同时蒸馏萃取结合气质联机分析北京地区红腐乳挥发性成分的研究

采用同时蒸馏萃取,结合气质联机,对北京地区的王致和腐乳的挥发性香成分进行了研究,并对溶剂和萃取时间进行了优化。研究结果表明,较优的同时蒸馏萃取条件是以二氯甲烷为萃取溶剂,300g腐乳加350mL水,加热萃取4h;挥发性成分总共鉴定出83种,其中醇类8种、醛类11种、酮类9种、酸类1种、酯类24种、酚及酚醚类6种、吡嗪类7种、含氧杂环类5种、含氮杂环类3种、含硫类2种,其它的混合成分7种,含量较高的成分主要有亚油酸乙酯、十六酸乙酯、苯乙醛、3-甲基丁醛、2,6-二甲基吡嗪、甲基吡嗪等。      

北京地区不同品牌腐乳挥发性成分比较分析

采用同时蒸馏萃取,结合气质联机对北京地区的2种王致和腐乳和3种老才臣腐乳的挥发性成分进行了比较分析.研究结果表明五种腐乳挥发性成分差别较大,共鉴定出93种挥发性成分,其中酯类30种、醛酮类22种、杂环类7种、酚类5种、醇类8种、醚类3种、含硫类1种、酸类2种、烃类14种及酰胺1种.其中含量较大的成分有亚油酸乙酯、十八碳酸乙酯、十六碳酸乙酯、十四碳酸乙酯、丁香酚、辛酸乙酯、苯乙醛、3-甲基丁醛等;对腐乳的香味贡献较大的是酯类如己酸乙酯、庚酸乙酯、辛酸乙酯等,醛酮类如3-甲基丁醛、2-甲基丁醛、苯乙醛等,杂环类如糠醛、甲基吡嗪、2,6-二甲基吡嗪等,以及丁香酚,茴香脑,3-甲硫基丙醛等.     

同时蒸馏萃取-气质联机分析燕麦片挥发性成分的研究

采用同时蒸馏萃取（SDE）结合气质联机（GC-MS）对燕麦片中的挥发性成分进行了定性研究,并用十五碳烷作为内标物进行了内标法定量分析。研究结果表明:共鉴定出72种挥发性化合物,其中醛类17种、酮类6种、醇类6种、酚类3种、烃类25种、酸类4种、酯类3种、杂环类5种、其他类化合物3种,含量较高的成分主要有芥酸酰胺（297.95μg/kg）、（E,E）-2,4-癸二烯醛（279.95μg/kg）、2,4-二叔丁基苯酚（275.16μg/kg）、己醛（200.88μg/kg）、棕榈酸（139.77μg/kg）、4-乙烯基-2-甲氧基苯酚（80.50μg/kg）、环己醇（80.07μg/kg）、（E）-壬烯醛（67.28μg/kg）、2-戊基呋喃（66.33μg/kg）、油酸酰胺（54.53μg/kg）、油酸（55.00μg/kg）、亚油酸（48.12μg/kg）、2,6-二叔丁基对甲酚（48.09μg/kg）、戊醇（39.91μg/kg）、2,3-丁二酮（37.36μg/kg）、苯乙醛（34.61μg/kg）、壬醛（34.36μg/kg）等。      

同时蒸馏萃取- 气质联用分析竹荪挥发性成分

采用同时蒸馏萃取法结合气质联用对竹荪的挥发性成分进行分析。考察不同溶剂和不同萃取时间对分析结果的影响。结果表明：乙醚为溶剂时,较佳萃取时间为3h,此时鉴定成分最多99 种成分;二氯甲烷为溶剂,较佳的萃取时间为2h,此时鉴定出76 种成分;两种溶剂共计从竹荪中提取鉴定出138 种挥发性成分,其中醛类23个、酮类19 个、醇类16 个、酚类4 个、酯类11 个、酸类11 个、烃类34 个、其他类20 个,其中含量较大的成分有十四碳内酯、6- 甲氧基-8- 酰氨基喹啉、5- 异长叶烯酮、6,10- 二甲基-5,9- 十一碳二烯-2- 酮、τ- 芹子烯、α- 杜松醇、十六碳酸等。     

同时蒸馏萃取结合GC-MS分析红托竹荪挥发性成分

采用同时蒸馏萃取法提取红托竹荪中的挥发性成分,用气相色谱-质谱联用（GC-MS）对挥发性成分进行了分析。结果表明通过双柱定性,以乙醚为溶剂时鉴定出81种成分,以二氯甲烷为溶剂时鉴定出89种成分;两种溶剂共计鉴定出108种挥发性成分,其中醛类11种、酮类8种、醇类9种、酚类2种、酯类15种、酸类23种、烃类17种、杂环类17种、其他类6种,其中含量较大的有亚油酸、棕榈酸、棕榈油酸、十五烷酸、11-顺-十八碳烯酸、醋酸、乙偶姻、肉豆蔻酸、十五碳酸、天然麝香葵子等。      

同时蒸馏萃取/气质联机分析郫县豆瓣酱风味成分的研究

分别以乙醚和二氯甲烷为溶剂,用同时蒸馏萃取法,结合气相-质谱联用技术分析了四川郫县豆瓣酱的挥发性香成分,并对萃取时间进行了优化,确定了较佳的时间分别为乙醚2h、二氯甲烷3h。通过GC-MS检测,两种溶剂萃取一共检测出56种化合物,含量较高的化合物有3-甲基丁醇、糠醛、苯乙醛、4-乙基苯酚、4-乙基-2-甲氧基苯酚、乙酸、十二酸、十四酸、十六酸、9,12-十八碳二烯酸、十四酸乙酯、十六酸乙酯、9,12-十八碳二烯酸甲酯、油酸乙酯、十八碳酸乙酯等。      

同时蒸馏萃取/气质联机分析郫县豆瓣酱风味成分的研究

分别以乙醚和二氯甲烷为溶剂,用同时蒸馏萃取法,结合气相-质谱联用技术分析了四川郫县豆瓣酱的挥发性香成分,并对萃取时间进行了优化,确定了较佳的时间分别为乙醚2h、二氯甲烷3h.通过Gc-MS检测.两种溶剂萃取一共检测出56种化合物,含量较高的化合物有3-甲基丁醇、糠醛、苯乙醛、4-乙基苯酚、4-乙基-2-甲氧基苯酚、乙酸、十二酸、十四酸、十六酸、9,12-十八碳二烯酸、十四酸乙酯、十六酸乙酯、9,12-十八碳二烯酸甲酯、油酸乙酯、十八碳酸乙酯等.     

同时蒸馏萃取/GC-MS分析干黄酱的挥发性成分

通过同时蒸馏萃取的方法提取干黄酱的挥发性成分,经过气质联机分析,共分析出73种物质,鉴定出3-甲基丁醛(13·36%)、亚油酸乙酯(10·49%)、2-甲基丁醛(7·00%)、(反,反)-9,12-十八碳二烯酸(6·97%)、油酸乙酯(5·97%)、十六酸(5·05%)、苯乙醛(4·28%)、糠醛(3·51%)、1-(1H-吡咯基-2-)-乙酮(3·01%)、糠醇(1·96%)、3-甲基-1-丁醇(1·32%)、5-羟甲基糠醛(0·97%)、3-甲硫基丙醛(0·84%)、2-甲氧基-4-乙烯基苯酚(0·82%)、2,5-二甲基-4-羟基-3(2H)-呋喃酮(0·27%)、3,4-二甲氧基苯酚(0·26%)等33种物质,总相对百分含量为76·84%。经过调配实验,确认了对干黄酱特征香气起主要作用的香料。     

采用同时蒸馏萃取-气相色谱/质谱分析小茴香的挥发性成分

通过比较精油收率及精油气相色谱分析含有的组分数量,确定同时蒸馏萃取方法提取小茴香挥发性成分较佳条件为乙醚萃取剂,小茴香∶乙醚∶水为10g∶40mL∶100mL,提取时间3h。气质联机分析所提取的挥发油,鉴定出反式茴香脑(7456%)、爱草脑(240%)、葑酮(105%)、茴香醛(351%)、1,8桉树脑(015%)、樟脑(005%)、萜烯类(297%)、香豆素(003%)、十八碳烯酸(018%)等43种化合物,总相对百分含量为8903%。     

同时蒸馏萃取结合气质联用分析牦牛酥油中特征挥发性物质

采用同时蒸馏萃取结合气质联用分析的方法对牦牛酥油以及其他奶制品中的挥发性风味物质进行提取与分析,从牦牛酥油中共鉴定出65种挥发性物质,与外观、色泽相似的其他奶制品进行对比分析发现,乳酸乙酯、辛酸乙酯、癸酸乙酯是牦牛酥油独特风味中重要的特征挥发性成分。建立这3种物质的内标定量分析方法,线性相关系数R2≥0. 997,线性范围为1. 0～50. 0μg/m L;乳酸乙酯检出限为0. 13μg/kg、回收率在86. 7%～104. 7%;辛酸乙酯检出限为0. 18μg/kg、回收率在89. 3%～98. 4%;癸酸乙酯检出限为0. 17μg/kg、回收率在83. 3%～89. 5%;相对标准偏差RSD值<2. 1%,测定牦牛酥油中乳酸乙酯含量范围在0. 54～5. 14 mg/kg,辛酸乙酯范围在0. 28～2. 20 mg/kg,癸酸乙酯范围在0. 34～3. 84 mg/kg。该方法能有效的去除复杂基质干扰,灵敏度好、准确性高。为区分牦牛酥油与其他相似奶制品、以及评价不同酥油间的风味品质提供了参考方法。     

克东腐乳生产过程中化学组分变化研究

以克东腐乳为研究对象,对克东腐乳后酵生产过程中化学组分的变化进行监测分析,揭示克东腐乳生产过程中化学组分的变化规律。结果表明,在腐乳后酵阶段,腐乳坯粗蛋白、粗脂肪含量随时间增加呈显著下降趋势(p<0.05);汤汁中粗蛋白、游离脂肪酸含量随时间增加显著上升(p<0.05);腐乳坯及汤汁中游离氨基酸态氮、总酸含量随时间增加显著上升(p<0.05);腐乳坯中还原糖含量随时间增加显著上升(p<0.05),而汤汁中还原糖含量总体呈现上升趋势,但数据具有一定的波动性;腐乳坯及汤汁pH呈显著下降趋势;食盐含量变化不显著,而水分含量变化显著(p<0.05)。本研究为其腐乳品质的提高、工艺的改进提供了一定的理论指导。      

传统发酵大豆制品挥发性成分和微生物多样性的研究进展

传统发酵大豆制品因独特的风味、丰富的营养而深受人们的喜爱,在我国和其他亚洲国家的膳食结构中占重要地位。豆酱、豆豉、腐乳和酱油作为四大传统发酵豆制品,其发酵过程正不断地被科研工作者剖析。该文对四大传统发酵豆制品的挥发性成分和微生物多样性进行了综述,以期为传统发酵大豆行业的发展提供参考。     

Comparison of volatile components in fermented soybean pastes using simultaneous distillation and extraction (SDE) with sensory characterisation

In this study, the volatile compounds in nine fermented soybean pastes were extracted and analysed by simultaneous steam distillation and extraction (SDE) and gas chromatography–mass spectrometry (GC–MS), respectively. A total of 91 volatile components were identified. The differences in volatiles were observed by applying principal component analyses (PCA) to GC–MS data sets. Most of the samples did not show apparent groupings; however, a three sample clustering (CJW, SIN and HAE) was observed for pastes made by Aspergillus oryzae inoculation. From the PCA of the sensory data, samples are primarily separated along the first PC (explained 68% of the total variance), between samples like SUJA, CHJA and SOHI with high intensities of ‘briny’, ‘soy sauce’, ‘musty’ and ‘astringent’ and the samples (CJW and SIN) with intense levels in ‘sweet-grain’, ‘sweet’ and ‘MSG’ attributes. The individual concentrations of volatile compounds such as isoamyl acetate, furfuryl alcohol, maltol, pyrazines, 1-octen-3-ol and 2-methoxy-4-vinyl phenol corresponded well to the intensities of related sensory attributes by the correlation analysis.     

Effects of soybean (Glycine max) germination on biologically active components, nutritional values of seeds, and biological characteristics in rats

We briefly reviewed the effects of soybean germination on biologically active components, nutritive value of seed and biological characteristics in rats. The purpose of this review is to evaluate the effects of soybean germination on nutritional values of seeds and the potential importance for the use of germinated soybeans, from a contemporary conception, in food preparation as well as on soybean possible influence in optimal health. Germination induced a substantial increase in the content of saponin, oestrogenic compounds and almost all phytosterols, particularly beta-sitosterol of seeds. Lecithin content increased slightly and gradually during germination process. Lipase and alpha-galactosidase activities increased whereas lipoxygenase activities reduced after a short period of germination (< or = 72 h). Therefore, the substantial odour and flavour scores of germinated soybean flour were improved. Germinated seeds were also beneficial to heat penetration, their thermolabile antinutritional factors were easier to inhibit than those of dry beans, also the seeds did not require a long cooking time to be palatable. Duration of the germination process greatly influenced the nutritional value and palatability of seeds and biological characteristics in rats. In rat bioassay, one-day germination of soybeans induced a significant increase of daily body weight gain, daily protein intake in rats and protein efficiency ratio (PER) of seed meal. Palatability of seeds was also improved whereas a 5-day germination resulted in a decrease of PER of seed meal (less than the value of unheated seeds) and induced thyroid enlargement in rats. A vapour thermal treatment (100 degrees C, 20 min) eliminated thyroid-active agents and improved PER of seed meal, food intake and final weight of rats. Well prepared germinated soybeans can be used as a good alternate to animal proteins for more balanced nutritional diet. Development of food products from germinated soybean may be another way to further increase the versatility and utility of soybeans for both developing and industrialized countries, as germination induced the modification of certain specific biologically active components, palatability and nutritive value of seeds.     

Enrichment of phosphatidyl choline – alcohol fractionation of carbon dioxide de-oiled lecithin from soybean (Glycine max)

Crude soylecithin was extracted with carbon dioxide at pressures of 120, 200, 240, 280 and 320 bar (12, 20, 24, 28 and 32 MPa, respectively) and at a temperature of 40°C to obtain de-oiled lecithin. The amount of phospholipids (acetone insoluble) increased with increasing pressure. The carbon-dioxide-extracted lecithin (CDEL) was fractionated with alcohol into alcohol-soluble and alcohol-insoluble fractions. Depending on the pressure, the alcohol-soluble fraction of CDEL was found to contain up to 70.0% phosphatidyl choline as against 21.1% present in crude lecithin. The alcohol-insoluble fraction of CDEL was found to contain up to 37.1% phosphatidyl inositol as against 12.3% in crude lecithin. The chemical parameters of CDEL and the alcohol-soluble and alcohol-insoluble fractions were evaluated.     

快速发酵金丝鱼挥发性风味成分的SPME-GC-MS检测

为改善传统咸鱼的风味,通过在腌鱼上接种Lactobacillus plantarum和Staphylococcus xylosus 2种微生物,建立快速发酵法生产风味金丝鱼干,并采用固相微萃取-气相色谱-质谱(SPME-GC-MS)联用法分析、鉴定金丝鱼原料和发酵后的风味成分,研究快速发酵对金丝鱼风味的影响.经NIST质谱数据库检索和文献[1]对照,各检出58、75种成分,其中以羰基化合物和醇类为主,醛类、醇类和酮类分别占60.96%和72.41%.3-甲基-1-丁醇、1-戊烯-3-醇、1-辛烯-3-醇、2-丁酮、3-甲基丁酸等是金丝鱼特征香气成分,酮类和短链不饱和醛及含硫化合物是影响发酵鱼制品风味的主要成分.     

Modelling respiration rate of soybean seeds (Glycine max (L.)) in hermetic storage

The dynamic of oxygen (O₂) and carbon dioxide (CO₂) concentration was characterized in soybean (Glycine max (L.)) samples hermetically stored in glass jars at 15, 25 and 35 °C and 13, 15 and 17% moisture content (m.c., wet base). Two correlations were used for smoothing gas concentration in time: linear and exponential. Then, the respiration rate at each temperature and m.c. combination was calculated as storage time progressed and oxygen was consumed and two predictive models for respiration were proposed: Model I (temperature and m.c. dependent) and Model II (temperature, m.c. and oxygen dependent). It was observed that respiration rate increased with storage m.c. and temperature. However, respiration rate was not mainly affected by O₂ until a critical concentration limit of about 2% was reached. Respiration rates were from 0.341 to 22.684 mg O₂/(kgDM d) and from 0.130 to 20.272 mg CO₂/(kgDM d) for a range of storage condition of 13–17% m.c. and 15–35 °C temperature. The respiration rate of soybean seeds obtained in this study resulted significantly lower than the rates reported in the literature for other grains at similar temperature and a_w (water activity) storage condition. For hermetic storage simulations in which O₂ concentration is not expected to drop below 2%, the simplest model (Model I) could be used, but if the O₂ concentration of the hermetic system is expected to be depleted, Model I would under estimate the time at which O₂ is consumed, and thus a model with O₂ dependency is recommended instead (Model II).     

Molecular identification of dominant microflora associated with 'Hawaijar' - a traditional fermented soybean (Glycine max (L.)) food of Manipur, India

The dominant microorganisms in 'Hawaijar', a traditional non-salted fermented soybean (Glycine max (L.)) food of Manipur, India, were isolated and identified by molecular techniques. Bacillus spp. were the predominant microorganisms in 'Hawaijar'. A total of 274 isolates were obtained from forty-one 'Hawaijar' samples collected from household preparations and markets of valley districts of Manipur. Phenotypic grouping followed by Amplified Ribosomal DNA Restriction Digestion Analysis (ARDRA), PCR amplification of 16S-23S rDNA region, RFLP by Hae III and Hind III double digest (by comparing MTCC type strains) and sequencing of 9-1514 region of 16S rDNA resulted in three major phylogenic groups. Bacillus subtilis group comprising B. subtilis and B. licheniformis representing 112 isolates, B. cereus group representing of 128 isolates and Staphylococcus spp. group comprising S. aureus and S. sciuri representing 23 isolates. A few bacterial isolates belongs to Alkaligenes spp. and Providencia rettgeri were also found. Genetic diversity of B. subtilis phylogenic group was investigated by RAPD-PCR. Eighty-two strains of B. subtilis phylogenic group were identified using RAPD-PCR using OPA-18 and OPA-20 primers. These strains will be investigated for potential starter culture selection.