超高效液相色谱法检测焙烤食品馅料中的二氧化硫脲

目的建立馅料中二氧化硫脲的超高效液相色谱测定方法。方法用0.05%乙酸水溶液提取,样品提取液经过离心,乙腈稀释过滤膜过滤后,以HILIC色谱柱为分析柱分离,采用超高效液相色谱-二极管阵列检测器(ultra performance liquid chromatography-photo-diode array,UPLC-PDA)检测,以乙腈和水为流动相,梯度洗脱,检测波长为284 nm。采用外标法定量。结果二氧化硫脲的线性范围为0.4~20.0 mg/L,相关系数不小于0.999,空白样品的加标回收的回收率为80.6%~102.2%,相对标准偏差为2.6%~5.0%。结论该方法简便、快速、准确、重现性好,适用于馅料中二氧化硫脲的检测。     

食品中黄曲霉毒素B_1的液相色谱-串联质谱测定法

建立了食品中黄曲霉毒素B1残留量的超高效液相色谱-串联质谱的检测方法。样品经乙腈+水(84+16)提取后,经多功能净化柱净化,超高效液相色谱-串联质谱法检测。本方法定量限为1μg/kg,线性范围为1~20 ng/mL;在黄曲霉毒素B1添加水平为1~10μg/kg时,在玉米样品中的回收率为95%~105%;在酱油样品中的回收率为96%~106%。     

超高效液相色谱法测定米粉中的二氧化硫脲

目的超声萃取结合超高效液相色谱(UPLC)技术,建立了米粉中二氧化硫脲的测定方法。方法米粉样品用60%乙腈水(v/v)提取,经离心、过滤后,氨基柱为分析柱进行分离,乙腈和水为流动相等度洗脱,二极管阵列检测器检测,以保留时间和紫外吸收光谱图定性,外标法定量。结果二氧化硫脲在2.0~100.0 mg/L浓度范围内线性关系良好,相关系数为0.9999;方法检出限(S/N=3)为4.0 mg/kg;添加水平为16.0、32.0和160.0mg/kg时,待测物的平均回收率分别为93.5%、107.0%和99.7%,相对标准偏差(RSD,n=6)分别为2.6%、5.2%和7.5%。结论本方法前处理简单、快速、准确,适用于米粉中二氧化硫脲的测定。     

分散固相萃取-离子排斥色谱法测定食品馅料中的二氧化硫脲

建立了分散固相萃取-离子排斥色谱快速测定食品馅料中二氧化硫脲的方法。样品采用0.05%乙酸溶液提取,以N-丙基乙二胺(PSA)和C18作为吸附剂的分散固相萃取法(d-SPE)进行净化,以Ion Pac ICE-AS1(250mm×9mm,5μm)离子排阻色谱柱进行色谱分离,以50%乙腈和10mmol/L硫酸溶液为流动相,进行梯度洗脱,在紫外检测器波长269nm下检测,柱温为30℃。在0.4~10μg/m L范围内目标物线性关系良好(R0.999),检出限(LOD,S/N≥3)和定量下限(LOQ,S/N≥10)分别为1mg/kg和3mg/kg,方法回收率在94%~106%之间,相对标准偏差(RSD)小于5%。该方法简单、快速、准确、重现性好,适用于食品馅料中二氧化硫脲的快速分析。     

液相色谱法检测馅料和米面食品中二氧化硫脲

本文建立了超声萃取结合液相色谱测定馅料和米面食品中二氧化硫脲的方法。用光谱扫描的方式,确定了二氧化硫脲的检测波长为274 nm;用HILIC-Z的柱子和0.2%（V/V）乙酸水溶液、乙腈为流动相,梯度洗脱可实现对目标物的较好分离;优化确定样品中二氧化硫脲的提取条件：0.1%（V/V）的乙酸水溶液为提取液,采用冰水浴的条件超声30 min。二氧化硫脲在0~250 mg/L的浓度范围内,线性关系良好,相关系数R2=0.9999,检出限0.2 mg/L,定量限0.5 mg/L,空白样品在三个水平（0.5 mg/kg、1 mg/kg、5 mg/kg）的加标回收实验中,回收率95.67%~100.37%,相对标准偏差（RSD）0.53%~4.45%,回收率和RSD均符合方法学要求。样品检测中,紫薯馅料和绿豆馅料中都检出了二氧化硫脲,含量分别是8.30 mg/kg、236.36 mg/kg。本方法具有操作简便,重现性好和准确度高的优点,可用于检测分析食品中二氧化硫脲。     

超高效液相色谱-串联质谱法测定猪肉中肾上腺素残留量

建立了猪肉中肾上腺素残留量的超高效液相色谱-串联质谱(UPLC-MS/MS)的检测方法。样品经乙腈+甲醇(95+5)提取,C_(18)色谱柱分离,超高效液相色谱-串联质谱仪检测。本方法定量限为10μg/kg,线性范围为5～500ng/mL。样品加标回收率为75%～98%,相对标准偏差为4.8%～7.9%,方法简便快速、灵敏度高,为猪肉中肾上腺素残留量测定提供了新的方法。     

分散微固相萃取-同位素内标法-超高效液相色谱-串联质谱法测定水果中的吗啉

目的建立分散微固相萃取-同位素内标法-超高效液相色谱-串联质谱测定水果中吗啉残留量的检测方法。方法样品经含1%甲酸的乙腈提取,经分散微固相萃取净化、超高效液相色谱BEH HILIC色谱柱分离后,经串联质谱检测,同位素内标法定量。结果吗啉在0~200μg/L浓度范围内线性关系良好,线性相关系数为0.9998。相对标准偏差(relative standard derivation,RSD)为1.2%~2.9%,加标回收率为93.0%~101.6%。结论本方法采用同位素内标法,具有灵敏度高、精密度和准确度好等优点,简便快捷,适合水果中吗啉的日常检测工作。     

PRiME HLB固相萃取-高效液相色谱-串联质谱法同时快速测定鸡蛋中48种兽药残留

建立固相萃取-高效液相色谱-串联质谱同时快速测定鸡蛋中48种兽药残留的分析方法。样品采用90%乙腈水溶液提取,用PRiME HLB小柱净化浓缩后用电喷雾离子源,正负离子扫描,多反应监测模式的高效液相色谱-串联质谱法进行检测,以基质匹配曲线外标法定量。正离子采用CAPCELL PAK C18 MGⅢ-H色谱柱,流动相为0.05%甲酸乙腈和0.1%甲酸水;负离子采用ACQUITY UPLC BEH C18色谱柱,流动相为5 mmol/L乙酸铵和乙腈。结果表明,鸡蛋样品中的48种兽药残留在0.5~50 μg/kg浓度范围内线性关系良好,相关系数(r)为0.9952~1.0000。方法检出限为0.01~0.55 μg/kg,定量限为0.03~1.83 μg/kg,样品回收率在63.3%~111.4%之间,相对标准偏差小于10%(n=3)。本方法操作快速简单,重复性好,灵敏度较高,适用于鸡蛋中48种兽药残留的快速筛查检测。     

液相色谱-串联质谱测定小麦粉中 11种真菌毒素

建立小麦粉中11种真菌毒素的超高效液相色谱-串联质谱检测方法。样品用乙腈-水溶液提取,经多功能净化柱Pribo Fast 100进行净化,采用XTerra MS C18色谱柱进行分离,以20 mmol/L乙酸铵溶液和乙腈梯度洗脱,利用超高效液相色谱-串联质谱进行分析。11种真菌毒素在测定浓度范围内线性关系良好,各组分相关系数R20.998,加标回收率范围72.4%~90.7%,方法精密度范围6.2%~11.8%,测定各组分真菌毒素定量限范围1.2μg/kg~2.0μg/kg。该方法前处理过程简洁、灵敏度高、重现性好,适用于小麦粉中11种真菌毒素的测定。     

亲水性色谱柱高效液相色谱法测定米面及制品中的二氧化硫脲

目的建立测定米面及制品中二氧化硫脲的亲水性色谱柱高效液相色谱(high performance liquid chromatography,HPLC)检测斱法。方法样品中的二氧化硫脲经0.5%乙酸提取液在冰浴中超声提取10 min,10000 r/min离心3 min后取上清液过0.22μm水相微孔滤膜待测。对10.00 mg/L的二氧化硫脲标准溶液色谱峰迚行光谱扫描,确定二氧化硫脲的最大吸收波长为272 nm。采用Waters XBridge BEH HILIC(150 mm×4.6 mm,3.5μm)色谱柱迚行分离,以纯水:乙腈=20:80(V:V)为流动相,外标法定量。结果二氧化硫脲在0~50 mg/L范围内,二氧化硫脲的浓度与色谱峰面积的大小成正比例线性关系。线性斱程为Y=1.3701X-0.4482,相关系数为0.9999。斱法检出限为2.00 mg/kg。在斱法检出限、2倍斱法检出限、10倍斱法检出限3个水平迚行加标回收实验与精密度实验,回收率分别为93.0%、95.0%、96.4%,相对标准偏差分别为5.2%、4.1%、2.5%。结论该斱法准确度与精密度符合GB/T 27404-2008《实验室质量控制觃范食品理化检测》的相应技术要求,斱法准确稳定可靠,满足米面及制品中二氧化硫脲的测定。     

Semi-quantitative estimation of the walnut content in fillings of bakery products using real-time polymerase chain reaction with internal standard material

A method for absolute quantification of walnuts in fillings of bakery products was developed. Macadamia nuts were used as an internal standard material. A duplex real-time polymerase chain reaction (PCR) with 5′-nuclease (TaqMan) probes labelled with FAM and JOE for walnuts and the internal standard, respectively, was used. Difference between threshold cycle values (Δc _T) for the analyte and the internal standard, plotted against logarithm of contents, was used to construct the calibration line. A level of 5?% (w/w) of the internal standard material was found to be suitable for quantification of walnuts in nut fillings, the calibration line being linear. The developed method was applied to bakery products from the market, and crucial factors for its routine applicability have been identified in sampling and sample preparation. The present study demonstrates that quantification of walnuts in the fillings of bakery products should be achievable by real-time PCR with an internal standard material when the reference filling, which is used for calibration, is comparable to the fillings of the samples, a calibration line of low variability is obtained, and the sample material is properly homogenized before weighing the analytical sample.     

Quantification of Hazelnut Content in Fillings of Cakes and Wafers Using Real-Time Polymerase Chain Reaction

A method for quantification of hazelnuts in fillings of cakes and wafers, using macadamia nuts as an internal standard material, was developed and evaluated. The method was based on quantitative adaptation of the previously developed real-time PCR for identification of hazelnuts. Calibration lines were constructed for two types of fillings, using series of model mixtures. The model mixtures for calibration of cake fillings consisted of hazelnuts and walnuts; the model mixtures for calibration of wafer fillings (pastes) consisted of hazelnuts and peanuts. Linear calibration lines were obtained for both types of matrix, and practical applicability of the developed method was demonstrated on food products from the market. The developed method may be useful for food control laboratories to facilitate analysis of food products with hazelnut filling.     

Survey of undeclared soy allergen levels in the most frequently recalled food categories with or without precautionary labelling

A comprehensive study was designed to determine the frequency and levels of soy allergen in packaged bakery and snack food products. A representative sample of products with no soy allergen disclosed on the label was analysed using two widely used enzyme-linked immunosorbent assay (ELISA) methods. Samples were chosen that either had no soy identified on the product label or which had a soy precautionary statement. Among 558 bakery and snack products, soy protein was detected in 17% of the products using the Neogen (NE) kit and 11% of the products using the Elisa Systems (ES) kit. The disagreement rates between kits were 8.8% for bakery products and 3.3% for snack products. Overall soy protein was detected at higher frequency in bakery products than in snack foods. Among 284 bakery samples, soy protein was detected in 25% of the samples with no precautionary statement and 19% of the samples which had a precautionary statement. Among 274 snack samples, soy protein was detected in 11% of the samples with no precautionary statement and 9% of the samples which had a precautionary statement. The sample repeatability was at an acceptable level (< 9%) for each method and food commodity. The reproducibility between kits was 23% for bakery foods and 36% for snack foods. None of the bakery (21) and snack (6) products without precautionary labelling (measured level > 5 ppm) had a higher level of soy protein per serving compared with the eliciting dose₁₀ (ED₁₀) of 10.6 mg for soy allergic patients. But the level of soy protein per serving may be clinically relevant to a subpopulation of soy allergic patients if a more stringent eliciting dose is applied. These findings emphasise that suitable detection methodologies and references doses are crucial for labelling accuracy and the safety of soy allergic consumers.     

Development of a quantitative GC-FID method for the determination of stearoyl-lactylates (E481/482) in foods

Sodium and calcium salts of stearoyl-lactylates (SLs) are food emulsifiers especially used in bread and bakery products to improve texture. They should be used at the lowest level at which the desired technological effect is achieved in a specific food category and at amounts not exceeding the maximums set by European Commission Regulation No. 1129/2011. In order to be able to evaluate whether these emulsifiers are used correctly but also to evaluate whether the commercial additive formulations comply with legislation, a quantitative GC-FID method was developed. An internal standard (nonadecanoyl-1-lactylate) was synthesized in-house and pure ester standards were isolated from commercial additive formulations. The method showed a limit of detection of 0.04 and a limit of quantification of 0.12 mg esters ml^?1. The commercial additive formulations analysed proved to be complex mixtures of free lactic and fatty acids together with only 50–60% esters. Besides SLs important amounts of palmitoyl-lactylates were present. Different food matrices (with low- and high-fat contents) were spiked with commercial SL formulations and recoveries ranged between 85% and 109%. Determination of SLs in commercial foods (such as bakery and bread) indicated that pre-treatment with amylase was essential to determine accurately the SL content due to the interaction of SL with the amylose.     

凝胶渗透色谱净化-气相色谱-质谱-内标法 测定焙烤食品中富马酸二甲酯

目的 建立凝胶渗透色谱净化-气相色谱-质谱-内标法测定焙烤食品中富马酸二甲酯残留量的方法。方法 试样经乙酸乙酯超声提取,经凝胶渗透色谱(GPC)净化,采用选择离子监测模式(SIM)进行气相色谱-质谱(GC-MS)测定,采用丁二酸二甲酯作为内标,以内标法定量。结果 富马酸二甲酯在0.02 ~ 5 mg/L 内呈良好的线性关系,相关系数(r)大于0.9999;0.1、0.2和1.0 mg/kg水平的空白糕点加标回收实验的回收率为92.0% ~ 107 %,相对标准偏差(RSD)为3.2% ~ 5.7 % (n=6);方法的检出限(LOD)为0.012 mg/kg,定量限(LOQ)为0.040 mg/kg。结论 该方法准确,灵敏度高,适用于糕点等焙烤食品中富马酸二甲酯残留水平测定。     

A novel real-time polymerase chain reaction (PCR) method for the detection of hazelnuts in food

A real-time PCR (polymerase chain reaction)-based method for the detection of hazelnuts (nuts of Corylus avellana or C. maxima) in confectionery and bakery products is described. The method consists of DNA isolation by chaotropic solid phase extraction and the subsequent PCR with hazelnut-specific primers and a TaqMan fluorescent probe. The primers and the probe are targeted to the hsp1 gene encoding for a low molecular weight heat-shock protein. The method was positive for five hazelnut varieties approved in Slovakia and negative for all other tested plant materials used in food industry including peanuts, walnuts, almonds, pistachio nuts, cashews and chestnuts. The intrinsic detection limit of the method was 13 pg hazelnut DNA, which corresponds to approximately 27 genome equivalents (1C). Using a series of model pastry samples with defined hazelnut contents, a practical detection limit of 0.01% (w/w) hazelnut was determined. Practical applicability of the PCR method was tested by the analysis of 20 food samples (confectionery and bakery products) along with ELISA. For all of the food samples, identical results were obtained by both methods, which conformed to the labelling. The presented PCR method is useful for sensitive and selective detection of hazelnuts in food samples and can be performed in one working day.     

食用香精在烘焙食品中的应用

烘焙工业一直被认为是中国的黄金工业,烘焙食品以其丰富的营养,色香味俱佳,不断影响着人们的一日三餐。随着人们饮食结构的调整和生活品质的提高,趋于携带方便化、品种丰富化、口味多样化的烘焙食品在预期阶段内仍保持着稳定的增长趋势。烘焙食品的加香,对整个烘焙食品有着举足轻重的作用,经常被用来不断创造出新口味而使产品风味多样化。品类繁多,造型变化多端的烘焙食品有其各自不同的生产工艺要求和特殊的操作方式,对香精的使用,既讲究方法、技巧,又讲究加入时间。一方面,市场需求的不断变化和快速发展为食用香精的使用提供了广阔的市场空间,另一方面也为食用香精在烘焙食品中的应用研究提出了新的研究课题,同时也给食用香精的生产企业提供了新的机遇。     

Consumers’ perception of bakery products with insect fat as partial butter replacement

Including insect ingredients into familiar food products could be a step in enabling a higher acceptance of insects in Western countries. This study investigates the potential of bakery products containing black soldier fly larvae fat (BSF LF) as an ingredient. Sensory and emotional profiling, WTP, liking and product preference were examined for cakes, cookies, and waffles by a total of 344 respondents. Each bakery product was formulated with 0%, 25% and 50% BSF LF as butter substitute. Results showed that BSF LF can replace 25% of butter in these bakery products without changing the overall food experience and liking. In waffles, the substitution might even be up to 50% without influencing consumer’s acceptance. The attributes related to texture and color were hardly affected indicating that this insect fat provides a similar structure and functionality to bakery products as compared with butter. Future research should explore the use of refined BSF LF to reduce off-flavors perceived in formulations containing a higher percentage of insect fat.     

茶与烘焙食品结合的研究进展

立足于传统饮茶向"吃茶"模式的转变,将茶与烘焙食品广泛结合,探讨茶与烘焙食品的相互影响,从茶对烘焙食品面团流变学特性影响、茶对烘焙食品品质影响、烘焙对茶活性成分的影响、茶烘焙食品研究开发四方面分析茶与烘焙食品结合的研究现状,基于此探讨了茶与烘焙食品深度研究方向。