我国小麦品质现状分析

为给小麦生产及粮食购销、加工企业提供小麦品种品质方面的信息，2003—2005年从全国各地征集了1334份小麦样品（包括369个品种），对其籽粒品质、面粉品质、面团特性及加工品质进行了测定和评价。结果表明，在所测试的品质性状中，稳定时间的变异系数最高（83．28％），其次为最大阻力、形成时间、拉伸面积、沉淀值、降落数值、延伸性、湿面筋和蛋白质含量，容重、出粉率和吸水率的变异系数较低（2．44％、2．84％、6．06％）。稳定时间、拉伸面积、形成时间、沉淀值、最大阻力等品质性状在品种间和年度间变化较大。与国家标准相比，2003、2004和2005年测试样品中分别达到强筋和弱筋小麦国家标准主要指标的品种数为7、24、39个和2、6、12个。与农业部1986、1990、1994年三次面包品质测定结果相比较，我国强筋小麦的烘焙品质呈逐步改良趋势。     

高粱籽粒的酿酒品质研究

北方各省种植的高粱以粳型品种占绝对优势，直链淀粉含量高，除红粒种外，东北、华北一带检相当部分澄黄色的白料品种；四川地方高粱品种中，糯高粱占７０％以上，支链淀粉占总淀粉的９０％以上，粒色普遍较深，多为黄、褐粒种。北方高粱一般单宁含量较低，粒色较淡，红褐粒种在１％以下；而四川高梁，无论粳与要含量普遍较高，约比北方红粒种高（０．５－１．５０个百分点。这一结果澄清了酿酒界过去”北方高梁酸效果不如四川高梁好     

云南核桃油的特征指标及脂肪酸组成分析研究

对采自云南省核桃主产地的9个核桃样品所提取核桃油以及直接采集的15个成品核桃油样品的主要特征指标和脂肪酸组成进行分析测定。结果显示：核桃油样品的折光指数为1．475-1．477,相对密度为0．916～0．924,碘值为143．7～152．2,皂化值为189．0—200．6;核桃油样品的脂肪酸组成：棕榈酸含量3．08％～7．91％（平均5．79％）,硬脂酸含量1．48％-2．75％（平均2．13％）,油酸含量17．45％～25．57％（平均21．83％）,亚油酸含量56．97％～66．12％（平均61．58％）,亚麻酸含量6．30％～9．65％（平均7．7％）,三种不饱和脂肪酸含量占检测脂肪酸总量的91％以上。     

单克隆免疫亲和柱—高效液相色谱法测定啤酒中伏马毒素B1、B2

研究了单克隆免疫亲和柱－高效液相色谱法测定啤酒中伏马毒素B1、B2的方法。啤酒样品经脱气后,通过FumoniTest免疫亲和柱净化,净化液经柱前衍生,Spherisorb C18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的伏马毒素B1、B2,5次重复实验的平均回收率为B1 86．1％－93．4％,B2 71．6％－82．0％。变异系数（CV）为B1 4．8％－7．2％,B2 6．3％－8．9％。检测低限为B1 0．005mg/kg,B2 0.01mg/kg。     

反相流动注射法测定啤酒中单宁的研究

反相流动注射法是一种快速、简便、精确,自动化操作的方法。在碱性（pH12的Na2B4O7-NaOH缓冲溶液）条件下,单宁能还原磷钨酸生成蓝色化合物在700nm有最大吸收峰。在最优的试验条件下,单宁浓度为0～10．0mg／L范围内峰高与浓度成线性关系,其线性相关系数为0．9996,方法检出限DL=16．8μg／L,精密度RSD=0．66％（n=12）。应用于实际啤酒样品中单宁的检测,加标回收率在99．25％－100．07％之间,具有较好的重现性和准确性;与标准分析方法比较,测定结果令人满意。     

单克隆免疫亲和柱-高效液相色谱法测定牛乳中黄曲霉毒素M1

研究了单克隆免疫亲和柱－高效液相色谱法测定牛乳中黄曲霉毒素M1的方法。样品通过离心脱脂,脱脂乳用免疫亲和柱净化,SpherisorM C18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的黄曲霉毒素M1 5次重复实验的平均回收率为80．4％－88．7％。变异系数（CV）为7．7％－8．9％。检测低限为0．05μg/kg。     

单克隆免疫亲和柱—高效液相色谱法测定酱油中伏马毒素B1、B2

研究了单克隆免疫亲和柱－高效液相色谱法测定酱油中伏马毒素B1、B2的方法。样品经离心和玻璃纤维滤纸过滤后,通过FumoniTest免疫亲和柱净化,净化液经柱前衍生,Spherisorb C18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的伏马毒素B1、B2,5次重复实验的平均回收率为B1 84．6％－89．2％,B2 60．3％－69．5％。变异系数（CV）为B1 5．5％－7．8％,B2 6．2％－9．3％。检测低限为B1 0．01mg/kg,B2 0.02mg/kg。     

陆英果实多糖的提取与含量测定

利用水提醇沉法从陆英果实中提取多糖,并应用分光光度法对多糖含量进行测定。样品溶液经0．2％蒽酮-硫酸溶液显色,在582nm处测定其吸光度,多糖含量为3．86％,测定结果的RSD值为3．76％（n=5）。结果表明,供试液在4h内显色稳定,重现性好,平均回收率为102．55％,RSD值为2．51％（n=3）。     

电感耦合等离子体质谱法(ICP-MS)测定甜菜颗粒粕中的砷含量

利用微波消化－电感耦合等离子体质谱法（ＩＣＰ－ＭＳ）测定甜菜颗粒粕中砷含量。对添加０．５,２．０,４．０ｍｇ／ｋｇ砷的甜菜颗粒粕样品,回收率为６８．２％－７１．４％。变异系数（ＣＶ）为２．７％。方法检测低限为０．１μｇ／ｋｇ。本方法具有前处理简单、快速,检测限低等特点,可用于甜菜粕中砷的检测和监控。     

低卡伯值麦草浆全无氯漂白的研究

对低卡伯值的麦草浆采用全无氯漂序0QP和0QP1P2进行漂白,探讨了不同目标白度（78．0％ISO至85．7％ISO）的工艺条件。研究结果表明,低卡伯值麦草浆经氧脱木素（0）和螯合预处理（Q）后,纸浆的kaPPa值为5．9,黏度为965ml／g。两段常压过氧化氢漂白后,纸浆的最高白度为85．7％ISO。其工艺条件如下：0段：氧压0．7MPa,反应温度100℃,反应时间60min,NaOH用量4．0％,MgSO4用量0．5％;两段常压过氧化氢漂白的工艺条件：反应温度80℃,总H2O2用量8．0％,但实际消耗的过氧化氢量较少,这主要是因为螯合处理后未漂浆的卡伯值仅为3．9,铁离子含量为29mg／kg,铜离子含量为19mg／kg,锰离子含量为5mg／kg。     

Determination of the Carbonyl Groups in Oxidized Starches by Sodium Borohydride

A method of carbonyl groups determination in starches oxidized with nitrogen tetroxide or sodium has been modified. The carbonyl groups undergo the reduction with sodium meta periodate borohydride, added in known excess in alkaline medium. The unconsumed amount of hydride is then oxidized with sodium periodate in alkaline medium and unconsumed iodate determined iodometrically. A blank test is unavoidable. Standard deviation 0.106% and variation coefficient 6,960% were found from 10 determinations of carbonyl groups in a sample of starch treated with nitrogen tetroxide to low degree of oxidation. Similarly, standard deviation 0,802% and variation coefficient 3,290% of dialdehyde starch, oxidized to high degree of oxidation by sodium metaperiodate, were found.     

婴幼儿配方乳粉中维生素A、E检测方法的比较研究

目的 以国家标准GB5009.82-2016第一法(GB方法)和AOAC 2012.10/ ISO20633:2015 (AOAC/ISO方法)为例,通过文本分析和实验数据比较反相液相色谱法(RF-HPLC)和正向液相色谱法(NP-HPLC)检测婴幼儿配方粉中维生素A和维生素E的差异,分析可能导致方法结果产生差异的原因,提出科学建议。方法 通过标准方法文本原理比对,分析两种方法的原理及技术步骤差异;通过质控样检测,分析两组结果的标准偏差、变异系数、95%重复性限、相对重复性限值、平均值、回收率等指标,比对两种方法的精密度和准确度差异;通过市售样品检测,分析两种方法检测结果的系统偏差和比例偏差,判别两种方法对婴幼儿配方乳粉的结果一致性。结果 从方法文本上看,AOAC/ISO方法较 GB方法的步骤更为简便,且标明了方法的适用浓度范围、重复性、重现性等关键指标,标注的检出限及定量限值也较GB方法更低;精密度方面,采用AOAC/ISO方法测得的重复性和重现性标准偏差、变异系数、95%重复性限、相对重复性限值结果,均低于GB方法测得的同类指标。准确度方面,AOAC/ISO方法和GB方法测定维生素AE时均表现出较好的回收率(100±5%);样品对比检测结果表明,维生素A两种方法的检测结果不存在系统偏差和比例偏差,结果一致;维生素E两种方法的结果既有系统偏差也有比例偏差,结果不一致。结论 AOAC/ISO 方法和GB方法原理及操作步骤存在明显不同,可能导致两种方法在测定维生素E含量时,结果呈现统计学显著差异。建议加强国内外检测标准的沟通协调,在检测目标物,样品称量方式,样品适用浓度范围等方面做进一步改进和完善。     

Detection of Campylobacter jejuni and Campylobacter coli from broiler chicken-related samples using BAX PCR and conventional International Organization for Standardization culture

In this study, the conventional International Organization for Standardization (ISO) culture method was compared with the DuPont Qualicon BAX system, a high-throughput, rapid molecular assay that can be used to detect several bacterial species, including Campylobacter jejuni and Campylobacter coli in diverse sample types. Standard enrichment culture is a time-consuming process, taking up to 6 days to obtain a confirmed result. Rapid molecular assays have been developed that provide results within 24 h. Naturally contaminated samples from the poultry production chain were examined for the presence of Campylobacter spp. Samples from broiler chicken ceca (n = 100), fresh chicken carcass rinses (n = 60), and bootsocks (gauze sock walked through a broiler chicken house; n = 50) were enriched according to the ISO 10272 method in Bolton broth specifically designed to detect Campylobacter spp. in complex sample types. Samples were enriched without blood for use with the BAX system using the Campylobacter BAX kits for the detection of C. jejuni and C. coli. Samples also were directly plated onto modified charcoal cefperazone deoxycholate agar, and results were compared with those from the enriched samples for the ability to detect Campylobacter spp. Campylobacter spp. were isolated from 49% of samples with conventional enrichment cultures, from 48% with direct culture, from 68% with the BAX system and enrichment cultures, and from 62% with the BAX system used directly with samples. Overall, the BAX system detected more positive samples than did the conventional culture method and is an effective methodology for the rapid and reliable detection of Campylobacter spp. from diverse sample types.     

ISO 12863卷烟引燃倾向标准评价方法的改进

为解决ISO 12863标准方法测试成本高、测试效率低的问题,结合样品抽样方案设计和统计学算法建立了一种测试支数动态调节的卷烟引燃倾向评价方法,并通过全长燃烧百分比（P-FLB）的二项分布计算分析了该指标偏差较大的原因。结果表明:①本文方法与ISO标准方法的准确性和重复性基本一致。②P-FLB仅是测定结果置信区间中置信度最高的一点,但其置信度仍然较低,导致理论上可产生10%~20%的最大偏差。③当全燃支数较少时（0~4支）,ISO方法更稳定,当全燃支数较多时（5~10支）,本文方法更稳定,当全燃支数超过6支时,卷烟产品的防火安全性能存在潜在风险。④80个LIP样品测试结果显示,与ISO方法相比,本文方法的平均检测时间和专用滤纸使用量均下降了59.65%,取得了较好的节支效果,提高了检测效率。      

纺织品中醛类化合物的高效液相色谱法测定

纺织品中的7种醛类化合物与2,4-二硝基苯肼在酸性条件下衍生化反应生成各自的醛腙衍生物,采用高效液相色谱-二极管阵列检测器测定了醛类化合物的含量,建立了同时测定纺织品中7种醛类化合物的检测方法。结果表明7种醛的衍生物得到良好的分离,各醛的浓度在0.15～7.5 ug/mL范围内呈现良好的线性关系,相关系数均大于0.9994,方法的平均回收率为85.4 %～97.8 %,相对标准偏差为0.2 %～7.6 %（n=7）,检出限范围为2.2～4.5 mg/kg,低于国标对相关醛类的限量要求。该方法能够满足纺织品中醛类化合物含量的测定,适用于纺织品中醛类化合物含量的分析确证。     

重度亚硫酸化改性栲胶鞣质分析方法

应用鞣质测定的标准方法对重度亚硫酸化改性栲胶进行分析 ,其鞣质含量仅为 3 .2 %,而鞣质的定性试验却表明滤液中仍存在大量的鞣质。说明需对此方法进行改进以适合此类产品的分析。在鞣质测定方法的基础上作了适当改进 ,对测定时的pH值、振荡时间及称样量对鞣质含量测定的影响进行研究 ,结果表明 :称样量为 10 10 .5 g/ 10 0 0ml、测定 pH值为 4.0± 0 .1、振荡时间为 10min时 ,鞣质吸收完全 ,并且平行实验的相对误差小 ,重现性好。这一改进方法可以作为重度亚硫酸化改性栲胶的生产控制和产品质量分析     

STATISTICAL METHODS FOR COLLABORATIVE ANALYTICAL TRIALS

International Standard ISO 5725: “Precision of test methods — Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests”, which has been adopted by the Analysis Committees of the institute of Brewing and the European Brewery Convention as a guide for conducting collaborative trials, is explained in simple terms and compared with the procedure previously used.     

Validation of ISO method 11290 part 2. Enumeration of Listeria monocytogenes in foods.

The European and International Standard method for the enumeration of Listeria monocytogenes, described in EN ISO 11290 Part 2: 1998 [EN ISO 11290-2 Microbiology of Food and Animal Feedingstuffs-Horizontal Method for the Detection and Enumeration of L. monocytogenes: Part 2. Enumeration; International Organisation for Standardisation, Geneva.] was validated by order of the European Commission (Standards, Measurement and Testing Fourth Framework Programme Project SMT4-CT96-2098). The objective was to determine the precision of the method in terms of repeatability (r) and reproducibility (R) using three different food types inoculated with various levels of L. monocytogenes and a typical background flora. The results are intended for publication in the associated standards. Cheese, meat, dried egg powder and reference materials were examined by 21 laboratories in 16 countries in Europe. Each participant received eight test materials per food type: blind duplicates at four inoculum levels (0, 10(2), 10(3), 10(4) cfu/g). In addition, two reference materials containing L. monocytogenes were included in the study. All test materials were subjected to stringent homogeneity and stability testing before being used in the collaborative trial. Participants were required to use only PALCAM agar for enumeration of L. monocytogenes, as prescribed by the reference method. Statistical analyses has been performed using a newly introduced approach for food microbiology (draft standard prEN ISO 16140 [prEN ISO 16140 Microbiology of Food and Animal Feedingstuffs-Protocol for the Validation of Alternative Methods, International Organisation for Standardisation, Geneva.], the precision data being calculated using robust estimates. Overall values for repeatability (r) of EN ISO 11290-2 when used with food test materials were r = log10 0.58 (expressed as an absolute difference between log10-transformed test results) or r = 3.8 (expressed as an absolute ratio between test results on the normal scale). For the reference materials (capsules containing approximately 5000 cfu), r = log10 0.34 (expressed as an absolute difference between log10-transformed test results) or r = 2.2 (expressed as an absolute ratio between test results on the normal scale). Overall values for reproducibility (R) of EN ISO 11290-2 when used with food test materials were R = log10 0.81 (expressed as a difference between log10-transformed test results) or R = 6.5 (expressed as an absolute ratio between test results on the normal scale). For the reference materials, R = log10 0.51 (expressed as a difference between log10-transformed test results) or R = 3.2 (expressed as an absolute ratio between test results on the normal scale). Further studies have been initiated by ISO TC34/SC9 to try to enhance the isolation of L. monocytogenes from foods and improve the confirmation procedures.     

138个小麦品种(系)戊聚糖含量的研究

为了了解小麦品种戊聚糖含量及其变化情况,选用138个小麦品种(系)作为试验材料,分析其籽粒总戊聚糖、水溶性戊聚糖和非水溶性戊聚糖含量。结果表明,总戊聚糖、水溶性和非水溶性戊聚糖质量分数的平均值分别为7.62%、1.08%和6.54%,变幅分别为5.76%~9.69%、0.62%~1.73%和4.69%~8.78%,标准差和变异系数分别为0.89、0.21、0.87和11.66%、18.98%、13.30%。总戊聚糖与水溶性戊聚糖含量呈显著正相关,总戊聚糖与非水溶性戊聚糖含量呈极显著正相关。采用最长距离法对参试的138个小麦品种籽粒的总戊聚糖、水溶性以及非水溶性戊聚糖含量进行聚类分析,结果聚为四类。同时,在本试验中,来源于豫、鲁及北方地区品种(系)的戊聚糖平均含量高于来源于苏、皖及长江流域地区品种(系),国外品种(系)的戊聚糖平均含量低于国内品种(系)。