文胸防滑肩带扣的研究设计

为解决肩带随时间松弛、常见肩带扣易松动等问题而导致的肩带滑落,通过分析影响肩带滑落的因素,介绍了现有应对肩带滑落的方法及存在的问题,基于棘轮单向旋转反向自锁的原理设计了一款新型肩带扣。详述了新型肩带扣结构、各部件作用及工作原理,并举例说明其用途。新型肩带扣可有效解决目前文胸穿戴中出现的常见问题而导致的肩带滑落,具有较好的应用前景。     

佛手瓜块根生全粉添加量对小麦粉加工特性的影响

为明确佛手瓜块根生全粉对小麦粉加工特性的影响,在比较佛手瓜块根生全粉和小麦粉基本组成成分差异的基础上,分析了不同添加量(质量分数分别为0、10%、20%、30%)佛手瓜块根生全粉对小麦粉的基本理化性质、糊化特性和流变学特性的影响。结果表明,佛手瓜块根生全粉的总淀粉和总灰分含量均高于小麦粉,而粗蛋白含量、粗脂肪含量和平均粒径均低于小麦粉。X射线衍射分析结果显示,佛手瓜块根生全粉在2θ为5.6°、14.2°、17.2°、19.6°、22.2°、23.9°处存在明显衍射峰,表明其属于B型结构淀粉。加工特性分析结果表明,佛手瓜块根生全粉的添加显著提高了混合粉的吸水性、膨胀度和透光率,降低了其溶解度和冻融稳定性；稳态流变特性研究结果显示,佛手瓜块根生全粉的添加提高了混合粉的表观黏度、稠度系数K、流动特征指数n和屈服应力τ₀；动态流变特性研究结果表明,佛手瓜块根生全粉的添加提高了混合粉的储能模量和损耗模量,降低了损耗角正切值；糊化特性研究结果表明,添加佛手瓜块根生全粉降低了小麦粉的糊化温度和峰值时间,提高了峰值黏度、低谷黏度、最终黏度、崩解值和回生值。佛手瓜块根生全粉显著改变了小麦粉的加工特性,研究结果旨在为佛手瓜块根生全粉的加工应用提供理论依据。     

封闭型水性聚氨酯合成及在纸张表面施胶中的应用

采用一步聚合法,以聚乙二醇350单甲醚（mPEG350）、丁二醇（BDO）、二羟甲基丙酸（DMPA）、异佛尔酮二异氰酸酯（IPDI）为原料进行聚合,得到一种封闭型的水性聚氨酯（BWPU）。将质量分数1%的BWPU与质量分数4%的PVA复配成施胶液（SSA）,用于纸张表面施胶。结果表明,当DMPA添加量为10%、n（mPEG350）∶n（BDO）=1∶0.2、n（—NCO）∶n（—OH）（R值）为1.8,甲乙酮肟（MEKO）添加量为21.3%时,制备得到的BWPU性能最佳,其粒径为291.0 nm,分散稳定性指数（TSI）为1.33。施胶后的纸张撕裂指数为11.9 mN·m²/g,挺度为95.8 mN,抗张指数为82.6 N·m/g,耐折度为3394次,接触角为79.69°,施胶度为28.14°;与原纸相比,各项指标分别提高了76.8%、43.4%、7.8%、71.2%、26.3%,1307.0%。与市售施胶剂施胶后纸张相比,各项指标分别提高了20.9%、8.1%、15.9%、15.2%、10.3%、24.0%。     

1-MCP处理结合低温贮藏对早生新水梨采后生理及品质的影响

目的：研究以品质调控为主要因素的保鲜技术。方法：以呼吸跃变型的早生新水梨果实为试材,经3.24 μL/L的1-MCP熏蒸处理后,放置于(10±1) ℃条件下贮藏;分别以不做任何处理、放置于(10±1) ℃和(1±1) ℃中贮藏的果实作对照一(CK1)和对照二(CK2),对贮藏期间的果实呼吸强度、乙烯释放速率、硬度、可溶性固形物含量、果皮色差值、褐心指数、失重率和腐烂率进行测定和调查,并进行相关性分析。结果：与CK1相比,(10±1) ℃贮藏结合1-MCP处理可抑制果实的乙烯释放速率和呼吸强度,推迟其高峰的出现,但对呼吸强度和乙烯释放速率的抑制效果仍显著低于CK2;可保持较高的可溶性固形物含量、减少果实水分的流失、延缓果实腐烂和褐变、维持果皮绿色(a*绝对值高、h°高)。整个贮藏期间,(10±1) ℃贮藏结合1-MCP处理的果实带皮硬度、果肉组织硬度、果实脆性和果肉紧实度显著高于CK1;但CK2对果实质地的保持效果仍高于(10±1) ℃贮藏结合1-MCP处理的效果;除呼吸强度、乙烯释放速率和褐心指数外,其他各项指标间均存在不同程度的相关性。结论：(10±1) ℃贮藏结合3.24 μL/L的1-MCP熏蒸处理安全贮藏期可达103 d,可溶性固形物含量稳定在12%左右,较好地保持了果实固有风味和色泽,可作为代替单一低温贮藏的保鲜技术之一。     

卷烟接装纸的液体动态渗透性能研究

在对比分析接装纸印刷面和非印刷面表面结构及性能的基础上,通过动态接触角法和动态渗透法,分析了接装纸印刷面和非印刷面的表面润湿和渗透性能,系统研究了液体在接装纸两面上的动态渗透过程。结果表明,接装纸的两面差异性导致了印刷面和非印刷面液体润湿和渗透的差异,动态渗透曲线的3个特征参数（t_max、t₉₅和A_b）可以表征不同来源接装纸的润湿和渗透性能。在0.5 s时,接装纸的非印刷面和印刷面接触角降低值的差值在8°以内,可以获得较好的上机适用性。     

根皮素对硫代乙酰胺诱导的小鼠急性肝损伤的保护作用

本实验旨在研究根皮素对硫代乙酰胺诱导的小鼠急性肝损伤的保护作用。采用硫代乙酰胺造模,诱导小鼠急性肝损伤,以槲皮素作为阳性对照药物,通过检测血清学指标（丙氨酸氨基转移酶ALT、天冬氨酸氨基转移酶AST、γ-谷氨酰转肽酶γ-GT、 碱性磷酸酶ALP和血清总胆红素TB）和组织病理切片方法,研究根皮素对小鼠急性肝损伤的保护作用。实验结果显示,在预先灌胃高、低剂量根皮素组别中,小鼠血清ALT 活性分别为（149.14±21.55） U/L和（189.43±16.64） U/L,AST 活性分别为（123.58±35.90） U/L和（168.64±33.32） U/L。-γ--GT 活性分别为（103.19±20.93） U/L和（129.30±27.91） U/L,ALP 活性分别为（19.67±3.32） King U/dL和（24.17±3.58） King U/dL,血清TB浓度分别为（198.14±29.64） -μ-mol/L 和（227.04±34.20） -μ-mol/L。相比于造模组,根皮素组ALT、AST、-γ--GT、ALP和TB明显降低（-n-=8,-p-<0.05）,而且降低幅度呈现剂量依赖性,根皮素处理组的小鼠肝组织病理学病变得到了显著改善。研究表明,根皮素对硫代乙酰胺诱导的小鼠急性肝损伤有显著的保护作用,是值得进一步研究的急性肝损伤保护的候选药物和食品添加剂。     

利用发芽大豆制备大豆酸奶的研究

为获得具有更高生理活性的大豆酸奶,作者研究了大豆发芽对豆浆的乳酸菌发酵性能、发酵豆浆的生理活性和豆浆风味的影响。结果表明：在最初72 h内,随发芽时间的延长,大豆的三氯乙酸可溶性氮和游离氨基酸含量显著提高（P＜0.05）;豆浆乳酸菌发酵性能明显改善,达到发酵终点（pH 4.5）的时间由7.2 h缩短至5.0 h,酸度则由42.18 °T提升至66.56 °T;乳酸、柠檬酸等有机酸的含量增加。发芽使乳酸菌发酵豆浆的硬度降低,质构更细腻。在生理活性方面,发芽72 h后,乳酸菌发酵豆浆的γ-氨基丁酸含量增加了19.83 mg/hg,苷元型异黄酮含量增加了115.02%;DPPH、ABTS和羟自由基清除率均显著提高（P＜0.05）。另一方面,发芽导致豆浆中异味成分含量明显增加。在综合考虑发芽对生理活性和风味影响的基础上,以发芽36 h的大豆制备大豆酸奶,考察了4种直投式发酵剂对于大豆酸奶风味及感官品质的影响。结果表明,发酵剂A发酵得到的大豆酸奶异味成分含量最低,感官品质最佳。     

文胸肩带压强分布分析

 为了找出肩带压强的分布规律,被测试者分别穿着4款文胸,做出直立、两臂上举、两臂前伸、端坐、放松坐和前倾90°的动作,采用AMI-3037-5S服装压力测量系统对肩带上6个主要测量点进行压强测量。结果表明：不同款式文胸在穿着时,肩带压强分布规律相同。在肩部的最高点处值最大,向前向后依次变小,但在肩带的最后端与文胸上比的交叉点处受到上比的作用,压强值会有所增加。人体做不同动作时,肩带上各点压强受到骨骼肌肉变化的影响也会产生不同的变化;与肩带交叉点处的骨骼凸起或肌肉紧张时,压强会增大。     

微生物多糖改善高透滤棒成形纸强度性能的研究

研究了黄原胶、普鲁兰多糖、葡聚糖、α-环糊精4种微生物多糖的添加方式和用量对高透滤棒成形纸强度、透气度等性能的影响。结果表明,普鲁兰多糖对高透滤棒成形纸的增强效果明显优于其他3种多糖,且浸渍处理比浆内添加更有利于强度性能的提升。利用不同打浆度的针叶木浆、针叶木浆与丝光浆混合浆、针叶木浆与黏胶纤维混合浆制备了具有不同透气度的高透成形纸,经普鲁兰多糖浸渍后,高透成形纸强度性能均随着上胶量增加而增加,透气度随上胶量增加无明显变化。与未浸渍纸张相比,浸渍普鲁兰多糖后,上胶量约3.0 g/m²,打浆度15°SR、18°SR、21°SR的针叶木浆所抄纸张抗张强度分别增加了69.9%、69.2%和67.5%,18°SR针木叶浆与丝光浆配抄纸张抗张强度增加了96.5%,与黏胶纤维配抄纸张抗张强度增加了126.0%。     

乌饭树树叶蓝黑色素对大米蛋白理化性质的影响

目的：研究乌饭树树叶蓝黑色素对大米蛋白组分结构性质和乳化性质的改善作用。方法：以乌饭树树叶为原料制备蓝黑色素,以乌米饭中大米蛋白为研究对象,模拟乌米饭染色过程并分析染色前后大米蛋白结构性质和乳化性质的变化。结果：乌饭树树叶蓝黑色素可与大米蛋白形成二元复合物,导致色度L*值和b*值降低,复合物颜色向蓝黑色转变。色素—蛋白复合物溶解度增加,而持油性显著降低。利用圆二色光谱分析大米蛋白二级结构,发现其α-螺旋与β-折叠的相对含量下降,β-转角和无规卷曲的相对含量上升。当色素质量分数低于1.5%时,起泡稳定性升高,而起泡性、乳化性和乳化稳定性降低。当色素质量分数高于1.5%后,起泡稳定性下降,起泡性、乳化性和乳化稳定性升高。结论：乌饭树树叶蓝黑色素通过改变大米蛋白二级结构可改善其乳化性质。     

Influence of Infrared Treatment on Mechanical Strength and Structure of Wheat Grains

The paper presents the relationship between the parameters (temperature and time) of infrared heating and wheat grain compressive resistance. Additionally, an attempt to explain the mechanism of decrease in the strength of grain under thermal processing was undertaken. Based on the results obtained, we reached the conclusion that thermal processing with infrared (IR) radiation leads to a decrease in wheat grain compressive resistance. The range of compressive resistance changes depends on the temperature and the time that the wheat grain is exposed to IR radiation: The higher the temperature and the longer the processing time, the lower grain compressive resistance. The lowest values of compressive force were recorded following the process carried out at 180 °C for 150 s. Changes of grain resistance are caused by damage done to their internal structure resulting from the thermal influence of infrared radiation. The damage scope is related to the temperature and processing time. There are particularly noticeable changes after processing at temperature above 150 °C and time exceeding 90 s. In the course of the process carried out under these conditions (t > 150 °C, τ > 90 s), a phenomenon of starch gelatinization occurs. Starch begins to gelatinize from the inside of the grains, which is characteristic of the absorption and heat transfer mechanisms occurring during electromagnetic wave heating.     

Control of post‐harvest brown rot on nectarine by Epicoccum nigrum and physico‐chemical treatments

Post-harvest physico-chemical treatments—water at 40 °C or 60 °C (HW), and sodium bicarbonate at 1 or 2.5% (SBC) at 20, 40 and 60 °C—were tested on peaches and nectarines in order to control brown rot caused by Monilinia spp. and to select the best physico-chemical treatment to be used in combination with pre-harvest applications of the biological control agent Epicoccum nigrum (ATCC number 96794). Experiments were carried out in France, Italy and Spain in order to test different experimental conditions. Monilinia rot was reduced in peach and nectarine treated with HW (40 °C for 2 min) in all three countries, the percentage of rot reduction was similar for France, Italy and Spain (over 40%). A synergistic effect between HW at 40 °C during 150 s or at 60 °C during 20 s and SBC was observed in all three countries. After preliminary experiments post-harvest treatment of HW (60 °C) + SBC (1%) during 20 s was selected to combine it with field treatments. Pre-harvest treatments with fungicide or E. nigrum did not reduce brown rot in any country. However, pre-harvest treatments with E. nigrum, chemical fungicide, and their integration followed by post-harvest physico-chemical treatment significantly reduced Monilinia rot compared to pre-harvest untreated fruits followed by post-harvest physico-chemical treatment in Italy (over 70%). Post-harvest treatments with E. nigrum were also tested in Italy on natural and artificial infections in nectarine over 3 years. E. nigrum, as fresh or formulated cells, at a concentration of 10⁸ conidia mL⁻¹ were effective, significantly reducing the incidence of brown rot compared to control, both under artificial and natural infection, from 43 to 100%. Copyright © 2007 Society of Chemical Industry     

Rehydration of Freeze‐Dried and Convective Dried Boletus edulis Mushrooms: Effect on Some Quality Parameters

ABSTRACT: Quality of rehydrated products is a key aspect linked to rehydration conditions. To assess the effect of rehydration temperature on some quality parameters, experiments at 20 and 70 °C were performed with convective dried and freeze‐dried Boletus edulis mushrooms. Rehydration characteristics (through Peleg's parameter, k₁, and equilibrium moisture, W_e), texture (Kramer), and microstructure (Cryo‐Scanning Electron Microscopy) were evaluated. Freeze‐dried samples absorbed water more quickly and attained higher W_e values than convective dried ones. Convective dehydrated samples rehydrated at 20 °C showed significantly lower textural values (11.9 ± 3.3 N/g) than those rehydrated at 70 °C (15.7 ± 1.2 N/g). For the freeze‐dried Boletus edulis, the textural values also exhibited significant differences, being 8.2 ± 1.3 and 10.5 ± 2.3 N/g for 20 and 70 °C, respectively. Freeze‐dried samples showed a porous structure that allows rehydration to take place mainly at the extracellular level. This explains the fact that, regardless of temperature, freeze‐dried mushrooms absorbed water more quickly and reached higher W_e values than convective dried ones. Whatever the dehydration technique used, rehydration at 70 °C produced a structural damage that hindered water absorption; consequently lower W_e values and higher textural values were attained than when rehydrating at 20 °C.     

土块处理机的碎土机理研究

本文在分析了土块处理机结构特点的基础上,阐述了其碎土机理。基于显式动力分析软件Ansys/Ls-Dyna,构造了刀片-土块在Ls-Dyna K文件中的本构模型,模拟土块在破碎机中的碰撞破碎过程,找出了最佳的进料斗倾斜角42°,同时在水稻盘育秧用土处理机上进行了碎土实验,得出α为38～42°时土块破碎效果最好,这为该机的改进提供了有力的理论依据。     

Thermal inactivation of polyphenoloxidase and peroxidase in green coconut (Cocos nucifera) water

Coconut water is an isotonic beverage naturally obtained from the green coconut. After extracted and exposed to air, it is rapidly degraded by enzymes peroxidase (POD) and polyphenoloxidase (PPO). To study the effect of thermal processing on coconut water enzymatic activity, batch process was conducted at three different temperatures, and at eight holding times. The residual activity values suggest the presence of two isoenzymes with different thermal resistances, at least, and a two‐component first‐order model was considered to model the enzymatic inactivation parameters. The decimal reduction time at 86.9 ^°C (D_{86.9 °C}) determined were 6.0 s and 11.3 min for PPO heat labile and heat resistant fractions, respectively, with average z‐value = 5.6 °C (temperature difference required for tenfold change in D). For POD, D_{86.9 °C} = 8.6 s (z = 3.4 °C) for the heat labile fraction was obtained and D_{86.9 °C} = 26.3 min (z = 6.7 °C) for the heat resistant one.     

The Biological Impact of Flash Pasteurization Over a Wide Temperature Interval*

Trials on the impact of flash pasteurization on beer quality showed that higher pasteurization temperatures with shorter holding times are favourable for beer quality. However, the killing effect in the temperature range up to 90°C has not been elucidated so far. Pasteurization temperatures of 50°; 60°; 72°; 84° and 90°C and pasteurization units of 0; 15; 80 and 500 PU were used. The associated residence times were calculated according to Del Vecchio et al.'s formula. The experiments with beer‐relevant yeasts and bacteria showed that Saccharomyces yeasts are much easier to inactivate than Lactobacilli and Pediococci. Furthermore, it can be stated that the commonly used PU calculation according to Del Vecchio reflects the actual killing characteristics in the temperature range from 60° to 72°C quite precisely. Although flash pasteurization with low PU figures at temperatures higher than 72°C and with very high amounts of bacteria may be insufficient, because the real inactivation effect is lower than indicated, there is no need to increase the PU load when changing to higher pasteurization temperatures and shorter holding times in practical application.     

Influence of ultrasound on mass transport during cheese brining

 The effect of ultrasound on mass transfer during cheese brining has been investigated. The rate of water removal and NaCl gain increased when ultrasound was applied in comparison with brining performed under static or dynamic conditions, suggesting that ultrasound improves both external and internal mass transfer. A simple diffusional model was developed to simulate mass transport during acoustic brining. Model parameters were estimated using experimental data from acoustic brining experiments carried out on cheese cylinders of 1.7×10^–2m radius and 3×10^–2 m height at different temperatures (5, 15 and 20  °C). Effective water (D _W) and NaCl (D _S) diffusivities estimated using the proposed model ranged from 5.0×10^–10m²/s and 8.0×10^–10 m²/s at 5  °C to 1.3×10^–9m²/s and 1.2×10^–9 m²/s at 20  °C. Both D _W and D _S varied with temperature according to the Arrhenius equation. Through the proposed model, water losses and NaCl gains of the experiments used in the parameter identification were accurately simulated (average %var=98.2%) and also of two additional acoustic experiments carried out under different conditions of temperature (10  °C) and sample size and geometry [parallelepiped of (6×2.5×1.25)×10^–2 m] to those used in the parameter identification (average %var=98.4%). Received: 22 September 1998 / Revised version: 20 November 1998     

Effect of microwave extraction temperature on the chemical structure and oil-water interface properties of fish skin gelatin

This study investigated the effect of microwave extraction temperature on the chemical structure and oil-water interface properties of fish skin gelatin. Results showed that increasing microwave extraction temperature from 55 to 75 °C led to the degradation of α subunits and breaking of the triple helical structure of gelatin, consequently exposing more hydrophobic groups and showing an improvement of amphiphilicity (58.35°-81.65°). Correspondingly, the interface pressure and adsorption also respectively increased from 8.00 to 8.90 mN/m and 43.70% to 93.66% due to its enhanced amphiphilicity. Furthermore, the volume-mean diameter and creaming index (CI) of emulsion obviously decreased, but the water holding capacity significantly increased, implying an improvement of emulsifying property. The rheological results showed the emulsion displayed a typical shear thinning behavior, and the apparent viscosity increased from 230 to 1339.4 Pa·s with the increase of microwave extraction temperature (55–75 °C) and concentration (1.0–3.0 wt%) at 0.1 s⁻¹. The possible reason is that more gelatin molecules participated in the formation of dense network structure of continuous phase due to the higher amphiphilicity. This work would provide guiding significance for green extraction of fish skin gelatin and its application in stabilizing emulsion.     

Changes in carotenoids and chlorophylls in fresh green asparagus (Asparagus officinalis L) stored under modified atmosphere packaging

Asparagus is a highly perishable product owing to its high respiratory rate, a reason why modified atmosphere packaging (MAP) has been used in order to increase the shelf‐life of fresh asparagus. Carotenoid and chlorophyll pigments are important compounds for the maintenance of both the nutritional and sensory quality of asparagus. In this study, green asparagus spears were stored under refrigeration at 2 °C for 14 days, under MAP at 2 °C for 26–33 days and under MAP at 10 °C for 20 days. Pigment profiles were determined using high‐performance liquid chromatography (HPLC), with three classes of compounds being detected, namely oxygenated carotenoids (xanthophylls), hydrocarbonated carotenoids (carotenes) and chlorophylls. The xanthophylls identified were neoxanthin, violaxanthin, lutein and zeaxanthin. Only β‐carotene was detected in the carotene fraction. In the chlorophyll pigments, three molecules were isolated, chlorophyll b, its epimer chlorophyll b′ and chlorophyll a. Also detected were the first degradation products of chlorophylls, pheophytins b and a respectively. Modified atmosphere packaging at 2 °C was found to be effective in extending the shelf‐life for up to 4 weeks and in preserving the colour of fresh asparagus. Copyright © 2004 Society of Chemical Industry     

Effect of preheating temperature on the microstructure of walleye pollack surimi gels under the inhibition of the polymerisation and degradation of myosin heavy chain

BACKGROUND: The physical attribute of heat‐induced gel texture is highly dependent on the microstructure of the gel. In this study the microstructures of walleye pollack surimi gels preheated at various temperatures with and without inhibitors (ethylenediamine‐N,N,N′,N′‐tetraacetic acid, iodoacetamide and leupeptin) were observed with a natural scanning electron microscope. RESULTS: Without inhibitors, gels preheated at 30 °C showed a fine and uniform network structure together with the highest polymerisation of myosin heavy chain (MHC) and the highest gel strength. At 60 °C, gels exhibited a broken, disrupted and loose cluster‐like structure together with the highest degradation of MHC and the lowest gel strength. Under the inhibition of polymerisation and degradation of MHC a fine network was observed up to 40 °C during preheating. However, after a second step of heating at 80 °C the microstructures were disrupted and resembled each other regardless of the preheating temperature. CONCLUSION: Heat‐induced gel formation is related to the polymerisation and degradation of MHC and the microstructure of the gel during preheating. Gelation occurred during setting even under the inhibitory condition, and the formation of covalent bonding by transglutaminase is not essential to the formation of a three‐dimensional network during setting but is essential to the gel strength enhancement effect of setting by subsequent heating at 80 °C. Copyright © 2010 Society of Chemical Industry