An enzymic method for the determination of starch in meat products

The starch content of meat products is determined as glucose by an enzyme-hydrolytic method using thermo-stable α-amylase and amyloglucosidase for hydrolysis. The method is compared with a polarimetric and an acid-hydrolytic method.The recovery in various cooked and uncooked sausages containing up to 12% starch ranged from 92 to 102% of the starch content estimated from the recipe. The average coefficient of variation was 2%. The presence of lactose did not influence the starch determination. In a collaborative study an average of 103% of the estimated starch value was recovered. The random and systematic errors were of equal size, each amounting to a maximum of 8% of the starch content of the sausages.The application of the method for food inspection purposes is discussed. The method is considered to be suited for starch analysis in meat products.     

发酵肉制品中组胺含量测定方法的比较

分别采用液相色谱法、中国国标法和中国国标改进法3种方法测定发酵肉制品中组胺含量,并对检测结果进行比较,旨在建立一种准确且适用于测定发酵肉制品中组胺含量的测定方法。结果表明,3种方法的标准曲线都呈现良好的线性关系;液相色谱法的精密度最高,相对标准偏差1%,而中国国标法的精密度最差,相对标准偏差接近5%;液相色谱法和中国国标改进法加标回收率均高于90%以上,优于中国国标法,准确度满足试验要求。液相色谱法和中国国标改进法均能满足测定发酵肉制品中组胺含量的试验要求。     

用铁离子快速测定肉制品中的亚硝酸钠

采用硫酸亚铁作还原剂,对与亚硝酸钠在酸性条件下反应,用硫氰酸钾作指示剂进行了研究,根据二价铁离子和三价铁离子浓度不同而显色不同的特点,提出了一种快速测定肉制品中亚硝酸钠的新方法。该法可精确测至0.1g,并与标准方法进行了比较,相对误差为10.43%。     

速测盒法快速测定肉及肉制品中亚硝酸盐

目的 了解亚硝酸盐速测盒的可靠性,为现场监督执法及基层快速检测提供有力的技术支撑。方法采用速测盒方法检测亚硝酸盐标准溶液、肉及肉制品中亚硝酸盐添加情况,并与《GB 5009.33-2016食品中亚硝酸盐与硝酸盐的测定》第二法(盐酸萘乙二胺法)进行对比。结果速测盒对亚硝酸盐最低检出限可达到0.1 mg/L;检测样品时,速测盒与盐酸萘乙二胺法阴性符合率为97.8%,阳性符合率为100.0%。不同环境温度下,只需将反应时间控制在5 min以上,则不会对检测结果产生影响。样品经简单处理后,显色剂滴加到样品提取液中,混匀后反应3～5 min,即可观察结果。检测单个样品20 min内即可出结果。结论速测盒法具有快速、准确、方便、灵敏等特点,适用于肉及肉制品中亚硝酸盐现场定性分析。     

催化动力学光度法快速测定卤肉制品中的痕量铬

目的 研究用催化动力学光度法快速测定卤肉制品中痕量铬所需的最佳条件。方法 以卤肉制品为样品,通过单因素实验建立Cr(Ⅵ)-H2O2-溴甲酚绿催化反应体系, 据此测定卤肉制品中的铬含量。结果 最佳试验条件为: 测定波长630 nm, pH4.4, 0.2 mL30%过氧化氢, 0.4 mL1 g/L溴甲酚绿, 60 ℃水浴加热5 min。该方法测定铬的检出限为0.256μg/mL, 相对标准偏差小于0.12（n=5）, 回收率为88.5%~106%。结论 与国标中方法相比, 该方法操作简单, 所用仪器价廉易得, 成本花费较少, 易于推广。     

An enzymatic method for the determination of fructans in foods and food products

 We report a new and non-equipment demanding method of measuring the content of fructans as well as the contents of free glucose, free fructose and sucrose in foods and food products enzymatically. This method comprises hydrolysis of fructans into d-glucose and d-fructose enzymatically and measurement of the released sugars enzymatically. Sucrose is hydrolysed by α-glucosidase instead of β-fructosidase, which is normally used. In addition, sucrose is measured in the form of d-fructose instead of the typical d-glucose form, and the fructanase used to hydrolyse the fructans has fewer side effects than the fructanase reported as normally used. The method is tested on ten standard substances and five fructan products, and nine foods and food products are also analysed. The enzymatic measurement of the released sugars is confirmed by measurements done by high performance anion exchange chromatography with pulsed amperemetric detection. Received: 1 March 1999 / Revised version: 23 April 1999     

Validation of UPLC method on the determination of formaldehyde in smoked meat products

The study was carried out to establish a formaldehyde (FA) detection method in smoked meat products with ultra-performance liquid chromatography (UPLC) method. The high-performance liquid chromatography method was developed by using steam distillation as extraction method and then derived by2,4-dinitrophenylhydrazine (DNPH). The final optimum conditions of derivatization for UPLC method were determined as follows: DNPH dosage of 0.3 mL, derivatization temperature of 60°C, derivatization time of 60 min, and twice extraction. This method was further applied to determine the content of FA in the smoked meat products from five companies. The internal FA in the smoked meat products ranged from 25.55 mg/kg meat to 49.20 mg/kg meat, and the surface FA was 34.04 mg/kg meat to 165.25 mg/kg meat. Thus, this study establishes a simple, fast, and reliable method for the analysis of FA in smoked meat products.     

Metabolomic approach for the detection of mechanically recovered meat in food products

Mechanically recovered meat (MRM) is generated by mechanical treatment of remnants following hand deboning. EU regulations exclude MRM from the definition of meat; as a consequence there is a need for robust analytical procedures to differentiate MRM from hand-deboned meat (HDM) and desinewed meat. Present study represents the development of an analytical platform for the detection of adulteration of meat products with MRM. Small molecular weight compounds were extracted from meat samples and analysed using GC–MS. Obtained metabolite profiles were modelled with OPLS-DA for the accurate classification of MRM, HDM and desinewed pork and chicken samples. Separation of three classes of products for fresh chicken and pork meat samples was achieved. In addition, the procedure also enabled proper prediction of samples not included in the model as well as pork commercial meat products. Compounds that could be potential markers for MRM detection in commercial products were also selected.     

Comparison between ion chromatography and a spectrophotometric method for determination of nitrates in meat products

Ion chromatography and colorimetry were used to determine nitrate ion concentration in 76 different pork meat products (salami, mortadella, wurstel, raw and cooked ham and other whole-muscle cooked products) and the results were compared. The comparison revealed that the two techniques yield quantitatively similar results, except in cases where the matrix was so complex that it might have influenced the analytical data. These results are consistent with those obtained by other authors who used UV spectrophotometric detection.

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Vergleich zwischen ionenchromatographischer und spektrophotometrischer Methode zur Bestimmung von Nitrat in Fleischwaren

Zusammenfassung Es wurden zwei Analysetechniken, Ionenchromatographie mit konduktimetrischem Detektor und Kolorimetrie, für die Mengenbestimmung des Nitrat-Ions in Fleischerzeugnissen verglichen. Die Ergebnisse der Untersuchungen an 76 verschiedenen Schweinefleischprodukten (Salami, Mortadella, Würstchen, Roh- und Kochschinken und andere gekochte Erzeugnisse mit ganzem Muskel) beweisen, daß die beiden Methoden im allgemeinen sich entsprechende Werte liefern, außer in den Fällen, in denen der komplizierte Charakter der Matrix den Analysewert beeinflussen kann. Die Ergebnisse sind mit denen von Autoren vergleichbar, die mit UV-Detektor gearbeitet haben.

     

食品中亚硫酸盐的毒性和检测方法综述

亚硫酸盐作为一类食品添加剂,具有漂白、防腐、抗氧化、抑制细菌生长等作用,被广泛应用于食品加工中。然而摄入过量的亚硫酸盐会对人体造成全身性的危害。如何控制食品中亚硫酸盐含量成为食品安全面临的一大难题。为了深刻地认识亚硫酸盐对人体的危害,解决食品中二氧化硫残留量超标问题,本论文对食品中的亚硫酸盐进行综述,介绍了食品中亚硫酸盐的存在形式、作用、限量标准及现状,重点阐述了食品中亚硫酸盐对人体的毒害作用,列举了目前国内外食品中亚硫酸盐检测方法,为食品中亚硫酸盐控制提供一定的参考与借鉴。     

Rapid determination of formaldehyde and sulfur dioxide in food products and Chinese herbals

Simple, sensitive and rapid methods for the determination of formaldehyde and sulfur dioxide were developed. The formaldehyde determination is based on the reaction between formaldehyde and acetylacetone solution, producing yellow 3,5-diacetyl-l-1,4-dihydrolutidine. Sulfur dioxide was detected as the deoxidize of sulfurous acid by zinc in acidic medium, which produces sulfureted hydrogen that make lead acetate paper blackening due to lead sulfide formation. The detection limits were 0.8 μg mL⁻¹ and 6.0 μg mL⁻¹ for formaldehyde and sulfur dioxide, respectively. The linear range were 0.8–20.0 μg mL⁻¹ for formaldehyde and 6.0–100.0 μg mL⁻¹ for sulfur dioxide determination. The main advantages of the new analytical procedure are the low background level, high selectivity, and very little sample preparation for on-site analysis of formaldehyde and sulfur dioxide in food or Chinese herbal samples with reference color card for qualitative or semi-quantitative determination. The results from these methods correlated well with those obtained from the standard methods.     

食品添加剂在肉制品保藏中的应用

介绍了肉制品保藏中常用的食品的添加剂的功能特性及其应用。     

解吸附电晕束电离质谱法快速检测功能保健食品中违禁添加的降糖类药物

目的 建立解吸附电晕束电离质谱快速检测保健食品中违禁添加的6种降糖类化学合成药物(那格列奈, 二甲双胍, 伏格列波糖, 格列吡嗪, 吡格列酮, 瑞格列奈)的分析方法。方法 通过DCBI-MS直接分析, 对比标准物质一级和二级质谱图, 对检测样品中非法添加的那格列奈、二甲双胍、伏格列波糖、格列吡嗪、吡格列酮、瑞格列奈等6种降糖类化学合成药物进行快速定性和半定量检测。结果 各目标物在一定范围内线性关系良好, 线性相关系数R2均大于0.98, 检测限均在1 mg/L以下, 相对标准偏差为8%~40%。结论 此方法可以完成降糖类违禁药物的快速检测, 定性准确, 专属性高, 同时完成半定量分析, 为进一步准确测定样品提供依据。     

Factors influencing the determination of nisin in meat products

Recovery of nisin from minced meat and meat emulsions was poor and variable. The rate of recovery was little affected by the presence of NaCl and/or NaNO₂, particle size, or the meat to extractant (0.02N HCl) ratio, but was significantly affected by the fat content of the meat. For nisin added at 100 iu/g, recoveries at the optimal meat to extractant ratio, 10% wt/wt suspension, ranged from 26% at 3% fat to 76% at 83% fat. At addition levels of 200 iu/g and greater, nisin recovery efficiency was reduced.     

CTAB electrophoresis and immunoblotting: a new method for the determination of soy protein in meat products

A CTAB electrophoresis method that is able to separate soy protein on the basis of molecular mass is introduced. The cationic detergent CTAB (N-cetyl-N,N,N-trimethylammoniumbromide) is not as denaturing as sodium dodecyl sulphate (SDS), and thereby allows separation of proteins that are virtually unchanged from their naturally occurring state. After blotting on a nitrocellulose (NC) membrane, the protein can be detected by a soy-specific antibody. Soy protein isolates, concentrates and hydrolysates as well as meat products containing these soy protein products were separated by CTAB electrophoresis and blotted on NC membranes. As little as 0.5% soy protein in meat products could be detected, even if the meat product had been heated to 120°C for 30 min during the manufacturing process.     

Isotachophoretic determination of added phosphate in meat products

From the phosphate content in meat and meat protein a new ratio of free (non-protein) phosphate/protein (16±2 mg/g) was calculated. From the level of soluble phosphate determined by capillary isotachophoresis (CITP), protein content determined by Kjeldahl method and with the use of the earlier-mentioned ratio the amount of added phosphates could be calculated. The method was compared with the spectrophotometric dry-ashing reference method on 34 samples and good agreement was found.     

Automated enzymatic determination of starch in meat products

Summary An automated method is described for the enzymatic determination of starch in some meat products. After solubilization with dimethylsulfoxide/hydrochloric acid, the starch was automatically determined with amyloglucosidase (EC 3.2.1.3) and hexokinase (EC 2.7.1.1)/glucose-6-phosphate dehydrogenase (EC 1.1.1.49) using a Technicon AutoAnalyzer II System. The analyses could be performed at a rate of forty samples per hour. The results agree very well with those obtained by the polarimetric method.

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Eine automatisierte enzymatische Bestimmung der Stärke in Fleischerzeugnissen

Zusammenfassung Eine automatische Methode zur enzymatischen Bestimmung der Stärke in Fleischerzeugnissen wird beschrieben. Nach Lösung in einer Dimethylsulfoxide/Salzsäure-Mischung, wurde Stärke mittels Amyloglucosidase (EC 3.2.1.3) and Hexokinase (EC 2.7.1.1)/Glukose-6-phosphatdehydrogenase (EC 1.1.1.49) mit Hilfe des Technicon AutoAnalyzers II automatisch bestimmt. Diese Methode ermöglicht 40 Proben pro Std. zu untersuchen. Die Ergebnisse stimmen gut mit den Analysenwerten der polarimetrischen Bestimmung überein.