大豆脂肪氧合酶的提取纯化及其特性研究

本实验以大豆为原料,经硫酸铵沉淀、葡聚糖凝胶柱G200分离沉淀,得到2种脂肪氧合酶（L0x）：LOX．1,LOX．2。对这两种同工酶的部分特性进行研究。其中LOX-1的反应最适pH为7．0,在pH9．0时无活性。而LOX-2最适pH为9．0,在pH7．0时也表现出较强活性。最适温度均为25℃。两种同工酶的热稳定性结果表明,LOX．1和LOX．2在40℃活性稳定,加热温度高于50℃时,活性急剧下降。在亚油酸为底物的反应体系中,LOX．1和LOX．2的K。值分别为8．2、12．2mmol／L。并对Ca2＋、Na＋、Cu2＋、和Fe3＋等不同的金属离子表现出不同的反应活性。     

麻鸭脂肪氧合酶的分离纯化及其性质研究

采用硫酸铵沉淀、离子交换层析、凝胶色谱等方法对麻鸭脂肪氧合酶(Shelduck Lipoxygenase)进行了纯化。结果显示,麻鸭LOX粗提液经60%⁸0%硫酸铵沉淀、DEAE离子交换层析、Superdex75凝胶过滤、SOURCE15Q离子交换层析后可达电泳纯,麻鸭LOX比活力为85714.3U/mg,纯化倍数98.64,经SDS PAGE分析麻鸭LOX的分子质量约为62 kDa。麻鸭LOX与大豆LOX的酶学性质差异较大,麻鸭LOX的最适温度为30℃,最适pH为6.0,且热稳定性和pH稳定性均优于大豆LOX。同时,Zn2+、Ca2+对麻鸭LOX的激活作用明显,而Mn2+对麻鸭LOX具有强烈的抑制作用。     

Partial Purification and Characterization of Asparagus Lipoxygenase

Lipoxygenase (LOX) from fresh asparagus was partially purified by extraction of acetone-washed asparagus powder with pH 4.5 potassium phosphate, ammonium sulfate fractionation and carboxymethyl-cellulose (CMC) chromatography. Asparagus LOX purified by ammonium sulfate fractionation had a pH activity optimum of 5.5–6.0 and was stable at pH 4.5–8.0 when stored at 2°C. Asparagus LOX was active on monolinolein as well as linoleic acid, but activity was very low on di- or tri-linolein. The CMC fractions with greatest LOX activity were nearly free of peroxidase activity while the protein fractions which did not bind with CMC at pH 5 were peroxidase active. The LOX activity in the purified asparagus extract was 90% inhibited by 1 mM cyanide when preincubated for 30 min at 25°C.     

烤烟催芽包衣种子试验

为了提高包衣种子的发芽率和出苗整齐度,进行了烤烟催芽包衣种子的试验.结果表明,催芽包衣种子较常规包衣种子的发芽势提高了21.7～35.8个百分点、发芽率提高了3.2～9.2个百分点.在大理州烟区催芽包衣种子可提前出苗5～7d,苗期与大田期烟株的生长势和生长整齐度均优于常规包衣种子.     

萌发荞麦种子蛋白质组分含量变化的研究

研究了荞麦种子萌发后总蛋白质和各蛋白组分如清蛋白、球蛋白、醇溶蛋白和谷蛋白的含量变化，结果表明：本试验条件下，山西甜荞和四川苦荞萌发后总蛋白质含量呈逐渐下降趋势。山西甜荞经过72h的萌发，其蛋白质总量由最初的11．90％下降到5．44％，下降了6．5个百分点。四川苦荞由萌发初的6．53％下降到0．96％，下降了5．6个百分点。荞麦清蛋白和球蛋白在萌发后均呈现下降趋势，与总蛋白质含量变化相一致。谷蛋白在萌发后至36h内含量下降，之后又快速增加。四川苦荞醇溶蛋白含量在萌发后逐渐增加．而山西甜荞则有逐渐下降趋势。     

Moisture Diffusivity in High Oleic Sunflower Seeds and Kernels

Moisture diffusivities in high oleic seeds and kernels were obtained from experimental thin layer drying rates in the range of 25–90°C air temperature and 4.2–33.5% initial moisture content (d.b.). Moisture diffusivity back-calculated from Fick´s second law of diffusion varied between 0.85.10^-10 and 7.26.10^?10 m²/s for seeds and between 0.37.10^?10 and 2.39.10^?10 m²/s for kernels. The Arrhenius activation energy for seeds and kernels resulted 31 and 24 kJ/mol, respectively. A new model based on the kinetic parameter of Page equation was proposed as a simple tool to predict water diffusion in high oleic sunflower seeds and kernelss.     

Action of Cyclodextrins on Germinating Seeds and on Micropropagated Plants

Effects of cyclodextrins on germinating barley seeds and on the growth of micropropagated strawberry plants were investigated. Treatment of barley seeds with α- or β-cyclodextrins resulted in a similar delay of germination as reported earlier [1]. The delay of germination occurred with agarose-immobilized as well as with free cyclodextrins. Since penetration of immobilized cyclodextrins into the seeds is limited, it was concluded that the delay resulted from complexation of growth factors. Soluble cyclodextrins caused a growth retardation with micropropagated strawberry plants and certain morphological changes resembling the ones observed when the action of auxins is enhanced in the respect to cytokinins.     

水酶法提取葵花籽油的工艺

研究了水酶法提取葵花籽油的工艺。通过三因素(水∶籽、酶∶籽、酶解时间)三水平的正交试验,确定了提油工艺参数,即干法粉碎脱壳葵花籽,m(水)∶m(籽)=5∶1,复合纤维素酶添加量为2.5%(w/w),搅拌速度250 r/min,反应温度50℃,酶解时间7 h,游离油得率达到90%左右。提取得到的葵花籽油色泽淡黄清亮,气味芬芳。     

Properties of Broad Bean Lipoxygenase

An improved method of assay of lipoxygenase (E.C.1·13·1·13) was introduced by initiating and following the reaction in the spectrophotometric cell. The enzyme was extracted from broad bean (View faba) and purified fifty folds. It oxidized linoleate but not oleate and the rate of linoleate and linolenate oxidation were found to be practically the same. The enzyme had an optimum pH of 6.0 and an optimum temp of 30°C. The activation energy was found to be 7.1 KCal/mole and the Km for linoleate 2.8 × 10^a-3M.     

葵花籽酸性植物蛋白饮料的稳定性研究

本文研究了以葵花籽为主要原料的酸性植物蛋白饮料的稳定性.探讨了不同HLB值对饮料乳化稳定性的影响,筛选出了适宜的稳定剂.实验结果表明,植物蛋白饮料的较佳的HLB值为12,适宜的复合稳定剂配比为0.25%,微晶纤维素、0.15%CMC-Na、0.25%复合乳化剂.     

樱桃谷鸭胸肉脂肪氧合酶的分离纯化及其酶学特性研究

用硫酸铵分级沉淀和DEAE-Sepharose柱层析法分离纯化樱桃谷鸭胸肉中脂肪氧合酶(lipoxygenase,LOX),同时对酶学性质进行研究。结果显示：在DEAE-Sepharose柱层析时,当NaCl洗脱浓度在0.3～0.35mmol/L时,LOX被分离出,LOX经过分离纯化后其纯化倍数可达到54.3,SDS-PAGE电泳显示其分子质量约为96kD;粗酶和纯酶性质略有不同;以亚油酸为底物,粗酶和纯酶的最适底物浓度分别为6.4、10mmol/L,最适反应温度分别为40、30℃,最适pH值分别是5.0、5.5;纯酶Km=1.139mmol/L、Vmax=0.07608U/min,纯酶与底物的亲和能力大于粗酶。     

Ultrastructure of Starch Grain Breakdown in Cotyledon Cells of Germinating Lentil Seeds

Fine structural changes associated with the breakdown of starch grains in the storage parenchyma cells of the cotyledons of Lens culinaris seeds during germination are described. In the initial germination phases each starch grain is found inside a double membrane. In more advanced states of germination (8–12 days) the starch grains show erosion from within, leading to the formation of a central cavity surrounded by irregular starch fragments. During this process the starch grain maintains its external shape. Following this it was possible to observe starch fragments dispersed throughout the cytoplasm.     

萌发大麦种子蛋白组分含量变化研究

采用蛋白质组分连续累进提取分析法，检测了垦啤8号、甘啤4号、Harrington、Es．terel四个品种大麦种子萌发前后各蛋白组分的含量变化。结果表明：大麦种子中清蛋白含量较低，占总蛋白含量的3％～5％，种子萌发后，清蛋白含量迅速升高，发芽第四天达到最大值，含量占10％左右，绿麦芽焙焦后，含量略有下降；球蛋白含量变化较为复杂，在种子发芽2天后达到最大值，由3％升至6％左右；醇溶蛋白在种子萌发过程中明显减少，Esterel品种变化最大，减少了总蛋白质的7．14％，其它三个品种减少了4到6个百分点；谷蛋白含量在萌发过程中略呈升高趋势，但变化不大。     

一种新型的绿色包装资源——葵花籽壳

探讨了葵花籽壳资源在包装领域再利用的多种途径。一般作为废弃物的葵花籽壳,不仅可以提取绿原酸,用于保鲜包装;提取天然色素,用于包装印刷;还可制浆造纸、制造纤维板与刨花板,生产纸与木材包装材料。     

Characteristics of Milk and Butter from Cows Fed Sunflower Seeds

Composition of milk and butter was evaluated from cows fed either control or experimental diets containing added fat of partially unsaturated fatty acid composition. The control diet concentrate mix consisted mainly of corn and soybean meal. The two experimental diets substituted either 20% high oleic sunflower seeds (>79% of fatty acids as oleic acid) or 20% regular sunflower seeds (>67% of fatty acids as linoleic acid) for part of the corn and soybean meal in the concentrate mix. Feeding lactating dairy cattle sunflower seeds resulted in lower concentrations of short and medium chain and higher concentrations of long-chain fatty acids in milk fat and butter. Milk unsaturated fatty acid concentrations were (28.9, 38.8, 45.6%), and butter unsaturated fatty acid concentrations were (29.6, 38.1, 44.3%) for control, high oleic sunflower seed, and regular sunflower seed treatment milk, respectively. Organoleptic evaluation indicated the high oleic sunflower seed and regular sunflower seed treatment butters were equal or superior in flavor to the control butter. The high oleic sunflower seed and regular sunflower seed treatment butters were softer, more unsaturated, and exhibited acceptable flavor, manufacturing, and storage characteristics.     

葵花籽流化床干燥的研究

通过三因素二次组合设计以及SPSS13.0等方法,对鲜葵花籽流化床干燥进行研究,获得回归方程,并利用其求得葵花籽流化床干燥最佳条件为空床气速1.4235m/s,热空气温度65.0693℃,流化床层高度(静止床)93.4934mm。     

葵花籽不同包装方式储存品质的研究

对黑糖味瓜子的主要原料葵花籽进行研究,对熟制后的葵花籽进行6种不同方式包装,研究产品在食品储存期加速试验中的理化指标及感官变化情况。结果表明:熟制后搭配吸氧剂包装的葵花籽产品质量指标符合GB/T 22165与GB 19300标准要求。不同包装方式产品在0~4个月的加速试验期内,酸价值和过氧化值逐步增加,其中新纸袋未投放吸氧剂的产品在加速试验4个月中酸价值和过氧化值峰值为1.92mg KOH/g与0.811g/100g,储存效果最差;新纸袋加吸氧剂包装的产品酸价值和过氧化值最低,为1.47mg KOH/g与0.051g/100g,储存效果最好。     

向日葵籽中酚酸含量的高效液相色谱测定方法研究

采用ALLTIMACl8色谱柱(250mm×4.6mmID,5μm),乙腈∶2%冰醋酸溶液(15∶85)为流动相,流速为1.0ml/min,SPD-6AV紫外检测器,柱温为室温,检测波长327nm。建立了测定向日葵籽中酚酸含量的高效液相色谱法,同时测定了部分向日葵品种中酚酸的含量。