酯、酸、吡嗪类化合物,并且不同香型的肉味香精中所含风味成分的种类和含量有较大的差异.研究结果对了解不同香型肉味香精的香气成分,合成不同的肉味风味料提供了参考.     

牛腩酶解液热反应制备清炖牛肉香精的挥发性成分分析

以牛腩酶解液热反应制备风味良好的清炖牛肉香精,采用固相微萃取技术提取其中的挥发性成分,并结合气相色谱-嗅闻-质谱联用技术对萃取成分进行鉴定。结果显示,从清炖牛肉香精中共鉴定出42种挥发性成分,包括烃类1种,醛类2种,醇类3种,酯类6种,酮类5种,酸类8种,醚类2种,杂环类化合物11种,其他化合物4种,其中杂环类化合物相对含量最高,其次是其他类化合物和醛类化合物。GC-O确定清炖香精9种关键性风味成分:大茴香醛、2,5-二甲基吡嗪、茴香脑、2-乙酰基吡咯、愈创木酚、2-乙基-6-甲基吡嗪、苯甲醛、α-松油醇、4-甲基-5-羟乙基噻唑。     

GC-O与GC-MS结合分析竹荪牛肉香精中的挥发性成分

采用同时蒸馏萃取结合气相色谱-质谱联机,通过双柱定性对竹荪牛肉香精中的挥发性成分进行分析,并通过谱库检索和保留指数比对,共计从竹荪牛肉香精中鉴定出化合物169 种,其中醇类26 种、醛类21 种、酮类9 种、酸类18 种、酚类4 种、酯类4 种、醚类6 种、烃类49 种、杂环及其他类32 种,其中十六醛、丁香酚、β-倍半水芹烯、茴香脑、β-红没药烯、α-姜烯、油醇等相对含量较大;通过气相色谱-嗅觉测定法,采用芳香萃取物稀释分析法对其特征风味成分进行了分析,共鉴定出33 种特征成分,其中2-甲基-3-呋喃硫醇、α-荜橙茄烯、反-佛手甘油烯、反式石竹烯,红没药醇对牛肉香精风味贡献相对较大。     

肉味香精的热稳定研究

利用电子鼻技术比较了几种成味香精(调配型鸡肉香精、调配型猪肉香精、热反应型猪肉香精、调配型牛肉香精、热反应型牛肉香精)的差异性,并对它们的耐热性能进行了表征研究,主要通过主成分分析法(PCA)、单类成分判断分析法(SIMCA)等多元数据统计方法分析了不同温度下(室温、80、121℃)样品之间的差异程度.结果表明,调配型猪肉香精、调配型牛肉香精、热反应牛肉香精耐热性能较差,经高温121℃处理后,香气损失较为严重,可应用于低温终端产品;调配型鸡肉香精、热反应猪肉香精耐热性能较好,经高温121℃处理后,香气无明显损失,适用于高温终端产品.     

10种市售鸡肉香精的挥发性风味化合物分析

为了研究市售鸡肉香精的香气组成,本文通过顶空-固相微萃取(HS-SPME)与气相色谱-质谱联用(GC-MS)分析10种商业样品,共检出挥发性化合物131种。其中,萜类、醛类和含硫化合物检出种类最多,分别有25、28和29种,另外,检出化合物还包括酯、呋喃(酮)、酮、吡嗪、酚、醇、酸类等。不同香精其香气组成差异较大,以香气组成最复杂的香精为代表,首次通过气相色谱-嗅闻检测技术(GC-O)剖析鸡肉香精的香气组成,共检出香气活性化合物30种。其中代表性香气活性物质及其主要香型分类如下:主体肉香(甲基(2-甲基-3-呋喃基)二硫醚、甲基糠基二硫醚)、特征脂肪香((E,E)-2,4-庚二烯醛、(E,E)-2,4-壬二烯醛)、葱蒜香(二甲基三硫、二烯丙基二硫醚)、辛香(4-甲氧基苯甲醛、4-乙基愈创木酚)、烘烤香(3-甲硫基丙醛)、甜香(2,4-二氢-2,5-二甲基-3(2H)-呋喃酮、4-羟基-2,5-二甲基-3(2H)-呋喃酮)、酸香(乙酸)和奶香(2,3-丁二酮)。     

市售酒香精成分分析在酒类真实性鉴别中的应用

目的采用液相色谱及气相色谱技术,对白兰地及白酒香精的香气成分进行检测,分析香精与真酒样的相似程度。方法通过高效液相色谱及气相色谱检测,得到3批次白兰地香精及6批次白兰地真酒样的18种香气成分数据,通过气相色谱检测,得到2批次白酒香精及6批次白酒真酒样的14种香气成分数据,数据经过归一化处理后,使用SPSS22.0软件,进行聚类分析(clusteringanalysis)和主成分分析(principal component analysis, PCA)。结果经过聚类分析及主成分分析,均能将香精与真酒样进行区分。结论利用部分香气成分数据结合多元统计分析,能够区分香精及真酒样,为鉴别真假酒技术提供新思路。     

氨基酸源对热反应牛肉香精中氯丙醇形成的影响

采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)仪对热反应牛肉香精及其原料中的氯丙醇进行了分析,并通过单因素试验考察了水解植物蛋白(hydrolyzed vegetable protein,HVP)液、酵母浸膏、VB1、牛肉酶解物、半胱氨酸、谷氨酸、牛骨素、甘氨酸和丙氨酸等原料对热反应牛肉香精中3-氯-1,2-丙二醇(3-chloro-1,2-propanediol,3-MCPD)生成的影响。结果发现,4种氯丙醇中3-MCPD是牛肉香精的主要污染物,且牛肉香精原料中都含有一定量的3-MCPD;牛肉香精原料中所检测的各种氨基酸源对3-MCPD的含量均有显著影响。     

Salmonella risk in imported fresh beef, beef preparations, and beef products

Additional guarantees (AGs) for Salmonella in imported defined animal-derived foods were agreed on for Finland when it was admitted to the European Community. The aim of this project was to evaluate the impact of these AGs on the prevalence of Salmonella in the Finnish beef supply and the adequacy of their scope. According to the quantitative Bayesian model, the efficacy of AGs was mainly dependent on the proportions of different beef categories imported and the true prevalence in the countries of origin. According to the model, AGs were able to reach their target in the referred year 1999 and kept the true Salmonella prevalence of beef imports below 1% with quantified uncertainty. The extension of AGs to all imported fresh beef would have reduced the Salmonella prevalence of beef imports from three- to fourfold, whereas expanding the implementation of AGs to all imports of fresh beef, beef preparations, and beef products would have resulted in a sixfold decrease. If current AGs targeting fresh beef intended to be sold as fresh or to be processed by the Finnish industry with processes not achieving 70 degrees C were not implemented, the 95% credible interval of Salmonella prevalence in the Finnish beef supply would be 0.2 to 1.3% (mean, 0.6%) instead of 0.1 to 1.2% (mean, 0.5%). However, if the prevalence in the exporting countries were to rise or the main import countries and/or magnitudes were to change, AGs would be of greater importance.     

Microbiological contamination of raw beef trimmings and ground beef

To survey the microbiological quality of beef trimmings and final-ground beef, samples were collected from eight commercial grinding facilities, including trimmings from fed-cattle, culled-beef cows, culled-dairy cows, imported-beef trimmings and finished-ground products. Trim samples (core and purge) and ground product samples (n=586) were evaluated for aerobic plate (APC), total coliform (TCC), Escherichia coli (ECC) and Staphylococcus aureus counts and the presence of Salmonella spp. and Listeria monocytogenes. As fat content in the trimmings increased, APC also increased. Trimmings from fed-cattle had higher (P<0.05) APC and TCC than trimmings from culled-beef cows, culled-dairy cows and imported trimmings. Purge samples produced higher (P<0.05) APC, TCC and ECC than core samples, but there were no difference (P>0.05) across fat percentages in APC, TCC, ECC or S. aureus counts. Final-ground beef samples had a 13.6 and 1.5 % incidence of L. monocytogenes and Salmonella spp., respectively. The results of this study indicate specific areas of potential that ground beef processors could capitalize upon to further improve the microbiological quality of their finished product. Ground beef processors should focus their efforts on reducing the microbial counts on incoming raw materials, especially those containing large proportions of subcutaneous fat, and processors should no longer incorporate the purge component of raw materials into ground beef. From this study, it is also apparent that ground beef processors should implement sanitation and manufacturing procedures that address L. monocytogenes contamination.     

卤牛肉与牛肉高汤联合生产技术

主要阐述卤牛肉与牛肉高汤联合生产工艺,分析了产生的经济效益。     

Consumer attitudes towards beef and acceptability of enhanced beef

The objective of this study was to evaluate consumer quality characteristics of enhanced steaks and roasts derived from cattle supplemented with vitamin E during finishing, and to assess the attitudes of these consumers towards beef. Twelve steers were fed either a control (E-) diet or a diet supplemented with dl-alpha tocopheryl acetate (E+). Paired strip loins and rounds were either used as controls (C) or were pumped (P) to 110% of raw weight to contain 0.4% sodium chloride and 0.4% sodium tripolyphosphate in the final product. Consumers (n=103) evaluated roasts and steaks for juiciness, tenderness, saltiness, and overall acceptability on a 9-point hedonic scale. Enhanced steaks and roasts were more acceptable than non-enhanced controls; E+ steaks were less acceptable than E- steaks. A beef quality questionnaire revealed that color, price, visible fat and cut were the most important factors underlying beef steak purchase, while tenderness, flavor and juiciness were weighted most heavily with regard to eating satisfaction.     

Differentiation between fresh beef and thawed frozen beef

In order to prevent meat retailers offering thawed, imported frozen beef as fresh domestic beef, the method of Gottesmann and Hamm for differentiating between fresh and frozen/thawed meat is recommended. The principle of this method is based on the fact that freezing and thawing of meat results in a release of the enzyme β-hydroxyacyl CoA-dehydrogenase (HADH) from the mitochondrion into the sarcoplasm; an elevated HADH activity in the muscle press-juice indicates freezing and thawing of tissue. The HADH colour test of Gottesmann and Hamm was modified by replacing the electron-transmitter meldolablue by resazurin which results in a much higher colour stability after reaction with fresh meat extracts.     

Freeze-drying of beef. I. Theoretical freeze-drying rates of beef

Summary. A theoretical model of freeze-drying is developed from which the dependence of drying rate and ice temperature on processing conditions can be calculated. The theory is based on the measured permeability and thermal conductivity of the completely dry material. When applied to beef steaks, the theory predicts that, at acceptable surface temperatures, the system is heat transfer limited and that the fastest sublimation rates should be obtained at high product surface temperatures combined with high cabinet pressures; if however the surface temperature is low (less than 20°C) the cabinet pressure should also be kept low. The probable effects of pre-drying treatments such as slow freezing and cooking are also discussed.     

Moisture sorption isotherm of fresh lean beef and external beef fat

The moisture sorption isotherm (MSI) of lean beef and fat beef was experimentally determined. The experimental procedure used was that of the COST 90 project with some modifications to accelerate equilibration. The procedure was validated with the standard reference material microcrystalline cellulose. The MSI of the beef at the highest humidity range was obtained by accelerating equilibration with changes of salts, using a low water activity salt for some time. This procedure was reliable for beef samples but not for the fat samples. No significant changes were found for lean beef in the temperature range 5–40 °C. Three models, GAB, Peleg and Lewicki, were used to fit the experimental data. The best fit was obtained with the GAB equation. The fat MSI was determined at 5, 15 and 25 °C and it was best fitted with the Lewicki model.     

牛肉大理石纹形态、分布状态与牛肉质量的研究

牛肉大理石纹是优质牛肉的主要技术指标.对牛肉大理石纹的形状、分布状态与牛肉质量的关系进行了研究.结果表明:牛肉大理石纹的适量形成、脂肪沉积形状小条近似粒状的均匀分布与牛肉的嫩度、多汁性和适口性有正相关性.