应用高效液相色谱-电感耦合等离子体质谱联用技术分析研究畜肉中硒形态

目的 应用高效液相色谱-电感耦合等离子体质谱联用技术（HPLC-ICP/MS）分析研究畜肉中Se（Ⅵ）、Se（Ⅳ）、SeCys、MeSeCys和SeMet 5种硒形态。方法 采用超声辅助蛋白酶ⅩⅣ和胰脂肪酶酶解提取畜肉中硒形态,以C18反相色谱柱为分析柱,10 mmol/L柠檬酸和5 mmol/L己烷磺酸钠（pH=4.0,含1%甲醇）为流动相,等度洗脱,HPLC-ICP/MS分析。结果 5种硒形态可在7 min内有效分离,在线性范围内相关系数均>0.999,线性良好;Se（Ⅵ）、SeCys、MeSeCys和SeMet 4种硒形态检出限为0.000 3~0.002 mg/kg,不同浓度水平的加标回收率为80.0%~103.3%,相对标准偏差均小于6.8%,有证标准物质ERM^? BC210a测定值在标准值范围内。结论 该方法适用畜肉中Se（Ⅵ）、SeCys、MeSeCys和SeMet的分析测定。畜肉中的硒形态主要为SeMet,同时含有少量的MeSeCys和SeCys。     

A simple UV-Vis spectrophotometric method for determination of β-carotene content in raw carrot, sweet potato and supplemented chicken meat nuggets

A simple, rapid and low cost analytical method for the determination of β-carotene content in four different food categories is developed and validated. This method is based on solvent extraction followed by UV-Vis spectrometric detection. Target compound was extracted with four different solvents, in which acetone appears to be an excellent extractant as recovery of the analyte at 1 μg/g concentration in spiked samples was in the range of 67.8-98.8%, with relative standard deviation (RSD) ranging between 4.8 and 6.6%. Intra- and inter-day assay precisions of the method at 0.1, 1.0 and 5.0 μg/g concentrations ranged in between 3.4 and 8.9%. The linearities for β- carotene in the pure acetone, raw carrot, sweet potato, and fortified raw and cooked chicken meat nuggets were 0.994, 0.995, 0.990, 0.984 and 0.984, respectively. For robustness, the analytical method was applied to 24 samples of four different food categories namely carrot, sweet potato and carrot and sweet potato supplemented chicken meat nuggets.     

Antioxidant Effects of Carnosine and Phytic Acid in a Model Beef System

Antioxidant and color stability effects of carnosine and phytate were compared in a fresh beef model system and in cooked beef. Both compounds increased the rate of pH decline in pre-rigor muscle. Phytate also increased the rate of post-mortem glycogen catabolism. Both antioxidants inhibited metmyoglobin formation in raw samples during storage. Phytate was more effective than carnosine for inhibition of lipid peroxidation. Heme iron content was negatively related to lipid peroxidation in cooked beef (r=–0.92). Phytate was also more effective for inhibition of iron release from heme during cooking. Phytate is recommended over carnosine as an effective antioxidant in cooked meats.     

影响肉品安全的主要因素和控制措施

肉品安全俨然已成为当今社会关注的焦点,肉品安全在未来将面临巨大挑战。本文综述影响肉品安全的主要因素,主要包括农药残留、兽药残留、病原微生物等,以及保证肉品安全的控制措施。     

蒸煮时间对滩羊肉蒸煮损失、嫩度及水分分布的影响

为了探究蒸煮时间对滩羊肉蒸煮损失、嫩度及水分分布的影响。对不同蒸煮时间处理下的滩羊肉蒸煮损失、剪切力进行测定,并结合低场核磁技术研究滩羊肉水分子T_2弛豫特性以及各指标间的相关性。结果表明:随着蒸煮时间的延长,滩羊肉的蒸煮损失和剪切力先增大后减小(P0.05)。LF-NMR检测到了4个明显的水分群,代表肉中的弱结合水(T_(21))、强结合水(T_(22))、不易流动水(T_(23))和自由水(T_(24))4种存在状态。延长蒸煮时间,弛豫时间先变长后缩短,T_(23)含量先减少后增加,T24含量先增加后减少。核磁成像结果显示,蒸煮时间的延长会使图像的亮度先增强后减弱。相关性分析结果表明,蒸煮损失与T_(23)、T_(24)呈显著正相关(P0.05),相关系数分别为0.966,0.994;剪切力与T_(23)呈显著正相关(P0.05),相关系数为0.846,与T23峰面积比例呈显著负相关(P0.05),相关系数为-0.504。说明不同蒸煮时间处理下的滩羊肉的蒸煮损失、嫩度及水分分布均具有显著的变化,且各指标之间具有显著的相关性。     

金属检测器在速冻禽肉制品中的应用

金属检测器是速冻禽肉制品企业必不可少的装置。本文介绍食品用金属检测器的工作原理、影响其检测灵敏度的因素以及速冻禽肉制品企业对金属检测器报警品的处理方法等。旨在为速冻禽肉制品企业选购、使用金属检测器以及对可疑品的处理提供参考,确保食品安全。     

不同发色剂在广式腊肉中的发色应用研究

研究了不同发色剂组合配方对广式腊肉感官及亚硝酸钠残留量的影响。结果表明采用添加0.3%茶多酚、7%蛋黄粉、0.04%红曲红发色剂组合配方可得到发色效果好且亚硝酸钠残留量极低的低硝广式腊肉。其感官质量与50mg/kg亚硝酸钠所腌制产品相似。     

不同植物油对植物肉风味及感官特性的影响

为探究不同脂肪酸组成的植物油对植物肉风味及感官品质的影响,将常用于食品加工且脂肪酸组成差异较大的5种植物油(菜籽油、大豆油、花生油、葵花籽油、棕榈油)添加到植物肉中,采用顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)对其进行风味分析,结合感官评价和质构分析等方法对5组植物肉进行对比。实验结果表明,5组植物肉的挥发性成分、感观属性、质构特性等存在显著差异。5组样品中共鉴定出79种挥发性组分,其中30种可被嗅闻到,主要包括吡嗪类、呋喃类、醛类、含硫类化合物。2,3,5-三甲基吡嗪、2-戊基呋喃、3-甲硫基丙醛等化合物的嗅闻强度最大。与其他样品相比,添加花生油的样品C和添加菜籽油的样品A中挥发性化合物种类和含量较多,但样品C的香气轮廓中油脂味较为突出,且该组样品的硬度与胶黏性较差,并不适用于植物肉的生产制作。样品A以肉香味为主,其硬度、弹性较大。研究结果表明,含芥酸、油酸较多的菜籽油更适用于植物肉的加工生产,对植物肉的风味、质构等感官品质具有明显增强作用。     

Identification of Species Origin of Meat and Meat Products on the DNA Basis: A Review

The adulteration/substitution of meat has always been a concern for various reasons such as public health, religious factors, wholesomeness, and unhealthy competition in meat market. Consumer should be protected from these malicious practices of meat adulterations by quick, precise, and specific identification of meat animal species. Several analytical methodologies have been employed for meat speciation based on anatomical, histological, microscopic, organoleptic, chemical, electrophoretic, chromatographic, or immunological principles. However, by virtue of their inherent limitations, most of these techniques have been replaced by the recent DNA-based molecular techniques. In the last decades, several methods based on polymerase chain reaction have been proposed as useful means for identifying the species origin in meat and meat products, due to their high specificity and sensitivity, as well as rapid processing time and low cost. This review intends to provide an updated and extensive overview on the DNA-based methods for species identification in meat and meat products.