Evaluation of 0.1% Ammonium Hydroxide to Replace Sodium Tripolyphosphate in Fresh Meat Injection Brines

ABSTRACT:  Paired USDA Select beef strip loins ( n  = 10), aged 2 d, were injected with either an alkaline-based (3.6% sodium chloride, 1% Herbalox seasoning, adjusted to pH 10 with ammonium hydroxide [approximately 0.1%, FFC grade]) or a phosphate-based (3.6% sodium chloride, 1% Herbalox seasoning, 4.5% sodium tripolyphosphate) brine. Steaks were evaluated for 19 d. Overall, phosphate-injected steaks performed better than alkaline-injected steaks with respect to cook yield, water holding capacity, lipid oxidation, color stability, tenderness, and juiciness. Phosphate-injected steaks also had less purge than alkaline-injected steaks, as confirmed by composition analysis. Phosphate-injected steaks were higher in moisture and ash content, and were nearly 2% lower in protein content. Alkaline-injected steaks had significantly lower aerobic (approximately 1 log lower) and anaerobic (approximately 2 log lower) plate counts. Final meat pH probably contributed to the differences observed between treatments. The final pH of phosphate-injected steak was 5.99 while that of alkaline-injected steak was 5.73. Further research should be conducted to determine the concentration of ammonium hydroxide needed in the alkaline-based brine to increase the final meat pH to similar levels found in the phosphate-injected steaks.     

Compensation of Pinhole Defects in Food Packages by Application of Iron‐based Oxygen Scavenging Multilayer Films

To protect sensitive food products from oxidative deterioration, multilayer barrier film systems and also modified atmosphere packaging are widely applied. However, the preservation of food quality in such packaging systems may be compromised by the presence of defects in the sealing layer of the films, especially when these are below a critical size, typically the detection limit of standard leak testers of 10 µm. The addition of an oxygen scavenger (OS) layer in barrier film structures could therefore provide extended protection against O₂ penetration through such defects. In this study, O₂ absorption of different multilayer film structures including an iron‐based OS were investigated under defined gas atmospheres. Measurement cells were thereby covered with plastic films of defined O₂ permeability to simulate conditions in a food package during storage with pinhole defect sizes of 10 and 17 µm. The results indicated that the OS film structures applied could only compensate for a defect size of 10 µm in the sealing layer. Analysis of the O₂ absorption of different multilayer film structures at 85% and 100% relative humidity showed that higher humidity accelerates the activation of the scavenger. After full activation, the scavenger kinetics are the same for 85% and 100% relative humidity. Long‐term storage experiments using the most effective film structure from the preliminary experiments were carried out to compare O₂ absorption of a snack food product in packages with and without an OS. The analyzed linear gradient of the reaction of the OS film and food product, respectively, indicated first‐order reaction kinetics with corresponding reaction constants calculated to be K (food product) 0.021 mg (O₂) mbar (O₂)^?1 day^?1 and K (OS film) 0.066 mg (O₂) mbar (O₂)^?1 day^?1. The reaction velocity of the OS was thus three times faster than that of the food. The applicability of OS multilayer film systems to compensate a critical pinhole defect size of 10 µm for sensitive food products could therefore be confirmed. The measurement of quality parameters for the status of lipid oxidation processes would help to verify this result. Copyright © 2012 John Wiley & Sons, Ltd.     

基于RFID技术的生鲜肉类产品全程可追溯系统设计

为了加强生鲜肉类产品全程跟踪和监控水平,实现生鲜肉类产品安全生产和流通,本文设计了基于RFID技术的生鲜肉类产品全程可追溯系统,并对其工作原理、系统拓扑结构、功能模块以及系统实现的关键技术进行了研究,实现了生鲜肉类产品从生产养殖、屠宰加工、仓储配送到销售终端全程信息的采集与监控,提升了生鲜肉类产品质量安全监管水平。     

基于改进型FCM聚类算法的彩色牛肉图像中筋膜区域分割方法研究

介绍一种基于HSI颜色空间的改进型FCM聚类算法,并将此算法运用于牛肉眼肌切面图像中筋膜区域的分割。该方法根据牛肉眼肌切面图像像素分布的特点,将H分量和I分量作为聚类分割算法的特征向量,改进了FCM聚类算法初始聚类中心的选取方法以及距离度量公式。结果表明:所提出的算法在保证FCM算法本身收敛速度快的同时,也提高了图像区域分割的精度和准确性,对噪声具有较强的抑制能力。     

HPLC检测火腿肠中大豆分离蛋白的方法研究

利用高效液相色谱(HPLC)法测定火腿肠中大豆分离蛋白的含量。色谱条件为:Xb ridgeBEH300 C4色谱柱;蒸发光散射检测器;梯度洗脱;流动相A:0.05%三氟乙酸-HPLC级水溶液,B:0.05%三氟乙酸四氢呋喃溶液;流速1.0 mL/min;检测波长254 nm;柱温30℃;进样量20μL。大豆分离蛋白在1%～9%含量范围内与特征峰面积呈良好的线性关系,回归方程为Y=2 923.1 X-970.85,相关系数R=0.994 2,平均回收率为99.30%,RSD为2.04%。HPLC法准确度、精密度、稳定性、重现性良好,为火腿肠中大豆分离蛋白的定量检测提供了可选择的方法。     

肉制品的质构特性及其评价

肉制品质构品质受添加物的种类和数量、肌肉蛋白质周围环境条件以及肉制品加工和贮藏方式的较大影响。文章针对含水量、pH及盐类、胶体和淀粉类、大豆蛋白质、生物酶制剂等影响肉制品质构品质特性的影响因素及其评价方法的研究进展进行综述。     

冷却肉中乳酸含量的酶电极生物传感器测定

为测定冷却肉中乳酸含量,建立了冷却肉中乳酸提取及酶电极生物传感器的测定方法。冷却猪肉用1 mol/L高氯酸水溶液匀浆去除蛋白质及脂肪后,以乳酸氧化酶生物传感器检测。检测结果显示,该测定方法线性范围0～0.50 mg/mL乳酸(R=0.999 7),检测限5.0×10-5mg/mL。回收率为97.5%~102.3%,相对标准偏差为2.6%~3.1%,日内测定变异系数(CV)为1.08%,日间测定变异系数为1.26%。该方法应用于冷却猪肉乳酸含量测定获得较好的效果。     

Effects of Marination with Three Weak Organic Acids and NaCI on Intramuscular Collagen of Beef Muscle

探讨3种弱有机酸（乳酸、醋酸和柠檬酸）结合NaCl腌制处理对牛肉肌内胶原蛋白的影响。牛半腱肌肉于4℃条件下分别经1．5％弱有机酸并与2％NaCl结合浸泡腌制24h,分析牛肉肌内热不溶性胶原蛋白的提取率及其氨基酸组成在腌制处理过程中的变化。结果表明：各腌制处理组热不溶性胶原蛋白提取率与对照组之间无显著差异（P〉0．05）;各腌制处理组胶原蛋白样品中总氨基酸含量都较对照组（82．06g／100g）降低,3种弱有机酸的单独腌制处理后牛肉胶原蛋白的氨基酸总量要比与NaCl的结合腌制处理更低。不同腌制处理组之间,牛半腱肌肉胶原蛋白中各种氨基酸的含量都有不同程度的差异,反映了腌制对其组成的影响。     

A simplified method for numerical simulation of gas grilling of non-intact beef steaks to eliminate Escherichia coli O157:H7

The objective of this work was to develop a numerical simulation method to study the heat transfer process and inactivation of Escherichia coli O157:H7 during gas grilling of non-intact beef steaks (NIBS). A finite difference and optimization algorithm was developed to determine the effective heat transfer parameters during grilling. After validation, these parameters were used in a finite element method to simulate the temperature profiles at various locations of NIBS (2.54 cm in thickness). The computer simulation results showed that E. coli O157:H7 may survive the heating processes if normal grilling conditions for intact beef steaks were used. Computer simulation results also suggested that E. coli O157:H7 might be effectively inactivated if NIBS (2.54 cm) were evenly flipped (every 4 min) and cooked for 16 min during cooking. The result of this study may help the food service industry to develop more adequate grilling methods and conditions to cook NIBS.     

Classification of geographical origins and prediction of δ13C and δ15N values of lamb meat by near infrared reflectance spectroscopy

Near infrared spectroscopy (NIRS) combined with chemometric analysis was investigated for its potential to classify the geographical origin and predict δ(13)C and δ(15)N values of lamb meat samples (n=99) from three pastoral regions and two agricultural regions of China. Principal component analysis (PCA), discriminant partial least squares analysis (D-PLS), linear discriminant analysis (LDA) and partial least squares regression (PLSR) were used for data analysis. D-PLS and LDA correctly classified 100% of the both pastoral and agricultural region samples, and gave a total correct classification of 88.9% and 75% to the five individual region samples, respectively. The best PLSR calibration models for predicting δ(13)C and δ(15)N of lamb meat were obtained with the determination coefficient (R(2)) 0.76 and 0.87, respectively. These results show that NIRS combined with chemometrics can be used as a rapid and effective method to discriminate the geographical origin and estimate the δ(13)C and δ(15)N of lamb meat.