荷叶超临界CO2萃取物抑菌活性研究

本文研究了荷叶超临界CO2萃取物的抑菌活性。结果表明荷叶超临界CO2萃取物对细菌、酵母、霉菌都有一定的抑菌作用,在酸性环境和碱性环境较为显著,对大多数细菌、酵母、霉菌的MIC不超过1.56g/l。高温长时间处理对萃取物抑菌活性影响较大,但高温瞬时处理对萃取物抑菌活性影响不大。     

荷叶超临界CO2萃取物抑菌活性研究

本文研究了荷叶超临界CO2萃取物的抑菌活性。结果表明：荷叶超临界CO2萃取物对细菌、酵母、霉菌都有一定的抑菌作用，在酸性环境和碱性环境较为显著，对大多数细菌、酵母、霉菌的MIC不超过1．56g／l。高温长时间处理对萃取物抑菌活性影响较大，但高温瞬时处理对萃取物抑菌活性影响不大。     

荷叶超临界CO2萃取物抑菌效果稳定性研究

研究荷叶超临界CO2萃取物的抑菌稳定性,结果表明:荷叶超临界CO2萃取物对细菌、酵母、霉菌都有一定的抑菌作用,偏酸环境抑菌效果较稳定,常温、低温、光照及高温短时加热处理后其抑菌效果还较稳定,高温长时间加热后其抑菌效果减弱。     

荷叶超临界CO2萃取物抑菌效果稳定性研究

研究荷叶超临界CO2萃取物的抑菌稳定性,结果表明荷叶超临界CO2萃取物对细菌、酵母、霉菌都有一定的抑菌作用,偏酸环境抑菌效果较稳定,常温、低温、光照及高温短时加热处理后其抑菌效果还较稳定,高温长时间加热后其抑菌效果减弱.     

荷叶生物碱的提取及其抑菌活性研究

本文研究了荷叶生物碱提取液的抑菌活性。结果表明荷叶生物碱提取液对细菌、酵母、霉菌都有较强的抑菌作用,在碱性环境较酸性环境显著,对大多数细菌、酵母的MIC不超过12%。高温长时间处理和中低温长时间处理对提取液抑菌活性影响较大,但高温短时处理对提取液抑菌活性影响不大。     

荷叶生物碱的提取及其抑菌活性研究

本文研究了荷叶生物碱提取液的抑茵活性．结果表明：荷叶生物碱提取液对细菌、酵母、霉菌都有较强的抑茵作用，在碱性环境较酸性环境显著，对大多数细菌、酵母的MIC不超过12%．高温长时间处理和中低温长时间处理对提取液抑菌活性影响较大，但高温短时处理对提取液抑菌活性影响不大。     

藏茴香超临界CO_2萃取物的化学成分及抗菌活性的研究

通过采用超临界CO_2萃取技术,并结合GC-MS联用技术对藏茴香萃取物的化学成分进行分离和鉴定,同时研究其抑菌活性。结果表明:对超临界CO_2萃取得到的藏茴香萃取物进行GC-MS分析得到匹配度在85%以上的化学成分共28种,占总离子峰相对含量的65.71%,其中主要成分有右旋香芹酮(43.1%)双戊烯(8.5%)、右旋萜二烯(6.88%)。藏茴香超临界萃取物对11种菌种有较好的抑制作用。为藏茴香进一步研究和开发利用奠定了一定的理论、实验基础。     

玉竹挥发油超临界CO2萃取条件及抑菌活性研究

运用超临界流体CO2萃取技术提取玉竹挥发油。采用正交试验研究萃取温度、萃取压力、分离温度、分离压力因素对玉竹挥发油得率的影响,以得率为主要标准,确定最佳工艺条件。结果表明：萃取温度35℃、萃取压力30MPa、分离温度20℃、分离压力9MPa为最佳提取工艺。通过抑菌试验发现,玉竹挥发油对细菌、霉菌、酵母菌、放线菌均有一定的抑菌活性,并具有良好的热稳定性。     

苦瓜提取物的抑菌作用及其稳定性研究

采用滤纸扩散法研究了苦瓜提取物和其不同溶剂萃取物的抑菌作用及温度、pH值、紫外光等因素对其抑菌活性的影响。结果表明:苦瓜提取物对细菌的抑制作用较强,其正己烷萃取物对酵母菌和霉菌有较好的抑制效果,苦瓜提取物的抑菌活性具有很好的热稳定性和紫外光稳定性,在pH4~6的条件下抑菌效果最佳。     

肉桂油抑菌效果研究

采用滤纸片法测定抑菌圈,平板划线法测定最低抑菌浓度(MIC),以及对单一菌种的气相抑菌实验和对空气中常见菌体的气相抑菌实验,研究了肉桂油对4种细菌、2种酵母、6种霉菌的抑菌活性及其最低抑菌浓度(MIC).结果表明:肉桂油对供试的细菌、酵母、霉菌均有较强的抑菌活性,并且对霉菌的抑菌活性更强一些,且肉桂油即使不直接加入到培养基中,其挥发成分在菌体表面对细菌、真菌和空气中常见菌体也均有较强的抑菌活性.对所有供试菌种的最低抑菌浓度(MIC)小于0.8mL/L,其中黑曲霉的MIC最低,达到0.05m1./L.     

冠突散囊菌发酵液的抗菌作用

采用滤纸片法研究茯砖茶浸提液、PDA原液和冠突散囊菌PDA发酵液对细菌、酵母菌、霉菌和放线菌的抑制作用及酸碱度、温度和紫外光照射对冠突散囊菌PDA发酵液抑菌作用的影响。结果表明：茯砖茶浸提液和冠突散囊菌发酵液对细菌有较强的抑制作用,而对酵母菌和霉菌抑制作用不明显。通过对冠突散囊菌PDA发酵液抑菌物质稳定性的初步研究,结果表明,发酵液中的抑菌物质对温度(40～120℃)、紫外光(照射10h之内)和酸碱(pH2～10)稳定。     

银杏叶提取物和银杏酸的抗菌活性研究

测定了含不同浓度银杏酸的银杏叶提取物和银杏酸对常见病菌的抑菌活性,以及不同pH条件和热处理对银杏酸抑菌活性的影响。结果表明银杏叶提取物中起抑菌作用的成分为银杏酸,银杏酸对G+(指GAs有抑制作用的菌株)菌的抑菌效果尤为显著,抑菌活性随浓度和作用时间的增加而加强,并具有一定的热稳定性。     

Stability of antioxidant peptides from duck meat after post‐mortem ageing

The stability of antioxidant peptides from aged duck meat during processing and simulated gastrointestinal digestion was investigated. The antioxidant peptides preserved a high stability in the presence of diverse NaCl or upon various time heating. The antioxidant activities were strengthened by the addition of 4–8% glucose or by heating at 100 °C, whereas they were lost under alkaline conditions. During in vitro digestion, the antioxidant activities increased with pepsin treatment but then decreased following trypsin digestion. Pepsin hydrolysed peptides into short fragments and results in the increased exposure of internal hydrophobic amino acids. With further treatment by trypsin, peptides can be hydrolysed completely and more free amino acids were released, leading to the decline in surface hydrophobicity. These variations might be responsible for the change in antioxidant activity during in vitro digestion. The antioxidant peptides from aged duck with high stability can be used as functional food ingredients to improve human health.     

Mobility of Water in a Starch-Based Fat Replacer by 170 NMR Spectroscopy

The effects of concentration, type and level of ingredients, heat and freeze/thaw treatments on the water mobility of starch-based fat re-placers were investigated. Water mobility in the starch-based fat re-placer samples containing gums, proteins or emulsifiers was similar to that of samples without additional ingredients. Water mobility was not affected by heat treatment, but was increased by freeze/thaw treatments. Water mobility in the solute containing samples was lower than in samples without additional ingredients and changed only slightly after heat and freeze/thaw treatments.     

荞麦抗感染多肽研究进展

近年来,国内外学者在荞麦种子内发现了很多抗菌肽、抗肿瘤多肽以及胰蛋白酶抑制剂等抗感染多肽,这些多肽的结构特征和实际应用的研究越来越受关注。主要综述了荞麦抗感染多肽的分子结构特征,抗菌、抗肿瘤、胰酶抑制等生理活性及其作用信号机制等方面的研究进展。     

A rapid method for determining the antimicrobial activity of novel natural molecules

Preservatives used in the Agro-food industries may be of natural origin or obtained chemically. Because of the increasing interest of consumers in food products that contain only natural ingredients, studies on preservative molecules of natural origin, such as organic acids or peptides, have been reported in the past several years. Such studies, which require numerous assays, may be limited by the large amount of molecules required. Microscale assays provide an opportunity for testing natural components available in low quantity. This study examined a rapid method that used microplates for the evaluation of anti-microbial substances. The method was validated using five foodborne pathogens. It required a low amount of product and was convenient for the determination of correlations between the bacterial growth inhibition and concentration of the antimicrobial substance.