Improving the antibacterial activity against Staphylococcus aureus of composite sheets containing wasted tea leaves by roasting

We used various kinds of wasted tea leaves to develop composite sheets with antibacterial properties. Antibacterial tests showed that the number of viable bacterial cells for the sheet containing wasted green tea leaves was around 10:⁶–10⁷ CFU/ml after 18 h culture compared to 108 CFU/ml for a tea-free sheet. This indicates that cell growth was signifi cantly inhibited. For sheets containing other types of tea leaves (oolong, black, hojicha, and pu-erh), living cells were not found, indicating that these sheets had superior antibacterial effects. Living cells were also not found in sheets containing wasted black tea leaves or roasted tea leaves at a concentration of 60% by weight after 6 h cultivation. Therefore, roasting treatment of wasted green tea leaves was examined to improve the antibacterial activity of the sheet. In particular, the focus was on structural conversion of catechins by heating.     

Effect of light irradiation on the antibacterial activity of compounded papers containing wasted tea leaves

The endurance of the antibacterial properties of compounded papers containing wasted green tea leaves needs to be examined before considering these papers for long-term use. Hence, compounded papers containing 60 wt% wasted green tea leaves were irradiated for 1–200 h using a xenon lamp to examine the effect of irradiation on antibacterial properties of the paper. Irradiation for 20 h (cumulative ultraviolet dose at 365 nm, 6.67 × 10⁶ J/m²) or longer was found to greatly increase the antibacterial activity of the paper to a level at which no bacterial cell was confirmed to be viable. The paper was also covered with various glass filters and irradiated for 1 h. Irradiation exclusively with visible rays did not significantly affect the antibacterial activity of the paper, whereas irradiation exclusively with ultraviolet rays, even for a short time, greatly increased the antibacterial activity.     

Preparation and properties of waste tea leaves particleboard

Urea-formaldehyde (UF) adhesive is the main source of formaldehyde emission from UF-bonded boards. The components in waste tea leaves can react with formaldehyde to serve as a raw material in the production of low formaldehyde emission boards. In our study, waste tea leaves and UF adhesive were employed in the preparation of waste tea leaves particleboard (WTLB). An orthogonal experimental method was applied to investigate the effects of process parameters on formaldehyde emission and mechanical properties of WTLB. The results indicated that: 1) waste tea leaves had the ability to abate formaldehyde emission from boards; and 2) density of the WTLB was a significant factor affecting its modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB).     

西双版纳橡胶厂臭气污染特点及控制措施建议

西双版纳橡胶加工厂生产过程中排放的大量恶臭气体已对周边环境造成严重污染;调查认为橡胶恶臭气体强度大,污染成分嗅阈值低,组成成分复杂,而胶厂选址不合理,污染治理设施缺乏或不到位,业主的环保意识不强,是造成橡胶恶臭污染的人为原因;对如何控制恶臭污染提出了建议。     

加工工艺对名优茶品质影响的研究

以狗脑贡茶、东江银毫茶、汝白银毫茶湖银毫茶为对象，探讨加工工艺对名优茶品质的影响。研究结果表明：适宜的摊青工艺有利于提高名优茶品质，尤其是对高山茶返修青时间适当延长其品质越好；高档名优茶的制作采用机械杀青能很好地达到杀青特别针对高海拔地区和水库库区茶叶的杀青，还牟提高品质；高山茶以不揉捻为好，有利于保证绿茶类名茶色泽翠绿多毫。     

树脂吸附法分离高纯茶多酚新工艺研究

研究了树脂吸附法分离纯化茶多酚的绿色工艺。浸提低品位茶叶得到的浸提液，乘热粗沙沙滤，调pH值至1．5，使色素、咖啡因和大分子物质得到预分离，然后细沙沙滤、上AB-8树脂进行吸附，依次用蒸馏水和pH值为2-4的5％的乙醇溶液洗脱处理，洗脱剂为质量分数60％的乙醇，洗脱液喷雾干燥得到茶多酚产品，纯度可达90．22％。     

Alpha-glucosidase inhibitory effect of mulberry (Morus alba) leaves on Caco-2

The effects of brewing time on dry weight content and alpha-glucosidase inhibitory active component released from mulberry (Morus alba) tea were studied. Different tea products showed significant differences in inhibitory activity against both sucrase and maltase. The most effective enzyme inhibition was observed when 3 to 5 min brewing time was applied in tea preparation. In a Caco-2 cell culture experiment the tea reduced the liberated glucose contents in both apical and basal sides of the cell monolayers. It can be concluded that hot water extract of mulberry leaves does have inhibitory effect against alpha-glucosidases, sucrase and maltase enzymes, and has a potential to be consumed as antidiabetic herb tea.     

青梅核仁中苦杏仁甙的水解研究

采用异烟酸-吡唑啉酮分光光度法,对分别腌制22 d4、5 d、90 d、180 d、360 d的青梅腌制废液中苦杏仁甙水解后产生的氢氰酸含量进行测定。结果表明:异烟酸-吡唑啉酮分光光度法有良好的精密度和准确度;苦杏仁甙完全水解的条件为pH<2,蒸馏时间80 min;腌制180 d的青梅腌制废液中苦杏仁甙基本水解完全,氢氰酸质量浓度为83.3 mg.L-1。     

利用N+诱变选育的茶树新品系"茶农8号"的特性

以经N 诱变后的福鼎大自茶种子为原始材料,经系统选种和无性繁殖,育成了综合性状优良的茶树新品系“茶农8号”。经1998-2003年品种比较实验,结果表明:该品系春季萌发期较早;绿茶品质佳,尤以香气和滋味表现突出;鲜叶中生化成分含量丰富,比例协调,其中含茶多酚27．89％、咖啡碱4．55％、氨基酸2．01％、茶多糖2．04％、水浸出物50．49％;对倒春寒的抗性较强,抗虫害能力强。     

Effect of Volatiles from Plants on the Selectivity of Tetranychus viennensis for Different Host Plants

Olfactory responses of Tetranychus viennensis to different plant odors were studied with a “Y” olfactometer and petri dishes, and volatiles from leaves of different plants were absorbed with solid phase microextraction and analyzed with gas chromatography–mass spectroscopy. The study showed that olfaction took place in the response when the Hawthorn Spider Mite looked for host plants, indicating that T. viennensis were attracted by odors from host plants. Different host plants have different attractions to T. viennensis; some attract strongly, while others do so to a lesser extent. The nonhost plants tested have neither attraction nor repulsion to the mite. The volatiles from leaves of different host plants such as Malus pumila, P. bretschneideri, Amygdalus persica, Armeniaca vulgaris, Malus spectabilis, Crataegus pinnatifida, and Prunus yedoensis consist of trans-3-hexen-l-ol,acetate, trans-3-hexenyl ester butanolic acid, α-farensene, etc., which do not exist in the nonhost plants such as Euonymus japonicus. Translated from Scientia Silvae Sinicae, 2004, 40(3) (in Chinese)     

银杏活性炭对4种有毒气体和铅镐离子的吸附作用

为了验证银杏活性炭的吸附效果,分别采用静态吸附法和动态吸附法,研究了银杏活性炭对部分有毒气体及铅、镉两种重金属离子的吸附作用.结果表明:银杏活性炭对甲醛、苯、氨气、三氯甲烷这4种气体的吸附能力都较强,其对甲醛的吸附能力最强.吸附率可达到140%;银杏活性炭吸附铅、镉离子的效果也较好,对铅离子的吸附量接近200 mg·g...     

Functional evaluation of horse chestnut seed and its application in the production of compounded paper for effective utilization of an untapped resource

Many streets in Europe and the US are lined with horse chestnut trees. However, its fruit is inedible and poorly utilized. Therefore, its effective utilization has been a big issue. For recycling of horse chestnut seed, it was separated into “sarcocarp and endodermis” and “outer theca”; each part was finely ground for analysis of its functions. Ground horse chestnut seed showed excellent antibacterial activity toward Staphylococcus aureus, Escherichia coli, and Streptococcus mutans. Antibacterial activity was particularly strong against E. coli, which is a Gram-negative bacterium. The “outer theca” part showed a higher antibacterial activity than did the “sarcocarp and endodermis” part. It was found that the polyphenol content of the “outer theca” of the horse chestnut fruit was approximately three times that of the “sarcocarp and endodermis”; these polyphenols are believed to play a role in the seed’s antioxidation capacity. The ground outer theca of horse chestnut seed showed oxygen radical absorbance capacity (ORAC) of 531 mmol Trolox equivalent (TE)/g. Antioxidant activity was assumed to contribute to the antibacterial activity. In other words, antioxidant activity was assumed to damage the peptidoglycan layer of the bacterial cell wall. For possible recycling of horse chestnut seed, compounded paper containing the ground outer theca blended with pulp fibers was prepared. In this study, compounded paper containing ground “outer theca” was prepared using a traditional Washi paper-making method. The compounded paper was found to retain high deodorizing activity of the ground theca. Furthermore, although mechanical properties deteriorated as the proportion of the ground outer theca increased, these parameters remained adequate for practical applications. The compounded paper may be expected to have a wide range of applications as a highly functional paper with high gas permeability, deodorant activity, and antibacterial activity.     

Environmentally benign methods for producing green culms of ma bamboo (<Emphasis Type="Italic">Dendrocalamus latiflorus</Emphasis>) and moso bamboo (<Emphasis Type="Italic">Phyllostachys pubescens</Emphasis>)

The objective of this study was to find an effective method for treating ma bamboo (Dendrocalamus latiflorus) and moso bamboo (Phyllostachys pubescens) using new water-based reagents containing copper. The effects of green-color protection using various treatments on bamboo culms were examined in this study. Two methods were used: heating in a water bath and ultrasonic dipping. The results revealed that excellent green-color protection (a* value of −6.2) was obtained when ma bamboo culms were treated with 0.25% ammoniacal copper quaternary compound-type B (ACQ-B) in a water bath at 100°C for 2 h. It was also found that the wettability of bamboo epidermis increasedsignificantly after pretreatment in a mixture of 1% KOH and surfactant in a water bath at 100°C for 30 min. Furthermore, pretreated moso bamboo culms exhibited excellent green-color protection after they were treated with 0.25% ACQ-B at 100°C for 2 h (a* value of −8.2). This novel treatment method definitely endows the bamboo culms with a fascinating green skin color and consequently could increase the economic value of bamboo products. No improvement in green-color protection was found when ultrasonic energy was added to the water bath at ambient temperature.     

Epigallocatechin gallate content change of the fresh tea leaf homogenates extracted by different methods in extraction and preservation

Introduction Tea polyphenols, extracted from tea leaves, is a hydroxyl phenol compound. Of the components of green tea (Camellia sinensis), the content of (?)-epigallocatechin gallate (EGCG) is high, and this catechin has been extensively studied (Harold …     

Reactivity of green tea catechins with formaldehyde

In the reaction of green tea catechins with formaldehyde at room temperature (25°C), tea catechins were found to have reactivity. In particular, (-)-epicatechin gallate and (-)-epigallocatechin gallate, which have a galloyl moiety at the C-3 position, showed higher reactivity than (+)-catechin, (-)-epicatechin, or (-)-epigallocatechin. Reactivity of various kinds of simple phenolic compounds and flavonoids with formaldehyde was also examined. Among these compounds, only phloroglucinol showed reactivity to the same degree as that of nongalloylated catechins. These results suggest that factors for reactivity with formaldehyde at room temperature may be the presence of a phloroglucinolic A-ring structure and the absence of the electron-attractive group such as a carbonyl group in Cring. The comparison of the reactivity of 3-O-acylated catechins with that of 3-O-galloylated catechins indicated that only a galloyl group effectively enhanced reactivity with formaldehyde.     

Behavioral response of Norway rats (<Emphasis Type="Italic">Rattus norvegicus</Emphasis>) to odors of different mammalian species

Behavioral responses to the odors of three predators of rodents (domestic cat (Felis catus), weasel (Mustela sibirica), Eurasian badger (Meles meles)), one non-predator mammal (rabbit (Lepus capensis)), and distilled water (control) were assessed in three types of Norway rats (Rattus norvegicus): wild (WNRs), domestic (DNRs), and albino laboratory Wistar (AWRs). Rats were taken individually to a testing apparatus consisting of a hide box and a testing arena. The behavioral activities, including concealing, heading out, approaching, and feeding behaviors in each trial were videotaped for 3 h. Results revealed that WNRs, DNRs, and AWRs all showed an aversion to the predator odors by spending more time concealing in the hide box: frequencies of approaching and feeding behaviors, as well as the amount of food intake were significantly lower than control group. Our results suggest that the response of DNRs and AWRs were “built-in” or innate in nature as they had never experienced the odors of the tested predators. Moreover, all three types of rats can distinguish between predator and non-predator odors, but the ability of WNRs was the highest, which can distinguish between sympatric and allopatric predators, while the ability of AWRs was the lowest, which spent most time in the hide box. The concealing and approaching behaviors were no significantly different among the five odor exposure groups. Also, the reactions of the three types of rats toward the control group (distilled water) significantly differ. This suggests that the duration of time spent in captivity plays an important role in shaping the response of rats to different predator odors.     

Composition of pyrolyzate from Japanese green tea

Green tea is a beverage that is produced by hot-water extraction of the leaves of tea (Camellia sinensis L.). As the amount of green tea consumption has increased, the importance of using the residue has grown. To address this problem, chemical compositions of two pyrolyzates obtained with an electric kiln, L and G, which were obtained from the tea leaf product and its hot-water extraction residue, respectively, were examined. Both pyrolyzates were alkaline, in contrast to the acidic pHs that are typical of pyrolyzates from wood materials. The major constituents were nitrogen-containing compounds, which accounted for up to about 70% (based on gas chromatography-mass spectrometry peak area). Caffeine was the main compound in both samples, although it might not be a pyrolysis product but actually sublimates from the samples and then condenses back into the pyrolyzates. Other nitrogen-containing compounds were formed mainly from proteins and amino acids. Acids and phenols, which are typical components in pyrolyzates obtained from wood materials and contribute to acidic pH, were rare in both samples. Other neutral compounds are known as compounds in pyrolyzates from wood materials. The pyrolyzates obtained in this experiment were novel and may have new uses.Contents of this report was presented in the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, 2002     

黄连木叶的多酚提取和抗氧化研究

以黄连木叶为原料,比较了不同溶剂以及超声和微波辅助对多酚提取率的影响,在单因素实验的基础上采用正交实验对多酚提取工艺参数进行了优化。结果显示最佳提取条件为乙醇50%、超声时间20 min、提取温度70℃、料液比1∶20,多酚得率15.39%。滤液经乙酸乙酯萃取,减压蒸馏,低温干燥成粉末,多酚纯度达到78.96%。用DPPH清除法对提取物的自由基清除作用进行测定,其体外抗氧化活性高于维生素C(Vc),与纯度为98%的茶多酚相当。     

香椿茶叶不同制作工艺比较

以汤色、滋味、外型、香味及叶底为评判指标,比较香椿茶叶不同制作工艺。结果表明:处理方案A为最佳工艺,即材料选用嫩绿叶,采用微波杀青,造形为颗粒状,于90℃烘干3 h。处理方案B效果较好,其工艺为材料选用嫩绿叶,采取烫漂方式杀青,造形为颗粒状,于90℃烘干3 h。     

A major facilitator superfamily transporter in Colletotrichum fructicola (CfMfs1) is required for sugar transport,appressorial turgor pressure,conidiation and pathogenicity

The major facilitator superfamily (MFS) is one of the largest membrane‐protein families. To investigate the role of MFS proteins in the fungal plant anthracnose pathogen Colletotrichum fructicola, the CfMFS1 gene was deleted. This resulted in reduced mycelial growth, conidial yield and decreased virulence on tea oil camellia leaves. In addition, ?Cfmfs1 showed increased sensitivity to osmotic stress and to a cell‐wall stressor. Further analysis revealed that CfMfs1 is required for conidial penetration and appressorial turgor pressure, both important for fungal pathogen invasion. Confocal fluorescence microscopy showed that CfMfs1 is localized to membranes of both hyphae and conidia, suggesting that it may be a membrane transporter. Our study provides evidence that CfMfs1 has a role in conidiation, sugar transport, stress response, conidial penetration, appressorial turgor pressure and virulence against tea oil camellia.