Ultrasound and basic electrolyzed water: A green approach to reduce the technological defects caused by NaCl reduction in meat emulsions

Meat emulsions were prepared by replacing water with basic electrolyzed water (BEW) and reducing NaCl content by 0, 10, 20, 30, 40, and 50%. The emulsions were sonicated in an ultrasound bath (25 kHz, 175 W, normal mode) for 0, 10, and 20 min. The physicochemical (pH, redox potential, water activity, and color parameters) and technological (cooking yield, emulsion stability, and texture) characteristics were evaluated. The US operation time of 20 min improved the emulsion stability, cooking yield, and texture of the emulsions with 10% and 20% NaCl reduction. The BEW-treated emulsions exhibited good fat retention and moderate water retention capacity. The combination of US and BEW for 20 min provided good emulsion stability and cooking yield for the formulations with up to 30% NaCl reduction, which exhibited texture profile similar to the control (0% NaCl reduction). Therefore, it is possible to produce reduced-salt meat emulsions using the combination of US and BEW.     

智能感官分析技术结合传统感官评价对细点圆趾蟹蟹肉制品品质特性研究

采用智能感官分析技术结合传统感官评价,研究了细点圆趾蟹蟹肉、细点圆趾蟹重组蟹肉、仿蟹肉块和仿蟹肉棒的感官品质。4类均为低脂类、可放心食用的食品。用电子舌技术与主成分分析法对4类蟹肉样品进行了区分和识别,用质构仪检测了4类样品的适口性（包括硬度、弹性、黏结性、胶性、咀嚼性和回复性）。结果表明,仿蟹肉制品与纯蟹肉在味道上存在明显差异,纯蟹肉较仿蟹肉制品具有更强的鲜味回味,但苦味、涩味和苦味回味相对较高;蛋白质类添加剂（TG酶）有利于提高纯蟹肉的感官品质,尤其可大幅度改良口感和质地,全质构分析测定结果与人的感官评价结果一致性较高。     

圆背角无齿蚌的主要营养成分

分析了取珠后圆背角无齿蚌肉（Ａｎａｔｏｎｔａ　ｗｏｏｄｉａｎａ　ｐａｃｉｆｉｃａ）的营养成分,结果表明：蚌肉的含水量为８１．３５％;干燥后的蚌肉中蛋白质含量为５６．５４％,灰分５．７８％,脂肪３．４８％,糖类３２．１７％,含有丰富的人体必需氨基酸（ＥＡＡ之和占总氨基酸量的３９．７３％）和呈味氨基酸（Ｇｌｕ、Ａｓｐ、Ｇｌｙ等）,此外蚌肉还含有丰富的Ｃａ、Ｐ、Ｆｅ和一定量人体必需的Ｚｎ、Ｃｕ等微量元素．     

Simultaneous determination of total homocysteine,cysteine, glutathione,and N‐acetylcysteine in brain homogenates by HPLC

We have developed a simple, fast, accurate, and cheap method for the simultaneous determination of total cysteine, homocysteine, glutathione, and N‐acetylcysteine in brain homogenates based on the reduction of disulfide bonds by tris(2‐carboxyethyl) phosphine, pre‐column derivatization of free thiol groups with 2‐chloro‐1‐methylquinolinium tetrafluoroborate followed by ion‐pair reversed‐phase high‐performance liquid chromatography separation with ultraviolet detection. The separation of thiol derivatives was achieved in 10 min. Linearity was observed in the range of 10–300, 0.7–10, 2–30, and 3–20 μmol/L homogenate with a limit of detection of 3.7, 0.2, 0.8, and 1.2 μmol/L homogenate for cysteine, homocysteine, glutathione, and N‐acetylcysteine, respectively. The precision, calculated as relative standard deviation, was in the range of 1.21–4.77, 1.53–14.35, 0.47–1.92, and 1.61–8.95% for cysteine, homocysteine, glutathione, and N‐acetylcysteine, respectively. The presented method was successfully applied to the selective determination of total amino thiols in pig brain tissue samples.     

Stability studies of potent opioid analgesic,morphine‐6‐O‐sulfate in various buffers and biological matrices by HPLC‐DAD analysis

The 6‐O‐ sulfate ester of morphine (M6S) has previously been shown to be an analgesic with greater potency and fewer side effects than morphine. However, being a sulfate ester derivative of morphine, the question exists as to whether this compound is stable in biological fluids and tissues with regard to pH‐ and esterase‐mediated degradation. To date, no studies have focused on the stability profile of M6S across the physiologically relevant pH range of 1.2–7.4. In addition, the stability of M6S is not known in rat plasma and rat brain homogenate, or in simulated rat gastric and intestinal fluids. This study determines the stability profile of M6S (utilized as the sodium salt) and demonstrates that M6S is highly stable and resilient to either enzymatic‐ or pH‐dependent hydrolysis in vitro .     

A Novel Galantamine-Curcumin Hybrid as a Potential Multi-Target Agent against Neurodegenerative Disorders

The acetylcholinesterase (AChE) inhibitors are the main drugs for symptomatic treatment of neurodegenerative disorders like Alzheimer’s disease. A recently designed, synthesized and tested hybrid compound between the AChE inhibitor galantamine (GAL) and the antioxidant polyphenol curcumin (CU) showed high AChE inhibition in vitro. Here, we describe tests for acute and short-term toxicity in mice as well as antioxidant tests on brain homogenates measured the levels of malondialdehide (MDA) and glutathione (GSH) and in vitro DPPH, ABTS, FRAP and LPO inhibition assays. Hematological and serum biochemical analyses were also performed. In the acute toxicity tests, the novel AChE inhibitor given orally in mice showed LD₅₀ of 49 mg/kg. The short-term administration of 2.5 and 5 mg/kg did not show toxicity. In the ex vivo tests, the GAL-CU hybrid performed better than GAL and CU themselves; in a dose of 5 mg/kg, it demonstrates 25% reduction in AChE activity, as well as a 28% and 73% increase in the levels of MDA and GSH, respectively. No significant changes in blood biochemical data were observed. The antioxidant activity of 4b measured ex vivo was proven in the in vitro tests. In the ABTS assay, 4b showed radical scavenging activity 10 times higher than the positive control butylhydroxy toluol (BHT). The GAL-CU hybrid is a novel non-toxic AChE inhibitor with high antioxidant activity which makes it a prospective multitarget drug candidate for treatment of neurodegenerative disorders.     

Effects of Seed Roasting Temperature on Sesame Oil Fatty Acid Composition,Lignan, Sterol and Tocopherol Contents,Oxidative Stability and Antioxidant Potential for Food Applications

Roasting is a key step for preparing sesame oil that leads to important changes in its organoleptic properties and quality. In this study, white sesame seeds were roasted for 20 min in an electric oven at different temperatures (120, 150, 180, 210, 250 and 300 °C). The oils extracted from unroasted and roasted seeds were compared for their chemical composition: fatty acids (including trans isomers), phytosterols, lignans (sesamin and sesamolin), tocopherols and total phenolic compounds, as well as their oxidative stability and antiradical capacity. There were no obvious differences in the oil densities, refractive indexes or iodine values, but the saponification values were affected by temperature. Relevant primary and secondary lipid oxidation were observed at T > 250 °C, resulting in a higher p-anisidine value and K232 as well as K268 values. Roasting improved oil yield (from 33.5 to 62.6%), increased its induction period (from 5.5 to 10.5 h) and enhanced the total phenolic content (from 152 to 194 mg/100 g) and antiradical activity of the extracted oil. Depending on roasting temperature, a gradual decline was recorded in total amounts of phytosterols (up to 17.4%), γ-tocopherol (up to 10.6%), sesamolin (maximum of 27.5%) and sesamin (maximum of 12.5%). All the investigated oils presented a low quantity in triglyceride polymers, clearly below the maximum tolerated quantity according to the European regulation. The optimal roasting temperature for obtaining high nutritional grade oil within the permissible values was 210 °C. The unsaponifiable components (including lignans and sterols) extracted from roasted seeds have been shown to be natural additives to fresh meatball products to extend shelf life. The results of this study may help to boost the nutritional content of plant-based diets by allowing for the use of roasted sesame seed oil and its components.     

Preparation of porous magnetic molecularly imprinted polymers for fast and specifically extracting trace norfloxacin residue in pork liver

Here, magnetic molecularly imprinted polymers were designed for norfloxacin via oil‐in‐water emulsifier‐free emulsion method. It was prepared by simply mixing norfloxacin, methacrylic acid‐co‐ethylene glycol dimethacrylate copolymer, and Fe₃O₄ together at room temperature. Characterized by multiple analytical tools, the particle size, pore size, pore volume, specific surface area, and saturation magnetization of the product were about 30 µm, 10–500 nm, 2.92 mL/g, 105.84 m²/g, and 3.052 emu/g, respectively. And the adsorption capacity was high at 27.04 mg/g towards norfloxacin. Combined with ultra high performance liquid chromatography, it was used to determine norfloxacin in real samples. Average recoveries were above 77.44% with relative standard deviations between 1.21 and 6.85% at three spiked levels (n = 3) for lake water and pork liver. The determination was achieved for the most complex biosample pork liver spiked with norfloxacin low to 30 ng/g, about 100 times less than the maximum residue limit regulated by Commission of the European Communities. All evidences demonstrated that the magnetic molecularly imprinted polymers can be used in practice for monitoring norfloxacin either in environmental water or meat product with high accuracy and reliability.     

复合式提取净化体系结合超高效液相色谱-串联质谱法检测畜禽肉中120种抗生素药物残留

建立了畜禽肉中兽药抗生素的复合式预处理方法，同时对8大类120种理化性质差异较大的目标化合物进行有效的提取和净化，并通过超高效液相色谱-串联质谱仪对其进行准确的筛查分析。样品经Na₂EDTA-Mcllvaine缓冲液溶解分散，由1.5%（v/v）甲酸乙腈提取，采用Oasis PRiME HLB通过式固相萃取、正己烷液液萃取两种方式先后对提取液进行净化。目标物在Atlantis^® T3色谱柱（100 mm×2.1 mm，3 μm）上，以乙腈和0.1%（v/v）甲酸水溶液为流动相进行梯度洗脱分离，在正离子（ESI⁺）多反应监测（MRM）模式下进行定性定量分析。实验考察了不同pH条件的提取溶剂和不同净化方式对目标化合物回收率的影响并优化其条件。所建立的方法确保120种兽药在1.0~50.0 μg/L范围内线性关系良好，线性相关系数（r²）≥ 0.9953，其中89种化合物的r² ≥ 0.9990。7种化合物的定量限（LOQ）为10.0 μg/kg，21种化合物的LOQ为5.0 μg/kg，其余92种化合物的LOQ均≤ 2.0 μg/kg。低、中、高3个添加水平下的平均回收率为71.5%~109.2%，相对标准偏差为0.6%~15.3%。该方法灵敏高效，回收率优良，重复性稳定，适用于畜禽肉中多种抗生素药物的同时筛查检测。     

Polarographic study on the presence of antibiotics in food

EU and Italian laws dealing for the presence of antibiotics or, more in general, drags in food established limits for different kinds of food. Suitable rules exist about the medical treatment of cattle in relation to the production of milk and meat. The adoption of a procedure to check the respect of the law limits is necessary. In this paper, the presence of different classes of antibiotics in milk and in homogenised meat is investigated. Generally, HPLC methods are applied for this purpose. In this paper, the application of polarographic analysis is studied and the results are compared with the chromatographic ones. The comparison is relative to all the phases of analysis including the sample preparation. The results show the advantage of the proposed procedure.