非对称富马酸酯类的合成及对西式火腿肠保鲜效果的研究

以马来酸酐为原料先进行CnH2n＋1OH（n＝2-9）醇解合成马来酸单酯，然后催化转型生成富马酸单酯，再与甲酸酯化合成了一系列非对称富马酸酯类，产率85％以上。抗菌试验表明，非对称富马酸酯类可使微生物的生长适应期（to）延长2-8倍，半对数生长期（t0.5）缩短1／3－2／3，相对生长量降低75％以上，生长势外（t0.5／t0）为对照的1／28－1／6，并可显著地诱导和促进微生物菌群的自溶作用。     

富马酸二酯类的合成及抗菌效果研究

以马来酸酐为原料先进行ＣｎＨ２ｎ＋１ＯＨ（ｎ＝２～９）醇解合成马来酸单酯，然后催化转型生成富马酸单酯，再与甲醇化合成一系列非对称富马酸酯类，产率８５％以上。抗菌效果试验结果表明，非对称富马酸酯类可使微生物的生长适应期（ｔ０）延长２～８倍，半对数生长期（ｔ０．５）缩短１／３～２／３，相对生长量降低７５％以上，生长势（ｔ０．５／ｔ０）仅为对照为１／２８～１／６并可显著了诱导和促进微生物菌群的自溶作用。     

非对称富马酸二酯类的合成及对细菌的抗菌特性研究

以马来酸酐为原料先进行ＣｎＨ２ｎ＋１ＯＨ（ｎ＝２～９）醇解合成马来酸单酯，然后催化转型生成富马酸单酯，再与甲醇酯化合成了一系列非对称富马酸酯类，产率８５％以上，抗菌效果试验结果表明，非对称富马酸酯类可使微生物的生长适应期（ｔ０）延长２～８倍，半对数生长期（ｔ０．５）缩短１／３～２／３相对生长量降低７５％以上，生长势（ｔ０．５／ｔ０）仅为对照的１／２８～１／６，并可显著地诱导和促进微生物菌群的自溶作     

高效防霉剂富马酸单甲酯的合成与抑菌活性研究

以TiSiW12O40/TiO2为催化剂，用富马酸与甲醇直接酯化合成了防霉剂富马酸单甲酯（MMF），通过正交试验确定了醇酸物质的量比、催化剂用量、反应温度和反应时间对反应产率的影响。得到最佳工艺条件为：n（富马酸）：n（甲醇）=1、0：1、0，催化剂用量为w（TiSiW12O40/TiO2）=2％（占富马酸的质量分数），反应温度为60℃，反应时间为3h，MMF的产率可达91．6％。抑菌活性试验和防腐保鲜试验结果表明，MMF对多种霉菌具有良好的抑制作用，尤其对黄曲霉菌、黑根霉菌和棒柬青霉菌的抑制作用更好，MMF的防霉和防腐保鲜效果优于DMF、丙酸钙。     

微波辅助萃取-气相色谱法测定茶叶中多种有机氯和拟除虫菊酯农药残留

建立了茶叶中18种有机氯和9种拟除虫菊酯农药残留微波辅助萃取．气相色谱分析方法。运用正交设计法对微波萃取条件进行了优化,茶叶样品用正己烷-二氯甲烷混合溶N（1：2,V／V）进行萃取,萃取液用弗罗里硅土和中性氧化铝混合层析柱净化,采用J＆WDB-1701毛细管柱分离,GC．ECD法同时测定。在0．4、0．2、0．1ml（0．5μg／m1有机氯农药＋1．0μg／ml拟除虫菊酯农药）三个水平添加时的平均回收率（n=5）分别为80．9％～118．5％、88．4％～120．7％、80．9％～116．3％;相对标准偏差分别为2．09％～6．70％、1．89％～6．49％、1．98％～11．87％。该方法的检出限为：有机氯农药0．0004～0．0048mg／kg,拟除虫菊酯农药0．0033～0．0400mg／kg。     

微波辐射下合成香料水杨酸苄酯的研究

在微波辐射下，以水杨酸和氯化苄为原料，NaHCO3作碱剂，四丁基氯化氨（TBAC）为相转移催化剂，碘化钾为催化剂合成了水杨酸苄酯。研究了水杨酸、NaHCO3、氯化苄和TBAC的摩尔比，碱浓度、微波功率、辐射时间等对产物收率的影响。实验结果表明：n（水杨酸）：n（NaHC03）：n（氯化苄）：n（TBAC）：n（KI）=1：1．2：1．0：0．05：0．06，碱浓度为20％，微波功率为320W，辐射时间为4min，水杨酸苄酯的收率可达83．6％。     

甘油单月桂酸酯的制备和应用

前言甘油单月挂酸酯是美国FDA批准公认的安全食品添加剂。LDs。＞259／kg添加量一般为0．1～0．2％，适用于面包和焙烤食品，干酪制品，人造奶油，乳制品，鱼糜，香肠和果蔬等。甘油单月桂酸酯，（GlycerylMonoLaurate，简称GML），是一种亲酯性非离子型表面活性剂，具有防腐和乳化功能．作为防腐用的GML单酯含量必须在90％以上，作为乳化用的GML单酯含量必须在70％以上。1．GML的制备称取月挂酸4009，甘油1849放入IL三口圆底烧瓶中，在CO。气流下加热sh，稍冷却后过滤，分出未起反应的甘油层，得到粗品，用适量的有机溶剂进行结…     

ASE—GC—MS／MS快速测定纺织品中8种磷酸酯类增塑剂

为了建立了一种快速提取和测定纺织品中8种磷酸酯类增塑剂[磷酸三苯酯（TPP）、磷酸邻三甲苯酯（ToCP）、磷酸间三甲苯酯（TmCP）、磷酸对三甲苯酯（TpCP）、磷酸三丁酯（TBP）、磷酸三辛酯（TOP）、磷酸二苯辛酯（DP（）P）和磷酸甲苯二苯酯（CDP）]的分析方法,采用加速溶剂萃取结合气相色谱-串联质谱（GC—MS／MS）技术,样品经乙酸乙酯提取,采用TG-5MS石英毛细管柱（30m×0．25mm×0．25μm）分离,选择反应监测（SRM）模式测定,外标法定量。试验结果表明,在0．01～1．0μg／mL范围内试验结果的线性关系良好（7〉O．99）,在添加浓度为0．05、2．0和5．0mg／kg水平内,平均回收率范围为（84．5±6．4）％～（106．5±1．4）％,相对标准偏差（RsD）为0．9％～8．5％,方法检出限（LOD）为0．06～0．9μg／kg,方法定量限（LoQ）为0．2～3．0μg／kg。该试验表明,该方法适合确证和定量测定纺织品中8种磷酸酯类增塑剂,而且便捷、灵敏和准确。     

富马酸单甲酯-3-没食子酸异戊酯的合成与性能研究

防腐剂富马酸单甲酯（MMF）与氯化亚砜作用,得到富马酸单甲酯单酰氯,优化条件为：n（MMF）：n（SOCl2）=1.0：4.0,反应时间为60min,富马酸单甲酯单酰氯产率96.5%;富马酸单甲酯单酰氯与抗氧化剂没食子酸异戊酯（i-AG）缩合,合成了兼具抗氧化性和防腐性能的化合物富马酸单甲酯-3-没食子酸异戊酯（MMF-3-i-AG）,优化条件为：n（富马酸单甲酯单酰氯）：n（i-AG）=1.0：1.0,吡啶作催化剂,m（吡啶）：m（i-AG）=1：1,110℃反应60 min,MMF-3-i-AG产率86.3%.用IR、1H NMR和元素分析对MMF-3-i-AG的结构进行了确认.研究了MMF-3-i-AG的抑菌活性和抗氧化性能,结果表明MMF-3-i-AG的抑菌能力与MMF相当,其抗氧化性能亦与PG相当.     

新型防腐剂富马酸淀粉甲酯的合成及抑菌活性研究

富马酸淀粉甲酯（SMF）的合成分为2步：先由富马酸单甲酯（MMF）与亚硫酰氯反应生成富马酸单甲酯单酰氯（MMFC）,MMFC再与可溶性淀粉反应可得SMF。用单因素试验法确定酯化度为12．03的SMF合成工艺为：摩尔比为3：1的亚硫酰氯和MMF在100℃下回流45rain,得无色MMFC液体,收率可达92％以上。摩尔比为40：1的MMFC与可溶性淀粉在25℃反应16h,再分别经40％乙醇溶液和10％KHCO,溶液洗涤至pH=7,所得白色固体即为富马酸淀粉甲酯,其抗菌活性与富马酸单甲酯相当。     

生物炭对土壤碳组分及烟草生长发育的影响

为探索生物炭对植烟土壤改良和烟草生长发育的影响效果,采用大田试验设置5个处理[T0(对照)：0 t/hm²生物炭+0.64 t/hm²氮肥;T1:0.5 t/hm²生物炭+0.64 t/hm²氮肥;T2:1 t/hm²生物炭+0.64 t/hm²氮肥;T3:1.5 t/hm²生物炭+0.64 t/hm²氮肥;T4:2 t/hm²生物炭+0.64 t/hm²氮肥],分析了生物炭对植烟土壤碳排放、有机碳组分以及烟草生理指标的影响。结果表明：(1)与T0相比,中低用量(0.5～1.5 t/hm²)的生物炭处理可降低土壤CO2排放总量;其中T1、T2和T3处理较T0分别降低28.14%、25.25%和8.41%;而高用量(2 t/hm²)生物炭处理则促进了土壤碳排放,T4处理较T0提高8.79%。(2)生物炭处理可提高土壤总有机碳、微...     

Reduction of aqueous chromate by Fe(II)/Fe(III) carbonate green rust: kinetic and mechanistic studies

This work describes the heterogeneous reaction between FeII in carbonate green rust and aqueous chromate, in NaHCO3 solutions at 25 degrees C, and at pH values of 9.3-9.6. Evidence for reduction of CrVI to CrIII and concomitant solid-state oxidation of lattice FeII to FeIII was found from FeII titration and from structural analysis of the solids using FTIR, XRD, SEM, and XPS methods. Results indicate the formation of ferric oxyhydroxycarbonate and the concomitant precipitation of CrIII monolayers at the surface of the iron compound that induce passivation effects and progressive rate limitations. The number of CrIII monolayers formed at the completion of the reaction depends on [FeII]t=0, the molar concentration of FeII(solid) at t=0; on [n(o)]t=0, the molar concentration of reaction sites present at the surface of the solid phase at t=0; and on [CrVI]t=0, the molar concentration of CrVI at t=0. Kinetic data were modeled using a model based on the formation of successive CrIII monolayers, -(d[CrVI]/dt) = sigma(1)j k(i)[S] [CrVI]([n(i - 1)] - [n(i)]) with k(i)[S] (in s(-1) L mol(-1)), the rate coefficient of formation of CrIII monolayer i, and [n(i)] and [n(i - 1)], the molar concentration of CrIII precipitated in monolayer i and monolayer i - 1, respectively. Good matching curves were obtained with kinetic coefficients: k(1)[S] = 5-8 x 10(-4), k(2)[S] = 0.5-3 x 10(-5), and k(3)[S] about 1.7 x 10(-6) s(-1) m(-2) L. The CrVI removal efficiency progressively decreases along with the accumulation of CrIII monolayers at the surface of carbonate green rust particles. In the case of thick green rust particles resulting from the corrosion of iron in permeable reactive barriers, the quantity of FeII readily accessible for efficient CrVI removal should be rather low.     

乳化剂替代部分油脂对黄鸡生产性能、屠宰性能及血清相关指标的影响

将288只黄鸡随机分为3个组,分别饲喂3种日粮:基础日粮、"基础日粮+乳化剂(0.5 kg/t)-0.5%油脂+0.45%玉米"和"基础日粮+乳化剂(1 kg/t)-1%油脂+0.9%玉米",研究添加不同水平乳化剂替代油脂对黄鸡生产性能、免疫器官指数、屠宰性能及血清相关指标的影响。结果表明:添加乳化剂同时减少油脂不影响黄鸡的生产性能,经济效益有所改善。对器官指数和屠宰性能无明显影响,改善了部分胴体指标;极显著降低了肝脏中甘油三酯的含量。     

嗜热链球菌与保加利亚乳杆菌麦芽复合汁增菌培养基的优化筛选

研究了在麦芽汁中添加不同的营养因子对嗜热链球菌S.t-3的细胞生长量的影响,进一步采用正交试验优化筛选出S.t-3的麦芽复合汁增菌培养基,并对保加利亚乳杆菌L.b-DR和L.b-S1进行了验证性增菌试验。结果表明,S.t-3、L.b-DR和L.b-S1在麦芽汁中能进行正常的产酸代谢,大豆蛋白胨、牛肉膏、酵母膏可显著促进S.t-3的细胞生长(P<0.05);K2HPO4不仅可以促进菌体增殖,而且还可缓冲基质pH值的变化,避免了低pH值对乳酸菌的伤害;利用L9(33)正交试验,筛选出S.t-3的麦芽复合汁增菌培养基最佳配比为:在10%的麦芽汁中添加0.5%大豆蛋白胨、0.5%酵母膏、1%牛肉膏、0.2%K2HPO4;在麦芽复合汁增菌培养基中,S.t-3、L.b-DR和L.b-S1,37℃恒温培养16 h,活菌数分别为2.42×109cfu/mL、2.85×109cfu/mL和4.81×109cfu/mL,与液体MRS培养基的活菌数相当,成本较MRS培养基降低1 000元人民币/t。     

Reactive dicarbonyl compounds and 5-(hydroxymethyl)-2-furfural in carbonated beverages containing high fructose corn syrup

α-Dicarbonyl compounds, namely glyoxal (GO), methylglyoxal (MGO) and 3-deoxyglucosone (3-DOG), as well as 5-(hydroxymethyl)-2-furfural (5-HMF) were found and measured in carbonated soft drinks (CSD). It was realized that high fructose corn syrup (HFCS) in regular CSDs was the major source of α-dicarbonyl compounds in beverages after comparison of levels in regular and diet CSDs. In two most commonly used HFCS formulas, 42% and 55% HFCS, the highest level of dicarbonyl found was 3-DOG, followed by MGO, and then GO. The stability of dicarbonyls in CSDs containing HFCS and (−)-epigallocatechin gallate (EGCG) which were incubated at 35 and 45 °C was investigated. It was found that EGCG decreased from 1 mg/mL to 0.5 and 0.3 mg/mL for 35 and 45 °C, respectively, in 16 days storage. Moreover, the reactions of EGCG with MGO, 3-DOG and 5-HMF were observed from the comparison of storage CSDs with and without EGCG under acidic conditions.     

Effect of vitamin E supplementation on fatty acid composition of muscle and adipose tissues of indoor lambs with special attention on rumen-derived trans monounsaturated fatty acids

Thirty male lambs were assigned to one of 3 concentrate diets supplemented with 45 (E0), 286 (E1) or 551 (E2) mg/kg DM of dl-α-tocopheryl acetate to test the effect of vitamin E supplementation on muscle, caudal and perirenal fatty acid (FA) compositions. Specific attention was paid to C18:1 10t, usually observed in high proportions with high-starch or high-unsaturated FA diets. Vitamin E supplementation increased the α-tocopherol plasma concentrations of lambs. It did not modify lamb growth and slaughter parameters. Vitamin E supplementation did not modify FA composition in most tissues but it increased the C18:2 n − 6/C18:3 n − 3 ratio in muscle and adipose tissues of the E1 group compared to E0 and E2 groups. Vitamin E supplementation enhanced the C18:1 10t proportion in muscle and adipose tissues and it decreased the C18:2 9c,11t proportion in adipose tissues, especially in the E2 group. These changes may not be favourable for the nutritional value of lamb meat.     

三聚氰胺对嗜热链球菌生长影响的研究

通过在MRS液体培养基里分别添加0‰、0.25‰、0.5‰、1‰、2‰、3‰及饱和的三聚氰胺,接种嗜热链球菌,在42℃下培养48h,通过测定培养液的pH变化和计数细菌总数来考察三聚氰胺对嗜热链球菌生长的影响。结果表明:嗜热链球菌不能以三聚氰胺为氮源物质而加以降解利用,三聚氰胺在水溶解度范围内对嗜热链球菌的生长没有促进作用,只有微弱的抑制效果。     

Effect of aeration and agitation on growth rate of Thermus thermophilus in batch mode

The growth kinetics of Thermus thermophilus HB27 was investigated in rich medium (Thermus medium) under batch cultivation at 65 degrees C in 3-l fermentors. The growth and oxygen consumption rates were highly dependent on the aeration and agitation rates. Volumetric mass transfer coefficient (K(L)a, h(-1)) and hence oxygen transfer rate (OTR, mol m (-3) h(-1)) into the fermentation broth increased with increased aeration and/or agitation rates. A K(L)a and OTR of 175.4 h(-1) and 31.7 mol m(-3)h(-1) respectively, corresponding to 500 rpm agitation and 2 vvm aeration with a mixture of air and oxygen, were required to avoid oxygen limitation. The maximum growth rate (mu(max), h(-1)), doubling time (t(D), h), and dry cell weight determined for T. thermophilus HB27 growing under these conditions were 0.27 h(-1), 2.67 h, and 3g/l respectively. This cell yield is higher than any previously published reports for growth of Thermus cultures, including studies that employed pressurized bioreactors.