Influence ofArtemisia princeps var.orientalis components on callus induction and growth

An in vitro study was performed to determine the potential application of tissue culture in determining allelopathic potentialof Artemisia princeps var.Orientalis (wormwood). Aqueous extracts and volatile substances ofA. princeps var.Orientalis were tested to determine their effects on callus induction and growth of several tested species. Extracts of 5%A. princeps var.Orientalis caused some reduction in concentration, induction, and growth of callus, although they looked normal, whereas the expiants of most receptor plants did not develop callus at higher concentration. Lettuce andEclipta prostrata were the most sensitive species, andA. princeps var.Orientalis was affected by its own extracts. The growth of calluses in MS 121 medium treated with essential oil ofA. princeps var.Orientalis was inhibited, and the degree of inhibition was proportional to the concentration of the essential oil.     

放线菌YIM31249发酵液萃取物的抗菌活性初步研究

从云南洱源采集的土壤样品中分离到一株放线菌YIM31249,进行摇瓶发酵,然后用乙酸乙酯萃取发酵液,对萃取物进行体外抗菌实验。试验表明：对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度(HIC)为0．24mg/mL,最低杀菌浓度(MBC)为1．88mg／mL;对灰霉和黑曲霉的MIC和MBC均为0．022mg／mL。因此,放线菌YIM31249菌发酵液中具有天然抗菌活性物质,且抗菌作用明显,有较广的抗菌谱。     

Use of rosemary extract in preventing oxidation during deep-fat frying of potato chips

The effect of using a rosemary extract on the stability of oil used for frying potato chips has been evaluated. Sliced potatoes were fried intermittently in soybean oil containing a natural extract from rosemary. The conditions used for frying were 185°C for 90 s. Two separate experiments, with and without replenishment of oil, were carried out. Oil samples were taken each day, not only from the frying pans but also by extraction with hexane from the chips. Changes in the induction period of the oil samples (Rancimat method) were determined. The induction period decreased as frying progressed. The reduction in the induction period was higher in the oil free of rosemary extract, and the chips were much darker in color. The oil containing the extract showed greater antioxidant activity, and reduced darkening and rancidity of the oil. Potato chips fried in the oil with added rosemary extract were more acceptable than chips fried in oil containing no extract until the last frying. The free radical scavenging activity of rosemary extract in comparison to other natural antioxidants was also determined by the reduction of O₂ ^.- in a hypoxanthine/xanthine oxidase system.     

New method for monitoring of adsorption column saturation and regeneration I. Demonstration of the measurement principle

A new method suitable for the on-line monitoring of adsorption column saturation/regeneration cycles was developed based on the discovery that the electrical resistance of adsorbents changes dramatically upon adsorption and returns to its original value upon desorption, and that this change can be measured reliably. The phenomenon was demonstrated on four different adsorbent/adsorbate systems, on both single particles and in a packed bed between parallel plates. The observed phenomenon was studied on the carbon/CO2 system in more detail, because of the availability of extensive literature data. It was found that the resistance change in this system correlated with the amount of CO2 adsorbed. The correlation was used to construct an adsorption isotherm based on resistance change data.     

Properties and antimicrobial activities of starch–sodium alginate composite films incorporated with sodium dehydroacetate or rosemary extract

Antimicrobial films were prepared with oxidized and acetylated corn starch–sodium alginate by incorporating sodium dehydroacetate or rosemary extract. Films incorporated with sodium dehydroacetate ≥ 0.1% or rosemary extract ≥ 0.3% had an anti‐Escherichia coli effect. Aspergillus niger could be effectively inhibited by the incorporation of sodium dehydroacetate ≥ 0.3%. Rosemary extract showed no inhibitory effect on Aspergillus niger. Sodium dehydroacetate and rosemary extract reduced the tensile strength and elongation at break, and increased the water vapor permeability of the films. Sodium dehydroacetate made the films more greenish–yellow with the increase of sodium dehydroacetate concentration. The color of the films became darker and more reddish–yellow as rosemary extract was increased. Fourier transform infrared (FTIR) spectra analysis revealed that sodium dehydroacetate and rosemary extract reduced starch crystallinity. The surface of the films became rougher as a result of an addition of sodium dehydroacetate and rosemary extract. These findings had potential applications in prolonging food shelf life based on different needs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fe(TSPc)-Catalysed Benzylic Oxidation and Subsequent Dealkylation of a Non-Phenolic Lignin Model

Abstract

The mechanism by which the phthalocyanine complex trisodium tetra-4-sulfonatophthalocyanineiron(JJJ) (Fe(TSPc)) promotes oxidation and dealkylation of non-phenolic benzyl alcohol units in lignin under alkaline conditions was investigated using simple lignin model compounds. The iron complex effectively oxidised benzylic hydroxyl groups in 2-hydroxyethyl apocynol (5), with the extent of oxidation increasing with the amount of Fe(TSPc) added. To a limited extent, Fe(TSPc) also catalysed the oxidation of 5 by small amounts of oxygen in the reaction mixture. However, the extent of oxidation did not increase on adding excess air or oxygen, as greater amounts of oxygen also increased complex degradation. Phenolic products were formed in these reactions in the presence of Fe(TSPc), but at a rate slower than that of the benzylic oxidation. Further experiments indicated that the phenolic products were formed by base-promoted loss of the ether group at C4 and that such dealkylation occurred more readily in oxidised products.     

落叶松太阳能热泵干燥特性研究

本文介绍了一种木材太阳能热泵干燥装置及其三种不同的运行方式,并以落叶松为试材,通过两组对比实验,分析干燥介质与干燥箱内的温度变化以及木材含水率变化之间的关系。结果表明太阳能水源热泵联合干燥的优化比传统干燥节能约76．7％,太阳能水源热泵联合干燥比传统干燥节能约66．2％,优化模式比只用太阳能水源热泵联合干燥木材时耗能更低,且干燥质量更好。     

ENHANCEMENT OF AMINO ACID PRODUCTION BY TWO-STEP AUTOLYSIS OF SPENT BREWER'S YEAST

A two-step autolysis process was proposed to enhance amino acid production from spent brewer's yeast. The technique was developed based on comparative study of the dynamics of production and release of proteins and amino acids during the autolysis of a concentrated suspension (22 wt.%) and a dilute yeast cell suspension (11.25 wt.%). The results suggest that, in the concentrated yeast suspension, proteins are more effectively broken down into amino acids, but the product release rate was lower due to a lower concentration gradient across the cell membrane. Thus, a two-step process, in which a high protein conversion occurred in a concentrated cell suspension during the first 13 h period, followed by a 26 h autolysis process within a dilute cell suspension, provided a higher overall yield of amino acids compared than the single-step process. The two-step process was found to result in a 25% higher amino acid yield with a weight fraction increase from 0.4 to 0.5 g/g dry wt. Other than these findings, the effect of adding NaCl to the suspension during autolysis was also investigated. It was found that, for the autolysis conditions employed in this study, the addition of NaCl did not significantly affect the production of protein but inhibited the production of amino acids.     

超临界CO2萃取灵香草精油及其化学成分研究

用超临界CO2萃取技术(SFE-CO2),对灵香草(Lysimachia foenum-graecum Hance)进行了萃取,得到灵香草萃取物。探讨了萃取压力、时间及温度等因素对萃取收率的影响,较佳的工艺为:压力25 MPa、温度40℃、时间4 h。超临界CO2法得到的灵香草萃取物收率为4.5%,高于水蒸气法的收率,且香气纯正。采用GC-MS技术对SFE-CO2法得到的灵香草萃取物化学组成进行了分析鉴定,共鉴定出37个化学成分,总质量分数为91.91%,其中主要成分为:苯乙酮、(Z,Z,Z)-9,12,15-十八碳三烯酸甲酯、(Z,Z)-9,12-十八碳二烯酸、9-十六碳烯酸、十七酸、十七酸乙酯、(Z,Z,Z)-9,12,15-十八碳三烯酸乙酯等化合物。     

紫外分光光度法测定脱硫液中栲胶含量

在实验室用紫外分光光度法测定了脱硫液中栲胶的含量,在pH值8-10范围时,由吸收光谱图可以看 出,该物质在320nm有最大吸收。利用分光光度法在该波长下进行比色测定,栲胶含量在0-30mg·L-1范围内 符合比尔定律,其线性回归方程为C=0．058 1A-0．013(R=0．999 80),回收率99．6％-100．3％,相对偏差小 于0．32％。该方法测定脱硫液中栲胶快速、准确、重现性好、试样无需特殊处理。