抗果蔬致腐真菌中草药的筛选及有效成分的分析

研究了陈皮、肉桂、丁香、五倍子、艾叶、辛夷、姜黄、川芎、虎仗和蜂胶10种中草药提取物对果蔬致腐真菌扩展青霉和黑曲霉的抑制作用。结果表明：中草药丁香提取物具有较强的抗菌活性，对扩展青霉和黑曲霉的MIC分别为25％和50％；通过GC-MS从丁香挥发油中分离分析出14种化合物，其中丁香酚的相对含量最高，达68％；抑菌试验表明，丁香挥发油MIC中丁香酚的浓度高于丁香酚的MIC。     

23种中草药提取物对芒果炭疽病菌的抑制作用研究

探讨了23种中草药提取物对芒果炭疽病菌的抑制作用，结果表明：丁香和黄芩2种中草药的提取物对芒果炭疽病菌具有很好的抑制作用，而夏枯草、紫草、艾叶和白茅根对炭疽病菌的生长具有促进作用。试验同时得出丁香提取物随浓度的降低，抑菌作用逐渐下降；而黄芩提取物浓度变化对抑菌作用没有明显影响。通过紫外一可见吸收光谱分析得知，丁香提取物中主要成分可能为丁香酚，黄芩提取物中主要成分可能为黄芩甙。     

香辛料提取物对葡萄主要致病菌抑菌效果的研究

采用11种香辛料提取物对葡萄的5种主要致病菌进行抑菌实验,并对5种抑菌效果较好的提取物最低抑菌浓度(MIC)值进行了测定,又比较了5种香辛料提取物的任意3种1∶1∶1比例配伍对参试菌的抑制作用。结果表明:丁香、百里香、牛至、八角茴香、肉桂提取物的抑菌效果较好,尤以丁香提取物对5种主要致病菌的抑菌作用最明显,其抑菌圈直径分别为:大肠杆菌17.45mm,金黄色葡萄球菌31.45mm,黑曲霉38.38mm,灰葡萄孢霉54.70mm,青霉25.18mm;这5种提取物的MIC也以丁香最低,分别为:大肠杆菌6.25mg/m L,金黄色葡萄球菌12.5mg/m L,黑曲霉3.13mg/m L,灰葡萄孢霉1.56mg/m L,青霉12.5mg/m L。配伍提取液的抑制效果以百里香、丁香、八角茴香的配伍方案最优,但低于丁香单一提取液的抑菌效果。表明丁香提取液可以应用于葡萄的保鲜。     

40种中药材提取物对烟草黑胫病菌的抑制作用

测定了崂山40种常见中药材提取液对烟草黑胫病菌的抑菌活性。结果表明,10 g/L乙醇提取物浓度下,有11种植物(占27.5%)提取物对烟草黑胫病菌抑制率达100%,有28种(占70%)抑菌率达80%以上。对公丁香提取液相对含量较高的4种组分的抑菌效果进行了进一步测定,结果表明,丁香酚和乙酸丁香酚酯10倍稀释液对黑胫病菌抑制率高,分别为100%和60.19%,说明丁香酚和乙酸丁香酚酯为公丁香的主要抑菌活性成分。本研究表明,公丁香提取物中活性成分丁香酚具有防治烟草黑胫病的良好应用潜力。     

八角挥发油成分分析与抑菌活性研究

:研究水蒸汽蒸馏法提取的八角挥发油的化学成分组成和抑菌活性.结果表明,八角挥发油的提取率为6.13%,从八角挥发油中分离鏊定出24种化合物,占挥发油总量的95.40%,其主要化学成分为反式大茴香脑和对烯丙基茴香醚,分别占76.93%和10.22%;挥发油对多种菌株有抑菌效果,对金黄色葡萄球菌、大肠杆菌、枯草杆菌、黑曲霉、黄曲霉和桔青霉的最小抑菌浓度分别为:10,20,20,0.625,2.5,5 mL/L.说明八角挥发油具有广谱的抗菌性,对霉菌的抑菌效果较好.     

丁香和肉桂挥发油的提取、主要成分测定及其抗菌活性研究

本文采用水蒸汽蒸馏法提取丁香和肉桂的挥发油,并对所得挥发油主要成分进行气相测定,通过体外抗菌试验,比较了这两种挥发油及其主要成分和目前常用化学防腐剂苯甲酸钠和山梨酸钾对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌和志贺氏菌等5株食品中常见污染菌的抗菌作用。结果表明丁香油中丁香酚含量为78.1%,肉桂油中肉桂醛含量为86.8%;这两种挥发油及其主要成分丁香酚和肉桂醛的抗菌作用均强于两种化学防腐剂,其中肉桂油与其主要成分肉桂醛表现出的抗菌活性最强,最小抑菌浓度(MIC)为200～1600mg/L;仅为苯甲酸钠和山梨酸钾MIC(6400～25600mg/L)的1/64～1/16;丁香油及其主要成分丁香酚的抗菌活性次之,MIC为800～1600mg/L,相当于苯甲酸钠和山梨酸钾MIC的1/16～1/8。     

巴西蘑菇抑菌作用的初步研究

采用水提,醇提2种不同方法,提取巴西蘑菇子实休事的抗菌有效成分,测定了2种提取物对8种食品腐败菌的最低抑菌浓度（MIC）。结果表明,1、水提液的MIC;金色葡萄球菌、枯草杆菌均为1.25%;变形杆菌、大肠杆菌、枯青霉为2.5%;面包酵母、黑曲霉为5%。2、醇提物的MIC;金色葡萄球菌、枯草杆菌、枯草霉和黑曲霉均为1.25%;变形杆菌为2.5A%,大肠杆菌、啤酒酵母、面包酵母均为5%。     

菊花脑茎叶抗病原菌活性及其有效成分研究

首次以菊花脑提取物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌等6种常见的病原细菌及黑曲霉、啤酒酵母等4种病原真菌进行了拮抗试验,结果表明菊花脑提取物A、B和C具有较强的拮抗病原菌的活性,且抗菌活性有明显的量效关系,其对各种供试病原细菌的最低抑菌浓度为0.3%～0.5% (g/ml),对供试病原真菌的MIC值从0.3%～1.0%不等。菊花脑提取物A(挥发油)显示了广谱的抗菌范围,其对供试细菌和供试真菌的抑菌效力相当,但菊花脑提取物B和C(非挥发性成分)对供试细菌的拮抗作用(MIC值为0.3%～0.5%)远大于对供试真菌(MIC值为0.7%～1.0%)的作用。菊花脑中起抗菌作用的主要成分是挥发油、总黄酮、苦味素、野菊花内酯等活性成分。     

丁香乙醇提取物的抑菌效果及其在馒头保鲜中的应用

研究了丁香中抗菌抑菌成分的提取和抑菌效果。选择乙醇为提取溶剂,通过试验确定其最优提取条件为乙醇浓度85%、温度90℃、料液比1∶18、时间6 h;通过紫外分光光度法测定丁香中主要抑菌成分丁香酚的含量为329 mg/g;通过牛津杯法测定抑菌效果,丁香粗提液对毛霉、金黄色葡萄球菌、大肠杆菌,酵母菌和曲霉的平均抑菌圈直径分别为20 mm,27 mm,20mm,15 mm和18 mm;并对丁香提取物抑菌效果的应用方面进行了研究,通过测定放置一定时间的馒头样品的吸光度值、菌落总数及理化指标酸度,得出丁香提取物对食品中常见致病菌的抑制作用显著,为丁香可开发成安全有效的天然食品防腐剂做了进一步的研究工作。     

中草药提取物对草莓保鲜效果的研究

本文以草莓失重率、可滴定酸含量、维生素C的含量作为评定指标,来研究三种中草药提取物对草莓的保鲜效果。通过单因素实验确定了每种中草药提取物的最佳保鲜浓度,其中八角茴香提取物最佳保鲜浓度是0.15%;丁香提取物最佳保鲜浓度是2%;银杏提取物最佳保鲜浓度是3%。     

Evaluation and improvement of antioxidant and antibacterial activities of supercritical extracts from clove buds

For the first time, extracts from clove buds obtained by supercritical carbon dioxide extraction were screened for antioxidant and antibacterial activities. Additionally, antioxidant and antibacterial activities of extracts obtained by the supercritical extraction of the clove bud–oregano leaf mixtures were studied. Supercritical extract of pure clove had the highest eugenol (64%) and total phenolic content (530.56 mg GAE/g_extract). All extracts had antioxidant activity comparable to synthetic antioxidants against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and formation of peroxides. Presence of 0.6% and 5% of oregano extract in the clove extracts obtained from the clove–oregano plant mixtures improved their antioxidant activity with respect to the extract from pure clove. Clove extract showed moderate antibacterial activities against selected Staphylococcus and Enterococcus bacterial strains. Presence of 50% of the oregano extract improved antibacterial activity of clove extract against all tested strains and resulted in a synergistic antibacterial activity against Methicillin-resistant Staphylococcus haemolyticus strain (MIC ? 1.25 μg/mL). Study demonstrated great potential of supercritical clove extract as natural functional ingredient and the possibility of increasing its antioxidant and antibacterial efficiencies in order to apply lower concentrations and to reduce undesirable flavour notes and toxicological effects in final products.     

野艾蒿提取物对金黄色葡萄球菌的抑制作用

本文以95%的乙醇为溶剂,采用超声辅助提取的方法对野艾蒿进行提取,得到的粗提物干膏用石油醚、乙酸乙酯和正丁醇依次萃取,得到不同的萃取组分。采用水蒸气蒸馏法提取野艾蒿中的挥发油。采用滤纸片法和二倍稀释法研究各个萃取组分和挥发油对金黄色葡萄球菌体外抑菌活性。并研究了野艾蒿提取物对金黄色葡萄球菌生长曲线的影响。以昆明小鼠为实验动物进行体内抑菌实验。体外抑菌实验表明各组分的抑菌能力大小为乙酸乙酯相正丁醇相石油醚相=挥发油。水相组分未检出抑菌活性。石油醚相、乙酸乙酯相、正丁醇相、挥发油的最小抑菌浓度(MIC)依次为为10.00,2.50,5.00,10.00mg/mL。乙酸乙酯相和正丁醇相对金黄色葡萄球菌的生长有显著的抑制作用(p0.05)。体内抑菌实验表明小鼠灌胃0.50 g/kg的野艾蒿提取物时,体内抑菌活性最好。比模型组的死亡率降低了77.78%。实验表明野艾蒿提取物对金黄色葡萄球菌具有抑菌活性。     

油橄榄叶提取物抗氧化及抑菌活性研究

目的 研究油橄榄叶提取物的成分组成和生物活性。方法 采用溶剂浸提法, 以水、50%、70%、90%乙醇(V:V)为溶剂提取油橄榄叶有效成分, 通过傅里叶变换红外光谱法(fourier transform infrared spectrometry, FTIR)、气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)等方法对所得提取物的结构特征与组成进行表征分析, 通过DPPH·清除能力、还原力以及滤纸片法分别研究了提取物的抗氧化活性和抑菌活性特征。结果 以90%乙醇为提取剂时, 提取物得率和提取物中总多酚含量最高, 提取物中酚类化合物以2,6-二叔丁基对甲酚和2,4-二叔丁基苯酚为主, 相对含量高达29.34%。提取物具有良好的抗氧化活性, 对灰葡萄孢(Botrytis cinerea)、扩展青霉(Penicillium expansum)表现出明显的抑菌活性。结论 首次发现橄榄叶提取物成分中主要酚类物质是2,6-二叔丁基对甲酚和2,4-二叔丁基苯酚, 提取物具有较强的抗氧化和抑菌活性, 为橄榄叶提取物作为抗氧化剂和抑菌剂提供了理论依据。     

COMPARISON OF CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF GLYCOSIDICALLY BOUND AND FREE VOLATILES FROM CLOVE (EUGENIA CARYOPHYLLATA THUNB.)

The present article reports on the chemical composition and antioxidant activity of clove glycosidically bound volatile compounds in comparison with their essential oil. The comparison of chemical composition of volatile aglycones with the chemical composition of essential oil revealed only eugenol as identical. To measure the antioxidative activity of the clove enzymatically released aglycones and its essential oil, two different assays were performed: the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method and the ferric reducing/antioxidant power (FRAP) assay. Both methods showed that the clove volatile aglycones possess lower antioxidant properties than its essential oil. The volatile aglycones radical-scavenging activity measured by DPPH method was lower than butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) activity. The reducing capacity measured by FRAP method for volatile aglycones was lower than BHA capacity and higher than BHT capacity. Some differences in activity obtained by two methods could be explained with different solvent polarity.

PRACTICAL APPLICATIONS

Many secondary metabolites are glycosylated and accumulate as nonvolatile glycosides. Since the glycosides are able to release their aglycones by enzymatic hydrolysis, these compounds could be considered as possible precursors of antioxidant substances in plant. They may contribute to the total antioxidant activity of plant and could be used as natural antioxidants.     

Characterization of solution blown thermoplastic polyurethane nanofibers modified with Szygium aromaticum extract

Abstract

Antibacterial wound dressing mats were produced via coating solution blown TPU nanofiber mats with Szygium aromaticum extract (clove oil). Soxhlet extraction was used to obtain clove oil (CO) and according to gas chromatography–mass spectrometry analysis, it was shown that extract was mostly composed of eugenol and β-caryophylene, which exhibit superior antimicrobial activity. TPU nanofiber mats were coated with obtained clove oil in order to obtain antibacterial nanofibers. Even 2?mg/cm² clove oil coated TPU nanofibers (E2/TPU) exhibited a zone of inhibition around 24 and 22?mm against S. aureus and E. coli, respectively. On the other hand, air permeability of nanofibrous mats decreased with the increasing amount of clove oil over 5?mg/cm², because clove oil caused changes in nanofiber morphology. However, the presence of clove oil did not affect the morphology of E2/TPU, where air permeability values of those dressings were close to that of neat TPU nanofiber mats.     

九宫香菊挥发油的抑菌活性

该试验旨在研究九宫香菊挥发油的抑菌活性并分析其主要成分。以大肠杆菌和金黄色葡萄球菌作为供试菌种,研究菊花提取物的抑菌活性。采用水蒸气蒸馏法提取挥发油,通过气相色谱-质谱法分析挥发油的主要成分。结果表明:九宫香菊的花序和鲜茎叶挥发油对金黄色葡萄球菌、大肠杆菌均有明显的抑菌作用。茎叶挥发油所含主要成分与花序较为相似,但茎叶中1-石竹烯含量相对更高,而无桧烯等成分。九宫香菊茎叶与花序的挥发油组成相似,花序与鲜茎叶均具有一定的抑菌活性。该试验为菊花鲜茎叶的开发提供参考。     

Effects of Allspice, Cinnamon, and Clove Bud Essential Oils in Edible Apple Films on Physical Properties and Antimicrobial Activities

ABSTRACT:  Essential oils (EOs) derived from plants are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria on contact and in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contamination by pathogenic bacteria. EOs from cinnamon, allspice, and clove bud plants are compatible with the sensory characteristics of apple-based edible films. These films could extend product shelf life and reduce risk of pathogen growth on food surfaces. This study evaluated physical properties (water vapor permeability, color, tensile properties) and antimicrobial activities against  Escherichia coli  O157:H7,  Salmonella enterica,  and  Listeria monocytogenes  of allspice, cinnamon, and clove bud oils in apple puree film-forming solutions formulated into edible films at 0.5% to 3% (w/w) concentrations. Antimicrobial activities were determined by 2 independent methods: overlay of the film on top of the bacteria and vapor phase diffusion of the antimicrobial from the film to the bacteria. The antimicrobial activities against the 3 pathogens were in the following order: cinnamon oil > clove bud oil > allspice oil. The antimicrobial films were more effective against  L. monocytogenes  than against the  S. enterica . The oils reduced the viscosity of the apple solutions and increased elongation and darkened the colors of the films. They did not affect water vapor permeability. The results show that apple-based films with allspice, cinnamon, or clove bud oils were active against 3 foodborne pathogens by both direct contact with the bacteria and indirectly by vapors emanating from the films.     

Comparative evaluation of the antioxidant efficacy of encapsulated and un-encapsulated eugenol-rich clove extracts in soybean oil: Shelf-life and frying stability of soybean oil

Microencapsulation of eugenol-rich clove extract obtained from clove buds by supercritical carbon dioxide (SC-CO₂) extraction was carried out in maltodextrin and gum arabic matrices using spray dryer. Microencapsulated powder with maximum encapsulation efficiency of 65% was obtained with 1:4.8:2.4 of clove extract: maltodextrin: gum arabic. The morphology of the encapsulated powder was determined from SEM photographs; while its phytochemical properties such as total phenolic content, total eugenol content and antioxidant activity were determined by biochemical assays. Food application in soybean oil was designed using the encapsulated clove powder as a source of natural antioxidant. Comparative evaluation of the antioxidant efficacy of encapsulated clove extract, un-encapsulated clove extract and commercial antioxidant BHT, individually administered in soybean oil, established encapsulated clove extract as a promising natural antioxidant in the same.     

Essential Oil and Phenolic Compounds of Artemisia herba-alba (Asso.): Composition,Antioxidant, Antiacetylcholinesterase,and Antibacterial Activities

Total phenols, flavonoids, flavonols, and flavanols of the methanolic extract of the aerial part of Artemisia herba-alba were determined. The extract was analyzed by liquid chromatography with photodiode array coupled with electrospray ionisation mass spectrometry and allowed to identify of 10 phenolic compounds. Apigenin-6-C-glycosyl flavonoids and caffeoylquinic acids were identified. Chlorogenic acid and 1,4 dicaffeoylquinic acid being the major constituents. The essential oil obtained by hydrodistillation was analyzed by gas chromatography–mass spectrometry. Twenty-three compounds, representing 97.8% of the total oil, were identified. The most abundant components were β-thujone (41.9%), α-thujone (18.4%), and camphor (13.2%). Methanolic extract and essential oil exhibited a considerable antioxidant activity as evaluated by 2,2-diphenyl-pycrilhydrazil hydrate scavenging activity, reducing power, β-carotene bleaching test, and chelating ability. The methanolic extract was found to be more efficient, while the essential oil exhibited the highest acetylcholinesterase inhibitory activity. Analysis of the antibacterial activity showed that A. herba-alba methanolic extract and essential oil are efficient against gram positive and gram negative bacteria.