小麦剥皮工艺与剥皮制粉关系探讨

分析了剥皮制粉工艺对剥皮麦的工艺要求和目前剥皮工艺存在的问题 ,介绍了FBPY小麦剥皮新技术的特点和剥皮工艺对剥皮制粉工艺的影响     

大豆浸出毛油脱胶新工艺

对大豆浸出毛油脱胶工艺路线中的膜除杂工艺、酶解法脱胶工艺进行了研究,并对影响酶解法脱胶工艺的主要因素进行了单因素实验,同时对各主要因素对该工艺的综合影响进行了正交优化,得出了该工艺的主要影响因素在该工艺中的最佳操作条件,即酶解4h、水化1.25h、预热温度为70℃、酶用量0.35g/750mL毛油.     

制钠技术中电解槽用阴极的国产化

文章对通过对内蒙古兰太实业股份有限公司制钠设备图纸审核得出的新制作工艺进行详尽的说明,制订了各类制作工艺—胎具制作工艺、焊接制作工艺、焊后热处理工艺、钳工划线工艺、镗床工艺、阴极筒加工工艺,依据制定的各类制作工艺进行改造后的阴极各项性能指标都达到了要求。通过此次成功改造,大大降低了公司的采购成本,缩短了产品的进货周期,同时也强化并提升了公司的设备制作技术,提高了公司设备制作方面的知名度。     

蜡染工艺优化

对蜡染工艺进行了研究探讨 ,比较了不同蜡染工艺对蜡染效果的影响 ,并确定了最佳工艺方案 ,以便对实际生产有一定的指导作用     

薄膜开关技术入门

本文对薄膜开关制造过程中的关键工艺——电路工艺、“架桥”工艺、面版工艺、粘胶层工艺、隔离层工艺作了较为详细的介绍,特别对网版制作与印刷技术中的诸多诀窍作了实质性的阐述。     

木质纤维素制备乙醇工艺的研究进展

本文介绍了国内外生物质能制乙醇的研究进展,包括预处理工艺、纤维素的水解、发酵工艺和脱水工艺,并对各种工艺的优缺点进行了论述,并对我国的燃料乙醇的发展提出了展望。     

制浆中段废水处理的研究进展

对物化处理、高级氧化工艺、生化工艺以及联合工艺用于制浆中段废水的处理应用进行了总结,并对各工艺的优缺点及应用前景进行了评价。     

油料预处理的现状与发展趋势

主要对油料预处理现有的各种工艺和主要设备进行了介绍,对不同工艺的优势和不足之处进行了比较,提出了改进油料预处理工艺和设备的必要性,并介绍了油料预处理工艺、设备、建筑等方面的发展趋势     

重定量高效工艺的纺纱实践

以C27．8tex纱为例,介绍了高效工艺流程,对相关工序提出了具体的工艺调整措施,并对普通工艺与高效工艺的细纱成纱指标进行了对比,结果表明重定量高效工艺是可行的。     

白酒贮存工艺研究进展

白酒贮存工艺的不同,对白酒质量产生的影响也不同。本文归纳和总结了近年来在白酒贮存工艺方面研究取得的成果,为了解白酒贮存工艺和科学地选择白酒贮存工艺用于企业生产实际提供参考。分别介绍了陶坛贮存工艺、不锈钢罐贮存工艺、水泥池贮存工艺、酒海贮存工艺以及瓶贮工艺的特点和对酒质的影响;总结了不同贮存工艺的优缺点及其适用性,以及使用不同贮存工艺时的注意事项;提出了白酒贮存工艺深入研究的展望。随着科学技术的发展,新型材料容器贮存工艺和新的质量稳固手段将使白酒按既定质量要求提升成为可能。     

涤锦复合超细纤维非织造布的染色

涤锦复合超细纤维非织造布宜采用分散染料浸染或轧染方式进行低温染色,染色过程需加入染色助剂和特殊处理。结果显示,浸染时加入1g/L匀染剂,轧染时加入5g/L防泳移剂,并在染前进行前处理定型,两种染色方式都能使织物具有良好的匀染性及色牢度。     

Toxic ratio as an indicator of the intrinsic toxicity in the assessment of persistent, bioaccumulative, and toxic chemicals

Persistence, bioconcentration, and toxicity (PBT) are important hazardous properties of organic chemicals. In PBT assessments, it is desirable that the three criteria P, B, and T are independent. However, this requirement is not fulfilled if an aqueous lethal concentration (LC50) is used as T indicator because LC50 includes both bioconcentration and intrinsic toxicity. Indicators for intrinsic toxicity such asthe internal lethal concentration (ILC) are independent of a chemical's bioconcentration potential. However, ILC50 data are scarce and difficult to measure. Therefore, the toxic ratio (TR) is proposed here as an alternative. TR is defined as the ratio of a chemical's LC50 estimated from a QSAR for baseline toxicity and the experimental LC50 value. TR can also be interpreted as a measure of the ILC relative to the ILC for baseline toxicity. A TR of 10 separates specifically toxic chemicals from baseline toxicants. With some 800 chemicals, the practicability of classifying chemicals in terms of TR is demonstrated. Employing TR as toxicity indicator leads to different T scores for 30% of the chemicals studied. The baseline toxicity of hydrophobic compounds with TR < 10 does not receive a high T score but is still indicated by a high B score. The toxicity of specifically toxic hydrophilic substances is given additional emphasis by high TR values. These classification changes require that the interpretation of the B and T dimensions in PBT assessments is redefined.     

CHARACTERISTICS OF TWO TRYPSIN ISOZYMES FROM THE VISCERA OF JAPANESE ANCHOVY (ENGRAULIS JAPONICA)

Two isozymes of trypsin (TR‐I and TR‐II) were purified from the viscera of Japanese anchovy (Engraulis japonica) by gel filtration and anion‐exchange chromatography. Final enzyme preparations were nearly homogeneous in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), and the molecular weights of both enzymes were estimated to be 24,000 Da by SDS‐PAGE. The N‐terminal amino acid sequences of the TR‐I, IVGGYECQAHSQPHTVSLNS, and TR‐II, IVGGYECQPYSQPHQVSLDS, were found. Both TR‐I and TR‐II had maximal activities at around pH 8.0 and 60C for hydrolysis of Nα‐p‐tosyl‐L‐arginine methyl ester hydrochloride. The TR‐I and TR‐II were unstable at above 50C and below pH 5.0 and were stabilized by calcium ion.     

Temperature-Controlled Pulsed Light Treatment: Impact on Aflatoxin Level and Quality Parameters of Peanut Oil

Peanuts are an economically significant crop that is commonly used for edible oil production; however, they are prone to contamination by aflatoxin (AFT)-producing fungi. Common methods to treat edible oils for AFTs often utilize high temperatures (>?100 °C) to thermally degrade the toxins. However, high temperatures often negatively impact product quality. In this study, pulsed light (PL) was assessed as a possible method to degrade AFTs in peanut oil. A pilot-scale PL applicator was used to treat 5-mL samples of peanut oil of 10 mm thick. Samples were treated for 1 to 10 min with or without temperature reduction (TR). The sample containers were placed in an ice water bath to mitigate increases in oil temperatures for the TR samples. The physical, color, and chemical quality parameters (peroxide value, free fatty acid, acidity value, and oxidative stability index (OSI)) of the oil were assessed in comparison to controls. Results show that significant AFT destruction was achieved using PL. There was a significant difference between reduction achieved when TR was employed, likely due to the combined effect of photochemical and thermal treatment. TR samples treated for 400 s experienced an AFT reduction of 48.4%, while those treated 600 and 800 s achieved 55.6 and 78%, respectively. The samples treated with TR showed lower quality degradation when compared to peanut oil samples treated without TR for equivalent treatment times. Using TR, PL resulted in a significant reduction of AFT, without losses in quality typically associated with thermal methods. At industrial scale, PL may offer an economical treatment of AFT-contaminated oil.     

The effect of withering on fermentation of tea leaf and development of liquor characters of black teas

Depression in polyphenol oxidase (PPO) activity during the withering of tea leaf (Camellia sinensis) in black tea manufacture affected the oxidative-condensation of tea flavanols in forming theaflavins (TF) and thearubigins (TR), which are associated with brightness, briskness and ‘body’ of tea liquors. In contrast to conventionally manufactured CTC teas, unwithered fresh leaf CTC produces a higher proportion of TF and lower TR, resulting in bright, brisk and thin liquors. Hardness of wither was accompanied by a further depression in PPO activity, and formation of TF also declined with a concomitant loss in brightness and briskness. The TR content increased up to a certain degree of wither and thereby improved the ‘body’ of the liquor. Very hard wither, accompanied by a large reduction in moisture content, restricts PPO activity. It appears that in the fresh leaf, high moisture levels together with dissolved oxygen accelerate the enzymic oxidation and produce large amounts of TF. Senescence of the leaf seems to facilitate the production of TR.     

Direct quantification and distribution of tetracycline-resistant genes in meat samples by real-time polymerase chain reaction

The evolution of antimicrobial-resistant bacteria has become a threat to food safety and methods to control them are necessary. Counts of tetracycline-resistant (TR) bacteria by microbiological methods were compared with those obtained by quantitative PCR (qPCR) in 80 meat samples. TR Enterobacteriaceae counts were similar between the count plate method and qPCR (P= 0.24), whereas TR aerobic mesophilic bacteria counts were significantly higher by the microbiological method (P < 0.001). The distribution of tetA and tetB genes was investigated in different types of meat. tetA was detected in chicken meat (40%), turkey meat (100%), pork (20%), and beef (40%) samples, whereas tetB was detected in chicken meat (45%), turkey meat (70%), pork (30%), and beef (35%) samples. The presence of tetracycline residues was also investigated by a receptor assay. This study offers an alternative and rapid method for monitoring the presence of TR bacteria in meat and furthers the understanding of the distribution of tetA and tetB genes.     

Studies of polymer polyphenols in tea

Polymer tea polyphenols (thearubigins=TR) were isolated from a black tea brew by ultrafiltration. The fraction of relative molecular mass (M_r)>5000 was examined using liquid chromatography. A partial separation of the TR fraction could be achieved by reversed-phase (RP)-HPLC and by gel-filtration chromatography, but not a complete separation into distinct peaks. After hydrolysis, the anthocyanidins delphinidine and cyanidine and some flavone-C-glycosides were detected. The amount of cyanidine was 0.26% (in the TR fraction M_r>5000). Gallic acid moieties were also determined after hydrolysis: the amounts were about 2.5% (in the TR fraction mentioned above). An HPLC separation system from the literature was employed to analyse the stability and extraction behaviour of the TR. An extract prepared by a 2-h Soxhlet extraction contained only small amounts of TR compared with a tea brew prepared by a normal 10 min extraction. This is due to incomplete extraction, not to destruction. Hot-plating the 10-min extract (90° C, 2 h) led to a decrease in the peak areas of theaflavin (TF) and other pigments.

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Untersuchungen über höhermolekulare Polyphenole des Tees

Zusammenfassung Höhermolekulare Tee-Polyphenole (Thearubigine=TR) wurden aus einem schwarzen Teeaufguß mittels Ultrafiltration isoliert und die Fraktion mit einer relativen Molekülmasse (M_r)>5000 chromatographisch untersucht. Mittels RP-HPLC und Gelfiltrationschromatographie gelang eine Antrennung der TR-Fraktion in verschiedene Bereiche, aber keine vollständige Auftrennung in diskrete Peaks. In Hydrolysaten der Fraktion wurden die Anthocyanidine Delphinidin und Cyanidin sowie Flavon-C-glykoside nachgewiesen; Cyanidin wurde mit 0.26% (bezogen auf die TR-Fraktion) ermittelt. Der Anteil an gebundener Gallussäure wurde ebenfalls in der isolierten TR-Fraktion bestimmt; die Gehalte lagen bei 2.5% bezogen auf die TR-Fraktion. Ein HPLC-Trennsystem für TR aus der Literatur wurde zur Untersuchung der Stabilität und des Extraktionsverhaltens der TR benutzt. Es wurde festgestellt, daß durch 2 h Soxhlet-Extraktion weniger TR als durch einen normalen Aufguß (Ziehzeit 10 min) extrahiert werden. Beim Warmhalten des normalen Aufgusses (2 h, 90 °C) tritt eine gewisse Abnahme der Theaflavin- und der TR-Gehalte ein.

     

Rapid method for measuring thearubigins and theaflavins in black tea using C18 sorbent cartridges

This communication describes the routine use of small inexpensive C₁₈ cartridges for rapid separation and accurate measurement of both thearubigins (TR) and theaflavins (TF) in a liquor brewed from black tea. The slow, traditional method overestimates TR content because of interference from flavonol glycosides. Comparison is also made favourably with other methods available for estimating total TF and sometimes TR in tea.     

Engineering packaging design accounting for transpiration rate: Model development and validation with strawberries

Integrative mathematical modelling for Modified Atmosphere Packaging (MAP) has been used to determine the gas composition inside a package, but can also be used to determine the packaging needs of fresh produce in terms of permeability to gases and water vapour. Transpiration rate (TR) is an important physiological process that influences relative humidity (RH) and condensation inside the package, and ultimately quality and shelf life. Strawberries are an extremely valuable crop, but they are susceptible to grey mould rot, fungal decay, moisture loss and condensation. Quantification of strawberry transpiration rate TR would be required to estimate the packaging material water vapour transmission rate (WVTR) and therefore optimise engineering packaging design. This study investigated (i) the impact of temperature and RH on strawberry TR, (ii) developed a predictive model for quantifying TR, (iii) integrated transpiration rate model into the engineering packaging design and quantified the target WVTR for packaging of strawberry and (iv) validated packaging design by comparison to commercial packaging. Experiments were conducted following an experimental design, considering two factors at three levels (3²), i.e. temperature (5, 10 and 15 °C) and RH (76%, 86% and 96%); TR was recorded during 5 days of storage. The results showed that both RH and temperature had a significant effect on TR. In a given temperature and RH range of study, it varied from 0.24 to 1.16 g/kg h. Mathematical model developed considering the effect of temperature and RH, was further validated at 12 °C and 76% RH, showing very good predictability (R² > 0.997). The TR model was found to be useful for describing the strawberry packaging requisites and for optimal engineering packaging design for strawberry. The target WVTR for achieving optimal RH of 90% at 5 °C was found to be 162 g/m² day. Packaging design validation showed that the package designed considering both gas and water vapour requisites of strawberry yielded favourable results for maintaining quality and shelf life of product.