淀粉羧甲基化影响因素的研究

本文以羧甲基淀粉（ＣＭＳ）的取代度（ＤＳ）为目标，采用最优试验设计－二次旋转正交回归设计，建立了制备ＣＭＳ关于ＮａＯＨ用量、反应温度、ＣｌＣＨ２ＣＯＯＮａ用量因素的非线性回归模型。并以模型为基础，对三个因素在制备ＣＭＳ时的贡献情况、各因素以及各因素间交互作用进行了研究。     

四川名茶矿质元素含量研究

分析了四川名茶矿质元素含量及特点。在所分析的１８种元素中，四川名茶Ｋ，Ｐ，Ｓ，Ｃａ，Ｍｇ元素含量较高（＞１５００ １０＾－６），Ｂａ，Ｃｒ，Ｖ，Ｃｏ，Ｓｅ含量较低（＜１０ １０＾－６）；与普通绿茶相比，四川名茶含有较高的Ｋ，Ｚｎ，Ｐ，Ｎａ，Ｎｉ，Ｃｕ，Ｓ，Ｓｅ，Ｃｏ元素，其高幅为０．３８％－１１５．６５％，而Ｍｇ，Ｍｎ，Ａｌ，Ｃａ，Ｂａ，Ｖ，Ｒｂ，Ｆｅ，Ｃｒ元素则为７．３２％－４６．６７％；红岩迎     

CMC－Na盐在食品工业中的应用

ＣＭＣ－Ｎａ盐在食品工业中的应用杨之礼，梁丽荣（广东省花都市南秀化工有限公司花都市５１０８００）ＣＭＣ－Ｎａ盐（以下简称ＣＭＣ），产品主要应用于食品、冶金、陶瓷、造纸等行业，近年来，ＣＭＣ在我国食品工业中的应用尤为广泛。一、ＣＭＣ产品一般介绍ＣＭＣ是...     

NaCl对足球菌ISK—1的发酵产物足球菌素ISK—1活性的影响

研究了足球菌ＩＳＫ－１发酵中ＮａＣｌ对足球菌素ＩＳＫ－１活性的影响。在ＭＲＳ培养基中添加８％的ＮａＣｌ，发酵２１￣２４ｈ，足球菌素ＩＳＫ－１活性达到最高，比无ＮａＣｌ时提高２５％。表明ＮａＣｌ具有提高足球菌素ＩＳＫ－１活性的作用。     

用水相沉淀聚合法制备高分子量PAN

以ＮａＣ１０３－Ｎａ２Ｓ２Ｏ５为氧化－还原引发剂，进行了丙烯腈（ＡＮ）与衣康酸（ＩＴＡ）等几种不同单体的水相沉淀聚合，制得高分子量的ＰＡＮ聚合体，系统地考察了引发剂浓度及配比，聚合温度，聚合时间，单体浓度以及第三单体甲基丙烯磺酸钠（ＭＡＳ）的加入等工艺条件对聚合转化率和聚合物相对分子质量的影响。     

利用多硫化钠和蒽醌对麦草进行深度脱木素的研究

对多硫化钠（ＰＳ）和蒽醌（ＡＱ）在麦草深度脱木素中的应用进行了研究。结果表明，添加２％的ＰＳ可在纸浆细浆得率提高２％的同时，使纸浆卡伯值降低１７．４％。ＮａＯＨ－ＰＳ／ＡＱ浆具有良好的可漂性。与ＮａＯＨ－ＡＱ浆相比，ＮａＯＨ－ＰＳ／ＡＱ浆在漂至相同白度时，可节约用氯量８％～１２％。除撕裂指数相近外，ＮａＯＨ－ＰＳ／ＡＱ浆具有更高的裂断长和耐折度。发现在ＮａＯＨ－ＰＳ／ＡＱ黑液中，含有相对较少的总固形物、有机物和ＣＯＤＣｒ含量。     

无水硝主成份(Na_2SO_4)快速分析方法的研究

根据复杂体系（Ｎａ２ＳＯ４ 、ＮａＣｌ、ＣａＳＯ４ 、ＭｇＳＯ４ 、水份和不溶物） 的组成情况及化学计量关系,应用方法联合自消原理,根据ＥＤＴＡ 络合滴定方法,对Ｎａ２ＳＯ４ 含量进行快速测定。该方法快速、准确、精密度高,只需约２０ 分钟便可得出Ｎａ２ＳＯ４ 含量     

电感耦合等离子体质谱法(ICP-MS)测定砂糖中31种微量元素

利用微波消化－电感耦合等离子体质谱法（ＩＣＰ－ＭＳ）同时测定了白砂糖和赤砂糖中３１种微量元素。白砂糖中检测出２３种,赤砂糖中检出２７种。结果表明,Ｃａ,Ｍｇ,Ｋ,Ｆｅ,Ｍｎ,Ｃｕ等６种元素在赤砂糖中含量比在白砂糖中含量高出４￣４００倍。Ｌｉ,Ｂａ,Ｎａ,Ｐ,Ａｌ,Ｖ,Ｃｒ,Ｎｉ,Ｚｎ,Ｇａ,Ｓｒ,Ａｇ,Ｓｎ,Ｓｈ,Ｂａ,Ｈｇ,Ｐｂ等１７种元素在白砂糖和赤砂糖中的含量无显著差别。本方法具有前处理简单     

Na2CO3—NaHCO3—Na2SO4（NaCl）—H2O体系相图在天然碱湖卤水生产小苏打工艺计

本文利用Ｎａ２ＣＯ３－ＮａＨＣＯ３－Ｎａ２ＳＯ４（ＮａＣｌ）－Ｈ２Ｏ体系相图对内蒙古合同查汉淖尔碱湖卤水碳化法生产小苏打进行了相图计算，并对计算结果进行了讨论。     

复杂体系(MgCl_2、MgSO_4、CaSO_4、NaCl和KCl)中MgCl_2含量的快速测定

根据复杂体系（ＭｇＣｌ２、ＭｇＳＯ４、ＣａＳＯ４、ＮａＣｌ和ＫＣｌ）的组成情况及化学计量关系,应用方法联合自消原理,用ＥＤＴＡ络和滴定方法,对ＭｇＣｌ２含量进行快速测定。该方法快速、准确、精密度高,只需约２０ｍｉｎ便可得出ＭｇＣｌ２含量。     

大豆分离蛋白对鲜切桃的保鲜效果

为探索鲜切桃的保鲜新方法,分别采用0（双蒸水,对照）和10、20、40 g/L的大豆分离蛋白（soy protein isolate,SPI）溶液浸泡鲜切桃后,将其在4 ℃条件下贮藏10 d,测定鲜切桃品质及褐变相关的生理生化指标。结果表明：20 g/L SPI处理的鲜切桃保鲜效果最好,能够抑制4 ℃贮藏过程中的乙烯释放率、呼吸强度和细菌生长;贮藏10 d后,与对照组相比,20 g/L SPI处理组具有较高的L*值、硬度、可溶性固形物含量,较低的质量损失率和腐烂率,且活性氧、丙二醛和总酚含量分别降低了24%、20%和17%,同时,多酚氧化酶活力降低了45.5%,过氧化物酶活力降低了22%,过氧化氢酶活力提高了44%。上述结果表明20 g/L SPI处理可以提高鲜切桃的贮藏品质及抗氧化能力、抑制褐变,从而延长贮藏期。     

Nutritional content of fresh and canned peaches

BACKGROUND: The objective of this study was to assess whether canned peaches could deliver nutrient levels comparable to fresh peaches. Fresh freestone peaches, fresh cling peaches and canned cling peaches were analyzed for vitamins A, C and E, folate, antioxidants, total phenolics and total carotenoids to assess how these nutrients were affected by the canning process and whether storage further changed these components. RESULTS: The vitamins and phytochemicals measured in this study were found to be present in canned cling peaches versus fresh freestone at statistically significantly higher levels (vitamin C, antioxidants and folate); higher but not statistically different levels (vitamin A); or lower, but not statistically different levels (vitamin E, total phenolics and total carotenoids). There were no statistically significant changes in nutrient content during storage for 3 months. CONCLUSIONS: The nutritional content of canned peaches has been shown in this study to be comparable to that of fresh peaches. There were no statistically significant decreases in those nutritional parameters measured in this study between fresh freestone peaches and canned cling peaches. Vitamins A and E along with total carotenoids decrease immediately upon processing, but appear to stabilize after the processing step, showing minimal additional changes upon storage for 3 months. This study shows that canned peaches can provide comparable nutrient levels to the consumer as fresh peaches, meaning that consumers can enjoy peaches year round without worrying about loss of nutrients in their diet. © 2012 Society of Chemical Industry     

Effect of chitosan on incidence of brown rot,quality and physiological attributes of postharvest peach fruit

The effect of chitosan (5.0 and 10.0 mg ml ⁻¹) on the incidence of brown rot (caused by Monilinia fructicola), quality attributes and senescence physiology of peaches was investigated. It was found that both concentrations of chitosan reduced the incidence of brown rot significantly and delayed the development of disease compared with the control, but were less effective than the fungicide prochloraz. Chitosan‐treated peaches were firmer and had higher titratable acidity and vitamin C content than prochloraz‐treated or control peaches. Compared to control (water‐treated) peaches, chitosan‐treated peaches showed lower respiration rate, less ethylene and malondialdehyde (MDA) production, higher superoxide dismutase (SOD) activity and better membrane integrity. Hence it can be concluded that chitosan has the potential to control brown rot, preserve valuable attributes and prolong the shelf life of postharvest peaches, presumably because of its antifungal property and inhibition of the ripening and senescence process of postharvest peaches. © 2000 Society of Chemical Industry     

Preliminary characterisation of peach cultivars for their antioxidant capacity

Eleven peach cultivars (white‐ and yellow‐flesh peaches, nectarines and canning clingstone peaches) were assayed for their antioxidant capacity and their content of some important organic compounds as well as vitamin C, carotenoids and phenols. Antioxidant capacity, determined by FRAP assay, varied between genotypes. Those with the highest value of Ferric Reducing Antioxidant Power (FRAP) were Federica and Springcrest. Antioxidant capacity was correlated to the amount of organic components with significant differences among the cultivars. In some case, antioxidant capacity was related to phenol content, as in yellow–flesh peaches. These results suggest the importance of genotype for determining antioxidant capacity, which, in turn, is related to the organic constituents, such as phenols, vitamin C and carotenoids.     

不同保鲜膜包装蟠桃在冷藏和常温货架期间品质的变化

该研究采取不同保鲜膜对蟠桃进行包装,研究其冷藏和常温货架的保鲜效果。以北京平谷蟠桃为试材,采用CK组和3个处理组,CK组为普通保鲜膜,处理组分别为防雾膜、PE膜、PLA膜,每10 d测量一次,在此基础上进行3 d常温货架实验,分析其感官品质、硬度、生理指标、营养物质的变化。结果表明,3个处理组的保鲜膜均具有气调作用,40 d时,CK组的O2含量最高,为20.53%,CO2含量最低,为0.21%,防雾膜组O2含量为19.90%,CO2含量为0.93%,PE膜组O2含量为20.33%,CO2含量为0.63%,PLA膜组O2含量为20.10%,CO2含量为0.98%,在冷藏期和常温货架期内,腐烂指数和褐变指数呈上升趋势,CK组最先出现腐烂和褐变现象,且腐烂指数和褐变指数均为最高,PLA膜处理组感官品质最优,与CK组相比较,其它3组处理均可以延缓果实衰老,减少果实营养物质损失,通过SPSS分析,综合得分CK组<防雾膜组相似文献   

长期贮藏大豆分离蛋白溶解性下降原因探讨——大豆分离蛋白中微量油脂氧化的影响

为了探寻大豆分离蛋白(SPI)在长期贮藏过程中溶解性不断下降的原因,文中研究了SPI中微量油脂存在的影响。制备了SPI、含2%未氧化大豆油SPI和含2%氧化大豆油的SPI 3组样品,采用真空包装,在贮藏12周过程中定期测定样品的溶解度、蛋白羰基、表面巯基、总巯基以及自由氨基等性质。结果表明:在贮藏过程中所有SPI的溶解性均有不同程度的降低,其中含油脂氧化的样品SPI溶解度的下降最快且溶解度最低。3组样品在贮藏期间的羰基、总巯基、自由氨基含量变化几乎无差别,但空白SPI的表面自由巯基含量始终高于含有未氧化大豆油的SPI和含氧化大豆油的SPI(P<0.05)。说明大豆蛋白贮藏期间发生了氧化反应,氧化油脂可以促进溶解度下降的加速,但是氧化油脂本身不是导致蛋白质氧化的唯一影响因素,导致大豆蛋白贮藏过程溶解度下降的原因比较复杂,需要进一步深入研究。     

甘油含量对大豆蛋白膜功能性质的影响

大豆蛋白膜是一种可降解、可食用和可再生的新型包装材料,但是其机械性能尚不能满足日常使用的需求。研究甘油含量对可食性大豆蛋白膜功能性质的影响,结果显示随着甘油含量的增加,大豆蛋白膜抗张强度下降,而断裂延伸率、水蒸气透过率和氧气透过率升高。当甘油添加量为大豆蛋白的30%时,大豆蛋白膜具有较好的机械性能。因此,甘油含量是影响大豆蛋白膜机械性能的主要因素之一。     

复合涂膜剂对海南咸水鸭蛋的保鲜

采用羧甲基纤维素钠(CMC-Na)与纳米二氧化钛(nano-TiO₂)2种材料进行复合,通过研究复合膜的性能,找出较合适的二氧化钛含量,用于咸水鸭蛋的涂膜保鲜研究。结果表明羧甲基纤维素钠膜中添加适量纳米二氧化钛能增强其抗张强度,降低水蒸气透过率和溶胀性能,添加4%nano-TiO₂的复合膜的综合性能较好。以CMCNa/4%nano-TiO₂的溶液涂膜咸水鸭蛋,考察其对蛋贮藏期间失重率、蛋清pH、蛋黄指数、哈夫单位、菌落总数等新鲜度指标的影响,发现不经涂膜的空白组贮藏到21 d时,已不适宜消费者食用,而CMC-Na/nano-TiO₂涂膜组到42 d时,还在可食用范围内,不添加nano-TiO₂的CMC-Na涂膜组可以将鸭蛋保鲜至35 d。所以CMC-Na涂膜可以延长咸水鸭蛋的贮藏期,添加nano-TiO₂的涂膜组比未添加的效果更好。     

酸性电解水对果蔬杀菌及保鲜效果的研究

本研究采用酸性电解水对新鲜菠菜、桃子及樱桃进行处理,考察了酸性电解水对上述果蔬在不同贮藏条件下保鲜效果的影响.结果表明,pH 3.04、有效氯浓度(ACC)30.2 mg/kg的强酸性电解水和pH 5.68、ACC 26.6 mg/kg的微酸性电解水浸泡处理5min均能使菠菜表面的微生物数下降2.0lg cfu/g以上...     

Vacuum Infusion of Citrus Pectinmethylesterase and Calcium Effects on Firmness of Peaches

Vacuum infiltration of Majestic peaches (Prunus persica) for 1 hr with a solution of Marsh grapefruit pectinmethylesterase (PME) containing 100 mg/L CaCl₂ significantly increased firmness of canned peaches. Mean firmness of peaches infused 2 hr and thermally processed was 13.9 J/Kg as compared to 3.2 J/kg for noninfused, processed controls. The calcium content increased from 278 to 432 mg/kg during 2 hr infusion of blanched peaches. Specific activity of PME in peach halves increased more than 20 fold after infusion.