Maillard反应对紫贻贝酶解液风味的影响

以紫贻贝酶解液为原料,采用氨基酸分析、GC-MS分析法、电子鼻技术并结合感官评价等方法研究Maillard反应对紫贻贝酶解液风味变化的影响。氨基酸分析表明:酶解液中的游离氨基酸除丙氨酸、脯氨酸、胱氨酸和蛋氨酸外,其余的大部分氨基酸参与了Maillard反应。GC-MS结果表明:未发生Maillard反应的样品EHS中挥发性成分主要为羧酸类和醛类,部分Maillard反应的样品NARS和充分Maillard反应的样品ARS中的挥发性化合物主要为羧酸类、酯类、酮类、醛类、吡嗪类、醇类、含硫类等化合物,说明Maillard反应是产生海鲜风味物质的主要途径。后两者的挥发性化合物组成差异显著,样品ARS含有的能产生海鲜味的挥发性成分种类明显比样品NARS的多,其含量也比样品NARS的丰富。电子鼻响应值分析表明:与样品EHS和样品NARS不同,样品ARS中产生了较多的芳香成分、氮氧化合物、烷类化合物、醇类化合物等。Maillard反应过程有利于海鲜风味成分的形成。     

浙江山核桃油脂香气萃取条件优化及组分分析

采用HS-SPME-GC-MS方法对浙江山核桃香气成分进行定性定量分析.通过单因素试验和正交试验,优化固相微萃取的条件,建立山核桃油脂香气组分分析的方法.结果表明:采用50 μm/30 mm DVB/CAR-PDMS萃取头,加入2 g 样品量,在50 ℃条件下萃取40 min,GC-MS色谱图峰面积最大;经HS-SPME-GC-MS分析,从浙江山核桃油中共检测出香气成分42种,主要包括醛类、醇类、烯类、酯类、酮类以及其他一些化合物.     

醋酸杆菌发酵雪莲果生产果醋饮料工程放大实验研究

通过以雪莲果为主要原料在200L发酵罐中经过酒精发酵和醋酸发酵2个阶段,获得雪莲果果醋产物,总发酵时间为200h,醋酸浓度可达到24.18g/L,对发酵产物进行GC-MS分析,发酵产物中酸类物质的含量占82.34%,其中醋酸的含量占到总量的74.70%.该放大实验的研究为液态发酵果醋饮料的发展和技术提升提供了重要的基础.     

草鱼不同部位气味研究

以草鱼为原料,用电子鼻对草鱼不同部位气味进行检测,并采用聚二甲基硅氧烷- 二乙烯苯(PDMS/DVB)涂层的固相微萃取头萃取草鱼的挥发性成分,结合气- 质联用仪(GC-MS)进行分离鉴定。结果表明,电子鼻能较好地判别出草鱼红肉与背肉、腹肉之间气味的差异,而草鱼背肉与腹肉之间气味的差异则无法判别。草鱼背肉、腹肉及红肉分别共鉴定44、42 种及55 种挥发性成分,均以挥发性羰基化合物和醇类为主,其相对百分含量分别为88.38%、74.88% 及82.54%。     

南海条浒苔和裂片石莼的油脂提取及其脂肪酸分析

以南海条浒苔和裂片石莼为原料,用索氏提取器进行油脂提取,通过脂肪酸室温甲酯化,应用GC-MS联用技术对提取的油脂成分进行了分析。最佳提取条件为:乙醚作溶剂、提取温度40℃、提取时间6h。得到条浒苔10种脂肪酸成分,其中7种为不饱和脂肪酸,占油脂总量的45.54%;裂片石莼10种脂肪酸中有6种不饱和脂肪酸,占油脂总量的49.89%。     

Phytochemical composition and antimicrobial activities of the essential oils from Satureja subspicata Vis. growing in Croatia

The present study describes the phytochemical profile and antimicrobial activity of Satureja subspicata Vis. essential oils, collected in Dalmatia (Croatia). Three samples of essential oils were obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC–MS. From the 24 compounds representing 97.47% of the oils, carvacrol (16.76%), α-pinene (13.58), p-cymene (10.76%), γ-terpinene (9.54%) and thymol methyl ether (8.83%) appear as the main components. The oils also contained smaller percentages of myrcene, linalool, β-caryophyllene, limonene, geranyl acetate, 1-Octen-3-ol, nerol, thymol and borneol. Furthermore, antimicrobial activity of the oil was evaluated using agar diffusion and broth microdilution methods. The antimicrobial test results showed that the oils had a great potential antimicrobial activity against all 13 bacteria and 9 fungal strains. Gram-positive bacteria are more sensitive to the investigated oil, with a range of 0.09 to 6.25 μl/ml than Gram-negative bacteria in the range which is significantly higher from 1.56 to 25.00 μl/ml. Results presented here may suggest that the essential oil of S. subspicata possesses antimicrobial properties, and is therefore a potential source of antimicrobial ingredients for the food and pharmaceutical industry.     

Distribution of POPs,pesticides and antibiotic residues in organic honeys from different production areas

Demand for honey is increasing, especially if it is organic and if its nutritional properties are linked to untreated environments in order to guarantee quality for health. Sources of contamination of honey can be divided into environmental and apicultural. Therefore, the distribution of persistent organic pollutants, pesticides and antibiotic residues from geographical areas with different contamination sources (high anthropic impact, intensive farming, husbandry and low anthropic impact) was investigated in order to confirm the potential transfer of xenobiotics into the supply chain and to give beekeepers tools for the selection of areas dedicated to organic production. The presence of polychlorinated biphenyls, polybrominated diphenyl ether and polycyclic aromatic hydrocarbons was confirmed, not only in proximity to highly urbanised centres, where the concentrations were higher, but in all environment contexts, confirming their ubiquity. No antibiotics or neonicotinoids were detected in 95 organic honeys, demonstrating the absence of apicultural treatments and consequently the good quality of honey of different areas. These results are important due to the undefined regulatory European situation on honey antibiotic limits.     

黑龙江产芫荽籽精油成分及其清除DPPH自由基能力研究

用水蒸气蒸馏法提取黑龙江产芫荽籽,以0.50%的产率获得精油。用GC-MS联机对精油进行了成分分析,检测出31个成分,解析鉴定了占精油99.726%的29个成分。主要成分芳樟醇占总精油含量的73.614%。该精油对DPPH(1,1-Diphenyl-2-picrylhydrazyl)自由基的清除率为94%。水蒸气蒸馏后残渣的甲醇萃取物对DPPH的最大清除率为91%。     

牡丹籽油超声辅助提取工艺优化及其GC-MS分析

目的:以牡丹籽为原料,利用超声辅助提取牡丹籽油.方法:通过单因素实验和正交设计实验考察了液料比、超声波功率、处理时间、温度和提取次数等因素对牡丹籽出油率的影响,确定了超声辅助提取牡丹籽油的较优工艺条件,并用GC-MS对牡丹籽油组分进行了分析.结果:以沸程60～90℃的石油醚作为溶剂提取牡丹籽油的较优工艺参数为:液料比8mL/g.超声波功率为350W、提取温度40℃,提取时间为30min,提取次数为3次.在该工艺条件下,牡丹籽出油率为24.89%.结论:该方法工艺简便合理,提取率较高,所得牡丹籽油中富含不饱和脂肪酸,其中亚油酸和亚麻酸的含量分别为22.78%和64.14%.     

鲜姜和干姜精油成分的GC-MS研究

本实验采用水蒸汽蒸馏法提取鲜姜和干姜中的精油,并利用GC-MS分析精油的成分.结果表明:鲜姜和干姜精油的提取率分别为0.29%和2.51%,而其干物质提取率则分别为7.7%和2.8%;鲜姜精油和干姜精油中共鉴定出60种化合物,其中有两种在鲜姜精油中未检测出,有12种在干姜精油中未检测出,相对含量在3%以上的成分在鲜姜和干姜中都有8种;鲜姜精油色泽透明、辛香、有柠檬味、略带鲜花香气,而干姜精油色泽浑浊,辛香,不具有鲜姜所特有鲜花香气.