啤酒大麦籽粒品质性状胚、胚乳、细胞质和母体遗传效应分析

采用3倍体胚乳禾本科作物种子数量性状遗传模型和统计分析方法,分析了啤酒大麦籽粒的蛋白质含量、淀粉含量、纤维含量、脂肪含量及β-葡聚糖的胚、胚乳、细胞质和母体植株遗传效应及狭义遗传率。结果表明,所测的5个品质性状主要受控于遗传主效应,环境互作效应较小。蛋白含量、淀粉含量、纤维含量、β-葡聚糖含量的表达主要受控于细胞质遗传效应,控制脂肪含量的遗传主效应以母体显性效应为主;蛋白质含量,淀粉含量、纤维含量和β-葡聚糖含量的狭义遗传率分别为69.75%、60.09%、57.69%和61.76%,脂肪含量性状未被检测到显著的狭义遗传率。加性遗传相关分析结果表明,蛋白质含量与纤维含量间存在细胞质、母体加性的完全正相关,蛋白质含量与β-葡聚糖含量,纤维含量与淀粉含量、β-葡聚糖含量存在极显著的的细胞质完全负相关。     

小麦胚乳中蛋白质、淀粉组分分布及各性状关系的研究

以小麦品种为9023的各系统面粉样品为试验材料,测定各样品蛋白质及组分含量、湿面筋含量、面筋指数、淀粉及其组分含量,研究小麦胚乳中蛋白质与淀粉及组分分布情况,并对蛋白质和淀粉及各性状间的关系进行初步研究.结果表明:小麦胚乳由内向外,蛋白质含量及球蛋白、醇溶蛋白和谷蛋白含量呈现递增的分布趋势,而淀粉和直链淀粉含量则逐渐减小;球蛋白、醇溶蛋白和谷蛋白含量两两呈现显著或极显著正相关,且与粗蛋白含量显著正相关;湿面筋含量与蛋白质含量、醇溶蛋白和麦谷蛋白含量均呈现极显著正相关关系;直链淀粉含量与总淀粉含量显著正相关,与支链淀粉含量负相关;直链淀粉含量与粗蛋白含量、球蛋白和醇溶蛋白含量均呈显著负相关,支链淀粉含量与谷蛋白含量、湿面筋含量显著正相关.     

风鹅现有工艺加工过程中品质的变化规律

通过对风鹅现有工艺加工过程中pH值、色泽、盐分含量、水分含量、硫代巴比妥酸还原物(thiobarbituric acidreactive substance,TBARS)值、总氮含量、非蛋白氮含量、游离氨基酸含量和游离氨基酸态氮含量等指标的测定,研究风鹅肌肉中品质变化规律及脂肪氧化和蛋白质水解可能对风味产生的影响.结果表明,盐分含量在加工过程中不断上升,水分含量不断下降;pH值和TBARS值在一定范围内波动;总氮含量、非蛋白氮含量、游离氨基酸含量、游离氨基酸态氮含量变化差异显著,风干结束后风鹅肌肉中蛋白质水解指数约为3.8％,游离氨基酸含量占非蛋白氮含量的78％以上,含量最多的游离氨基酸含量为Arg、Thr、Glu、Leu和Ala等,而增加较多的游离氨基酸含量是Asp、Leu、Tyr、Val、Ile和Lys等,大部分游离氨基酸的含量都超过其阈值很多倍,可能对风鹅的风味产生重要影响.     

水分含量对马铃薯淀粉凝胶体系脂肪吸收的影响

以马铃薯淀粉为原材料,与水进行模拟,在180 ℃条件下对马铃薯淀粉凝胶样品进行常压油炸,研究油炸样品中总油脂含量,以及各部分油脂含量的分布情况。结果表明：随着水分含量的增加,马铃薯淀粉凝胶体系油炸样品的总油脂含量、表面油脂含量和表面渗透油脂含量呈逐渐增加的趋势。随着油炸时间的延长,马铃薯淀粉凝胶体系油炸样品的总油脂含量和组织结构油脂含量呈逐渐增加的趋势,表面渗透油脂含量呈逐渐降低的趋势。随着水分含量的增加,表面渗透油脂含量在油炸样品总油脂含量中占据最大部分,其次是组织结构油脂含量,最少的是表面油脂含量。不同部分油脂含量的变化呈现一定的规律性,但变化幅度有一定的差异。     

茶树油/海藻酸钠涂膜抑制鲜切苹果褐变的研究

以吸光度为优化指标和抑制鲜切苹果褐变为目标,在单因素的基础上采用响应面法进行优化抑制鲜切苹果褐变的茶树油/海藻酸钠涂膜最佳制备工艺条件,建立了海藻酸钠含量、甘油含量和茶树油含量对制备茶树油/海藻酸钠涂膜的数学模型。结果表明:海藻酸钠含量和茶树油含量对吸光度的影响显著,甘油含量对吸光度的影响不显著,影响的大小顺序为茶树油含量海藻酸钠含量甘油含量;海藻酸钠含量与茶树油含量的交互作用对吸光度影响显著,海藻酸钠含量与甘油含量、甘油含量与茶树油含量的交互作用对吸光度的影响不显著;抑制鲜切苹果褐变的茶树油/海藻酸钠涂膜的最佳制备工艺为海藻酸钠含量1.30%、甘油含量1.99%和茶树油含量0.26%,此条件下吸光度的试验值为0.015。     

晋南野菜和蔬菜硝酸盐、亚硝酸盐和维生素C含量分析

目的对山西南部的10种野菜和4种常食用蔬菜的硝酸盐、亚硝酸盐和维生素C含量进行测定。方法硝酸盐含量测定采用镉柱法;亚硝酸盐含量测定采用盐酸萘基乙二胺法;维生素C含量测定采用2,6-二氯酚靛酚滴定法。结果苜蓿、黄瓜和西红柿的硝酸盐含量低于轻度污染水平,亚硝酸盐含量低于亚硝酸盐含量的限量标准,维生素C的含量较低,属于一级蔬菜,可以安全生食;马齿苋、荠菜、蒲公英的硝酸盐含量低于中度污染水平,亚硝酸盐含量低于或相当于亚硝酸盐含量的限量标准,维生素C的含量高或较高,属于二级蔬菜,不宜生食,可盐渍和熟食;苣荬菜、车前草、苦菜、胡萝卜的硝酸盐含量过高,低于重度污染水平,不宜生食和盐渍,可以熟食;藜菜、菠菜、白蒿、地肤的硝酸盐含量高于1234mg/kg,属于高度污染水平,亚硝酸盐含量超过或相当于亚硝酸盐含量限量标准,维生素C的含量高或极高,不宜食用或限量食用。结论大多数供试野菜的各个指标含量均高于栽培蔬菜。     

微波处理对几种粮食品质影响的比较研究

采用2.45 GHz工业微波炉照射绿豆、小米、燕麦和大米,研究微波处理对其品质的影响,为粮食的微波防虫防霉提供试验数据.结果表明:微波处理后绿豆和小米的水分含量显著降低,燕麦和大米的水分含量变化不大;绿豆和大米的蛋白质含量基本不变,小米蛋白质含量略有降低,燕麦蛋白质含量略有升高;绿豆和小米的水溶性蛋白质含量变化不大,燕麦和大米的水溶性蛋白质含量略有降低;绿豆、小米和大米的游离氨基酸含量均降低,燕麦游离氨基酸含量变化不大;绿豆和燕麦还原糖含量均有所升高,小米和大米还原糖含量变化不大;4种样品碘蓝值均显著升高;绿豆、小米和大米脂肪含量均显著降低,燕麦脂肪含量变化不大;绿豆和大米游离脂肪酸含量降低,小米和燕麦游离脂肪酸含量升高.     

猕猴桃品种对猕猴桃脆片品质影响的评价

目的:以6个品种的猕猴桃为原料,筛选出最适合加工成脆片的品种。方法:采用真空冷冻干燥的方法制备猕猴桃脆片,测定猕猴桃脆片的得率、脆片中水溶性果胶含量、酸溶性果胶含量、可溶性糖含量、总酸含量、糖酸比、抗坏血酸含量及脆片的硬度和脆度等9个指标,并对猕猴桃脆片进行感官评价。结果:不同品种猕猴桃脆片的得率、营养物质含量和感官指标不同。其中金艳猕猴桃脆片的得率、水溶性果胶含量、可溶性糖含量和硬度较高,总酸含量和脆度较低;金梅猕猴桃脆片的得率、水溶性果胶含量、可溶性糖含量和抗坏血酸含量较高,总酸含量、硬度和脆度较低;金圆猕猴桃脆片的水溶性果胶、酸溶性果胶、结合果胶、可溶性糖、总酸和抗坏血酸含量较高,脆片的硬度和脆度较低;金桃猕猴桃脆片的得率、糖酸比、抗坏血酸等含量及脆片的硬度和脆度较高,脆片的水溶性果胶和总酸含量较低;翠玉猕猴桃脆片的得率、糖酸比和脆度较高,脆片的酸溶性果胶含量、结合态果胶含量、可溶性糖含量、总酸含量和脆片的硬度较低;东红猕猴桃脆片的得率、酸溶性果胶含量、结合态果胶含量、可溶性糖含量、糖酸比和脆片的硬度较高,脆片中水溶性果胶含量、总酸含量和脆片的脆度较低。结论:品种对猕猴桃脆片的得...     

蛎菜的营养成分分析

分析蛎菜的一般营养成分.结果表明:蛎菜中粗蛋白含量为14.78%,脂肪为0.67%,灰分为16.70%;蛎菜氨基酸中苯丙氨酸的含量相对较高,占总氨基酸含量的11.08%;蛎菜中矿物质含量丰富,有害元素含量较低;不饱和脂肪酸中亚麻酸的含量最高,占总脂肪酸含量的16.42%.     

大叶麻竹笋腌制过程中质地变软原因探究

以大叶麻竹笋为原料,研究其腌制过程中总酸、水分含量、NaCl含量、乙醇不溶物含量、原果胶含量、纤维素含量和木质素含量与硬度的关系。同时,对样品腌制过程中的微观结构进行观察。结果表明：大叶麻竹笋腌制过程中硬度的变化与总酸含量、NaCl含量、乙醇不溶物含量、原果胶含量和纤维素含量密切相关。同时,大叶麻竹笋腌制过程中组织微观结构发生明显的变化。     

Degradation of naled and dichlorvos promoted by reduced sulfur species in well-defined anoxic aqueous solutions

This work examines the reaction of reduced sulfur species (e.g., bisulfide, thiosulfate, thiophenolate) with naled, a registered insecticide, in well-defined anoxic aqueous solutions at 5 degrees C. High concentrations of reduced sulfur species can occur in the porewater of sediments and in anoxic subregions of estuaries. The dominanttransformation product from the reaction of naled with reduced sulfur species is dichlorvos, which indicates that debromination is the major reaction pathway. Dichlorvos is also a registered insecticide which is more toxic than naled. The second-order rate constants for reaction of naled with bisulfide and thiophenolate at 5 degrees C are 10.2 +/- 0.4 M(-1) s(-1) and 27.3 +/- 0.9 M(-1) s(-1), respectively, while the second-order rate constant for the reaction of naled with hydrogen sulfide and thiophenol are not significantly different from zero. The second-order rate constant of the reaction of naled with thiosulfate at 5 degrees C is 5.0 +/- 0.3 M(-1) s(-1). In contrast, the second-order rate constant of the reaction of dichlorvos with bisulfide at 25 degrees C is (3.3 +/- 0.1) x 10(-3) M(-1) s(-1). The activation parameters of the reaction of naled with bisulfide were also determined from the measured second-order rate constants over a temperature range. The results indicate that reduced sulfur species can play a very important role in the transformation of naled and dichlorvos in the coastal marine environment. It can be expected that in the presence of reduced sulfur species, naled is almost immediately transformed into the more toxic dichlorvos, which has an expected half-life of 4 days to weeks.     

无机水合氧化物对磷酸根的吸附行为

制备出一种新型的无机水合氧化物吸附剂,并用该氧化物对磷酸根水溶液进行吸附试验.实验分析了pH值、吸附温度和吸附时间对吸附容量的影响,同时也讨论了吸附过程相关的动力学、热力学和扩散速率.结果表明:该吸附过程为吸热吸附,它主要是以离子交换形式进行的.高温吸附与Langmuir等温吸附方程的拟合要优于低温吸附,高温下的吸附速率为一级动力学而低温吸附更趋于抛物扩散方程.     

反应温度和时间对抗坏血酸/精氨酸Maillard反应体系中挥发性化合物形成的影响

采用顶空固相微萃取-气相色谱-质谱联用技术对抗坏血酸/精氨酸反应体系在不同反应温度和时间下的产物进行鉴定,共鉴定出包括吡嗪、醛、呋喃、醇和吲哚在内的24种化合物,其中14种吡嗪化合物为主要香味化合物。考察了反应温度和时间对产物特别是对吡嗪化合物的影响。结果表明,随着反应温度的升高和反应时间的延长,吡嗪类化合物的总量均增加;其中,随反应温度的升高,相对其他吡嗪化合物2-乙基-6-甲基吡嗪、3-乙基-2,5-二甲基吡嗪的量明显增加;随反应时间的延长,2-乙基-6-甲基吡嗪的量明显增加。     

Generation of superoxide anions by a glycation reaction in conventional laboratory media

We reported that generation of superoxide anion (O(2)(-)) was detected from conventional laboratory media. The generated O(2)(-) is non-enzymatic converted to hydroxyl radicals, which cause damage to lipids, proteins, and nucleic acids. However, the O(2)(-) generating mechanism from culture media is unclear. We considered that the O(2)(-) generation was implicated in a glycation reaction between reducing sugar and proteins, which is the early stage of Maillard reaction. It has been suggested that the glycated proteins, such as Schiff base and Amadori compounds, undergo a spontaneous autoxidation reaction, catalyzed by transition metal ions, involving the O(2)(-) generation. Therefore, we investigated the effect of Chelex 100 on the O(2)(-) generation from brain-heart-infusion (BHI) medium, which is a nutritional culture medium for bacteria. However, the O(2)(-) generation from the BHI medium treated with Chelex 100 was significantly increased in comparison to it treated without Chelex 100. The quantity of O(2)(-) generation from BHI medium was significantly increased by addition of glucose, and in alkaline environment as well as a glycation reaction model system that autoclaved a mixture solution of glucose and tryptophan. In addition, the O(2)(-) generation from BHI medium was significantly inhibited by pyridoxamine that is a Maillard reaction inhibitor. Therefore, it was suggested that the O(2)(-) generation from BHI medium is closely related to the glycation reaction of amide compounds such as proteins containing in the medium without the transition metals.     

无机水合氧化物对磷酸根的吸附行为

制备出一种新型的无机水合氧化物吸附荆，并用该氧化物对磷酸根水溶液进行吸附试验。实验分析了pH值、吸附温度和吸附时间对吸附容量的影响，同时也讨论了吸附过程相关的动力学、热力学和扩散速率。结果表明：该吸附过程为吸热吸附，它主要是以离子交换形式进行的。高温吸附与Langmuir等温吸附方程的拟合要优于低温吸附，高温下的吸附速率为一级动力学而低温吸附更趋于抛物扩散方程。     

液相化学发光法测定粮食中的微量铜

以碘-鲁米诺化学发光反应作指示反应,利用Cu(Ⅱ)对Cr(Ⅵ)-KI反应的抑制作用,建立了化学发光法测定微量铜的新方法。方法灵敏度高,线性范围宽,仪器设备简单,操作方便。用于粮食中微量铜的测定,结果满意。     

植物油热聚合反应动力学研究

以大豆油为原料,通过作图法和稳态近似法确定了油脂的热聚合反应级数、速率常数及动力学方程,结果显示,亚油酸酯异构化反应为一级反应,动力学方程为：c18：2/18：0=11.46e^-0.0137t;大豆油热聚合反应为一级连串反应,动力学方程为：cC=11.46（1-e^-0.0137t）,反应的速率常数为：：k=0.0137.     

对羟基苯甲酸丁酯合成方法的改进

以磷钨酸为催化剂，用丁醇作共沸脱水剂，由对羟基苯甲酸和正丁醇合成对羟基苯甲酸丁酯。讨论了该催化酯化反应的各种影响因素，找出了最佳工艺条件，本工艺特点是反应时间短（３．５ｈ）脂收率高（大于９２．７％）产品质量好，无需后处理。     

Atmospheric chemistry of hydrazoic acid (HN3): UV absorption spectrum, HO reaction rate, and reactions of the N3 radical

Processes related to the tropospheric lifetime and fate of hydrazoic acid, HN3, have been studied. The ultraviolet absorption spectrum of HN3 is shown to possess a maximum near 262 nm with a tail extending to at least 360 nm. The photolysis quantum yield for HN3 is shown to be approximately 1 at 351 nm. Using the measured spectrum and assuming unity quantum yield throughout the actinic region, a diurnally averaged photolysis lifetime near the earth's surface of 2-3 days is estimated. Using a relative rate method, the rate coefficient for reaction of HO with HN3 was found to be (3.9 +/-0.8) x 10(-12) cm3 molecule(-1) s(-1), substantially larger than the only previous measurement. The atmospheric HN3 lifetime with respect to HO oxidation is thus about 2-3 days, assuming a diurnally averaged [HO] of 10(6) molecule cm(-3). Reactions of N3, the product of the reaction of HO with HN3, were studied in an environmental chamber using an FTIR spectrometer for end-product analysis. The N3 radical reacts efficiently with NO, producing N2O with 100% yield. Reaction of N3 with NO2 appears to generate both NO and N2O, although the rate coefficient for this reaction is slower than that for reaction with NO. No evidence for reaction of N3 with CO was observed, in contrast to previous literature data. Reaction of N3 with O2 was found to be extremely slow, k < 6 x 10(-20) cm3 molecule(-1) s(-1), although this upper limit does not necessarily rule out its occurrence in the atmosphere. Finally, the rate coefficient for reaction of Cl with HN3 was measured using a relative rate method, k = (1.0+/-0.2) x 10(-12) cm3 molecule(-1) s(-1).     

Role of diffusion in chemical oxidation of PCE in a dual permeability system

The effect of in situ chemical oxidation (ISCO) with permanganate (MnO4-) on tetrachloroethene (PCE) in a dual permeability system consisting of low permeability clay with high permeability sand lenses was investigated by two-dimensional laboratory experiments. The experiments imitate a field remediation at a former dry cleaning facility in Denmark. Results from laboratory experiments and field observations both show that after an application of MnO4- in the sand layer, the diffusion rate into the matrix is decreased due to reaction with PCE and the natural oxidant demand (NOD) related to the clayey till. A narrow but very efficient reaction zone is created in the clayey till. Initiallythe zone developed rapidlyfollowed by a slower expansion with time. PCE will counter diffuse into the reaction zone, where it will be degraded as long as MnO4- is present. A mass balance for the laboratory experiment revealed that the reaction between MnO4- and the clayey till was responsible for up to 90% of the total MnO4- consumption. Based on laboratory experiments, the high MnO4- consumption from reaction with clayey till appears to have been the limiting factor for the oxidation of PCE at the field site and is thus impairing the efficiency of ISCO as a remedy.