Thermo-physiological and comfort properties of Ugandan barkcloth from Ficus natalensis

The United Nations Educational, Scientific and Cultural Organization in 2005 proclaimed that Ugandan barkcloth largely produced from mutuba tree (Ficus natalensis) as a “Masterpiece of the Oral and Intangible Heritage of Humanity”. An exploratory investigation of thermo-physiological and comfort properties of barkcloth, a nonwoven material produced through a series of pummeling processes from mutuba tree in Uganda, is fronted. Barkcloth was extracted from the F. natalensis tree in Nsangwa village, Buyijja parish in Mpigi district, Central Uganda. Thermal conductivity, thermal diffusivity, thermal absorptivity, thermal resistance, fabric thickness, and peak heat flow density were measured using an Alambeta device, whereas a Permetest device was used for the measurement of the moisture vapour permeability and evaporation resistance. The study was carried out under relative humidity of 40% and at a laboratory room temperature of 24°C and the results show that the thermal conductivity is in the range of cotton fabrics rendering barkcloth from F. natalensis, a comfortable fabric. The lower value of thermal absorptivity of barkcloth compared to the value of cotton renders the fabric a warm feeling when in contact with the skin. Barkcloth had a higher moisture vapor permeability compared to cotton and other fabrics, meaning its clothing comfort properties are reasonable.     

沙柳皮基微晶纤维素的制备及其性能表征

为开发利用沙柳资源,减少环境污染,以沙柳皮为原料,采用化学处理方法提取分离出纤维素,并制备了微晶纤维素。通过扫描电子显微镜镜（SEM）和X射线衍射等手段对其形貌和结晶结构进行表征,使用显微镜对微晶纤维素的粒径进行分析。结果表明,通过逐步处理,半纤维素和木质素被去除,纤维素结晶度提高,制备得到棒状结构的微晶纤维素,聚合度为185.7,微晶纤维素长度主要分布在20-60 μm之间,平均长度为46±15 μm,平均直径为10±3 μm。在一定程度上解决了沙柳资源浪费问题,同时为微晶纤维素来源又增添一新途径。     

绿色拒水拒油餐桌布的制备

为实现餐桌布绿色拒水拒油效果,选用棉织物、棉/亚麻混纺织物和亚麻织物,采用浸轧加烘燥工艺对3种织物进行拒水拒油功能整理。通过测试及分析整理后织物的拒水拒油等级,研究环保型含氟整理剂对织物拒水拒油功能的影响,并对整理后织物接触角、透气性、悬垂性和耐水洗性能进行表征分析。棉织物与棉/麻织物在含氟整理剂648-2质量浓度为25 g/L时织物拒水拒油效果最佳;亚麻织物在含氟整理剂648-2质量浓度24 g/L时织物拒水拒油效果最佳;通过对比分析发现,亚麻织物最适合作为绿色拒水拒油餐桌布,整理剂质量浓度为24 g/L时亚麻织物的拒水等级为5级、拒油等级为8级,织物接触角为140.3°。     

棉秸秆提取天然纤维素纤维的工艺及其纤维形态结构

通过对棉秸秆皮外观观察以及定量测定各段棉秆皮成分含量,确定棉秸秆脱胶提取纤维素纤维分为三段脱胶。对棉秸秆一煮法工艺提取纤维素纤维,采用正交实验,以提取纤维的细度、拉伸断裂强度、残胶率、纤维可挠度为评价指标,通过利用模糊正交法综合评价方法,对不同段棉秸秆提取天然纤维素工艺进行研究。实验得到,第一段棉秆脱胶一煮法优化工艺为：NaOH浓度为35g/L,温度为100℃,时间为2.5h,双氧水浓度为10ml/L,第二段棉秆脱胶一煮法优化工艺为：NaOH浓度为30g/L,温度为100℃,时间为2.0h,双氧水浓度为10ml/L,第三段棉秆脱胶一煮法优化工艺为：NaOH浓度为30g/L,温度为90℃,时间为2.5h,双氧水浓度为8ml/L。通过JSM-6460LV扫描电镜观察了各段棉秸秆提取纤维素纤维的外观形态,提取的天然纤维素纤维属工艺纤维,纤维表面不光滑,且纤维表观粗细不均匀     

高温脱胶对棉秆皮纤维成分与结构的影响

研究棉秆皮纤维高温脱胶技术,讨论高温时NaOH用量对棉秆皮纤维成分与结构的影响。通过SEM、FT-IR、XRD对棉秆皮纤维高温脱胶前后的表面形态、聚集态结构进行了表征。通过测定脱胶后的黑液残碱量表明反应是否充分。对脱胶后的棉秆皮纤维进行断裂强力测试和热性能分析,从中得出脱胶效果较好的工艺参数。实验结果表明：高温脱胶后的棉秆皮纤维半纤维素和木质素下降明显,纤维素含量提高到接近93%;棉秆皮纤维的断裂强力和热稳定性与碱用量有关。     

低温等离子与生物酶对羊毛针织物的联合改性

采用不同条件对羊毛针织物进行改性.结果表明:低温等离子作为生物酶的前处理能够改善织物的抗毡缩性,蛋白酶对提高羊毛的抗毡缩性方面具有决定性作用,但易引起织物胀破强度的下降,TG酶处理也能降低织物的毡缩率并提高织物胀破强度.低温等离子与生物酶联合改性使羊毛针织物在保证强度的情况下,毡缩率下降明显,达到机可洗标准.DTA分析表明:低温等离子与蛋白酶和TG酶联合改性对羊毛α螺旋结构蛋白无影响;羊毛的热降解温度升高,热稳定性提高.     

Effect of pectin on plasma lipids and caecal enzyme activity in rutin‐supplemented mice

BACKGROUND: Few previous reports have considered the effects of dietary fibre on the plasma lipids and caecal enzyme activity of mice fed a rutin‐supplemented diet. This investigation studied the effects of pectin on the plasma lipids and caecal enzyme activities of mice fed a diet supplemented with the quercetin glycoside rutin. RESULTS: Male mice were randomly divided into two groups and fed either a pectin–rutin (PR) diet or a cellulose–rutin (CR) diet for 14 days. Plasma cholesterol and triglyceride concentrations and caecal β‐glucosidase and β‐glucuronidase activities were measured. The plasma cholesterol and triglyceride concentrations were significantly higher in the CR diet group, as were the caecal β‐glucosidase and β‐glucuronidase activities. The caecal β‐glucuronidase/β‐glucosidase activity ratio was significantly higher in the PR diet group, indicating differences in the metabolic activity of the intestinal flora. CONCLUSION: The PR diet greatly affected the caecal enzyme activities. A pectin diet supplemented with the quercetin glycoside rutin might affect the lipid metabolism and metabolic activity of the intestinal flora. The plasma lipid‐lowering effects of the PR diet might have been partially caused by the metabolic actions of the intestinal gut flora. Copyright © 2009 Society of Chemical Industry     

薛荔籽果胶对高脂膳食去势大鼠脂质代谢及盲肠内环境的影响

目的：研究薛荔籽果胶对高脂膳食去势大鼠脂质代谢及盲肠内环境的影响。方法：将40 只健康雌性Sprague-Dawley（SD）大鼠随机分为5 组,其中1 组作为空白对照进行卵巢伪切除手术（Sham组）,另外4 组进行双侧卵巢切除手术（OVX组）,1 周后分为模型对照组和饲喂5%、10%、15%薛荔籽果胶低、中、高剂量组。喂养4 周后解剖测定大鼠血脂和肝脂含量、肝脏组织形态,以及盲肠内容物含水率和短链脂肪酸（shortchainfatty acids,SCFAs）含量等指标。结果：模型对照组大鼠的血脂以及肝脏质量、肝脏脂肪含量、每克肝脏中胆固醇、甘油三酯含量显著高于双侧卵巢伪切除组（P＜0.05）。薛荔籽果胶对双侧卵巢切除大鼠的血脂浓度几乎没有影响,而肝脏质量有升高趋势,但无显著性差异;同时能显著升高盲肠壁湿质量、盲肠壁表面积、盲肠组织湿质量和盲肠内容物湿质量（P＜0.05）;也能升高盲肠内容物中各SCFAs和总SCFAs含量,且具有明显的剂量关系。结论：薛荔籽果胶对高脂膳食引起高脂血症去势大鼠的血脂、肝脂没有降低效果,反而升高了肝脂水平,但在肠道方面,能改善高脂膳食去势大鼠肠道健康。     

Characterization of Crude Esterase Activity from Two Plants Used in Cheese Making: Cynara cardunculus L. and Ficus carica L.

For centuries, extracts of Cynara cardunculus and the latex of Ficus carica have been used in cheesemaking, thanks to their proteases that clot milk casein. Since esterase activity is important to release odorous compounds in cheese, in this study we characterized the esterase activity of an extract of Cynara cardunculus and the latex of Ficus carica. The results, obtained by titration, spectrophotometric techniques, zymograms, and tests on agar plates, show the presence of esterase activity in the samples tested, with affinity towards the esters of short chain fatty acids, such as acetic, propionic, and butyric acid. In conclusion, this study provides a background information on esterases of two plants used in cheesemaking and represents a starting point for further investigations of their applications, not only in dairying but also in other industries involved in the processing and transformation of lipids.     

凝固浴温度对有机溶剂法再生竹纤维素纤维结构与性能的影响

以竹纤维素浆粕为原料,以NMMO(N-甲基吗啉-N-氧化物)水溶液为溶剂制得了纺丝原液.在不同的凝固浴温度条件下,制备了各种再生竹纤维素纤维,并对其结晶、取向、力学性能和染色性能等进行了研究.实验结果表明:在较低的凝固浴温度下纺制得到的再生竹纤维素纤维的性能较好.     

Effect of different thermal treatments and freezing on the antioxidant constituents and activity of two Bahraini date cultivars (Phoenix dactylifera L.)

Effect of several thermal treatments and freezing on the antioxidant properties of fresh dates of two cultivars (namely Khalas and Khunaizi) was investigated. Levels of phenolics, total flavonoids and anthocyanins were estimated. Antioxidant activity was measured by ferric reducing ability of plasma (FRAP), diphenylpicrylhydrazyl (DPPH) and deoxyribose assays. Results indicate differential effects of the treatments on the phenolic constituents. Generally, mild treatments and freezing significantly increased the level of total phenolics in both cultivars by 80–180%. All treatments increased in the level of free phenolics in Khalas (between 10% and 540%). In khunaizi, the level of bound phenolic increased in all treatments (9–250%). The level of total flavonoids increased by almost all treatments in both cultivars (33–500%). Most treatments increased the FRAP value in khalas (up to 80%). Significant differences were noticed among the various treatments with regard to DPPH and OH radicals quenching capacities. Results may find applications in food science, food technology and nutrition.     

绿茶及其提取物对鸡血浆蛋白的影响

探讨灌喂绿茶及其提取物对鸡血浆蛋白含量及其蛋白组分的影响。选择40日龄肉鸡为研究对象,采用单因素实验,108只约1.5kg的肉鸡按照体重相近原则随机分成四组:对照组、灌喂绿茶组、茶多酚(TP)组、表没食子酸儿茶素(EGCG)组。分别在饲喂后1.5、4、8h进行鸡翅下静脉采血。结果表明:与对照组相比,灌喂茶多酚和EGCG在4h内明显提高鸡血浆总蛋白的含量;SDS-PAGE电泳分析血浆蛋白组分显示,绿茶对蛋白组分的影响较小,而EGCG导致分子量为107.1ku和58.9ku条带在4h后消失。     

Variations in mass and enzyme activity of rumen microorganisms: Effect of barley and buffer supplements

Four ruminally cannulated cows were used to investigate effect of barley with or without buffer on modifications of mass and enzyme activity in rumen microorganisms. Animals were given restricted feed (80% of ad libitum intake) of 7 kg DM day^?1 and with three successive diets. The diet H consisted of 100% Cocksfoot hay. The diet HB was 65% hay with 35% pelleted ground barley with infusion of bicarbonate salt for the diet HBB. The rumen was sampled before (-1 h) and after feeding (+ 5 h) to isolate liquid-and solid-associated microbial population. ¹⁵(NH₄)₂SO₄ was continuously infused into the rumen as a microbial marker. For all diets microorganisms associated with particles constituted a mean of 74% of the total rumen microbial mass. The density of microorganisms adherent to particles was similar (P > 0.05) for the different diets and the two sampling times, but fibrolytic enzymes activities (xylanase, CMCase, glycosidases) in this microbial population were maximal (P < 0.001) 23 h after feed intake. Xylanase (P < 0.05) and CMCase (P < 0.01) activities just before feeding varied according to diet; they were highest with diet H and similar between barley supplemented diets. Higher glycosidase activities were measured with diet H and HBB than with diet HB 5 h after feeding.     

Effect of Alkyl Phenol from Cashew Nutshell Liquid and Sisal Fiber Reinforcement on Dry Sliding Wear Behavior of Epoxy Resin

A phenalkamine made from the reaction of alkyl phenol from cashew nut shell liquid (CNSL) and alkaylamine was added at three different weight percentages (30%, 40%, and 50%) as a hardener for curing the epoxy polymer. The effect of phenalkamine concentrtation on mechanical and dry sliding wear resistance properties were compared to synthetic aliphatic amine (TETA) cured epoxy network. It was obsererved that incorporation of phenalkamine improves the dry sliding wear resistance property of the epoxy network along with the impact strength and elongation properties. Epoxy composites incorporating sisal fiber placed unidirectionally (either parallel, anti-parallel, or perpendicular to the sliding direction) were prepared in a vacuum infusion process using phenalkamine as a crosslinking agent. It was observered that wear resistance of longitudinally oriented fibers composite was found to be higher owing to the area of fibers exposed to sliding asperities being smaller. With the goal to understand the brittleness behavior of epoxy networks, fractured surfaces of the epoxy networks were analyzed using optical microscope. A correlation was found between the mechanical and wear resistance properties of the epoxy networks.     

Dietary fiber from coconut residue: effects of different treatments and particle size on the hydration properties

The present work is aimed at the production of dietary fiber from underutilized coconut residue left after the extraction of milk, by subjecting it to physical treatments such as water washing, hot water washing, boiling water washing and pressure cooking, as well as solvent extraction. The fat content was reduced from 62% to 45% and 41% by treatment with boiling water and pressure-cooking, respectively. Water-holding, water retention and swelling capacities increased with decreasing fat content. A marked increase was observed in hydration properties when the fat content decreased from 10 to 2%. The hydration properties were maximum for 550 m particle size coconut fiber. For the higher particle size (1,127 m), the oil was trapped inside the fiber matrix, resulting in decreased hydration properties, whereas for the lower particle size (390 m) the rupture of the fiber matrix was responsible for low hydration properties. An attempt was made to compare the hydration properties of coconut dietary fiber with other commercially available dietary fibers.     

Protein co-precipitates from milk and blood plasma: Preparation and investigation of some functional properties

Various processing methods were investigated for the production of milk and porcine blood plasma co-precipitates. Factors considered included pH and temperature treatments as well as the ratio of milk to plasma proteins in mixtures of the raw materials. The recovery of protein in precipitates was measured and the following method was selected accordingly for further studies: pH adjustment of skim milk and blood plasma mixtures to pH 9.5, heating to 70° C, readjustment of pH to 9.5, holding for 3 min, cooling to 68°C, pH adjustment to 3–5, holding for 5 min, cooling to ambient temperature and final pH adjustment to 4.7. Two co-precipitates (70/30 M/P and 30/70 M/P) were prepared from a 70:30 and a 30:70 mixture of skim milk (M) and blood plasma (P). Some of the functional properties of these preparations were measured and compared with those of total milk protein (TMP) and blood plasma precipitate (P) prepared by the same procedure as well as acid-precipitated casein. The protein contents of preparations freeze-dried at pH 7.0 varied between 91.5 and 92.3% and those freeze-dried at pH 4.7 varied between 93.1 and 96.0%. The solubility profile and emulsifying capacity of the 70/30 M/P compared favourably with those of caseinate and TMP. The solubilities of 30/70 M/P and 100% P were, however, poor. The viscosity of solutions of 70/30 M/P was considerably higher than those of caseinate and TMP solutions. Water adsorption isotherms of protein preparations were constructed and are presented in graphical form. Precipitates freeze-dried at pH 7.0 adsorbed more moisture than the same preparations freeze-dried at pH 4.7. These differences were especially evident a water activities >0.8.     

Materials based on maize biopolymers: Effect of flour components on mechanical and thermal behavior

The present study describes the effects of glycerol, relative humidity (RH) and the minor components of corn flour on mechanical and thermal properties of native flour, defatted flour, and starch‐based materials. The kinetic of retrogradation for these different materials were dissimilar. For all samples, strain at break shows a maximum value as a function of RH followed by a decrease, explained by the appearance of water and glycerol clusters. Starch controls the mechanical properties of corn flour‐based material and their variations with temperature and humidity. Lipid and protein have negative effect on mechanical properties of thermoplastic flour toward starch but they did not have a plasticizing effect on the physicochemical behavior of the matrix. T_gs decreased as a result of water content increase.     

Effect of ultrafiltered fractions from casein on lactic acid biosynthesis and enzyme activity in yoghurt starter cultures

In this work, five ultrafiltered fractions (UFs) with molecular mass less than 3 kDa (kilo‐daltons) from casein hydrolysates treated with alcalase, flavourzyme, neutrase, papain and trypsin, respectively, were obtained. The effect of five UFs on the fermentation for lactic acid (LA) production by mixed cultures of Streptococcus thermophilus (St) and Lactobacillus delbrueckii subsp. bulgaricus (Lb) during 72 h of cultivation was investigated. Compared with the control, LA production was, respectively, enhanced by 23.66%, 39.01%, 29.74%, 49.64% and 47.40% with the supplement of UF‐A, UF‐F, UF‐N, UF‐P and UF‐T at 24 h. The possible mechanism of LA production enhanced was elucidated by the time course analysis of the specific activity of glucokinase, phosphoglucose isomerase, 6‐phosphofructokinase, pyruvate kinase and lactate dehydrogenase during fermentation process. In addition, the results obtained showed the diverse influence of five UFs on the bacterial fermentation was attributed to their different amino acid distribution.