硬脂酸涂覆碳酸钙填充聚丙烯的性能研究

采用廉价的硬脂酸为偶联剂，对碳酸钙进行涂覆后填充聚丙烯（ＰＰ），研究其对ＰＰ加工性能和机械性能的影响．结果表明：硬脂酸是有效的偶联剂，当用质量百分比为２％的硬脂酸涂覆ＣａＣＯ３后填充ＰＰ时，能使ＰＰ的综合性能有较大的改善；当涂覆ＣａＣＯ３的填充量为４０％（质量百分比）时，填充体系的抗冲性能为纯ＰＰ的２倍以上，而对ＰＰ本身固有的优良的抗拉伸性能影响不大，并能增加其熔体流动速率，改善加工性能．     

烟草感染赤星病后有关酶动态的研究

本文研究１１个烟草品种感染赤星病后过氧化物酶（ＰＯＤ）同工酶、多酚氧化酶（ＰＰＯ）、硝酸还原酶（ＮＲ）和抗坏血酸氧化酶（ＡＡＯ）活性的变化规律。结果表明：抗赤星病强的品种，ＰＰＯ在接种３６ｈ内活性升高，以后下降；ＰＯＤ同工酶活性变幅大而快，接种初期活性稍有下降，然后增强，其中以阴极端２、４同工酶带增加较快，接种１８０ｈ后就由弱酶带变为强带；ＮＲ活性变化不大；ＡＡＯ活性提高。抗赤星病弱的品种，ＰＰＯ活性低于对照；ＰＯＤ同工酶变化不大，呈下降趋势；ＮＲ活性变幅大；抗坏血酸氧化酶在接种初期活性下降，８４ｈ后回升。     

聚邻苯二胺固定葡萄糖氧化酶在微带金电极上的性质

用电化学方法在纳米级微带金电极上聚合邻苯二胺（ＰＰＤ）的同时实现了葡萄糖氧化酶（ＧＯＤ）的固定。制得的ＧＯＤ－ＰＰＤ－Ａｕ酶电极呈现典型的酶催化反应动力学特征，具有抗干扰、响应速度快、稳定性好的优点，固定化葡萄糖氧化酶的表观米氏常数为５．４ｍｍｏｌ／Ｌ．     

培养基组成对Y—216菌株超氧化物歧化酶生产的影响

超氧化物歧化酶（ＳＯＤ）是一类具有重要保健价值的生物酶，但目前对微生物ＳＯＤ的研究主要集中于ＳＯＤ的提纯和菌种选育方面，而对其发酵生理学的研究还缺少报道．鉴于此，对一株ＳＯＤ高产菌株Ｙ－１２６形成ＳＯＤ的最适培养基组成进行了研究，实验结果表明：适宜于该菌ＳＯＤ形成的最适碳源为蔗糖，最适氮源为蛋白胨，最适碳氮比为１∶１（重量比），添加Ｆｅ３＋（５００μｍｏｌ／Ｌ）可明显促进菌株生长和提高其ＳＯＤ的含量．在初步优化的营养条件下，ＳＯＤ生产量可达到２．１９×１０４Ｕ／Ｌ，具有实际应用前景．     

桃褐变调控方法的研究

本文对控制多酚氧化酶（ＰＰＯ）活力的方法进行了探索，证明利用三因子二次回归组合设计所得到的回归方程能准确反映因子与指标之间的关系，并能预示因子（氯化钠、柠檬酸、抗环血酸）用量的多少对指标（ＰＰＯ活力）影响的程度与趋势。在各因子对指标的重要性及交互效应的分析方面，也提供了完整、准确、严谨的分析方法。     

葡萄叶片中单宁,木质素,PPO活性与抗黑痘病的关系

本研究以野生种葡萄（华东葡萄、掌裂草葡萄，秋葡萄）、栽培葡萄（红富士）的健全和病叶为试材，调查了４个种或品种的病情指数，测定了单宁与木质的含量和ＰＰＯ活性，结果表明，野生种葡萄经载培葡萄抗病；单宁和木素含量、ＰＰＯ活性与葡萄的抗黑痘病能力呈正相关。这些酚类物质在葡萄抗病研究中具有重要意义，可作为葡萄抗病性鉴定的指标。     

鲜切莲藕酶促褐变底物的分析确定

鲜切莲藕贮藏期间的酶促褐变及其褐变底物的研究结果表明：切分后莲藕组织中新合成的及与多酚氧化酶（ＰＰＯ）作用的酚主要为ＦＰ，鲜切莲藕贮藏６ｄ后游离酚（ＦＰ）与褐变度（ＢＤ）两者的变化呈显著的负相关（ｒ＝０．９５９），组织中ＰＰＯ活性与ＦＰ、儿茶酚表现为同步的先升后降的变化规律，采用薄层层析和高压液相色谱确定儿茶酚在鲜切莲藕褐变前后发生明显量的变化，由儿茶酚与ＰＰＯ作用后产物的紫外吸收光谱与鲜切莲藕自然褐变产物基本相同的结果，初步认为儿茶酚是鲜切莲藕的主要褐变底物。     

注射成型微泡PP/CaCO3复合体系研究

研究了采用化学发泡法进行微发泡的ＰＰ／ＣａＣＯ３复合体系的注射成型工艺,复合体系中ＣａＣＯ３填充量可达８０份,当发泡剂用量为０．６份～１．０份,交联剂用量为０．１份～０．３份,成核剂适量时,所得ＰＰ／ＣａＣＯ３复合材料的综合性能优良,比ＰＰ降低成本约为３０％。     

张裕为什么选择博德乐——对进口灌装设备的先进性和技术含量的评论

张裕为什么选择博德乐——对进口灌装设备的先进性和技术含量的评论郭松泉１９９６年１１月９日星期六，一个阳光明媚的日子，在山东烟台的葡萄酒博物馆，举行了中国张裕公司和意大利博德乐集团（ＧＲＵＰＰＯＢＥＲＴＯＬＡＳＯＳｐＡ）的１２０００瓶／小时灌装线的签约...     

草莓褐变过程中主要氧化酶的活性变化

室温下草莓酚类物质逐渐减少，总的多酚氧化酶和游离多酚氧化酶活性则持续升高，ＳＯＤ活性先降后升，ＰＰＯＤ活性先升后降，丙二醛含量呈上升趋势。低温处理可抑制多酚氧化酶活性的增加，使酚类物质保质较高水平。ＳＯＤ、ＰＯＤ活性高于室温处理，丙二醛含量增加受阻。表明低温通过调节氧化酶活性而抑制褐变过程。     

山药中多酚氧化酶的活性测定及其护色研究

研究了山药中多酚氧化酶(PPO)的最适pH值、最适温度,设计了不同护色方案,以确立山药的最佳护色条件。采用分光光度法研究pH值、温度对酶活性的影响;比较不同护色液对酶活力的影响;将山药经不同护色条件护色后,低温烘干,粉碎过筛得山药粉,用分光光度法测定其甲醇-水溶液(1∶1)的吸光度。结果表明,以邻苯二酚为底物,山药PPO的最适pH值为5.6,最适温度为35℃,山药的最佳护色条件为:以0.25%的Na2SO3为抗氧化剂,并配以0.25%的柠檬酸和1.5%的NaCl为护色液。     

宣木瓜多酚氧化酶酶学特性与抑制剂研究

研究宣木瓜不同部位的多酚氧化酶(PPO)的活性及其温度、pH值、底物专一性等特性和抑制方法。结果表明：果心中的PPO活性明显高于果皮和果肉,宣木瓜组织的褐变主要是由多酚氧化酶引起;PPO最适底物为邻苯二酚;最适温度20℃,在80℃处理5min即可钝化PPO的活性;最适pH5.5,在酸性条件下稳定性优于碱性;抗坏血酸、L-半胱氨酸、亚硫酸氢钠、柠檬酸和氯化钠均能有效的抑制PPO的活性。     

Color and Bind Strength of Restructured Pork Chops: Effect of Calcium Carbonate and Sodium Alginate Concentration

The effects of calcium carbonate concentration (0.00-0.26%) and sodium alginate concentration (0.0-1.4%) on the amount of discoloration and the raw- and cooked bind-strength of restructured pork chops were investigated. Alginate slightly increased and calcium carbonate decreased the amount of discoloration in the restructured chops. The beneficial effect calcium carbonate had on discoloration did not appear to be due to increased pH. Restructured chops prepared with alginate were more discolored (P<0.05) than restructured chops prepared with salt and phosphate. The optimum concentration of calcium carbonate and alginate required for minimum discoloration and maximum raw-and cooked bind-strength was 0.13% and 0.7%, respectively.     

Color and Color Stability of Frozen Restructured Beef Steaks: Effect of Sodium Chloride, Tripolyphosphate, Nitrogen Atmosphere, and Processing Procedures

This study investigated the effect of mixing and grinding, tempering, addition of sodium chloride and sodium tripolyphosphate and processing under a nitrogen atmosphere on the color of restructured beef steaks initially and at 1-month intervals for 3 months of frozen storage. Mixing and grinding and manufacture under a nitrogen atmosphere had the greatest detrimental effect on the extent of discoloration initially; this was probably due to low oxygen concentration. Tempering and the addition of sodium chloride without sodium tripolyphosphate produced the most rapid increase in rate of discoloration during frozen storage. Tripolyphosphate partially counteracted the detrimental effect of sodium chloride, however, this effect did not appear to be due to the higher pH produced by the phosphate or the chelating ability of the phosphate. Surface discoloration and overall color were highly correlated with surface metmyoglobin (r= -0.87) and overall met-myoglobin (r= -0.94).     

氯化钙处理对鲜切莴苣品质及γ-氨基丁酸代谢的影响

目的：探究氯化钙处理对鲜切莴苣贮藏期间品质及γ-氨基丁酸（γ-aminobutyric acid,GABA）代谢的影响。方法：鲜切莴苣丝分别用蒸馏水及质量分数0.5%、1.0%、1.5%、2.0%的氯化钙溶液处理10 min,置于10 ℃贮藏48 h,测定品质指标及GABA含量变化,以筛选最佳氯化钙处理条件,并在此基础上进一步探究钙调控GABA合成的机制。结果：氯化钙处理能明显延缓质量损失率、菌落总数、褐变指数的上升,抑制抗坏血酸、叶绿素含量的下降,促进GABA合成,其中质量分数1.0%氯化钙溶液处理能最有效地延缓鲜切莴苣品质的下降,且能诱导GABA的合成;进一步研究表明,氯化钙处理可以提高谷氨酸脱羧酶、二胺氧化酶、多胺氧化酶、4-氨基丁醛脱氢酶的活力,促进谷氨酸及多胺的分解,从而促进GABA生成。结论：氯化钙处理不仅可以明显维持鲜切莴苣贮藏期间的品质,还可以促进GABA的合成,提高营养价值。     

The effect of calcium carbonate and sodium alginate on the color and bind strength of restructured beef steaks

This study investigated the effect of calcium carbonate concentration (0·00-0·26%) and sodium alginate concentration (0·0-1·4%) on the amount of discoloration and the raw and cooked bind-strength of restructured beef steaks. Alginate slightly increased and calcium carbonate markedly decreased the amount of discoloration in the restructured steaks. The protective effect of the calcium carbonate did not increase with increasing concentration and did not appear to be due to increased pH. The amount of discoloration in restructured steaks prepared with alginate was similar to that in conventionally prepared restructured steaks. The optimum concentration of calcium carbonate and alginate required for minimum discoloration and maximum raw and cooked bind-strength was 0·13% and 0·7%, respectively.     

EFFECT OF PACKAGING MATERIAL ON THE QUALITY OF POTATOES TREATED WITH ISOPROPYL N-(3-CHLOROPHENYL) CARBAMATE (CIPC)

Katahdin and Russet Burbank potatoes, treated with isopropyl N-3(-chlorophenl) carbamate CIPC and stored for four months at 5C in either mesh or polyethylene bags (two packaging materials frequently used for potato storage), were tested for enzymatic discoloration, phenolic and ascorbic acid concentration. CIPC residues in tubers stored in polyethylene bags were significantly (p < 0.0l) higher than those stored in mesh bags. Tubers stored in polyethylene showed significantly (p<0.05) higher discoloration and phenolic concentration, and lower ascorbic acid concentration than those stored in mesh bags. Differences in CIPC retention of the tubers stored in the two packaging materials may have been responsible for some of the differences in quality factors since CIPC was shown to significantly (p<0.0l) increase the enzymatic discoloration and phenolic concentration, and decrease the ascorbic acid concentration of both cultivars.     

稻壳制备活性炭研究

该文比较磷酸法和氯化锌法对稻壳活化效果,研究氯化锌法对稻壳和脱硅稻壳活化工艺,探讨料液比、活化液浓度、活化温度和活化时间对活化效果影响。结果表明,氯化锌法对稻壳活化效果要优于磷酸法,稻壳和脱硅稻壳采用氯化锌法活化最优条件相同:料液比1∶2.5,活化液浓度60％,活化时间60 min,活化温度600℃,产品各项吸附性能指标均能符合国家要求。     

Hurdle technology for minimally processed radishes: a response surface methodology approach

Response surface methodology was used to determine the optimum processing conditions that yielded maximum vitamin C content, minimum discoloration and minimum polyphenoloxidase activity after 4 days of refrigerated storage of minimally processed radishes. Ascorbic acid (0–2 %), sodium chloride (0–1 %) and immersion time (0–2 min) at 50 °C were the factors investigated related to polyphenoloxidase activity (PPO), vitamin C (VITC) and total color difference (ΔE). Experiments were conducted according to a Box-Behnken Design with three factors at three different levels. For each response, second order polynomial models were developed using multiple linear regression analysis. Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The response surfaces showing the interaction of process variables were constructed and analyzed. Based on desirability function, optimum operating conditions were found to be 2 % of ascorbic acid, 0 % of NaCl and 1.5 min of immersion time at 50 °C. At this optimum point, relative PPO activity, relative VITC content and ΔE values were 0.218, 3.227 and 4.929, respectively.     

佛手瓜多酚氧化酶酶学特性研究

以佛手瓜中的多酚氧化酶为研究对象,对其酶学特性的研究表明：佛手瓜果实多酚氧化酶的最适pH 值为7.5,最适温度为30℃,底物浓度与酶活性呈正相关;该酶迅速催化焦性没食子酸的酶促氧化反应,但对邻苯二酚、对苯二酚和间苯二酚的催化活性较低。抗坏血酸、柠檬酸、四硼酸钠、MgCl2 和EDTA-2Na 对佛手瓜多酚氧化酶的抑制作用依次减弱,抗坏血酸、柠檬酸对佛手瓜多酚氧化酶的抑制作用随着浓度的升高而加强。