油菜籽中单宁的提取,组成及性质的研究

油菜粕中单宁最佳提取条件为７０％的丙酮水，温度３０℃，粒度５０目。提取率８３％。某粒中硫代葡萄糖甙只残留６．４７μｍｏｌ／ｇ，植酸几乎没有被提取。菜籽单宁是含有水解单宁和缩合单宁的混合型单宁。分子量范围在１３００￣２９００之间。     

Effect of Condensed Tannins in the Analysis of Dietary Fiber in Carob Pods

Insoluble and soluble dietary fiber (IDF and SDF) determined gravimetrically from ripe carob pods after enzymatic treatments, were 32.6% and 6.8%, on dry matter basis. About 50% of the weight of the DF residues corresponded to tannins and protein, because of protease inhibition, and protein-tannin complexes prevented the removal of these constituents in carobs. Nonstarch polysaccharides (14.7% dry weight) and composition were determined by GLC analysis in acid hydroly-sates of samples. The results were discussed showing that the content of DF obtained by enzymatic procedures, including the suggested AOAC method, may be overestimated because of the presence of condensed tannins.     

不同皮渣浸渍发酵时间对葡萄酒中缩合单宁构成及感官品质的影响

为明确不同皮渣浸渍时间对葡萄酒中缩合单宁的影响,以赤霞珠和西拉为材料,进行不同浸渍发酵时间处理,对葡萄皮和葡萄籽以及葡萄酒中缩合单宁的含量、组成、缩合单宁以及相关口感指标等进行了分析.结果 表明,不同葡萄品种中缩合单宁的初始含量、聚合度及没食子酰化率都有显著差异(P＜0.05).葡萄皮中缩合单宁的平均聚合度显著高于葡萄...     

葡萄酒缩合单宁测定方法的比较研究

目的：对比葡萄酒中测定缩合单宁的甲基纤维素沉淀法(MCP法)和蛋白质沉淀法(A-H法),以寻找一种快速准确的测定方法。方法：采用两种方法测定不同类型、产地、品种葡萄酒的缩合单宁,考察其测定值和变异系数;采用液相色谱-质谱联用法(HPLC-MS法)测定缩合单宁含量,采用吸光度法(A280)测定总酚含量,并与上述两种方法的结果对照。结果：(1)MCP法和A-H法均只适用于红葡萄酒缩合单宁测定,MCP法精度略高但差异不显著。(2)MCP法测定值平均为A-H法的9.13倍,但二者存在较好的线性关系(R2=0.6029)。MCP法与HPLC-MS法线性关系良好(R2=0.7733),A-H法较差(R2=0.4843)。(3)MCP法与总酚存在良好的线性关系(R2=0.9095),A-H法与总酚无显著线性关系(R2=0.2872)。结论：两种方法均能反映红葡萄酒缩合单宁含量,但MCP法与HPLC-MS法、总酚具有更高的一致性,如采用A280测定总酚,应采用MCP法测定缩合单宁。     

Effect of Condensed Grape Tannins on the In Vitro Activity of Digestive Proteases and Activation of Their Zymogens

Only at concentrations substantially higher than those likely to occur in human diets did grape tannins have a significant adverse effect on the in virro digestion of bovine serum albumin (BSA). The activities of pepsin and chymotrypsin were at such levels (concentrations greater than 0.1%) significantly reduced. In contrast, that of trypsin increased markedly due to denaturation of BSA by the tannins. Tannin concentrations in excess of 0.5% strongly inhibited the activation of chymotrypsinogen, while the activation of trypsinogen by enterokinase was drastically reduced at concentrations as low as 0.05% due to precipitation of the substrate. BSA digestion was markedly reduced in sequential multizymogen experiments at tannin concentrations of 0.5% but not at 0.1%.     

中国菜籽饼粕品质特征及其影响因素研究

在全国17个油菜主产县区采集菜籽粕样品112份、菜籽饼样品111份、35份主要加工环节的样品以及10个品种纯种双低菜籽、34份混杂商品菜籽。对上述样品主要营养成分、抗营养/毒性成分的化学分析结果显示:国产菜籽粕、菜籽饼中性洗涤纤维含量分别为34.45%±8.44%、30.66%±3.11%,国产菜籽粕硫苷含量为(79.1±44.99)μmol/g。中性洗涤纤维、硫苷含量高、变异大是国产菜籽饼粕区别于加拿大卡诺拉粕的主要品质特征。纯种双低菜籽硫苷含量为(35.2±6.52)μmol/g,商品菜籽硫苷含量为(78.5±21.76)μmol/g,混杂是引起菜籽饼粕硫苷含量偏高、变异增大的主要原因。低温冷榨饼、预压浸出粕、螺旋热榨饼和液压热榨饼的中性洗涤纤维含量分别为(32.0±2.31)%、(34.6±3.40)%、(47.2±3.43)%、(51.5±7.48)%,相互间差异都达到极显著水平(P<0.01),中性洗涤纤维含量的增加主要发生在焙炒、压榨、脱溶等热处理环节,过热处理是导致当前国产菜籽饼粕品质降低的关键。中性洗涤纤维可作为饼粕热加工质量的适宜控制指标。     

pH Dependence of Complex Formation Between Condensed Tannins and Proteins

The interaction between condensed grape tannins and some proteins was studied turbidimetrically. Tannins precipitated protein efficiently at pH values up to the isoelectric point of the individual protein. At slightly higher pH values there was a sharp decrease in complex formation. This “critical pH” was usually observed within approximately 0.5 pH unit of the isoelectric point. A close correlation (r = 0.96) was obtained between the isoelectric point and the critical pH of proteins. The effects of pH and ionic strength on turbidity formation by tannins and bovine serum albumin showed that an increasing salt concentration tended to increase turbidity at pH 3, but it had no significant effect at pH 4. In contrast at pH 5 high salt concentration tended to decrease turbidity. Employing an ultrafiltration technique, the binding behavior of interacting tannin and protein was described by a typical Brunauer type II adsorption curve.     

On Rapeseed Meals. Part XXVI. Some Remarks on the Biological Value of Rapeseed Meal Proteins after Silage

The influence of propionic bacteria on the biological value of potato-rapeseed meal protein ensilage was investigated. The inoculation of the ensilage with Propionibacterium Petersoni T 112 led to the reduction of the content of goitrogenous compounds (isothiocyanates and oxazolidinethiones) and to an increase of the nutritive value (NPU, PER) of the rapeseed protein. The increase of the protein value is greater by the application of propionic bacteria than by toasting of rapeseed meal.     

Effect of Heat Treatment Upon the Chemical Composition of Cottonseed Meal and Upon the Reactivity of Cottonseed Condensed Tannins

The effects of heat treatment on the chemical composition of cottonseed meal (CSM), with or without the addition of cottonseed hulls (containing condensed tannins; CT), and upon reactivity of the CT were studied. Heat was applied in a forced draught oven at 100°C for 2 h. Fluorodinitrobenzene (FDNB)-available lysine, free gossypol, extractable- and bound-CT concentrations, in vitro total nitrogen (N) solubility and the in vitro rumen degradation of the two major seed proteins (52 and 48 kDa) present in cottonseed kernel (which does not contain CT) were determined. The reactivity of CT was assessed by determining N solubility and rumen degradation of cottonseed kernel proteins in the presence or absence of polyethylene glycol (PEG; molecular weight (MW) 3500), which binds and inactivates CT. Heat treatment reduced the concentrations of free gossypol and FDNB-available lysine by small amounts, reduced measurable total CT content by 13%, reduced the solubility of total N, and reduced potential degradability of the 52 and 48 kDa cottonseed storage proteins by mixed rumen microorganisms. Addition of hulls further depressed solubility of total N and ruminal degradation of the two major storage proteins in cottonseed kernel. The action of PEG in vitro indicated that only part of the depression caused by hull addition could be explained by the presence of CT in the hulls, and that the effects of CT upon N solubility and potential degradability in heated CSM were similar to that in unheated CSM. Addition of hulls also substantially reduced FDNB-available lysine. In commercially produced materials, CSM from the Brisbane mill had a lower total CT content, lower N solubility and lower ruminal protein degradation rate than CSM from the Narrabri mill, but a similar level of FDNB-available lysine. Although application of heat inactivated 13% of the total CT, such that it could no longer be extracted and detected with butanol/HCl, it did not seem to change the overall effects produced by CT in reducing N solubility and protein degradation. The effect of hull addition in reducing available lysine has considerable relevance for feeding CSM to monogastric livestock. Interactions involving heat, hulls and CT need to be further studied.     

Effect of Processing on Mycotoxin Content in Grains

Mycotoxins that commonly occur in cereal grains and other products can contaminate finished processed foods on account of their high toxicity. The mycotoxins that are commonly associated with food grains include aflatoxins, ochratoxin A, fumonisins, deoxynivalenol, and zearalenone. Various food-processing operations include sorting, trimming, cleaning, cooking, baking, frying, roasting, flaking, and extrusion that have variable effects on mycotoxins. The nature of the processing operation viz. physical, chemical, or thermal plays an important role in this; usually, the processes that utilize the higher temperatures have greater effects on mycotoxin dissipation. In general, the processes are known to reduce mycotoxin concentrations significantly, but do not eliminate them completely. However, roasting and extrusion processing result in lowest mycotoxin concentrations, since these involve higher temperatures. It is observed that very high temperatures are needed to bring about high reduction in mycotoxin concentrations, approaching acceptable background levels. The treatment with chemicals like ammonia, bicarbonate, citric acid, or sodium bisulfite is also effective in resulting in significant decline in mycotoxin concentrations.     

品种和加工方式对双低菜粕有效能和氨基酸有效性的影响

用精确饲喂技术评价了3个品种的中国双低油菜和1个加拿大卡诺拉的脱脂种籽和商品饼粕的能量和氨基酸的有效性。结果表明,4个脱脂种籽的氮校正真代谢能和氨基酸真消化率没有差异（P＞0．05）;而4个商品饼粕的脱脂样品的氮校正真代谢能和氨基酸真消化率有极显著或显著差异。研究结果证实,不适当的加工方式不仅降低了氨基酸的有效性,而且影响家禽对能量的利用效率。     

品种和加工方式对双低菜粕有效能和氨基酸有效性的影响_注

用精确饲喂技术评价了 3个品种的中国双低油菜和 1个加拿大卡诺拉的脱脂种籽和商品饼粕的能量和氨基酸的有效性。结果表明 ,4个脱脂种籽的氮校正真代谢能和氨基酸真消化率没有差异 (P >0 .0 5 ) ;而 4个商品饼粕的脱脂样品的氮校正真代谢能和氨基酸真消化率有极显著或显著差异。研究结果证实 ,不适当的加工方式不仅降低了氨基酸的有效性 ,而且影响家禽对能量的利用效率。     

Variability in the Quantities of Condensed Tannins and Other Major Phenols in Peach Fruit During Maturation

Quantities of condensed tannins and the major monomeric phenols were maximum between the first and second swell of fruit growth in six melting flesh peach cultivars. Quantities of tannins were higher and vanillin-proanthocyanidin ratios were lower in low quality, astringent fruit than in white or yellow flesh, commercial quality fruit. Major monomeric phenols in all cultivars were chlorogenic acid, neochlorogenic acid, isochlorogenic acid, catechin, and epicatechin. Quantities of these compounds varied by cultivar and also were greater in the low quality, astringent fruit between the first and second swell of growth.     

油菜籽和菜籽油中叶绿素测定方法的确定

借鉴并采用国际标准ISO 10519：1997《分光光度计测定油菜籽中叶绿素的含量》和AOCS Cc13i-96：1997标准《植物原油中叶绿素色值的测定》方法，对国内油菜籽及菜籽油中叶绿素含量进行方法比对测定，确定了适用于我国油菜籽和菜籽油中叶绿素含量测定的方法。通过大量分析测定和实验数据的汇总，证实确定的方法是科学可行的。     

菜籽油中芥酸含量对动物食用安全性的影响

采用气相色谱法分析双低冷榨菜籽油和普通菜籽油的芥酸含量;运用掺食法喂饲小鼠含两种菜籽油的饲料(含油量2%),连续饲养5 周,观察小鼠、体质量、摄食量、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、脏器( 心、肝、脾、肺、双肾、睾丸、卵巢) 质量的变化;研究菜籽油中芥酸含量对小鼠食用安全性的影响。结果表明,双低冷榨菜籽油芥酸含量为4.744%,普通菜籽油芥酸含量为 32.595%,双低冷榨菜籽油芥酸含量明显低于普通菜籽油。喂饲双低冷榨菜籽油饲料组小鼠血清TC、TG 水平低于普通菜籽油饲料组;血清HDL-C 水平略高于普通菜籽油饲料组;与普通菜籽油饲料组相比,喂饲双低冷榨菜籽油饲料对小鼠血脂水平有良好影响。与正常对照组和双低冷榨菜籽油组相比,普通菜籽油组小鼠心脏质量和肝脏质量明显升高,可能与芥酸使脂肪沉积于心脏和肝脏有关。喂饲两种菜籽油对小鼠体质量、摄食、其他脏器质量均无明显影响。     

提高菜籽粕生物学效价制油新工艺

详细阐述了菜籽的营养价值 ,以及利用新的制油方法提高菜籽粕生物学效价的工艺原理 ,而动物试验又进一步证实了该工艺的可行性及推广应用价值。     

双低油菜籽加工工艺设计初探

简述了菜籽加工工艺设计的工作体会，分析了生产线中主机设备的选型。     

油菜籽中多酚的分布及加工过程对菜籽多酚含量的影响

对油菜籽壳粕和脱壳后的菜籽肉粕中提取液的总酚含量、对DPPH 自由基清除能力以及FRAP 抗氧化能力进行比较,并采用液质联用法对提取液中的主要成分进行鉴定,对其中的芥子酸和芥子碱进行定量分析。结果表明：菜籽肉粕提取液中的总酚含量、对DPPH 自由基清除能力以及FRAP 抗氧化能力约为菜籽壳粕中的两倍,芥子酸和芥子碱的含量分别为菜籽壳粕中的约2.5 倍和1.5 倍。通过对实验室溶剂除油的菜籽粕与工业高温粕比较发现,高温榨油过程会使菜籽的总酚含量、抗氧化性、芥子酸和芥子碱含量有所下降,其中总酚含量下降了12.06%,DPPH 自由基和FRAP 抗氧化值分别降低10.0% 和5.6%,芥子酸和芥子碱含量分别下降了5.6% 和21.12%。     

浓香菜籽油在不同加工单元下多环芳烃和风味品质的变化规律

分析了炒籽、压榨和脱胶等单元下油菜籽和油中多环芳烃的含量,明确了多环芳烃在浓香菜籽油3个加工单元中的迁移规律。在此基础上,考查了炒籽升温速率和脱胶单元对浓香菜籽油中多环芳烃形成和风味品质的影响。结果显示,炒籽和压榨单元均造成油菜籽及菜籽油中多环芳烃含量增加,炒籽后的油菜籽中苯并[a]芘、PAH4和EPA16含量分别增加0.40、3.79和10.51 μg/kg。脱胶单元使菜籽油中多环芳烃含量降低,其中轻质PAHs含量减少7.96 μg/kg。炒籽升温速率对浓香菜籽油中多环芳烃含量具有显著影响（P<0.05）。高升温速率下浓香菜籽油中苯并[a]芘、PAH4和EPA16含量分别为0.91、7.18和40.92 μg/kg;低升温速率下样品含量分别为0.38、3.21和27.99 μg/kg。炒籽升温速率对浓香菜籽油中多酚、生育酚和甾醇含量,以及挥发性化合物种类和含量影响不显著（P>0.05）。脱胶处理后,菜籽油中酸价下降0.45 mg/g,过氧化值增加0.49 mmol/kg;菜籽油L*和b*明显提升,a*降低;菜籽油中脂质氧化产物和美拉德反应产物含量分别降低31.19%和53.05%。研究结果可为浓香菜籽油生产中工艺参数优化提供有价值的参考。     

江苏省不同地区棉菜籽饼粕品质分析研究

为了解江苏省棉菜籽饼粕的品质，对该地区部分棉菜籽的常规营养组分含量以及部分抗营养因子含量进行了检测。检测结果：菜籽饼粕粗蛋白含量为33．95％－41．34％，粗脂肪1．87－7．85％，粗纤维10．43％－13．78％，KOH溶解度22．27－52．03％，芥酸含量0．01－7．19mg/g，硫甙含量10．62－65．58umol/g，棉籽饼粕粗蛋白32．08－43．91％，粗纤维11．12％－17．36％，粗脂肪0．36％－1．20％，游离棉酚310－1300mg/kg，检测结果表明，棉菜籽饼粕的质量差异较大，在使用棉菜籽饼粕时应充分考虑其品质差异对饲料产品质量的影响。