产油脂真菌PJX-29抗氧化活性成分研究

对一株红树林来源的产油脂真菌PJX-29发酵产物中的抗氧化成分进行分离和鉴定。利用溶剂萃取、硅胶柱色谱及制备HPLC等分离手段从发酵产物中分离得到2个甘油酯类化合物和其他5个化合物,通过理化性质分析及波谱学方法鉴定其化学结构分别为:十五碳单甘油酯,9″,12″-十七碳二烯酸,十六烷基甘油酯,6-戊基-α-吡喃酮4,,6-二羟基-9,10-二甲基苯乙酮,双(8-8’-7羟基-4-甲氧基-5-甲基香豆素),对羟基苯甲酸6,-氨基苯甲醛,并以DPPH法评价了化合物的抗氧化活性,结果表明化合物1,化合物2和化合物6具有较强的抗氧化活性,其IC50分别为:(11.38±0.61)(、9.33±0.80)和(11.12±1.01)μg/mL。     

盐生海芦笋来源真菌Salcoli6发酵产物抗肿瘤活性成分研究

采用活性追踪的方法,对一株盐生海芦笋来源真菌Salcoli6发酵产物中的抗肿瘤活性成分进行分离和鉴定。利用溶剂萃取、硅胶柱色谱及制备HPLC等分离手段从发酵产物中分离得到7个化合物,通过理化性质分析及波谱学方法鉴定其化学结构分别为枝孢菌素(1)、异枝孢菌素(2)、2-乙酰基喹唑啉(3)、萘满酮(4)、3-羟基-2-甲级色原酮(5)、3-甲级异苯并呋喃(6)、对-羟基苯乙酸(7);以SRB法评价化合物的抗肿瘤活性,化合物3、4和7对p388细胞具有强的细胞毒活性,IC50值分别为12、24μg/mL和6μg/mL,其他化合物没有活性。     

海洋放线菌Nocardiopsis sp.HM-01 的抑菌活性及抑菌物质鉴定

该研究针对一株海洋放线菌HM-01 进行形态学及16S rDNA 分析,并对该菌株的发酵液提取物进行抑菌特性研究,采用antiSMASH 对该菌株亲缘性较高的基因组序列进行次级代谢产物基因簇预测,并结合液相色谱-质谱分析,鉴定主要抑菌活性物质。结果表明,该菌株被鉴定为拟诺卡氏菌属（Nocardiopsis）。Nocardiopsis sp.HM-01 发酵液提取物对大肠杆菌、金黄色葡萄球菌、鳗弧菌、阴沟肠杆菌、铜绿假单胞菌等均有明显抑制活性,且以RP 培养基在发酵第9 天时效果最明显。鉴定出主要的抑菌活性物质为desferrioxamine E 和icosalide B。     

马杜拉放线菌（Actinomadura sp.）FXJ1.344发酵产物的分离鉴定与活性分析

分离鉴定来源于江西酸性红壤中的马杜拉放线菌（Actinomadura）FXJ1.344所产生的次级代谢产物,并对其中生物活性物质进行分析。采用无水乙醇提取放线菌FXJ1.344发酵菌丝体,粗提物依次用硅胶柱层析法和凝胶柱层析法分离纯化,高效液相色谱法进行制备,并采用超高效液相色谱串联质谱法和核磁共振分析鉴定化合物结构。最终得到2个纯化物,分别为6-hydroxytetrangulol和tetrangulol。用滤纸片扩散法和对倍稀释法检测其抑菌活性,结果表明这2个纯化物均有较好的抗藤黄微球菌（Micrococcus luteus）活性,其最小抑菌浓度分别为3.90 μg/mL和15.6 μg/mL。     

桦褐孔菌次生代谢产物清除自由基活性成分的分离纯化及初步鉴定

首先采用二苯基苦基苯肼自由基薄层实验法对桦褐孔菌次生代谢产物进行清除自由基活性的研究,发现桦褐孔菌菌株的次生代谢产物具有较强清除自由基的活性。并采用中压液相色谱(MPLC)、凝胶柱层析(SephadexLH-20)、硅胶柱层析和重结晶多种方法对其活性成分进行分离纯化,得到具有清除自由基活性的纯化合物LWZc和LWZf。利用薄层层析(TLC)、高效液相色谱(HPLC)、核磁共振(1H-NMR)和液质联用(HPLC-MS)等方法对LWZc和LWZf进行纯度鉴定和结构解析,结果表明:LWZf为一种已知化合物对羟基苯甲酸(C7H6O3),具有较强的清除自由基活性,从桦褐孔菌中分离得到该化合物是首次报道;初步推断LWZc化合物的可能结构为3-乙酰基-4-氨基-苯基-核糖甙(C13H17NO6),是一种新化合物,该化合物的纯品清除自由基的能力相对较弱。     

一株木防己拟盘多毛孢的鉴定及其次生代谢产物分析

目的:研究分离自葡萄状枝瑚菌Ramariabotrytis子实体的16072314菌株分类学地位及其次生代谢产物成分。方法:采用形态学观察结合ITS序列分析法对16072314菌株进行菌种鉴定;利用硅胶柱色谱、凝胶柱色谱、制备薄层色谱和半制备高效液相色谱对16072314菌株固体发酵产物的化学成分进行分离纯化,根据理化性质及波谱数据分析鉴定化合物。结果:经鉴定16072314菌株为木防己拟盘多毛孢Pestalotiopsis cocculi;从16072314菌株的代谢产物中分离纯化了8个化合物,分别鉴定为7-羟基香豆素,阿魏酸,麦角甾醇,对羟基苯甲醛,对羟基苯乙醇,齐墩果酸,β-谷甾醇,过氧麦角甾醇。结论:8个化合物均为首次从木防己拟盘多毛孢中分离得到,阿魏酸为首次从拟盘多毛孢属中分离得到。本研究为拟盘多毛孢属的真菌资源利用和开发奠定了基础。     

酱香型大曲中高温放线菌的筛选及风味成分分析

从高温酱香型大曲中分离得到一株耐热性良好的放线菌FBKL4.010,通过形态学、生理生化特征鉴定、16S rRNA基因序列分子生物学鉴定,确定该菌株归属于高温放线菌科（Thermoactinomycetaceae）莱斯氏菌属（Laceyella sp.）,经过进一步系统发育学比对分析鉴定为1?株糖莱斯氏菌（Laceyella sacchari）,其最适生长温度为45?℃;同时针对白酒酿造体系设计纯种菌株固态发酵实验,采用固相微萃取与气相色谱-质谱联用技术分析菌株挥发性代谢产物,结果表明,该菌株在固态发酵体系下能够代谢产生大量吡嗪类、芳香类物质,为发酵液赋予特征性豆豉、坚果风味,其中四甲基吡嗪占总挥发性成分的43.318%,其被认为是酱香白酒风味的主体成分之一,为日后深入探究该菌株在酱香风味形成中的作用提供了理论支持。     

土壤真菌Tolypocladium sp. HU35P-1次级代谢产物化学成分的研究

目的研究土壤真菌Tolypocladium sp. HU35P-1次级代谢产物的化学成分。方法采用硅胶柱色谱、Sephadex LH-20柱色谱及高效液相色谱(HPLC)等,分离纯化Tolypocladium sp. HU35P-1大米固体发酵产物的乙酸乙酯层提取物,根据理化性质和波谱数据进行结构鉴定。结果分离得到3个化合物,分别为tolypyridone A(1)﹑尿嘧啶(uracil)(2)﹑3-甲基哌嗪2, 5-二酮(3)。结论化合物1为首次从弯颈霉属中分离得到。     

浓香型白酒窖泥放线菌的原位分离及代谢特性研究

以川南某浓香型白酒生产企业50年窖龄且发酵正常的窖泥为研究对象。通过高通量测序技术分析细菌群落结构以及放线菌群落结构,利用原位分离法从中分离得到2株放线菌,结合形态鉴定、生理生化和16S rRNA基因序列比对分析确定菌种属,并对其进行耐酸、耐乙醇特性研究,基于风味导向思路,分别对2株菌进行液态培养和固态培养,采用顶空固相微萃取法和气相色谱质谱联用对发酵挥发性产物进行分析,为放线菌的相关研究和应用提供理论参考。结果显示,放线菌在该窖泥样品含有较高操作分类单元(operational taxonomic unit,OTU),相对丰度达(10.7±3.4)%,且主要分布于链霉菌亚目(Streptomycineae)和科里氏杆菌亚目(Coriobacterineae)。采用原位分离法分离放线菌,将分离得到的2株菌编号为A1、A2,菌株A1鉴定为桑氏链霉菌(Streptomyces sampsonii),菌株A2鉴定为鲁地链霉菌(Streptomyces rutgersensis)。菌株A1、A2均可在pH>4.3或乙醇体积分数<6%的环境中生长。菌株A1在液态和固态发酵条件下都会产生大量土臭素以及萜烯类物质,菌株A2在液态条件下能产生多种酯类,其中己酸乙酯相对含量(5.384%)较高,而固态条件下能够检测出大量的3-羟基-2丁酮、2,3-丁二醇和吡嗪类物质。     

高温大曲中高产吡嗪类物质芽孢杆菌的筛选与应用

采用高温培养和固态发酵,从高温大曲中筛选高产吡嗪菌株,并通过顶空固相微萃取及气相色谱-质谱联用（HS-SPME-GC-MS）技术检测菌株代谢产物。将高产吡嗪菌株应用于大曲生产,使用超高效液相色谱-串联质谱（UPLC-MS/MS）检测强化大曲中吡嗪类物质含量。结果表明,共筛选出6株高产吡嗪菌株（编号为X1、X2、X4、X6、X8、X9）,均被鉴定为芽孢杆菌（Bacillus）,其代谢产物共检出33种挥发性香气化合物,其中菌株X1代谢的吡嗪类物质含量最高为9 049.45 μg/kg;高产吡嗪菌株发酵主要对大曲贡献酱香、烘焙香以及花果香气;菌株X1强化大曲吡嗪类物质含量提升效果最好,其中四甲基吡嗪、2,3,5-三甲基吡嗪、2,6-二甲基吡嗪含量相比对照大曲分别提升2.36倍、2.56倍、2.33倍,并且液态菌剂的效果要普遍优于固态菌剂。     

冠突散囊菌抑菌产物培养基优化及分离鉴定

采用响应面法优化冠突散囊菌FS-10产抑菌活性物质的发酵培养基配方,采用高效液相色谱、基质辅助激光解吸电离飞行时间质谱和傅里叶红外光谱对其抑菌活性产物进行分离纯化及结构鉴定.结果表明,冠突散囊菌FS-10产抑菌物质最佳培养基的配方为:碳源(无水葡萄糖)7.5％、氮源(硝酸钠)0.65％、氯化钾4.5％,优化后发酵液对浓...     

纳豆菌液态发酵荞麦产物中抗氧化活性物质的分离鉴定

本实验通过超高效液相色谱-串联质谱（ultra performance liquid chromatography-tandem mass spectrum,UPLC-MS/MS）技术鉴定纳豆菌液态发酵荞麦的发酵产物多酚提取物中多酚组成与结构,且通过超滤、乙醇分级沉淀、大孔树脂柱层析定向分离抗氧化肽,并采用UPLC-MS/MS鉴定多肽组成与结构。从发酵产物中共分离鉴定出8种多酚类化合物：咖啡酸、原儿茶酸、丁香酸、绿原酸、儿茶素、芦丁、牡荆素、金丝桃苷。采用超滤、乙醇分级沉淀及XAD-16大孔树脂对发酵产物进行分离纯化,获得富含抗氧化肽的体积分数40%乙醇溶液洗脱组分（蛋白质量分数为66.51%、氧化自由基吸收能力为1 731.52 μmol/g）。从发酵产物中共分离鉴定出27 条多肽,搜索Mascot数据库得到23 条均为七肽以上多肽,在BIOPEP数据库中搜索均未经报道,且所有肽段都包含疏水性氨基酸,其中有11 条肽段含有至少一个强抗氧化氨基酸。GDKIYNVF中的IY片段、CRNLLLYPAGA中的LY片段、PWFFTST中的PW片段以及QGSGGPPIV中的GPP片段等在BIOPEP数据库中均被报道具有抗氧化活性。所鉴定的多酚、多肽是发酵产物发挥抗氧化活性重要的物质基础。     

Characterisation of odour‐active compounds in lupin flour

BACKGROUND: Lupin ingredients are promising alternatives to soybean products owing to their similarly high protein content. Lupin flour exhibits a green and bean‐like off‐flavour in higher amounts. The aim of this study was to characterise and identify the main odour‐active compounds in lupin flour. RESULTS: The orthonasal aroma of lupin flour was evaluated by means of aroma profile analysis and was found to be characterised by grassy‐green, metallic, fatty, fruity, hay‐like, cheese‐like, and meat‐like odour qualities. Volatile compounds of lupin flour of Lupinus angustifolius cv. Boregine were extracted with dichloromethane and isolated by solvent‐assisted flavour evaporation. Aroma extract dilution analysis (AEDA) was carried out with the obtained extract. In total, 50 odorants were detected by high‐resolution gas chromatography–olfactometry. AEDA revealed 26 odour‐active compounds with flavour dilution factors higher or equal to 32. The substances were unequivocally identified by their odour characteristics, their retention indices and their mass spectra using one‐dimensional or two‐dimensional gas chromatography–mass spectrometry, respectively. CONCLUSION: A series of unsaturated and saturated aldehydes, ketones, carboxylic acids, alkyl‐methoxypyrazines and terpenes were identified for the first time as odour‐active contributors to the aroma of lupin flour. Copyright © 2009 Society of Chemical Industry     

Pod storage time and spontaneous fermentation treatments and their impact on the generation of cocoa flavour precursor compounds

Most of volatile flavour compounds occurred during the cocoa postharvest operations including pod storage and fermentation whom effects on these metabolites were aimed by the present study. Three different spontaneous fermentation treatments were performed on the farm, and the main isolated yeasts were identified using PCR-DGGE technique. Fermented cocoa beans were solar-dried, and their flavour compounds were identified using solid phase microextraction technique–gas chromatography–mass spectrometry. The main results showed that Pichia kudriavzevii was common yeast involved in the cocoa fermentation. Thirty flavour precursor compounds grouped into six chemical families including alcohols and pyrazines were identified in raw cocoa samples. ACP showed that short durations of pod storage and fermentation promote the formation of flavour precursors of cocoa. No spontaneous cocoa fermentation treatment influenced the occurrence of aroma compounds. The generation of flavour compounds depends only on the pod storage and the fermentative microorganisms of cocoa.     

类芽孢杆菌发酵原料浸提液提升再造烟叶品质

为提升再造烟叶品质,利用烟草中分离的类芽孢杆菌制备静息细胞,对再造烟叶原料浸提液进行发酵处理;采用连续流动分析、气质联用仪（GC-MS）、热裂解-气相色谱质谱（Py-GC/MS）等方法,测定了发酵过程中浸提液中蛋白质、还原糖、氨基酸含量变化;分析了其主要挥发性香味成分;并利用发酵浸提液浓缩涂布制备再造烟叶样品,进行热裂解产物分析和感官评价。结果表明:①发酵浸提液和对照组中的蛋白质、还原糖含量在5 h内持续减少,而氨基酸含量先增高后降低,且发酵浸提液的蛋白质、还原糖含量低于对照,氨基酸含量高于对照;②发酵液中香味物质种类和总量较对照组均有所增加,其中糠醛、糠酮等致香组分增幅明显;③对比再造烟叶裂解产物,发现发酵浸提液浓缩后涂布样品裂解产生的γ-丁内酯、2,3-二氢-5-甲基呋喃、糠醛等典型烟气致香组分提高;④发酵液浓缩后涂布的再造烟叶样品感官品质较对照样品明显提升。利用类芽孢杆菌发酵烟草浸提液,对于提升再造烟叶的感官品质具有促进作用。      

Volatile Compounds Produced by Lactobacillus paracasei During Oat Fermentation

This study investigated the profiles of volatile compounds produced by Lactobacillus paracasei during oat fermentation using gas chromatography‐mass spectrometry coupled with headspace solid‐phase microextraction method. A total of 60 compounds, including acids, alcohols, aldehydes, esters, furan derivatives, hydrocarbons, ketones, sulfur‐containing compounds, terpenes, and other compounds, were identified in fermented oat. Lipid oxidation products such as 2‐pentylfuran, 1‐octen‐3‐ol, hexanal, and nonanal were found to be the main contributors to oat samples fermented by L. paracasei with the level of 2‐pentylfuran being the highest. In addition, the contents of ketones, alcohols, acids, and furan derivatives in the oat samples consistently increased with the fermentation time. On the other hand, the contents of degradation products of amino acids, such as 3‐methylbutanal, benzaldehyde, acetophenone, dimethyl sulfide, and dimethyl disulfide, decreased in oat samples during fermentation. Principal component analysis (PCA) was applied to discriminate the fermented oat samples according to different fermentation times. The fermented oats were clearly differentiated on PCA plots. The initial fermentation stage was mainly affected by aldehydes, whereas the later samples of fermented oats were strongly associated with acids, alcohols, furan derivatives, and ketones. The application of PCA to data of the volatile profiles revealed that the oat samples fermented by L. paracasei could be distinguished according to fermentation time.     

Thermal degradation products of wood

Thermal degradation products of woods arising at 450°C have been separated by gas chromatography on a DB-1701 capillary column. GC retention times and mass spectral data of 104 polysaccharide derived pyrolysis products are tabulated. The elemental composition of 76 identified compounds are also presented. The mass spectra were obtained by electron impact ionization (EI). However, the molecular mass of all degradation products with Mw>76 was determined by chemical ionization (CI) using iso-butane as reagent gas. The peak assignment was proved in 38 cases by mass spectrometry of authentic compounds and 32 degradation products were identified according to the literature. The spectral data are presented as a Mass Peak Index showing the intensity of the nine most abundant peaks.     

Classification of Chinese Vinegars Using Optimized Artificial Neural Networks by Genetic Algorithm and Other Discriminant Techniques

The aims of this study were to explore the most important volatile aroma compounds of Chinese vinegars and to apply the artificial neural networks (ANN) to classify Chinese vinegars. A total of 101 volatile aroma components, which include 21 esters, 16 aldehydes, 15 acids, 19 alcohols, 10 ketones, 9 phenols, 5 pyrazines, 3 furans, and 3 miscellaneous compounds, were identified by gas chromatography mass spectrometry. On the basis of sensitivity analysis, 6 and 11 volatile aroma compounds were selected and proved to be useful for classifying Chinese vinegars by fermentation method and geographic region, respectively. The variables with the greatest contribution in the classification of Chinese vinegars by geographic region were 2-methoxy-4-methylphenol and acetic acid, whereas 3-methylbutanoic acid and furfural played the most important roles in fermentation method classification. ANN could classify Chinese vinegars based on fermentation method and geographic region with a prediction success rate of 100%. This level was higher than the accuracy of cluster analysis, linear discriminant analysis, and K-nearest neighbor. Results showed that ANN was a useful model for classifying Chinese vinegars.     

白酒地域特征鉴别技术研究进展

白酒因原料以及发酵过程中微生物群落差异,在微量元素、同位素及风味等方面形成独特的地域特征。通过仪器分析结合化学计量学方法可以进行白酒地域特征鉴别。本文依据地域特征的不同成因,分别从酿酒原料、微生物发酵产物两个方面对白酒地域特征鉴别的仪器分析方法（如电感耦合等离子体质谱法、同位素比值质谱法、色谱法、光谱法以及仿生传感器法等）进行了分类探讨;并论述了不同方法的适用领域及存在的问题,提出了白酒地域特征鉴别的关键问题及发展方向,以期为白酒的分析鉴别提供参考。     

辣椒制品中大红粉的筛查及检测

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