转基因大豆Roundup Ready调控元件在食品加工过程中降解变化的研究

35S启动子可能会通过基因的水平转移插入到某一致癌基因上游，活化并导致癌症的发生。为了解转基因植物中调控元件的安全性问题，以转基因大豆Roundup Ready为实验材料，针对Roundup reaqdy转基因大豆中CaMV35S启动子及NOS终止子的序列，设计了不同长度片段的引物，通过对CaMV35S启动子和NOS终止子的PCR扩增，研究了豆腐、豆奶、豆粉3种大豆加工食品中磨浆、煮浆、调配、均质、杀菌、喷雾干燥等关键工艺对Roundup Reaqly大豆中调控元件的影响。结果表明调控原件在食品加工过程中的降解变化与其所处位置有较大关系。扩增长度相近的2个片段，包含大豆基因组。DNA序列的片段受加工过程的影响较小，在3种豆制品的所有加工过程中均能检测到。而只包含CaMV35S启动子序列的片段仅能在原料中检测到，原料经过磨浆后。片段大小降至200bp以下。NOS终止子受食品加工工艺的破坏和影响较小，在被检测食品的每一个加工过程中都能够检测到NOS终止子片段。     

干热加工工艺对大豆转基因成分及调控元件的影响

以转基因大豆为材料,运用定性PCR方法研究干热加工工艺对转基因大豆内源基因Lectin、外源基因Cp4epsps以及启动子CaMV35s和终止子Nos的影响。结果发现:大豆经过130℃干热加工3min后,内源基因Lectin降解到407bp以下;经过120℃加热9min后,外源基因Cp4 epsps降解到408bp以下;干热加工对启动子的片段长度并没有影响,而当加工条件达到130℃加热9min时,终止子125bp的片段会产生降解。结果表明,不同温度和时间的干热加工工艺对大豆转基因成分及调控元件的降解均有不同程度的影响。     

干热和湿热工艺对大豆转基因成分及调控元件影响的比较研究

以转基因大豆为试验材料,运用定性PCR的方法研究了干热和湿热两种制粒加工工艺对转基因大豆内源基因Lectin、外源基因Cp4 epsps以及启动子和终止子的影响。结果发现大豆经过130℃干热处理3 min或100℃湿热处理15 min后,内源基因降解到407 bp以下;经过120℃加热9 min或100℃湿热处理15 min后,外源基因降解到408 bp以下;干热处理对启动子的片段长度并没有影响,而当加工条件达到130℃干热9 min时,终止子125 bp的片段开始会产生降解;当100℃、3 min湿热处理后启动子和终止子都会产生降解。结果表明,不同干热和湿热制粒工艺对大豆转基因成分及调控元件的降解均有不同程度的影响。     

红枣豆奶生产工艺优化及基础配方的研究

为了探讨红枣豆奶生产的最佳工艺条件及基础配方,从浸泡液种类、浸泡液添加量、浸泡时间、磨浆料液比、煮浆时间、杀菌时间、均质压力等豆奶加工中的关键技术进行研究,确定适合红枣豆奶的最佳工艺参数。通过正交试验确定各基础料的最佳添加量。研究结果表明,红枣豆奶制备的最佳工艺和基础配方为:选取0.5%的NaHCO_3溶液,以1︰3(g/g)的豆液比浸泡4 h,在80℃以1︰8(g/mL)的料水比磨浆,得到的豆奶在90℃下煮浆15min。添加浓缩枣汁1%、黄豆7.5%、白砂糖6.5%,采用两次均质,均质压力分别为35和40 MPa,最后在121℃杀菌22min,所得的红枣豆奶色香味俱佳。     

粉碎和膨化工艺对大豆转基因成分及调控元件的影响

以转基因大豆为试验材料,运用定性PCR的方法研究了粉碎、膨化两种加工工艺对转基因大豆内源基因Lectin、外源基因Cp4 epsps以及启动子和终止子的影响。结果表明,粉碎和膨化加工工艺对大豆转基因成分及调控元件的降解有不同程度的影响。     

酸豆奶饮料的研制

本试验以大豆、白砂糖为主要原料,通过泡豆、纯化酶、磨浆、调配、杀菌、均质、乳酸菌发酵等工序,研制出一种风味清香,细腻爽口,营养丰富的新型酸豆奶饮料,并确定了最佳生产工艺条件。     

转基因大豆水酶法制油过程中内、外源基因降解规律研究

以转基因大豆为原料,经过挤压膨化预处理,使用水酶法提取大豆油,探索水酶法提取转基因大豆油的过程中内、外源基因的降解规律。通过定性PCR技术检测大豆内源Lectin基因和外源EPSPS基因以及启动子和终止子的降解变化。结果表明:转基因大豆原料经过挤压膨化后,其内源Lectin基因降解至1067 bp以下,挤压膨化过的大豆经过碱性蛋白酶水解离心得到油相、水相和渣,各相中内源Lectin基因没有发生降解;外源EPSPS基因以及启动子与终止子经过挤压膨化、水酶法等工艺,基因片段没有发生降解。这说明转基因大豆的外源EPSPS基因比内源Lectin基因稳定。实验结果为水酶法提取转基因大豆油的大规模应用提供参考,为转基因大豆内、外源基因的稳定性研究提供了理论依据。     

大豆及豆制食品中转基因成分检测分析

建立大豆及豆制食品中转基因成分分析的real-time PCR扩增体系和方法。选择市售的大豆、豆粉、豆干、豆腐、豆浆和腐竹等6种大豆及豆制食品,针对不同的样品探索高质量基因组DNA的提取方法,扩增大豆内参基因lectin进行质量检测。针对我国批准的3种主要转基因大豆品系(GTS40-3-2,A2704-12和MON89788)设计特异性的引物和探针,进行real-time PCR检测。购买3种转基因大豆品系的标准品作为质控对照。从该6种大豆及豆制食品中均提取到了高质量的基因组DNA,建立了稳定的针对外源基因特异性、结构特异性和品系特异性片段检测的real-time PCR扩增体系。成功建立了6种大豆及豆制食品中针对3种转基因大豆品系成分检测的real-time PCR方法。     

食品中转基因大豆成分的定性和定量检测

为建立食品中转基因成分的定性定量分析，运用传统的定性PCR方法检测大豆加工产品中转基因成分的存在，运用Taqman探针技术，对存在的转基因成分进行准确定量。对于定量过程中由于扩增效率的不同造成的误差，通过大豆的内源基因Lectin进行校正，根据△Ct值对应于校正曲线计算出转基因大豆的含量。本方法灵敏度达到0．1％，误差范围小于30．0％。可用于转基因大豆的监测管理。     

PCR法检测大豆加工食品中的转基因成分

通过分子生物学手段,以聚合酶链式反应(PCR)技术为基础,建立了检测大豆加工食品中转基因成分的方法。实验分别采用CTAB法和试剂盒(Kit)法对大豆锅巴、豆浆、豆奶粉、豆腐、豆腐丝等五种大豆加工食品中的DNA进行了提取,用内标基因Lectin对此两种方法的提取效果进行了比较,并以提取的DNA为模板,利用不同的引物分别对目标基因35S和NOS进行了PCR扩增和琼脂糖凝胶电泳检测。结果表明:Kit法的DNA提取效果优于改良CTAB法,上述五种大豆加工食品中均检测出35S启动子和NOS终止子,且均含有转基因成分。     

Effect of critical processing procedures on transgenic components in quality and quantity level during soymilk processing of Roundup Ready Soybean

By taking 2.5% (w/w) transgenic Roundup Ready Soybean as raw materials, with the detecting technology of traditional PCR and real-time fluorescence quantitative PCR, this study analyzed the influence of such critical processing procedures as jordaning, siruping, blending, homogenization and sterilization in soymilk preparation on the fragment size of endogenous gene lectin and exogenous gene epsps, as well as the quantification of transgenic component in Roundup Ready Soybean, and discussed the degradation mechanism of DNA in the course of transgenic soybean processing. The results indicated that, different processing procedures differ in their impact on the degradation of endogenous gene and exogenous gene. Physical mechanical action, such as the jordaning, can make endogenous and exogenous genes degrade, and has more effect on the later. The jordaning process degraded the DNA of endogenous gene from 1883 to about 836 bp, and exogenous gene from 1512 bp to about 408 bp. In the blending procedure, exogenous gene DNA was also degraded from about 408 to 190 bp, but there was no obviously action on the endogenous gene. After the endogenous and the exogenous genes were degraded to some degree, such as 836 and 408 bp, respectively, they were not evidently affected by siruping procedure at 100 °C for 15 min. However, endogenous gene was further considerably degraded from around 836 to 162 bp in the sterilization procedure at 121 °C for 30 s. The effect of the homogenization step on endogenous and exogenous genes was similar to that of siruping procedure. In addition, jordaning and siruping greatly damaged to exogenous gene, which rapidly decreased the transgenic content from 2.5 to 1.656% and 0.435%, respectively. While the endogenous gene was not evidently affected by the blending and homogenization procedures, the exogenous gene DNA was remarkably degraded in the two procedures. Therefore, the transgenic content continued decreased to 0.377% after homogenization procedure. Hereafter, the endogenous gene was further considerably degraded more than the exogenous gene in the sterilization procedure, which caused a little bounce of the transgenic content in the final product to 0.518%.     

富碘黑大豆植物蛋白饮料的生产工艺

介绍了富碘黑大豆植物蛋白饮料的中试生产工艺、配方和操作要点，并对大豆的浸泡、磨浆、脱腥、均质、灭菌等关键工艺进行了讨论。     

Effect of Raw Material Preparation on Rice Vermicelli Quality

The physicochemical properties of high amylose rice flour prepared from wet milling and dry milling were examined and the rice vermicelli quality made from these flour samples was evaluated. The effect of flour particle size on rice vermicelli quality was also determined. The milling method affected chemical compositions and all physicochemical properties of the flour. A higher degree of starch damage occurred in drymilled flour. Rice vermicelli made from dry‐milled flour had higher cooking losses and softer texture than that made from wet‐milled flour and the commercial reference products. Flour particle size influenced both cooking and textural quality of rice vermicelli but did not influence the water absorption index. Flours with larger particle sizes gave vermicelli with higher cooking loss and less desirable texture than flours with smaller particle sizes. Flour with particle sizes less than 200 mesh produced acceptable vermicelli in terms of cooking and textural quality.     

Nested PCR detection of genetically modified soybean in soybean flour, infant formula and soymilk

Due to the Brazilian market introduction of the genetically modified (GM) crop Roundup Ready™ (RR) soybean, the ability to detect GM crops has become a legal necessity. In order to detect the presence of RR soybean, a polymerase chain reaction (PCR) amplification method was evaluated for the detection of RR in soybean mixtures and commercially available soy flour, infant formula and soymilk powder. To detect the presence of RR soybean, a nested PCR resulted in an amplicon of 169 bp, present for all soybean mixed samples containing 0.01-10% GM soybean and absent for 0% GM soybean. None of the analysed infant formulas showed a positive signal after the nested PCR; four out of six soy flour samples and 15 out of 25 soymilk powder samples were positive for the presence of RR soybean. Results show that the nested PCR method used is adequate to determine the presence of GM soybean in the presented products.     

Differences in quality and quantity of transgenic component in Roundup Ready soybean during bean curd preparation

Using 2.5% (w/w) transgenic Roundup Ready soybean as raw material, the effects of critical processing procedures on the fragment sizes of endogenous gene lectin and transgenic gene epsps and the quantity of transgenic component during bean curd preparation were analysed. The results showed that the different processing procedures differed in their impact on the degradation of endogenous and transgenic genes and that the transgenic content of the intermediate products and final product was consequently changed. Physical mechanical action such as jordaning caused both endogenous and transgenic genes to degrade but had more effect on the latter. The jordaning process degraded the DNA of endogenous gene from 1883 to 836 bp and that of transgenic gene from 1512 to 408 bp. The adding CaSO₄ process, predominantly a chemical reaction, had less influence on the transgenic gene than on the endogenous gene, the latter being degraded from 836 to 407 bp. The extrusion moulding process resulted in a significant degradation of DNA in transgenic gene from 408 to 190 bp but had no obvious effect on the endogenous gene. After the critical processing procedures of jordaning, syruping, adding CaSO₄ and extrusion moulding during bean curd preparation the transgenic content of the intermediate products and final product was 1.656, 0.435, 1.150 and 0.797% respectively. Copyright © 2007 Society of Chemical Industry     

新型大豆食品——大豆酸凝乳粉的研究

以大豆为原料,用嗜热链球菌和保加利亚乳杆菌比例1:1之混合菌种为发酵剂,并添加适量添加剂A和B,经喷雾干燥制得的大豆酸凝乳具有与酸牛乳相似的外观和口感,产品得率达92%。本实验确定了制作大豆酸凝乳粉的最佳工艺条件,并经正交实验确定了由大豆酸凝乳粉制备酸凝乳的最佳发酵条件。     

Effect of Soybean Varieties and Growing Locations on the Physical and Chemical Properties of Soymilk and Tofu

ABSTRACT: Soybean varieties and growing location greatly affected the protein content and color of soymilk and the protein content and yield of tofu ( P < 0.05). Protein content of soybeans was the most important affecting factor for the qualities of soymilk and tofu. There were significant correlations between the protein contents of soybeans and soymilks ( P < 0.05). There were also significant correlation between the soybean protein and the total solid content of soymilk (P < 0.05). Tofu moisture content had significant effect on the hardness and yield of tofu (P < 0.05). The correlation between soybean protein and tofu yield was significant at P < 0.05. The protein content and yield of tofu can be predicted by analyzing soybean protein.     

菲律宾蛤仔蒸煮液多糖回收工艺及微胶囊化

目的 回收菲律宾蛤仔蒸煮液中的多糖并采用微胶囊包埋技术对多糖进行脱腥和保护。方法 采用超滤醇沉工艺回收菲律宾蛤仔蒸煮液多糖, 以该多糖为芯材, 大豆蛋白和麦芽糊精为壁材, 采用喷雾干燥法制备微胶囊, 通过单因素和正交试验优化制备工艺。结果 菲律宾蛤仔蒸煮液多糖回收工艺为: 蒸煮液固形物含量调整为10%, 3万分子量超滤膜除杂, 透过液加入3倍体积乙醇, 室温醇沉24 h, 沉淀冻干得菲律宾蛤仔蒸煮液多糖粗品, 总糖含量大于80%, 回收率高于70%; 喷雾干燥法制备菲律宾蛤仔蒸煮液多糖微胶囊工艺参数为: 乳化剂用量0.1%、多糖浓度10 mg/mL、壁材比例3:1、均质时间3 min, 得到的微胶囊的包埋率达到68.63%。结论 超滤醇沉工艺适用于菲律宾蛤仔蒸煮液中多糖的回收, 该多糖采用喷雾干燥法微胶囊化包埋处理, 能够很好地掩盖其腥味, 并起到保护作用。该研究为菲律宾蛤仔蒸煮液的综合开发利用提供思路。     

Quantification of Human IgE Immunoreactive Soybean Proteins in Commercial Soy Ingredients and Products

ABSTRACT:  The objective of this study was the detection and quantification of human IgE immunoreactive soybean proteins in commercially available soy ingredients and products. Optimum dilutions of primary antibody and antigens as well as detection sensitivity were determined for the implementation of a sandwich ELISA method using plasma from soy sensitive subjects (IgE ranging from 0.35 to 98.7 IU/mL). Human IgE immunoreactivity of commercial soybean ingredients showed that the plasma of subjects with strong allergic reaction to soybean presented proportionally higher immunoreactive response. Soy protein isolate and soy protein concentrate contained less immunoreactive proteins than soy flour and grits. As expected, a hypoallergenic soybean product presented the lowest IgE immunoreactivity. Hydrolyzed and fermented soy ingredients showed negligible human IgE immunoreactivity when proteins and peptides were < 20 kDa. The IgE immunoreactivity of soymilk samples ranged from 3.4 to 68.9 ng IgE/mg extracted protein. Tofu contained about 20-fold higher IgE immunoreactivity than soymilk products (median 171 ng IgE/mg extracted protein). Furthermore, soy cheese products presented twice the IgE immunoreactivity than tofu products (median 359 ng IgE/mg protein). Meat analogues presented considerably high extracted protein concentration (median 67.9 mg/g product). The findings of the current investigation demonstrate sandwich ELISA as a reliable immunochemical method with good repeatability, sensitivity, and low detection limit to quantify IgE immunoreactive proteins in soy ingredients and products. Quantitative measurement of specific IgE is likely to become an increasingly valuable tool for soybean industry to comply with food labeling for manufacturers, thus protecting soy-sensitive consumers.