清炖猪肉汤香气物质的分析鉴定

对实验所用猪肉的氨基酸组成及脂肪酸组成进行分析。将猪肉清炖3 h的肉汤,采用溶剂辅助蒸发提取,气相色谱-质谱联机分析,通过谱库检索和保留指数核对,鉴定出70种化合物;进一步采用稀释法-气相色谱-嗅闻分析,结合保留指数、气味特征及与标准品比对,鉴定出24种香气活性物质。所鉴定的气味活性化合物主要为脂肪族的醛类、酮类、醇类及含硫化合物,稀释因子较高的(log2FD≥9)有庚醛、壬醛、(E)-2-壬烯醛、(E,E)-2,4-癸二烯醛、2-十一酮、3-羟基-2-丁酮、3-(甲硫基)丙醛、糠硫醇、二甲基三硫醚、2-噻吩硫醇、双(2-甲基-3-呋喃基)二硫醚、1-辛烯-3-醇、γ-癸内酯。     

Process and Characteristics for a Surimi-like Material Made from Beef or Pork

Beef or pork was chopped, screened, and washed; water was removed by centrifugation to make surimi-like, water-washed beef or pork. Processing parameters were evaluated to develop the optimum processing techniques to yield the most functional material. Regardless of fat content in the starting material, water-washed beef or pork contained <1% fat. Water-washed muscle was lighter (reduced redness and yellowness) than the original starting material but had more color than fish surimi. Washed beef or pork formed gels with greater hardness than commercial fish surimi above 55°C after heating at 0.5°C/min. Salt soluble protein of water-washed beef or pork was higher than that of commercial fish surimi.     

莱克多巴胺在猪不同可食组织中的残留

系统研究莱克多巴胺(RCT)在猪可食组织中的残留代谢规律。对60头健康猪以25mg/kg的剂量混饲给药8d。在停药1、2、3、4、5、6、7、8、9、14、21d和28d分别屠宰3头猪,取猪里脊等可食用组织和尿液利用快速检测前处理试剂盒-超高效液相色谱/串联质谱法测定残留量。结果显示：猪肾脏中残留量最高,停药1d时平均残留量为96.3μg/kg;肝脏其次,停药1d时平均残留量为67.7μg/kg;猪后臀尖肉再次,停药1d时平均残留量为15μg/kg;猪里脊肉中残留量最少,停药1d时平均残留量仅为8.9μg/kg。肾脏、肝脏和猪里脊肉中RCT均在停药9d后降至检测限以下,而后臀尖肉中RCT在停药7d后降至检测限以下。     

石墨炉原子吸收分光光度法测定自制阳性猪肉中铅的不确定度评定

目的评估用石墨炉原子吸收分光光度法测定自制阳性猪肉中铅的不确定度,以找出影响不确定度的因素,为评价检验结果提供科学依据。方法建立猪肉中铅含量不确定度的数学模型,分析不确定度来源,并进行不确定度的评定。结果自制阳性猪肉中铅的含量为0.236 mg/kg,扩展不确定度为0.026 mg/kg(包含因子k=2),影响不确定度的主要因素是标准曲线线性拟合和分析仪器。结论可通过控制标准曲线校准过程和加强对分析仪器的保养维护,来降低石墨炉原子吸收分光光度法测定猪肉中铅含量的不确定度。     

Application of Electronic Nose for Measuring Total Volatile Basic Nitrogen and Total Viable Counts in Packaged Pork During Refrigerated Storage

The objective of this study was to predict the total viable counts (TVC) and total volatile basic nitrogen (TVB‐N) in pork using an electronic nose (E‐nose), and to assess the freshness of chilled pork during storage using different packaging methods, including pallet packaging (PP), vacuum packaging (VP), and modified atmosphere packaging (MAP, 40% O₂/40% CO₂/20% N₂). Principal component analysis (PCA) was used to analyze the E‐nose signals, and the results showed that the relationships between the freshness of chilled pork and E‐nose signals could be distinguished in the loadings plots, and the freshness of chilled pork could be distributed along 2 first principal components. Multiple linear regression (MLR) was used to correlate TVC and TVB‐N to E‐nose signals. High F and R² values were obtained in the MLR output of TVB‐N (F = 32.1, 21.6, and 24.2 for PP [R² = 0.93], VP [R² = 0.94], and MAP [R² = 0.95], respectively) and TVC (F = 34.2, 46.4, and 7.8 for PP [R² = 0.98], VP [R² = 0.89], and MAP [R² = 0.85], respectively). The results of this study suggest that it is possible to use the E‐nose technology to predict TVB‐N and TVC for assessing the freshness of chilled pork during storage.     

高效液相色谱-串联质谱法测定猪肉及猪肉制品中牛磺酸含量

建立猪肉及猪肉制品中牛磺酸含量的高效液相色谱-串联质谱(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)检测方法.样品经水超声提取后,经乙腈沉淀蛋白,正己烷除脂肪,采用HPLC-MS/MS法定量测定.结果 表明:在1～...     

电子鼻检测不同贮藏温度下猪肉新鲜度变化

采用电子鼻研究冷却猪肉在不同贮藏温度(－ 18、0、4、10、20℃)条件下新鲜度变化规律。选用优化后的进样体积(1500μL)进样,对实验数据进行主成分分析(PCA)、货架期模拟及拟合感官评分的偏最小二乘回归分析(PLS)。结果表明：5 种温度条件下贮藏不同时间肉样挥发性气味差异显著,贮藏温度越高肉样新鲜度发生显著下降时刻越早,预测时间分别为336、180、72、48、18h。对4、20℃条件下电子鼻检测数据与感官评分拟合后进行PLS 分析,相关系数分别高达0.9982和0.9998,表明电子鼻能代替感官评定。逐一选取每一根传感器进行PLS 拟合后发现,TA/2、T40/1、T40/2、P30/2、P40/1、P10/2、P10/1 是对不同新鲜度肉样挥发性气味具有良好特异性响应的传感器。     

Effects of Eubacterium coprostanoligenes and Lactobacillus on pH, Lipid Content, and Cholesterol of Fermented Pork and Mutton Sausage-Type Mixes

Pork and mutton sausage-type mixes produced using Eubacterium coprostanoligenes with or without Lactobacillus as starter culture showed changes in pH, cholesterol and lipid content. Viability of E. coprostanoligenes was assessed by culturing samples from each treatment and analyzing for coprostanol, a cholesterol metabolite. The pH and/or cholesterol decreased (P < 0.05) in the sausage-type mixes inoculated with E. coprostanoligenes or Lactobacillus or their combinations. Variability in lipid content was observed among and within treatments. Very low (6.2 μg/g dry matter) concentrations of coprostanol were produced in sausage-mixes and cultures except when inoculated with 2.0 g of E. coprostanoligenes (from 8.2 to 130.6 μg/g dry matter).     

笋干菜糯米营养保健香肠的开发研究

研究了笋干菜营养香肠的生产工艺,探讨了影响其质量的因素:笋干菜的添加量、糯米的添加量、糯米的颗粒度及肥、瘦肉的比例。并在此基础上采用正交实验得出了最佳工艺条件和配比,结果表明:五花猪肉79%,糯米用量15%,笋干菜用量6%,肥、瘦肉比例2:8,糯米颗粒度30目时香肠质量最佳。