调整型内衣压力对人体生理指标的影响

为考察内衣压力对人体生理指标的影响,设计1组着装实验。15名青年女性作为受试者,穿着紧身衣于静止、运动10 min及运动后3种状态下,观察受试者心率,呼吸率,摄氧量,通气量,呼吸交换率,相对摄氧量等7个代表性生理指标的变化。结果发现,内衣的宽裕量和压力覆盖位置是影响生理指标变化的主要因素。通过对人体各受压点与各项生理指标的相关性分析得出二者之间存在相关性。静止时呼吸因子与腰部以上及胸部压力存在相关,静止时心率因子与各点压力基本不相关;运动时呼吸因子与前胸处受到的压力相关,运动时心率因子与前腰部压力相关。     

Laboratory study of treatment of trichloroethene by chemical oxidation followed by bioremediation

Studies were conducted with columns containing soil and emplaced trichloroethene (TCE) to investigate the potential for TCE source zone remediation with chemical oxidation followed by biologically mediated reductive dehalogenation. Following permanganate flushing of four columns, which resulted in rapid but incomplete removal of TCE DNAPL, no biological activity was observed following the addition of distilled water amended with ethanol and acetate, including two of the four columns that were bioaugmented with a TCE-dechlorinating microbial culture. Flushing with unsterilized site groundwater led to consumption of acetate and ethanol, accompanied by manganese reduction and methanogenesis. Reductive dechlorination of TCE to cis-1,2-dichloroethene (cis-DCE) followed the onset of ethanol and acetate biodegradation in bioaugmented columns only. Partial dechlorination of TCEto ethene was observed only in one of the bioaugmented columns after it was inoculated for a third time. At the end of the study (290 days), a trace amount of cis-DCE was observed in one of the two columns which was not bioaugmented. Reduced conditions created by biostimulation were also conducive to reduction of Mn(IV) from MnO2 in both bioaugmented and nonbioaugmented columns resulting in an increased dissolved manganese (Mn2+) concentration in groundwater.     

Prediction of Degradability of Starch by Gelatinization Enthalpy as Measured by Differential Scanning Calorimetry

It was investigated whether the degradability of starch could be predicted by differential scanning calorimetry (DSC). Degradation of potato starch with a varying degree of gelatinization. of isolated starch of different origins, and of raw materials differing in origin and technological treatment was determined with α-amylase and bovine ruminal fluid. Gelatinization enthalpy and the gelatinization temperature of starch were determined by DSC. There was a good correlation between gelatinization enthalpy measured by DSC and degradation with α-amylase and ruminal fluid for potato starches with varying degrees of gelatinization and for isolated starch granules of different origins. For raw materials of different origins there was a good correlation between gelatinization enthalpy and degradation with α-amylase, whereas the correlation between gelatinization enthalpy and degradation with ruminal fluid was poor. There was a good correlation between gelatinization enthalpy and degradation with both α-amylase and ruminal fluid for (technologically treated) raw materials of one and the same origin. There was no relation between starch degradation and gelatinization temperature.     

Feasibility of Coupling Dehydration-Impregnation by Soaking Treatment of Meat with Fermentation by Lactobacillus sakei

This study examined the feasibility of coupling dehydration-impregnation by soaking (DIS) with a subsequent lactic fermentation in the treatment of meat. A series of beef fillets were subjected to 3 different DIS treatments. The resulting DIS-treated fillets had 3 different characteristics in terms of water activity, salt, and fermentable sugars contents. Fillets treated with the DIS with the shortest immersion time (5 h) and the highest salt concentration in the DIS bath (100 g/L) were inoculated with Lactobacillus sakei. A control group was left without inoculation. After 24 h incubation at 25 °C, only inoculated fillets showed signs of lactic fermentation. At 24 h, these fillets had a d-lactic acid content of 68 μmol/g dry basis and a high population of L. sakei revealed by methods of plate count and quantitative PCR. DIS could therefore be compatible with a subsequent fermentation step by L. sakei. Practical Application: Traditional meat preservation processes often combine unit operations such as salting, smoking, fermentation, and drying. In tropical countries, high temperatures and high relative humidity, poor infrastructure, and improper slaughterhouse practices explain the need for more drastic processes (more salt, more water loss) for meat preservation. Dehydration-impregnation by soaking (DIS) could be used as a rapid pretreatment of meat, in order to counteract tropical conditions. This study validates a novel approach whereby DIS is coupled with lactic fermentation by surface inoculation with Lactobacillus sakei. With a final drying step this process could be used for the treatment of whole meat pieces.     

Production of beta-galactosidase by Bifidobacteria as influenced by various culture conditions

Beta-Galactosidase production by Bifidobacterium longum CCRC 15708, Bifidobacterium longum B6 and Bifidobacterium infantis CCRC 14633 was first examined with B. longum CCRC 15708 showing the highest production of beta-galactosidase and the highest specific activity. Further study with B. longum CCRC 15708 revealed that the highest level of beta-galactosidase was produced with lactose and yeast extract as carbon and nitrogen sources, respectively. Optimal enzyme production occurred at an initial pH of 6.5 and at 37 degrees C. Under these optimum culture conditions, a maximumbeta-galactosidase activity of 18.6 U/ml could be obtained after 16 h of fermentation in a medium contain 4% lactose, 3.5% yeast extract, 0.3% K2HPO4, 0.1% KH2PO4, 0.05% MgSO4.7H2O and 0.03% L-cysteine. The highest transgalactosylation activity was also detected in this culture after 14-16 h of fermentation.     

Absorption of chloroanisoles from wine by corks and by other materials

Sixty 750 mL bottles of a white wine were each spiked with deuterium-labelled 2,4,6-trichloroanisole (d₅ TCA) and then sealed with a variety of wine corks. Thirty months later, approximately half of the d_5-TCA had been absorbed by each of the corks, regardless of supplier, bleaching treatment or whether the corks were natural or agglomerate. In addition to the added labelled TCA, every one of these corks also contained endogenous (i.e. unlabelled) TCA. Fifteen of the corks, mostly agglomerates, imparted some of their endogenous TCA into the wines. There was no direct relationship between the amount of endogenous TCA in the corks and that found in wines. The high variability in the distribution of endogenous TCA between wine and cork contrasts with the relatively uniform distribution of the d₅-_-TCA. This contrasting behaviour distinguishes between wines tainted prior to closure and wine tainted by corks. Natural bark corks in wine bottles can also absorb 2,3,4,6-tetrachloroanisole (TeCA) and pentachloro-anisole (PCA) from bottled wine. Bottle storage of commercial wines that had become tainted with TeCA and PCA during production resulted in the corks absorbing most of these two compounds, so that the wines were no longer tainted to a significant extent. Soaking whole corks in wine spiked with chloroanisoles, under conditions typically employed in the wine industry to test batches of corks for possible taint, resulted in most of the TCA in the wine being absorbed by the corks. Thus, if five corks are being soaked in wine in order to test for taint, four sound corks could reabsorb TCA that had leached into the surrounding wine from a single contaminated cork, reducing the concentration of TCA to a point where it escapes detection. Soaking corks singly rather than in groups of five will therefore be a more sensitive method of screening batches of corks for taint than soaking them in groups of five. Plastic materials such as the lids of glass containers used to store wine samples were also able to absorb chloroanisoles via both direct liquid contact and the vapour phase. Wine cask bladders and polyethylene film were particularly effective in removing TCA from wine.     

Fractionation of oligosaccharides by nanofiltration

Two loose nanofiltration membranes (NF‐CA‐50 and NF‐TFC‐50) and one dense ultrafiltration membrane (UF‐CA‐1) were used to fractionate commercial oligosaccharide mixtures by applying diafiltration in a ‘dead‐end’ filtration cell at 40 bar constant pressure with a maximum volume concentration ratio (VCR) of 6 at each fractionation. The rejections of a monosaccharide (glucose) and a disaccharide (lactose) were determined for each membrane; the results indicated that fractionation between these two sugars was possible using the two nanofiltration membranes. During the nanofiltration purification of a commercial oligosaccharide mixture, yields of 19% (w/w) for monosaccharides and 88% (w/w) for di‐ and oligosaccharides were obtained with the NF‐TFC‐50 membrane after four filtration steps, indicating that removal of the monosaccharides is possible with only minor losses of the oligosaccharide content of the mixture. The ultrafiltration membrane, at the same time, gave purification levels similar to the NF‐TFC‐50 membrane with fewer diafiltration steps but with higher losses of di‐ and oligosaccharides (12% (w/w) for monosaccharides and 53% (w/w) for di‐ and oligosaccharides on the third run). © 2003 Society of Chemical Industry     

ICP-AES法测定面制食品中的硼元素

本文研究了电感耦合等离子体发射光谱法(ICP-AES法)测定面制食品中硼砂含量的方法。采用微波消解样品,ICP-AES法测定面制食品中硼元素含量。结果表明:方法线性良好,相关系数为0.9991,检出限为0.46mg/kg,高中低3个梯度浓度加标回收率在91.7%~105.0%。该方法测定面制食品中微量的硼元素,方法简单、精密度高及准确度好。     

Inhibition of Staphylococcus aureus by oleuropein is mediated by hydrogen peroxide

The inhibition of Staphylococcus aureus by oleuropein is shown to be largely due to hydrogen peroxide production by oleuropein. The reaction is initiated by noninhibitory levels of hydrogen peroxide present as a result of tryptone oxidation in the underlying medium. Inhibition is abolished by catalase and anaerobic incubation conditions, and the effect of tryptone can be replicated by exogenous H2O2. S. aureus strains with reduced catalase activity show greater sensitivity to oleuropein. A mechanism for hydrogen peroxide production is proposed. Inhibition is not entirely due to H2O2, since some organisms with similar sensitivity to H2O2 as S. aureus were resistant to oleuropein, suggesting that there may be a cooperative effect between H2O2 and oleuropein itself.     

EPR Study of Radicals Generated in Starch by Microwaves or by Conventional Heating

Irradiation of starch with microwaves or heating at relatively low temperature (483 K) generates radicals with anisotropic EPR signals (signal I and II) of lorentzian shape and similar g factors (g_av=2.006 and 2.007 in X and Q band, respectively). Signal I, exhibiting a doublet hyperfine structure (HFS) with A_av=1.19 mT (X band) and A_av=1.24 mT (Q band), was ascribed to a carbon radical with an unpaired electron localized at C₍₁₎ of the glucose unit, from which a hydrogen atom was abstracted. The electron interacts with the nuclear spin of the β‐hydrogen at C₍₂₎. Signal II, with g factor values similar to that of signal I but without HFS, was assigned to a radical with unpaired electron localized also at C₍₁₎ of the glucose unit from which, however, two hydrogens (α and β) were abstracted from C₍₁₎ and C₍₂₎, respectively. Signals I and II show different saturation ability in the power range 0.3–30 mW. Radicals generated in the native starch at higher temperature (503 K) exhibit more intensive EPR spectra, with dominating signal II and lower HFS constant of the signal I. The same trend of weakening of the HF interactions is observed for oxidized starch, proving that the β‐hydrogen is abstracted more easily from C₍₂₎ at higher temperature. The decay of the radicals generated by microwaves or by heating at 483 K, during storing at 293 K, occurs monotonously, according to a second order kinetics. On the other hand, the radicals formed at higher temperature (503 K) represent nonmonotonous changes with the time of storing at 293 K. Such behavior may be explained assuming nonuniform distribution of thermally generated radicals, which partially do not contribute to the signal intensity leading to the significant broadening of the EPR lines. During relaxation the radicals became better dispersed which makes them active in EPR.     

异麦芽低聚糖的生产

<正> 在现今的食品工业中,消费者对功能性食品的需求日益增加,相关的产品与行业异军突起。作为一种能防止蛀牙,又含双歧杆菌的增长因子,能改善肠内菌丛的食品添加剂,异麦芽低聚糖深受市场的关注,并已得到广泛的应用。 异麦芽低聚糖通常被称为“ALO混合物” (Anomalously LinkedOligosaccharides,不规则连接的低聚糖),成分包括异麦芽糖、潘糖、异麦芽三糖及其他几种支链低聚糖。它带有甜味,不被酵母发酵,具有低粘度、高保温性、抗微生物污染、防焙烤产品老化等功能特性。     

Induction of autolytic breakdown of RNA in yeast by addition of ethanol and by drying/rehydration.

Autolytic degradation of RNA in suspensions of yeast at 50°C has been further studied as a means of preparing single-cell protein (SCP) suitable for human consumption. Membrane disorganisation with initiation of autolysis was promoted by addition of ethanol (5 % v/v) or, more effectively, by first air-drying yeast in a fluid-bed dryer and rehydrating it at 4°C, or at 50°C, before incubation at 50°C. Water was a poor suspension medium, but nearly complete breakdown of RNA within 1.5 h was achieved with a buffer, or with a 0.5 m solution of NaCl. Salt in high concentration possibly destroyed ribosomal structure. With pressed commercial baker 's yeast, a consideration of its composition suggested that an ideal procedure for removing RNA would result in the loss of about 24% of dry matter, with the production of SCP containing 54% protein. With careful timing, SCP with 48% protein could be obtained from air-dried yeast on extraction with 0.5 M-NaCl, with a loss of 32% of the dry matter. Active dried baker 's yeast also autolysed rapidly at 50°C, and had a relatively low proteinase activity. After extensive autolysis of baker 's yeast, the residual nucleic acid (about 5 % of that initially present) was characterised by a relatively high ratio of adenine/guanine.     

Production of quarg by ultrafiltration

The increased protein concentration in UF concentrate caused some problems in achieving the desired pH for quarg making when yogurt and mixed lactic cultures were used. Yogurt culture could ferment concentrated milk to a lower pH than the mixed culture. With the increasing concentration during UF, levels of total ash, calcium and phosphorus in the concentrate increased, but these increases were much lower at pH 4.6. Quarg obtained from UF concentrated sour milk was rated close to conventional quarg and had no bitter taste. A high heat treatment of milk before lactic fermentation and subsequent UF concentration resulted in a quarg with a smoother texture. Diafiltration of UF concentrated milk did not result in significant elimination of excessive calcium. The quality of the quarg was also poor with respect to taste, body and texture. Thus diafiltration would be of little use in quarg making.     

The sorption of iodide by soils as influenced by equilibrium conditions and soil properties

The sorption of iodide was reduced when soil was dried before equilibration with an iodide solution. With undried soils, sorption continued for > 48 h, maximum sorption occurred at pH values < 5 but a secondary sorption peak occurred at pH 8.5 to 9.0, particularly with a soil containing a high level of organic matter. Temperature had only a small effect on sorption over the range 10 to 35 °C. Maximum values for the sorption of iodide by two surface soils (0 to 10cm) at pH 6.6 to 6.8, assessed with a soil: solution ratio of 1:10, an equilibrium time of 40 h and at room temperature, were 25 and 6 fig I/g soil, respectively. The amounts of iodide sorbed by these soils, and by soils taken from successive 10 cm layers to a depth of 40 cm at the same two sites, were closely related to the contents of organic matter in the soils but not to contents of iron or aluminium oxides or of clay. Treatment of the surface soils with hydrogen peroxide to destroy organic matter greatly reduced the sorption of iodide at the pH of about 5.5 that resulted from the treatment. The removal of iron and aluminium oxides with Tamm reagent also resulted in a marked reduction in sorption at pH < 5. The results indicate that sorption was due in part to soil organic matter and in part to iron and/or aluminium oxides. At pH > 6, organic matter appeared to be the major sorbing constituent but under more acid conditions the oxides appeared to be increasingly important.     

食用油脂中挥发性卤代烃的HS-SPME-GC联用分析

目的：建立进出口油脂中挥发性卤代烃(VHHs)的顶空-固相微萃取-气相色谱(HS-SPME-GC)联用分析方法。方法：采用Supelco公司5种SPME纤维头对食用油脂进行顶空萃取,比较不同萃取纤维的萃取效率,分别考察萃取温度、时间、顶空体积等对萃取效果的影响。用毛细管色谱柱分离萃取成分、气相色谱-电子捕获检测器(GC-ECD)进行检测。结果：优选的SPME纤维头为75μm碳分子筛-聚二甲基硅氧烷(CAR/PDMS)。于15mL顶空萃取瓶中加入9mL食用油,在60℃恒温水浴中萃取30min后,290℃解吸3min进行GC分析。方法检测限为0.02～1.4ng/mL,回收率在89%～105%之间,相对标准偏差(RSD)小于8.5%(n=5)。结论：该方法具有操作简便、快捷、灵敏度高、检测限低、不使用有机溶剂等特点,适合于食用油脂中挥发性卤代烃的检测。     

Comparative study on decontamination of mixed feeds by radicidation and by pelletisation

Feed components contaminated with Salmonella act as vehicles in the transmission of these bacteria to animals and hence to meat and poultry. Sanitary improvements in processing, bagging and storage do not always effectively reduce Salmonella contamination rates and therefore ingredients or mixed feed should be decontaminated at the end of processing. Enumeration of Enterobacteriaceae was used to assay the decontamination effect of pelletisation of mixed feed. A working temperature over 80° usually reduced the bacterial count by a factor of 10⁵; lower temperatures currently used, reduced it by a factor of 10³ only. In similar dose-range-finding tests on decontamination with ⁶⁰Co gamma rays, about 0.5 Mrad were required for reductions in the counts of the most resistant Enterobacteriaceae by a factor of 10⁵. Survival curves being usually non-linear, ‘gross effective dose’ had to be used as a parameter. Neither loss of nutritive value nor the occurrence of orally toxic factors was observed when rats were fed for 2 years on a ration containing 35% fishmeal irradiated at 0.8 Mrad. A combination of improved sanitation, pelletising at the highest possible temperature and, if still required, terminal low-dose irradiation of the hermetically bagged material seems, therefore, a promising approach to the manufacture of Salmonella-free feeds.     

Enhancement of Drug Bioavailability by Cyclodextrins

The reassuring results of toxicity of orally administered ß-cyclodextrin and the realization of its industrial production opens a new way in the formulation of non-parenteral drug preparations. It is assumed that the utilization of ß-cyclodextrin in oral drug preparations will be a common process within a decade. The molecular encapsulation of drugs – i.e. complexation with cyclodextrin – has numerous advantages out of which one of the most important is the improved bioavailability. By inclusion complexation of a drug with cyclodextrin the drug becomes molecularly dispersed in a hydrophylic matrix, therefore the poorly soluble drug will become more soluble and will dissolve with an increased dissolution rate in aqueous milieu. The improved solubility generally leads to higher blood-level of the drug, which is manifested also in the biological response. The same dose of the drug results in an higher biological effect when applied a cyclodextrin complex, or to achieve an unaltered effect the drug dose can be reduced.     

Optimization of nano-emulsions production by microfluidization

The purpose of this study was to produce an oil-in-water nano-emulsion with different compositions of the continuous and dispersed phases through microfluidization. The aqueous phase was a solution of maltodextrin with five different emulsifying ingredients including modified starch (Capsul and Hi-Cap), sodium caseinate (SC), whey protein hydrolysate (WPH), or whey protein concentrate (WPC), while the oil phase consisted of d-limonene or fish oil. Results showed that micofluidizer was capable of producing nano-emulsions (D32 as small as 150 nm) with a narrow size distribution. Generally, moderate microfluidization pressures (42–63 MPa) and cycles (1–2) were the optimum conditions beyond which, there were adverse changes in the emulsion size. For the two oils tested as the dispersed phase, fish oil emulsions had lower Sauter mean diameters (D32) but with wider size distributions than d-limonene. When different emulsifying ingredients were compared, Hi-Cap produced nano-emulsions with the narrowest distribution but highest D32 (about 600 nm). Nano-emulsions with WPC had the smallest D32 (about 200 nm) but the widest size distribution. It was found that a d-limonene volume fraction of 0.10 was the optimum dispersed-phase concentration in terms of emulsion droplet size (D32). Also, adding a surfactant (Tween 20) helped to reduce the emulsion size significantly during microfluidization, but it lead to extensive flocculation of emulsion droplets because of surfactant–biopolymer interactions and emulsifier displacement.     

Detection of Konjac glucomannan by immunoassay

Konjac glucomannan is a hydrocolloid that has been used in food applications. The European ban on the use of Konjac glucomannan means that the detection and analysis has potential applications in the food industry, particularly detection of food adulteration. The aim of this work was to develop an assay capable of detecting Konjac glucomannan as an isolated sample and within food matrices. An indirect competitive ELISA was developed utilising a polyclonal antibody raised against Konjac glucomannan. The ELISA was found to be specific for Konjac glucomannan and sensitive, with a detection limit of 0.1 ng mL^?1. Increasing salt concentration and freeze/thaw cycles did not affect the performance of the assay. The ELISA was able to detect Konjac glucomannan in admixtures with other gums and also in confectionery that had been spiked with Konjac glucomannan. The ELISA has potential as a kit for the differentiation of Konjac glucomannan from other hydrocolloids and detection in food.     

Biodegradation of Wool by Bacteria and Fungi and Enhancement of Wool Quality by Biosurfactant Washing

Biodegradation of Ryeland and Shetland wool by Bacillus subtilis W3 and Streptomyces albidoflavus were investigated. The effect of treating raw wool with Rhamnolipid was also studied. It is shown that the wool surface morphology is improved with effective displacement of surface contaminants revealing a smooth outer cuticle layer after just 2 days. These results have important practical implications for the establishment of a quick and easy biodegradable process for wool scouring finishing in textile industry or for the pre-treatment of keratinous waste materials before degradation by bacteria or fungi. This methodology provides an environmentally friendly alternative to conventional chemical pre-treatments.