新型大豆保健食品生产工艺

本文阐述大豆中几种生理活性成分及其作用机理,同时对大豆多肽、大豆低聚糖大豆膳食纤维和大豆卵磷脂的生产工艺进行较为全面介绍。     

硝酸银诱导不同大豆品种中大豆抗毒素生成量的差异

目的:研究硝酸银对不同黄豆、青豆和黑豆诱导大豆抗毒素生成量的比较。方法:以0.01mol/L硝酸银为诱导剂,采用分析型高效液相法测定9种不同品种大豆产生大豆抗毒素的生成量。应用C18反相色谱柱(4.6mm×250mm,5μm),以乙酸水溶液(pH3)和乙腈为流动相,进行梯度洗脱,流速1mL/min,柱温40℃,检测波长285nm。结果:在相同的提取和测定条件下,硝酸银诱导大豆生成大豆抗毒素的生成量由高至低顺序为青豆、黑豆、黄豆。结论:本研究结果可为合理选择不同种类的大豆进行大豆抗毒素的研究和应用提供依据。     

大豆异黄酮、大豆皂甙纯化工艺研究

通过比较纯化方法确定以吸附法进行分离纯化,通过对五种大孔吸附树脂HPD-100、HPD-300、HPD-600、AB-8和H103的吸附性能研究,确定选择H103从豆粕乙醇提取物的水分散液中吸附异黄酮和皂甙。再在柱后串联对皂甙有良好吸附性的HPD-600吸附剂回收流失皂甙。经树脂纯化后大豆异黄酮和大豆皂甙的纯度分别为37.3％,53.4％,产品中总有效成分含量为90.7％。     

高效液相色谱法分析大豆和大豆低聚糖浆中糖的组成与含量

采用高效液相色谱法(HPLC)对大豆种子及市售的大豆低聚糖浆中的可溶糖进行了分析,并利用α-半乳糖苷酶酶解大豆低聚糖浆及结合HPLC分析来推测大豆低聚糖浆的糖组成。HPLC分析条件为:Sugar-D色谱柱,75%乙腈为流动相,柱温40℃,流速为1.0ml/min,示差折光检测器。Sugar-D色谱柱的分离效果好,基线稳定,相对标准偏差1.0%～2.0%,标准回收率96.7%～100.7%。分析结果表明大豆种子和市售的大豆低聚糖浆中均含有果糖、蔗糖、蜜二糖、棉子糖、水苏糖以及二种保留时间介于蔗糖与蜜二糖之间的未知成分,而大豆低聚糖浆中还含有葡萄糖(半乳糖)和甘露三糖;大豆种子中主要含有蔗糖和水苏糖,而大豆低聚糖浆中含有较多的蔗糖、果糖、水苏糖和葡萄糖(半乳糖),功能性低聚糖主要为水苏糖和甘露三糖。     

高压液相色谱法测定大豆异黄酮含量

大豆试样在酸性条件下水解后,采用岛津LC-10AtvpHPLC仪,紫外检测器(SPD-10Avvp),波长 254 nm,色谱柱:Inertsil ODS-3柱(5μm,4.6 mm×250 mm),流动相:甲醇:5％ 醋酸溶液30％～70％梯度洗脱,流速:1.0 ml/min,柱温:50℃条件下,测定水解提取物中大豆异黄酮含量。测定结果表明:不同品种、产地的大豆中异黄酮含量为 1.40 mg～3.30 mg/g,大豆胚芽中异黄酮含量最高,为13.18mg/g;其它豆类,如红豆、绿豆、青豆、豌豆等异黄酮含量为0.37mg～1.2mg/g,此测定法能为大豆的选育种、栽培及大豆异黄酮含量评价提供依据。     

大豆异黄酮富集及分离技术研究进展

综述了大豆异黄酮的富集研究方法,并从薄层层析法、硅胶柱层析法、C18制备级色谱柱分离法、葡聚糖凝胶色谱法和高速逆流色谱法等几方面归纳与综述了大豆异黄酮的分离工艺.     

超滤法提取大豆低聚糖的研究

大豆低聚糖是一种功能性低聚糖 ,具有促进双歧杆菌增殖的作用。本文对采用超滤技术提取大豆乳清前处理液中的大豆低聚糖进行了研究 ,探讨了压力和温度对大豆乳清前处理液超滤特性的影响 ,确定了每种膜的最佳超滤压力和超滤温度 ,并在此条件下进行超滤状况和膜阻力变化的研究 ,同时根据所得成品的成分分析选出了大豆乳清最佳超滤用膜 ,最后通过比较几种不同的清洗方法的清洗效果 ,选出了合适的超滤膜清洗方法。     

国内外大豆生产的现状和大豆品种创新问题

介绍了世界和中国的大豆收获面积、单产和总产情况.论述了中国大豆超高产育种、高产育种、高产高油育种、高蛋白育种、抗性育种等取得的成效.最后谈及我国大豆产业发展需要解决的几个问题.     

大豆膳食纤维研究发与应用

本文介绍大豆膳食纤维生理功能和来源,并对大豆膳食纤维添加剂的制备及其研究开发与应用作了详细介绍,还介绍几种大豆膳食纤维食品生产。     

大豆胚芽综合利用的研究

大豆胚芽具有很高的营养价值，其富含生理活性物质维生素E，大豆异黄酮和甾醇等。对大豆胚芽的营养成分进行了分析和论述，并对其综合利用提出了几点建议。测试结果表明：大豆胚芽含有28%蛋白质，8.7%油（其中不饱和脂肪酸含量高达80%），油中含VE190mg/100g，大豆异黄酮1.23%，甾醇0.37%。     

牛奶中无乳链球菌DNA提取方法的比较

目的以牛奶中的致病性无乳链球菌作为研究对象,对9种常用的细菌核酸提取方法进行比较。方法选用紫外分光光度计法和实时荧光PCR法对各方法进行系统评估。结果超声波处理结合天根吸附柱的方法能提取到得率较高、纯度较好的DNA,结合实时荧光PCR法后对牛奶中无乳链球菌的检测灵敏度能达到90 cfu;天根吸附柱法提取所得DNA得率稍低,结合实时荧光PCR法后对牛奶中无乳链球菌的检测灵敏度也能达到90 cfu;溶菌酶法和超声波破碎提取法用于实时荧光PCR后对牛奶中无乳链球菌的检测灵敏度能达到350 cfu;Chelex-100法更适于纯菌的检测,该法结合实时荧光PCR法对无乳链球菌的检测灵敏度能达到350 cfu的灵敏度。结论应根据样品类型、方法要求和检测成本来选择适合的核酸提取方法。     

Comparison of sulfuric acid treatment and multi-layer silica gel column chromatography in cleanup methods for determination of PCDDs,PCDFs and dioxin-like PCBs in foods

Two typical cleanup methods, sulfuric acid treatment and multi-layer silica gel column chromatography, for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in seventeen food samples were examined and compared. Vegetables, fruits, cereals, fish, meat and dairy foods were extracted by conventional methods (shaking with acetone/n-hexane or with n-hexane after alkaline treatment). The extracts were cleaned up by sulfuric acid treatment or multi-layer silica gel column chromatography, followed by several column chromatographic steps. Of the samples treated, the vegetable, fruit and cereal samples could be directly applied to the multi-layer silica gel column after extraction. However, the samples containing fats and oils such as fish, meat and dairy foods needed to be treated several times with concentrated sulfuric acid before multi-layer column chromatography, because these samples plugged the column with oily residues. Both cleanup methods gave similar values of isomeric concentrations and showed similar efficiency of purification, and the recoveries ranged from 40 to 120%. These results are considered to provide useful data for the efficient analysis of dioxins in foods which have wide-ranging compositions.     

Alternative cutting methods to minimize transfer of nervous system tissue during steak preparation from bone-in short loins

Fresh beef products, such as steaks, may become contaminated with potential specified risk materials (SRMs), such as central nervous system tissue, during the fabrication of bone-in loin subprimals. The objective of this study was to evaluate current and alternative cutting methods that could be used to minimize the transfer of nervous system tissue (NST) tissue during preparation of steaks from bone-in short loins. Bone-in short loins were cut according to three methods. (i) Cutting method I-The vertebral column bones were removed prior to cutting the loin into steaks from the medial (vertebral column) to lateral (flank) side. (ii) Cutting method II--The loin was cut into steaks from the vertebral column side to the flank side prior to removal of the vertebral column bones. (iii) Cutting method III--The loin was cut into steaks from the flank side to the vertebral column side prior to removal of the vertebral column bones. Results indicated that surface areas along the vertebral column cutting line had detectable (0.10 and 0.22% NST/100 cm2) and, thus, higher potential SRM contamination than resulting steak surfaces or the cutting blade. Overall, there were no detectable (<0.10% NST/100 cm2) differences in NST contamination of steaks produced by the three cutting methods. Immunohistochemical evaluation of areas on excised and ground steak surfaces indicated that regardless of cutting method, there was generally "no" to "moderate" staining, suggesting that detectable (0.137 to 0.201% NST) contamination from these samples was most likely due to peripheral nerve detection. These results imply that steaks may be cut from bone-in short loins prior to removal of the vertebral column bones without affecting the transfer of NST to resulting steaks at concentrations <0.10% NST/100 cm2.     

大米中吡虫啉和噻嗪酮残留分析方法

研究了分别用高效液相色谱和气相色谱测定大米中吡虫啉和噻嗪酮残留量的检测方法。采用乙腈作为大米中吡虫啉和噻嗪酮的共同提取溶剂,部分提取溶液通过氟罗里硅土固相萃取小柱净化,以Wa-ters-C18色谱柱为分离柱,乙腈–水(20∶80,体积比)为流动相,用高效液相色谱二极管阵列检测器检测(检测波长270 nm)吡虫啉的残留量;部分提取溶液通过氨基固相萃取小柱净化,以弹性石英玻璃毛细管柱为分离柱,用气相色谱电子俘获检测器检测噻嗪酮的残留量。结果表明,样品在不同水平的加标回收试验中,吡虫啉的平均回收率为89.2%～96.4%,相对标准偏差为2.5%～8.5%;噻嗪酮的平均回收率为86.6%～105.8%,相对标准偏差为2.6%～5.5%;两种农药的最低检出浓度均为0.02 mg/kg。该测定方法简单、准确、精密度高、重现性好。     

绿茶中氯氰菊酯检测的5种净化方法比较

目的比较分析5种不同净化方法(Cleanert TPT小柱、Qu ECh ERS、Tea Column小柱、GCB小柱、GCB/NH_2小柱)对绿茶中氯氰菊酯检测结果的影响。方法采用不同的固相萃取(solid phase extraction,SPE)净化方法,对仪器、色谱柱及定量方法的选择均进行了考察,计算不同方法的回收率和相对标准偏差(relative standard deviation,RSD)。结果采用Cleanert TPT净化小柱的回收率低于50%,以Qu ECh ERS净化包、Tea Column、GCB、GCB/NH_2小柱处理后的样品回收率均可达到80%以上。结论在所选的5种净化方法中,4种净化方法均满足GB/T 27404-2008《实验室质量控制规范食品理化检测》的相关要求,检测机构可根据自身情况选择或进行改进。     

现行黄曲霉毒素液相色谱检测法的比较与评价

目的 综合评价检测黄曲霉毒素的几种现行液相色谱-荧光法。方法 采用均质(涡旋)、超声辅助液液萃取技术对样品中的黄曲霉毒素进行提取, 免疫亲和柱和多功能柱净化。并采用不同的检测技术[三氟乙酸(TFA)柱前衍生法、光化学柱后衍生法、碘和溴柱后衍生法、大体积流动池直接检测及光化学柱后衍生串联大体积流动池]对玉米质控样品中黄曲霉毒素进行了分析。结果 各方法的检测结果均较理想, 可满足常规样品的检测要求。结论 超高压液相色谱-大体积流动池检测法在有效提高工作效率的同时, 大量减少了有毒有害试剂的使用量, 且具有最高的检测灵敏度, 可满足GB 2761-2011中对各类样品中黄曲霉毒素的限量要求。采用乙腈-水或甲醇-水体系均能达到较好提取黄曲霉毒素的目的。免疫亲和柱的净化效果较多功能柱好。     

藻胆蛋白的提取纯化研究进展

本文从提取原料、细胞破碎方法、粗提和纯化方法等几方面对近期有关藻胆蛋白的提取纯化研究做一介绍。常用的提取原料有螺旋藻、多管藻、条斑紫菜等;细胞破碎方法有反复冻融法、化学试剂处理法等五种;粗提方法主要有盐析法等四种;而常用的纯化方法有羟基磷灰石柱层析法、DEAE-纤维素离子交换柱法和葡聚糖凝胶柱层析法等三种。实际应用中为获得较好的提取纯化效果,经常混合使用多种细胞破碎方法和多种纯化方法。     

Recent advances in methodology for analysis of phytate and inositol phosphates in foods.

This review summarises the methods available for the analysis of phytate and structurally related molecules, i.e., inositol polyphosphates. Phytate has been determined by colorimetry, low pressure ion exchange column chromatography, phosphorus-31 fourier transform nuclear magnetic resonance spectroscopy (31P FT NMR), near-infrared reflectance spectroscopy and high performance liquid chromatography (HPLC). Among these techniques anion exchange column chromatography and HPLC were shown to be best suited for separation of inositol phosphates. Since inositol phosphates do not have a characteristic absorption spectrum, their detection in HPLC analysis is limited to methods employing monitoring of refractive index, post column reaction products, conductivity or indirect detection although other detection methods may be feasible. As refractive index detection under isocratic eluent conditions is relatively easy to manipulate, anion-exchange HPLC methods using a low capacity column or ion-pair HPLC methods are recommended for the analysis of inositol phosphates in nutritional studies.     

Modification of cleanup methods for dioxin analysis in green leafy vegetables and comparison of packing methods for a multi-layer silica gel column

To determine polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) in green leafy vegetables, the cleanup method was modified, and packing methods for a multi-layer silica gel column were compared in food samples. First, the additional cleanup was examined for a mono-ortho PCBs fraction obtained by alumina column chromatography from spinach extract. Small solids such as rough crystals that remained after concentration of the mono-ortho PCBs fraction were identified as long-chain hydrocarbons from leaf epicuticular wax by GC/MS. Cleanup using an activated carbon silica gel column with n-hexane as the washing solvent was effective. Next, multi-layer silica gel columns packed by wet packing and dry packing were compared using komatsuna, salmon and butter as samples. The columns prepared by both methods gave similar values at each isomeric concentration level and showed similar efficiency with favorable recoveries.     

Evaluation of New Methods for the Assessment of Used Frying Oils

Three methods recently introduced for quality assessment of frying oils were compared. These were: column chromatography of polar components, dielectric constant measurement, and GLC of triglyceride dimers. For a given frying operation all three methods correlated well with each other and with time of frying, while large differences were obtained for samples of unknown history. The dielectric readings were found to represent a net balance of opposing effects from two groups of compounds. The GLC method was found to be simpler and more specific than the column technique.