以硫酸盐浆为原料的吸水材料的制备及其性能

为了替代以石油为原料的吸水材料,实验制备了2种以纸浆为原料的吸水材料.对未干燥的漂白硫酸盐浆,采用TEMPO-氧化后可引入新的羧基和醛基.研究发现,醛基有利于改善吸水材料湿状态下的强度,原因可能是形成了半缩醛结合,氧化后纸浆纤维逐渐分散.分析表明,分散速率随氧化剂用量的增加而增大.冷冻干燥可使物料具有多孔性的泡沫状结构,该结构具有较大的表面积.即使在一定的压力下,较大的表面积也可赋予物料较高的吸收速率和较好的吸收能力.风干干燥使物料形成一种具有较小吸收速率和较大吸收能力的压实薄层.     

高微孔活性炭纤维电磁波吸收性能测试分析

通过水蒸气活化法控制纤维孔隙及比表面积,制备不同比表面积和微孔率的活性炭纤维,并测试其微观形貌、比表面积、孔结构、XRD图谱、介电常数、电磁波吸收性能。结果表明,在900℃的水蒸气中活化15 min制备的活性炭纤维可获得最优的电磁波吸收性能,将其按10%的质量比与石蜡混合制备厚度为3 mm的测试样,测得电磁波损耗(<-10.000 d B)频宽达到6.74 GHz。制备的高微孔活性炭纤维材料质量轻、电磁波吸收频带宽,是一种有效的电磁波吸收材料,可为其他电磁波吸收材料的研究提供参考。     

壳聚糖-植酸钠膜的制备及性能研究

本试验以壳聚糖和植酸钠为主要原料进行膜的制备。对壳聚糖-植酸钠膜的厚度、不透明度、紫外吸能力、溶胀度、溶解度、透湿性、红外分析和热重分析图进行研究。结果表明:随着植酸钠浓度增加,膜的厚度增加,不透明度也增加;紫外光谱结果表明,植酸钠浓度越高紫外吸收能力越强;随着植酸钠含量增加,膜的溶解度,溶胀度逐渐降低;植酸钠浓度为1.25%时,膜有最低的水蒸气透过率。结论:3%壳聚糖/1.25%植酸钠在室温下的成膜效果最好。     

干扰剂对甘氨酸螯合铁脂质体吸收效率的影响

为研究常见的非血红素吸收干扰剂对甘氨酸螯合铁脂质体吸收效率的影响,采用外翻肠囊法,以小肠单位面积铁累计吸收量为指标,评价了甘氨酸螯合铁脂质体在不同干扰剂存在时其铁的吸收效率。结果显示,与甘氨酸螯合铁相比,脂质体中的铁具有更高的吸收效率;植酸、锌离子对甘氨酸螯合铁的吸收有明显抑制作用,抗坏血酸对其吸收有促进作用,但这些干扰剂对甘氨酸螯合铁脂质体中铁的吸收没有明显影响。总体上,甘氨酸螯合铁脂质体铁剂既有更高的吸收效率也有更好的吸收稳定性。这可能是因为脂质体不仅可以防止甘氨酸螯合铁与外界的相互作用,而且它的纳米载体特性可能会影响甘氨酸螯合铁的吸收途径。     

生物酶预处理改善麦草氧碱制浆性能的研究

以麦草为原料,经生物酶（脂肪酶、木聚糖酶、二者的复合酶）预处理后,采用碳酸钠氧碱制浆工艺制备麦草生物化学浆,研究生物酶预处理对麦草纤维形貌、纸浆纤维形态及纸浆成纸物理性能的影响。结果表明,经复合酶预处理后,麦草浆卡伯值为13.08、纸浆成纸白度可达40.9%ISO,较未经酶预处理的纸浆分别低1.34、高6.8%ISO;经碳酸钠氧碱制浆工艺制备的纸浆细小纤维含量明显下降,成纸抗张指数可达97.4 N·m/g,较未经酶预处理的纸浆成纸抗张指数（86.2 N·m/g）提高了12.9%,生物酶预处理可明显改善麦草的生物化学制浆性能。     

花椒挥发油超临界CO2萃取的工艺优化及GC-MS分析

本文以花椒油得率为指标,通过响应面法优化超临界CO_2法萃取花椒挥发油工艺,并利用GC-MS分析挥发油的成分,同时以水蒸气蒸馏法作对比。结果表明,当温度42℃,压力30 MPa,提取180 min时,超临界CO_2法的得率高达12.70%,是水蒸气蒸馏法得率的2.27倍。GC-MS分析发现两种提取方法所得挥发油的组成相似,含量差异较大,主要成分有花椒油素(32.99%/10.56%)、芳樟醇(4.68%/4.84%)、桉叶油醇(3.92%/5.84%)、α-松油醇(4.55%/7.04%)、4-萜烯醇(2.95%/10.42%)、乙酸松油酯(5.19%/7.24%)、薄荷酮(5.40%/4.41%)、茴香脑(2.91%/3.73%)等,其中超临界CO_2法所得挥发油中的花椒油素含量最高,达到32.99%。这说明与传统的水蒸气蒸馏法相比,超临界CO_2萃取法的提取效率更高,而且所得挥发油含有高含量的花椒油素,这为花椒油素的提纯,花椒挥发油的开发利用提供了参考。     

太平洋鳕鱼排酶解产物的制备及其钙螯合活性研究

目的以太平洋鳕鱼排为原料,制备具有良好钙螯合活性的酶解产物,并对其促钙吸收转运功效进行评价。方法采用动物蛋白水解酶、中性蛋白酶和菠萝蛋白酶分别进行水解,比较3种酶解产物的水解度与蛋白回收率,确定最佳水解酶,并研究酶解产物的钙螯合活性与促钙吸收转运活性。结果经动物蛋白水解酶制备的酶解产物水解度与蛋白回收率最高。当酶解时间为320 min时,该酶解产物的钙螯合活性最高。氨基酸分析表明谷氨酸、甘氨酸、天冬氨酸、丝氨酸和苏氨酸等特定氨基酸所占比例较高。该酶解产物对Caco-2细胞无毒性作用,能够明显促进钙转运率。结论太平洋鳕鱼排酶解产物具有较好的钙螯合活性与促钙转运活性。     

纳豆激酶微胶囊制备及其释放与Caco-2细胞模型吸收的评价

为防止纳豆激酶在胃中失活,提高其在小肠内的吸收能力,本研究以聚乙二醇-聚乳酸-羟基乙酸共聚物(PEG-PLGA)为壁材,以包封率为指标,通过正交实验探究双重乳液蒸发法制备纳豆激酶微胶囊的最适条件,接着采用上述条件分别以PEG-PLGA和叶酸-聚乙二醇-聚乳酸-羟基乙酸共聚物(FA-PEG-PLGA)为壁材制备纳豆激酶微胶囊,最后对两种微胶囊体外缓释效果、细胞毒性及在Caco-2单层细胞模型中的吸收效果进行评价。结果表明,PEG-PLGA纳豆激酶微胶囊最适制备条件为壁材浓度5 mg/mL、聚乙烯醇(PVA)浓度1%、二级均质转速17500 r/min、二级均质时间7.5 min;PEG-PLGA和FA-PEG-PLGA纳豆激酶微胶囊的平均粒径分别为271.33和255.75 nm,包封率分别为61.54%±2.36%和58.76%±2.54%,ζ电位分别为(-20.17±1.42)和(-24.73±2.36) mV。体外模拟缓释结果表明,经胃环境(pH2.0)2 h后,两种微胶囊中超60%纳豆激酶被保留,经肠环境(pH7.0)22 h缓释效果良好。两种微胶囊对Caco-2细胞均无明显毒性且细胞吸收良好,顶侧表观渗透系数分别高达2.367×10^-6和3.497×10^-6 cm/s,激光共聚焦显微镜观察结果同样表明两种微胶囊在Caco-2细胞中均有很好的吸收效果,且FA-PEG-PLGA微胶囊比PEG-PLGA微胶囊吸收效果更佳。     

脂质体理化参数对甘氨酸螯合铁脂质体吸收的影响

采用大鼠在体单向肠灌流法,以吸收速率常数(Ka)和表观渗透系数(Papp)为指标,评价了主要理化参数对甘氨酸螯合铁脂质体的吸收效率的影响。结果表明,壁材中随着胆固醇和吐温80含量增加,卵磷脂与胆固醇由20∶0(g/g)提高到20∶2(g/g);卵磷脂与吐温80由10∶0(g/g)提高到10∶5(g/g);以及卵磷脂与芯材由10∶1(g/g)提高到10∶2(g/g)有利于甘氨酸螯合铁脂质体的吸收;但随着胆固醇、吐温80以及芯材含量的进一步增加,甘氨酸螯合铁脂质体吸收下降。随着粒子平均粒径由100 nm增加到1000 nm,甘氨酸螯合铁脂质体是Ka和Papp分别降低到了43%~65%和24%~40%。此外,与甘氨酸螯合铁相比,经脂质体包封后其吸收效率显著提高。因此,脂质体可能不仅是一种载体,它还可能影响芯材的吸收过程,脂质体的壁材组成、粒径大小等理化参数对其吸收有显著影响,而合理的理化参数有利于提高脂质体的吸收效率。     

响应面法优化超临界干燥制备紫草色素脂质体

采用超临界CO_2反向萃取乙酸乙酯紫草素提取液,超临界CO_2流量为15 L/min,压力为28MPa,温度30℃,紫草色素提取率为5.4%,然后应用超临界干燥法制备高溶解度的紫草色素脂质体。采用响应面优化设计法,以脂质体的水溶解度为优化指标,考察了超临界压力、超声波功率、卵磷脂-辛烯基琥珀酸淀粉钠(SPC-OSAS=1:1)和紫草色素的摩尔比对脂质体溶解度的影响。结果表明:在所选取的3个因素中,超临界的压力对脂质体的水溶性的影响最大,超声波功率次之,当超临界的压力为22.0 MPa,超声波的功率为262 W,卵磷脂-辛烯基琥珀酸淀粉钠(SPC-OSAS)与紫草素的摩尔比为2.05,固定化干燥温度35℃,固定化干燥时间2 h,紫草色素乙醇溶液提取物流速15 L/min时,此条件下可得到的紫草素脂质体,具有最大的水溶解度,达到638.54μg/m L,通过该工艺所制备的紫草素复合纳米粒平均粒径为10 nm,粒径均匀分布;结果准确,重现性好,相对于紫草素原料,紫草素脂质体复合纳米颗粒在80℃的耐热稳定性大大提高。通过对脂质体的HPLC分析,乙酰紫草素的含量最高,达到了30.23%。     

活性金黄SRE对棉织物的浸轧-真空脱水-湿蒸染色工艺

为提高活性染料传统轧-蒸染色的固色率和染深性,将真空脱水技术引入棉织物的活性染料轧-蒸染色过程。研究了棉织物含水率、汽蒸时间和碳酸钠用量对活性金黄SRE湿蒸染色的影响,并比较了活性金黄SRE采用浸轧-真空脱水-湿蒸(P-Vac-S)工艺与传统浸轧-湿蒸(P-S)工艺染色棉织物的染深性和耐摩擦色牢度。结果表明;浸轧含25 g/L活性金黄SRE染液的棉织物,将其含水率真空脱水至20%~30%,再进行湿蒸,棉织物的上染率(K/S值)和染料固色率相对较高;含水率为(25±2)%的棉织物湿蒸染色的适宜汽蒸时间和碳酸钠质量浓度分别为5 min和25 g/L;采用活性金黄SRE经P-Vac-S工艺染色棉织物的K/S值比采用P-S工艺染色的K/S值高15%~30%,但是经前者染色棉织物的耐摩擦色牢度比后者略差。     

CO2辅助挤压对马铃薯渣可溶性膳食纤维的影响

以马铃薯渣为原料,研究CO2辅助挤压各工艺条件对马铃薯渣可溶性膳食纤维的影响。结合马铃薯渣颜色、持水力、持油力和膨胀力的变化,得出CO2辅助挤压最佳工艺参数为:CO2发生剂柠檬酸与碳酸氢钠添加质量比为1∶1、添加量30%(质量分数)、挤压温度185℃、物料含水量25%(质量分数)、螺杆转速170 r/min。在此工艺条件下,挤压所得马铃薯渣可溶性膳食纤维含量较高,色泽较好,水合特性得到较好地保持,可为马铃薯渣膳食纤维的改性提供参考。     

改性乳清蛋白对凝固型酸奶品质及胆酸盐结合能力的影响

本研究利用酶结合苹果酸复合改性乳清蛋白（WPI-E+MA）,添加至凝固型酸奶,以期改良凝固型酸奶质构及胆盐结合能力。通过蛋白质浓度、持水力、游离巯基、粒径、粘弹性及胆酸盐结合能力等指标,评价WPIE+MA对凝固型酸奶品质、凝胶结构及胆酸盐结合能力的影响。结果表明,WPI-E+MA能够改善凝固型酸奶的持水力、表观粘度、剪切应力与粘弹性,8%添加量时达到最优;酸奶的凝胶网状交联结构因WPI-E+MA的添加变得更加致密、聚合度更高。脱氧胆酸钠（SDC）、胆酸钠（SC）、牛磺胆酸钠（STC）结合率均在8%的添加量达到最大值,结合能力良好。WPI-E+MA可有效改善凝固型凝固型酸奶的品质并显著提高胆酸盐结合能力。     

丁香酚对静电纺丝抑菌吸水衬垫结构和功能性质的影响

利用静电纺丝技术包埋丁香酚制备了一种高吸湿性抑菌吸水垫，研究丁香酚添加量对纺丝溶液和纳米纤维吸水垫理化性质的影响，并检测吸水垫的抗氧化和抑菌效果。结果表明，纺丝溶液表观黏度随着丁香酚添加量增加而下降，纳米纤维中“囊泡”结构则呈现增加趋势。吸水垫断裂伸长率随着丁香酚添加量的增加而降低。丁香酚添加量为15%时吸水垫抗拉伸强度最大，但继续加大丁香酚的添加量，抗拉伸强度则呈现明显下降的趋势。吸水垫溶胀率和水蒸气透过率随丁香酚添加量增加而降低。当丁香酚添加量为20%时吸水垫的1,1-二苯基-2-三硝基苯肼自由基和2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力最强，分别为83%和78%。此外，抑菌实验表明纳米纤维吸水垫对大肠杆菌和金黄色葡萄球菌均具有良好的抑制效果。本方法制备的抑菌吸水垫能有效吸收包装内肉汁积液，减缓产品氧化速率，并抑制微生物繁殖。     

Effects of murta (Ugni molinae Turcz) extract on gas and water vapor permeability of carboxymethylcellulose-based edible films

The effect of murta (Ugni molinae Turcz) leaves extract on water vapor permeability (WVP) and gas permeability (GP) of carboxymethylcellulose (CMC)-based films was studied. Two ecotypes of murta leaves “Soloyo Grande” (SG) and “Soloyo Chico” (SC), were analyzed for their composition (HPLC-MS) and SC extract revealed a higher concentration of flavonols than the SG extract. The film forming solution was prepared with 2 g of CMC, 0.4 ml of glycerol and 0.5 ml of sunflower oil in 100 ml of water (Control), 50 ml of water and 50 ml of each exctract (SC50 or SG50) and 100 ml of each extract (SC 100 or SG 100). The addition of murta leaves extract modified the WVP and GP of the films. The WVP decreased significantly (P?0.05) with the incorporation of SG extract in the film but not with the SC extract (P>0.05). The CO₂ and O₂ permeability of the films were influenced by the kind and concentration of murta leaves extract used. The CO₂ permeability, with SG extract was higher than without extract (P?0.05) and with SC extract was not modified. The O₂ permeability with murta leaves extract were lower than without extract. Therefore, it is possible to consider that films with SC acts only as barrier to the oxygen, but with SG the water vapor and gas barrier properties were modified, being more permeable to the CO₂ and acting as barrier to O₂ and water vapor.     

静电纺丝结合热诱导交联制备的抗菌吸水衬垫对冷鲜肉的保鲜效果

为减轻托盘包装冷鲜肉贮藏期间的品质降低，本实验利用静电纺丝结合热诱导交联技术制备了一种高吸湿性抑菌吸水垫。首先，比较了市售无尘纸吸水垫与静电纺丝吸水垫的溶胀率和溶胀损失率，然后在4 ℃托盘包装条件下对两种吸水垫的冷鲜肉保鲜效果进行验证，并与空白组（不使用吸水垫）进行对比。结果表明，静电纺丝吸水垫的溶胀率显著高于无尘纸吸水垫（P＜0.05），当柠檬酸添加量为9%（以聚乙烯醇质量计）时，静电纺丝吸水垫具有较高的溶胀率和较低的溶胀损失率。在贮藏期内，3 组样品的菌落总数、挥发性盐基氮含量、挥发性气味等指标随贮藏时间的延长而呈上升趋势，但静电纺丝吸水垫组样品的增幅明显小于空白组和无尘纸吸水垫组。3 组样品的颜色随冷藏时间的延长而加深，其中静电纺丝吸水垫组冷鲜肉的L*值和a*值显著高于空白组和无尘纸吸水垫组（P＜0.05）。结论：本方法制备的抑菌吸水垫能有效吸收包装内肉汁积液，抑制微生物繁殖，提升托盘包装冷鲜肉的感官品质。     

Development of regenerable MgO-based sorbent promoted with K2CO3 for CO2 capture at low temperatures

To improve their CO2 absorption capacity, alkali-based sorbents prepared by impregnation and wet mixing method of potassium carbonate on supports such as activated carbon and MgO (KACI30, KACP30, KMgI30, and KMgP30), were investigated in a fixed bed reactor (C02 absorption at 50-100 degrees C and regeneration at 150-400 degrees C). Total CO2 capture capacities of KMgI30-500 and KMgP30-500 were 178.6 and 197.6 mg CO2/g sorbent, respectively, in the presence of 11 vol % H2O even at 50 degrees C. The large amount of CO2 capture capacity of KMgP30-500 and KMgI30-500 could be explained by the fact that MgO itself, as well as K2CO3, could absorb CO2 in the presence of water vapor even at low temperatures. In particular, water vapor plays an important role in the CO2 absorption of MgO and KMgI30-500 even at low temperatures below 60 degrees C, in marked contrast to MgO and CaO which can absorb CO2 at high temperatures. The CO2 capture capacity of the KMgI30-300 sorbent, however, was less than that of KMgI30-500 due to the formation of Mg(OH)2 which did not absorb CO2. MgO based-sorbents promoted with K2CO3 after CO2 absorption formed new structures such as K2Mg(CO3)2 and K2Mg(CO3)2 x 4(H2O), unlike KACI30 which showed only the KHCO3 crystal structure. The new Mg-based sorbents promoted with K2CO3 showed excellent characteristics in that it could satisfy a large amount of CO2 absorption at low temperatures, a high CO2 absorption rate, and fast and complete regeneration.     

棉短绒碱-过氧化氢制浆工艺的探讨

在对棉短绒的成分作了基本分析的基础上进行了碱-过氧化氢制浆工艺的探讨,并对用棉短绒制取具有较高白度和吸水高度的纸浆工艺条件进行了初步的研究.结果表明,使用此种方法所得纸浆的得率为 86%,吸水高度为 58mm/5min,纸浆的白度 88 68% ISO.     

Chromium(III) in cactus pad and its possible role in the antihyperglycemic activity

The antihyperglycemic activity of cactus pads and pulp fruit of species of Opuntia genus has been documented; however, the mechanism of action has not yet been clarified. Thus, cactus pad and pulp fruit extracts of Opuntia dillenii were used to evaluate their effects on blood glucose concentration and glycemic curve of Sprague–Dawley rats. After acute administration, no significant differences were observed in the glycemic curve among cactus pad, pulp fruit and control groups. However, the glycemic peaks and glycemic curves obtained in the groups corresponding to both cactus pad and pulp fruit as well as the Cr(III) group were less pronounced than in the control group after 8 days of daily intake. Besides, a slight decrease of fasting blood glucose was observed, maintaining within the normal levels, after 8 days of daily intake of cactus pad extract. Therefore, the possible role of Cr(III) present in high amounts in these vegetable foods was suggested, for the first time, to explain their antihyperglycemic activity.     

Effects of pre‐emulsifying fat/oil on meat batter stability,texture and microstructure

The effects of pre‐emulsified beef fat and canola oil (CO) (25%) with Tween 80 (T‐80) or sodium caseinate (SC) were studied in beef meat batters prepared at three protein levels (9%, 12% and 15%). Raising meat protein level to 15% resulted in low emulsion stability of products prepared with CO. Using pre‐emulsified beef fat with Tween 80 (BF‐T80) showed significantly higher fat and water losses at all protein levels. There were no differences in fat and water losses between pre‐emulsified beef fat and CO when SC was used at the 9% and 12% protein levels compared to the controls (non pre‐emulsification). Light microscopy revealed fat globule coalescence in the CO meat batters prepared with 15% protein and BF‐T8 treatments, as well as formation of fat channels and more protein aggregation; both resulted in lower emulsion stability. Using SC to emulsify fat/oil produced a finer dispersion of fat globules compared to all the other treatments.