Effect of gaseous ozone treatments on DON,microbial contaminants and technological parameters of wheat and semolina

Deoxynivalenol (DON) is an important mycotoxin produced by several species of Fusarium. It occurs often in wheat grain and is frequently associated with significant levels of its modified form DON-3-glucoside (DON-3-Glc). Ozone (O₃) is a powerful disinfectant and oxidant, classified as GRAS (Generally Recognised As Safe), that reacts easily with specific compounds including the mycotoxins aflatoxins, ochratoxin A, trichothecenes and zearalenone. It degrades DON in aqueous solution and can be effective for decontamination of grain. This study reports the efficacy of gaseous ozone treatments in reducing DON, DON-3-Glc, bacteria, fungi and yeasts in naturally contaminated durum wheat. A prototype was used to dispense ozone continuously and homogeneously at different concentrations and exposure time, in 2 kg aliquots of durum wheat. The optimal conditions, which do not affect chemical and rheological parameters of durum wheat, semolina and pasta, were identified (55 g O₃ h^?1 for 6 h). The measured mean reductions of DON and DON-3-Glc in ozonated wheat were 29% and 44%, respectively. Ozonation also produced a significant (p < 0.05) reduction of total count (CFU/g) of bacteria, fungi and yeasts in wheat grains.     

Stability and colour characteristics of PEF-treated cyanidin-3-glucoside during storage

The stability and colour characteristics of PEF (pulsed electric field)-treated cyanidin-3-glucoside (Cy-3-glu) was investigated during storage at 4, 24 and 37 °C. The degradation of Cy-3-glu was analyzed using a first reaction kinetics while its colour characteristics was evaluated using colour indices such as colour density (CD) and CIE L^∗a^∗b^∗ parameters. PEF had no post-effect on the stability and colour characteristics of Cy-3-glu during storage while the storage temperature had a significant effect (p < 0.05). The degradation of PEF-treated Cy-3-glu during storage conformed to the first-order reaction kinetics with regression coefficients R² greater than 0.9300. Corresponding to 4, 24 and 37 °C, the degradation rate constant k in Cy-3-glu significantly increased in the exponential order level of 10⁻⁴, 10⁻³ and 10⁻², while the t_1/2 (the time that 50% Cy-3-glu degradation would take) and D-value (the time that 90% Cy-3-glu degradation would take) of Cy-3-glu during storage decreased in the exponential order level of 10³, 10² and 10. The reduction of CD was closely related to the Cy-3-glu content in this study, the Cy-3-glu content was perfectly predicted using CD with a higher coefficient R² > 0.9999. A significant decrease in b^∗ and H⁰ value was obtained at all storage temperature (p < 0.05). A positive correlation was found between the Cy-3-glu content and b^∗ value or H⁰ value with a coefficients R² > 0.8400 during storage. ΔE increased significantly, ΔE was less than 2 at 4 °C while it was greater than 2 at 24 and 37 °C.     

响应面法优化提取杨梅果渣中矢车菊-3-葡萄糖苷的研究

以杨梅果渣为原料,研究矢车菊-3-葡萄糖苷的提取条件。在单因素实验的基础上,通过Box-Behnken响应面优化杨梅果渣矢车菊-3-葡萄糖苷的提取工艺,得到最佳工艺参数为:乙醇浓度53%,提取温度67℃,提取时间67min。经回归分析表明:回归方程的R2=0.9983,R2Adj=0.9826,预测值为5.32mg/g。经验证,在最佳提取条件下,矢车菊-3-葡萄糖苷的得率为5.25mg/g,回归模型预测值与实测值的相对误差<1%。      

Analysis of deoxynivalenol and deoxynivalenol-3-glucosides content in Canadian spring wheat cultivars inoculated with Fusarium graminearum

Contamination of wheat grains with Fusarium mycotoxins and their modified forms is an important issue in wheat industry. The objective of this study was to analyse the deoxynivalenol (DON) and deoxynivalenol-3-glucosides (D3G) content in Canadian spring wheat cultivars grown in two locations, inoculated with a mixture of 3-acetyldeoxynivalenol (3-ADON)-producing Fusarium graminearum strains and a mixture of 15-acetlyldeoxynivalenol (15-ADON)-producing F. graminearum strains. According to the analysis of variance, significant differences were observed among the cultivars for Fusarium head blight (FHB) disease index, Fusarium-damaged kernel percentage (%FDK), DON content and D3G content. When the effect of chemotype was considered, significant differences were observed for FHB disease index, FDK percentage and DON content. The D3G content and D3G/DON ratio were not significantly different between the chemotypes, except for D3G content at the Winnipeg location. The Pearson correlation coefficient between DON and D3G was 0.84 and 0.77 at Winnipeg and Carman respectively. The highest D3G/DON ratio was observed in cultivars Carberry (44%) in Carman and CDC Kernen (63.8%) in Winnipeg. The susceptible cultivars showed lower D3G/DON ratio compared with the cultivars rated as moderately resistant and intermediate. The current study indicated that Canadian spring cultivars produce D3G upon Fusarium infection.     

Comparative analyses of copigmentation of cyanidin 3-glucoside and cyanidin 3-sophoroside from red raspberry fruits

Cyanidin 3-glucoside (Cy 3-glu) and cyanidin 3-sophoroside (Cy 3-soph) from red raspberry extracts were selected as pigments, and five phenolic acids as copigments. The influences of pH, temperature, structure of anthocyanins and copigments, and molar ratio of anthocyanins to copigments on the copigmentation effect were analyzed with a UV–Visible spectrophotometer. The reaction was thermodynamically defined in terms of ΔH⁰, ΔG⁰ and ΔS⁰ values.     

Simple validated method for simultaneous determination of deoxynivalenol,nivalenol, and their 3-β-D-glucosides in baby formula and Korean rice wine via HPLC-UV with immunoaffinity cleanup

A simple and reliable method for the simultaneous determination of major type B trichothecene mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), along with their 3-β-d-glucosides (DON-3-glucoside (DON3G) and NIV-3-glucoside (NIV3G)) in baby formula and Korean rice wine was validated in the present study. The method was based on immunoaffinity cleanup followed by analysis using an HPLC-UV technique. The method was validated in-house for two matrices as follows: linearity (R² > 0.99) was established in the range of 20–1000 μg kg^–1; accuracy (expressed as recovery) ranged from 78.7 to 106.5% for all the analytes; good intermediate precision (relative standard deviation < 12%), and adequate detection and quantitation limits (< 4.4 and < 13.3 μg kg^–1, respectively) were achieved. Furthermore, the estimated measurement expanded uncertainty was determined to be 4–24%. The validated method was successfully applied to the analysis of 31 baby formulas and Korean rice wines marketed in Korea.     

Isolation,identification, and color characterization of cyanidin-3-glucoside and cyanidin-3-sophoroside from red raspberry

The major anthocyanins were isolated by Amberlite XAD-7 and Sephadex LH-20 column chromatography from the acidified, methanolic extracts of red raspberry, their purity was over 85%. Moreover, the major anthocyanins were identified as the cyanidin-3-glucoside (Cy-3-glu) and cyanidin-3-sophoroside (Cy-3-soph) using HPLC-PDA and HPLC/ESI-MS. Their UV–vis absorption spectra and color index were also investigated. Cy-3-glu and Cy-3-soph had the similar UV–vis absorption spectra in all investigated pH values, the bathochromic shift occurred progressively in the spectra with pH increase. However, the molar absorptivity of Cy-3-soph was lower than that of Cy-3-glu as pH increased except at pH 4.6 and 5.7. The color index of Cy-3-glu and Cy-3-soph in buffer solution were described by CIEL*a*b* coordinates L* (lightness), C* (chroma) and H° (hue angle). The L* and C* values had the similar change behavior. With increasing pH, the L* and C* values of Cy-3-glu and Cy-3-soph increased and reached a maximum at pH 5.7. Afterwards, the L* and C* values presented a decrease with increasing pH from 6.5 to 7.6. However, H° decreased for Cy-3-glu and Cy-3-soph with pH increasing from 1.0 to 5.7, respectively. Afterwards, H° kept constant and nearly identical for Cy-3-glu and Cy-3-soph although pH value continued increasing from 5.7 to 7.6. It could be concluded that the glucosyl and sophorosyl substitution at 3-position of cyanidin had no significant effect on spectra characteristics and color indices of anthocyanins except the molar absorptivity and the C* value.     

表面增强拉曼光谱在食品添加剂和违法添加物检测中的应用

食品安全问题一直是广大人民群众关注的热点,现有的检测技术多限于实验室内部,具有专业性强、成本高、耗时长等缺点.表面增强拉曼光谱技术作为一种新兴的分析检测技术,具有操作简便、耗时短、消耗少、无损害、灵敏度高等优势,在食品快速检测行业具有广阔的应用前景.本文简述了表面增强拉曼光谱技术在食品添加剂及违法添加物快速检测中的最新...     

糖类代替石油原料制取食品添加剂和配料发展动向

石油烃类原料是不可再生资源；近年原油涨至每桶60美元；用石油烃类原料生产食品添加剂有残留物等问题。因此国内外均在探索用来源广阔安全可靠的淀粉质原料代替石油原料的可行性。本文归纳有关已经在利用淀粉质原料和今后用糖类代替石油原料制取食品添加剂和配料的潜在可能性，和读者共同探讨。     

Kinetic analysis of the degradation and its color change of cyanidin-3-glucoside exposed to pulsed electric field

The degradation and its corresponding color change of cyaniding-3-glucoside (Cy-3-glu) exposed to pulsed electric field (PEF) was investigated in the study. In an aqueous-methanol solution of H₂O (0.5% TFA) and methanol (MeOH) (7:3, v/v), the degradation of Cy-3-glu, which was exposed to PEF at 1.2, 2.2 and 3.3 kV/cm, was increased as the electric field intensity and the treatment time increased (p<0.05), the degradation kinetics was well fitted to a first order reaction. The degradation kinetic constant k _A increased while the half-lives (t _1/2) and decimal reduction time (D values) decreased with an increment of the electric field intensity. PEF had a greater effect on the visual color, lightness L ^* value and redness a ^* value had a slight increase (changing towards the positive direction) while yellowness b ^* value and hue angle H value presented a significant decrease (changing towards the negative direction) (p<0.05), the total color difference (ΔE) showed an increase with an increase of the treatment time and the electric field intensity, the change in b ^* value and H was well fitted to the first-order reaction. Furthermore, a good positive linear correlation between b ^* value and Cy-3-glu content, their regression coefficients were 0.994, 0.999, and 0.997 at 1.2, 2.2, and 3.0 kV/cm, respectively.     

食品添加剂对面包中丙烯酰胺的抑制研究

面包在高温烘烤过程中会产生丙烯酰胺,对食品安全带来一定危害。研究了食品添加剂对面包中丙烯酰胺含量的影响,主要包括硫酸钙、柠檬酸、茶多酚及其复合物。研究结果表明,硫酸钙、柠檬酸、茶多酚及其复合物,都具有降低面包中丙烯酰胺含量的作用。添加3种添加剂的复合物(硫酸钙1.0%、柠檬酸1.0%、茶多酚0.04%)后,面包中丙烯酰胺含量下降了63.3%。研究结果为降低面包中丙烯酰胺含量提供一条途径。     

利用中压制备液相色谱从桑葚中快速制备矢车菊素-3-葡萄糖苷单体

单体花色苷的快速大量制备长久以来是花色苷产业化中的难题,而中压制备液相色谱在产业应用中有着很大的开发空间。选取花色苷组分较单一的桑葚为实验原料,经提取分离总花色苷后使用填装有反相C18填料的耐压玻璃柱作为中压制备液相色谱柱,纯化制备矢车菊素-3-葡萄糖苷单体。结果显示：3 个色谱分离峰中目的峰（峰2）经高效液相色谱和质谱确证为由矢车菊素-3-葡萄糖苷（cyanidin-3-glucoside,C3G）和矢车菊素-3-芸香糖苷（cyanidin-3-rutinoside,C3R）组成,采用峰面积归一化法计算得到C3G纯度为73.56%;通过对峰2采用切割方式进行收集,C3G纯度达到98%以上,单次收集到C3G单体溶液650?mL。中压制备液相色谱法单次上样量大、步骤简洁、成本低廉,可为矢车菊素-3-葡萄糖苷单体的规模化生产提供一定的参考。     

Characterization and application of isotope-substituted (13C15)-deoxynivalenol (DON) as an internal standard for the determination of DON

The powerful combination of liquid chromatography and mass spectrometry (MS) is often limited by matrix effects during ionization in the MS ion source. The use of fully isotope-substituted (¹³C₁₅)-deoxynivalenol ((¹³C₁₅)-DON) as an internal standard (IS) corrects matrix effects and improves the accuracy of analytical methods using mass spectrometry for the quantitative determination of the Fusarium mycotoxin deoxynivalenol (DON). The IS was characterized with respect to its chromatographic purity by liquid chromatography-ultraviolet light and its isotope distribution by time-of-flight mass spectrometry. Its low-energy collision-induced dissociation behaviour was compared with DON. Moreover, this work describes the successful application of (¹³C₁₅)-DON as IS for the determination of DON in maize using high-performance liquid chromatography (HPLC) electrospray (ESI) with tandem mass spectrometry. The results demonstrate that the IS can successfully correct for fluctuations during extraction and clean-up of the sample as well as the ionization of DON in the MS ion source. Random variations in ionization affect the IS in the same way as the analyte. Recoveries for DON in maize of 76% ± 1.9% (external calibration) or 101% ± 2.4% (internal calibration) were reached, respectively, after sample clean-up.     

从WTO通报看各成员对食品添加剂的管理

食品添加剂已成为继农药残留之后的热点安全问题,也日益成为食品和农产品贸易中的重要技术壁垒。通过总结归纳自WTO成立以来各成员发布的有关食品添加剂的通报,研究了WTO各成员对食品添加剂的管理措施。     

矢车菊素-3-葡萄糖苷与大豆蛋白相互作用的多重光谱分析及分子对接

采用多重光谱技术和分子对接技术,研究矢车菊素-3-葡萄糖苷（cyanidin-3-glucoside,C3G）与β-伴大豆球蛋白和大豆球蛋白的相互作用。结果表明,C3G以静态、动态组合模式强烈的猝灭β-伴大豆球蛋白/大豆球蛋白的内源荧光,且C3G对大豆球蛋白的结合亲和力强于β-伴大豆球蛋白。C3G与β-伴大豆球蛋白/大豆球蛋白结合的主要相互作用力不同,但n（结合位点数）表明C3G和大豆蛋白以物质的量比1∶1形成稳定的复合物。C3G能够诱导大豆蛋白二级结构部分展开,促使部分α-螺旋转变为β-折叠,使大豆蛋白多肽链解折叠;并降低β-伴大豆球蛋白色氨酸残基微环境疏水性,而对大豆球蛋白氨基酸残基微环境没有明显影响。C3G的大部分酚羟基参与成键,其与大豆蛋白的结合依靠疏水作用力和氢键为主导的多种作用力维持。大豆球蛋白对C3G具有更好的稳定、递送性能,但可能不利于C3G生物活性的发挥。     

食品添加剂的微胶囊方法及应用

介绍了微胶囊化特点、多种微胶囊化的方法以及国内外对食品添加剂微囊化的应用。     

Interaction between Cyanidin 3-glucoside and Cu(II) ions

The interaction between cyanidin 3-glucoside (Cy 3-glc) and Cu(II) in a binary solvent (methanol–water, 1:1, (v/v)) and in a phosphate buffer was studied. It is demonstrated that Cy 3-glc and Cu(II) ions form a complex that is manifested by appearance of a new absorption band. In the complex, the reduction of Cu(II)–Cu(I) and oxidation of Cy 3-glc takes place. The association constant of the complex formation was calculated using the Rose–Drago method. The complex stoichiometry in the binary solvent was 1:1, and the association constant was K = (28,600 ± 2600) M⁻¹. Interaction of Cy 3-glc and Cu(II) ions has two stages “fast” and “slow”. The kinetics of these processes has been investigated. Thermodynamic data for the “fast” process: enthalpy (ΔH^∗) and entropy (ΔE^∗) of activation, were calculated.     

折光法检测食品添加剂乳酸的含量

目的 建立一种用折光法检测食品添加剂乳酸的含量的方法。方法 配置标准乳酸浓度梯度, 使用阿贝折射仪测得标准品的折光指数, 绘制出乳酸的标准曲线, 并测量样品的折光指数, 带入标准曲线计算样品中乳酸含量, 并将折光法计算得到的乳酸含量与国标法滴定值进行比较。结果 折光法线性方程为Y=9.2545X?12.3305, 相关系数r2为0.9999。折光法与滴定法的最大偏差为0.51, 折光法检测乳酸的相对标准偏差为0.1%(n=6)。结论 相比滴定法, 折光法取样量少, 操作简单、检测快速, 为乳酸含量的快速检测提供了一种新的检测方法。