发酵桂叶渣挥发性芳香气体成分固相微萃取气相色谱-质谱联用分析研究

采用顶空固相微萃取气质联用的方法分析发酵桂叶渣的挥发性香味成分,固相微萃取的条件为：萃取时间10 min,萃取温度90℃,色谱分离得到106种挥发性成分,66种可被鉴定,其主成分为乙酸乙酯(8.375%)、己酸丁酯(6.337%)、丁酸丁酯(4.866%)、δ荜澄茄烯(4.612%)、 r衣兰油烯(4.405%)、α衣兰油烯(3.416%)、古巴烯(3.313%)等。     

油菜体内及土壤中咪鲜胺的残留检测与消解动态

采用固相萃取( SPE) - 高效液相色谱紫外检测(HPLC - UV)建立了油菜中咪鲜胺的残留量检测方法,并 进行咪鲜胺消解动态研究。提取液经石墨碳和C18固相萃取柱净化、浓缩后测定。咪鲜胺在各样品中的添加回收 率为80. 1% ～91. 8% ,变异系数为1. 8%～9. 6%。咪鲜胺在油菜中消解较快,半衰期为4～6d; 30g制剂/666. 7m2 于油菜盛花期施药2 次,油菜收获时,油菜籽中咪鲜胺残留量最高为0. 20mg/kg,土壤中咪鲜胺残留量最高为 0. 49mg/kg。     

内标校准液相色谱荧光法测定食用油中苯并(a)芘

采用内标苯并（b）屈校正,建立了正相固相净化－反相液相色谱－荧光分光光度法测定食用油中苯并(a)芘的方法。正相Plus Silica固相萃取柱作为净化柱,反相C18柱作为分离柱。以苯并（b）屈作为内标,测定了苯并(a)芘的校正因子。使用本方法,苯并(a)芘在液态食用油和固态食用油中的检出限分别为0.01和0.03μg/kg。苯并(a)芘在不同食用油回收率在83%～108%之间,方法的日内精密度和日间精密度分别小于7.7%和13.2%。     

固相萃取-超高效液相色谱串联质谱测定茶产品中吡蚜酮

建立了Cleanert PCX固相萃取,超高效液相色谱-串联质谱(UPLC-MS/MS)测定干茶、抹茶和速溶茶粉中吡蚜酮残留量的分析方法。干茶、抹茶和速溶茶粉中的吡蚜酮经甲醇和水的混合溶液提取、Cleanert PCX固相萃取柱富集净化和Acquity BEH C18色谱柱分离后,通过UPLC-MS/MS多反应监测模式(MRM)测定,外标法定量。在0.005~1.000 mg·kg^-1添加范围内,吡蚜酮的平均回收率为77.0%~95.1%,相对标准偏差(RSD,n=5)为1.8%~6.9%,方法的定量限(LOQ)为0.005~0.010 mg·kg^-1。该方法在灵敏度、准确度和回收率上均符合农药残留检测的要求,可为茶产品中吡蚜酮残留量的测定和风险评估提供分析方法。     

花生△12脂肪酸脱氢酶基因AhFAD2B在酿酒酵母中的表达及功能分析

花生油中亚油酸(LA,C18:2Δ9,12)含量很高,为了研究花生Δ12脂肪酸脱氢酶(Δ12 FAD)的功能,用RT-PCR方法从花生未成熟种子中扩增出AhFAD2B的cDNA,连接到酵母表达载体p416中,并转化酿酒酵母K601,得到工程菌Kp4AFAD2B。气相色谱分析脂肪酸成分,结果表明该基因能在酵母K601中表达,并使菌株产生了两种新的脂肪酸即棕榈二烯酸(C16∶2Δ9,12)和亚油酸(C18∶2Δ9,12),含量分别占总脂肪酸的2.1%和9.2%,棕榈油酸(C16∶1Δ9)和油酸(C18∶1Δ9)含量与对照相比相应地下降,证明该基因编码的Δ12脂肪酸脱氢酶除能作用于C18∶1Δ9,还具有催化16碳的C16∶1Δ9底物在Δ12位脱氢生成C16∶2Δ9,12的功能,但在两种底物之间可能更偏爱C18∶1Δ9。     

分散固相萃取法测定黄瓜中的喹啉铜残留量

建立了分散固相萃取（d-SPE）-高效液相色谱（HPLC）分析测定黄瓜中喹啉铜残留量的方法。样品采用乙腈和0.1 mol/L盐酸混合溶液提取,C₁₈填料净化,高效液相色谱仪分离,紫外检测器检测。其色谱条件为：色谱柱SunFireC₁₈（4.6×150 mm,5 μm）,流动相为十二烷基硫酸钠磷酸盐缓冲液-乙腈（65∶35）体系,流速0.6 mL/min,检测波长250 nm。结果表明：在0.02、0.2、2 mg/kg三个添加水平下,喹啉铜回收率在92.3%~107.7%之间,相对标准偏差（RSD）在2.0%~7.7%之间。该方法操作简单、灵敏度和准确度高,能够用于黄瓜中喹啉铜的残留分析。     

国际棕榈油生产概况及我国进口情况

目前，随着全球经济发展以及人民生活水平的提升，人们对于油脂的需求不断提高，在油脂中，植物油占总量约80%，其余由黄油、猪油和鱼油等动物油脂构成。尽管近些年油脂总产量不断增加，但动物油脂的产量基本上维持不变，油脂产量的增长主要来自于植物油脂，特别是棕榈油产量的增长。棕榈油具有独特的营养成分、相对低廉的市场价格以及相对多样的用途，在国际油脂市场具有很强的竞争力，现在棕榈油已经成为全球第2大食用植物油，由于全球棕榈油生产地主要集中于马来西亚、印度尼西亚等少数国家，而消费区域非常广泛，因此棕榈油国际贸易量很大，占全球植物油贸易总量一半以上。     

固相萃取和分散固相净化-串联质谱测定茶鲜叶和干茶中的农药残留

建立了茶鲜叶和干茶中9种农药的残留分析方法。样品中的残留农药经乙腈提取,Florisil/GCB固相萃取柱和PSA/GCB分散固相联合净化,超高效液相色谱串联质谱（UPLC-MS/MS）和气相色谱质谱联用（GC-MS）测定。在0.005~1.000 mg·kg^-1的添加水平下,目标农药在鲜叶和干茶中的平均回收率在70.3%~103.9%,相对标准偏差（RSD）<20.0%。在0.005~2.000 mg·kg^-1浓度范围,目标农药在鲜叶和干茶基质中的线性关系良好,r>0.995 4。定量限（LOQ）为0.005 mg·kg^-1。实际样品检测结果表明,该方法灵敏度高,重现性好,能够满足农药多残留检测的要求。     

分子印迹固相萃取和电喷雾质谱法联用测定茶叶中四种儿茶素

为了对茶叶样品中微量儿茶素进行快速准确分析,利用分子印迹固相萃取(MIPs-SPE)与电喷雾质谱(EIMS)联用技术进行了茶叶中四种儿茶素—表儿茶素(EC)、表没食子儿茶素(EGC)、表儿茶素没食子酸酯(ECG)、表没食子儿茶素没食子酸酯(EGCG)的分离测定。首先以表儿茶素(EC)为模板分子,采用紫外聚合方法合成分子印迹聚合物(EC-MIPs),功能单体为甲基丙烯酸(MAA),交联剂为乙烯二醇二甲基丙烯酸酯(EDMA),引发剂为偶氮二异丁腈(AIBN)。利用EC-MIPs作为固定相制备EC-MIPs-SPE柱,对茶叶样品进行分离萃取后采用EIMS对洗脱液中儿茶素单体进行检测,分别与常规C18和非分子印迹聚合物(NIP)固相萃取方法进行比较。结果表明EC-MIPs-SPE法对儿茶素类单体有特异性识别能力,对茶中主要干扰物质咖啡因、茶碱的结合能力远小于儿茶素分子。最佳萃取条件为:水相上样,用50%(v/v)甲醇/水溶液淋洗除去非特异性结合干扰物,1%(v/v)醋酸的甲醇洗脱特异性结合的四种儿茶素单体。对真实茶叶样品测试发现:经过EC-MIPs-SPE法预富集,可以去除94.2%的咖啡因和全部茶碱干扰,同时可得四个主要儿茶素信号,相对强度分别为:EC(12.1%),EGC(8.2%),ECG(35.4%),EGCG(45.7%)。本法可特异性地识别和分离儿茶素单体,有效消除咖啡因和茶碱干扰,可用于茶叶中微量儿茶素分离鉴定。     

基于固相萃取的粮油产品前处理技术研究进展

粮油是人类生存的必需品,提供了人体不可缺少的三大基本营养素。粮油质量安全是国家重视、消费者关心的热点问题,检测是保证粮油产品消费安全的重要抓手。固相萃取是从粮油样品中提取待测物的重要手段,萃取材料是决定提取分离效率的关键因素。本文主要综述了基于固相萃取的粮油产品前处理技术研究进展,讨论了不同材料的优势及不足,并对粮油产品检测中新型萃取材料发展趋势进行了展望。     

Alternative Sources of n-3 Long-Chain Polyunsaturated Fatty Acids in Marine Microalgae

The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented.     

人参挥发油成分的GC-MS分析

目的用索氏提取法乙醚提取人参挥发油化学成分的GC-MS分析,确定化学成分的种类及相对含量。方法采用乙醚为溶剂用索氏提取法提取人参中的挥发油(即人参的脂溶性成分),用面积归一化法测定各组分的体积分数,并采取气质联用(GC-MS)对挥发油进行鉴定及含量测定。结果鉴定了71个化合物,主要为脂肪酸和酯、挥发油。结论乙醚提取人参,得到的化合物经知网、万方数据库查询,在人参挥发油中未见报道的有23种。     

Studies on the seed oils ofParkia biglobosa andParkia bicolor

The seed oils ofParkia biglobosa andParkia bicolor (Mimosaceae) have been analysed for their possible edible utility and to provide some physical data on both oils. The fatty acid composition of the oils was identified. Six major fatty acids were identified in the oil ofP. bicolor while five were identified in that ofP. biglobosa by Gas Chromatography (GC) and Gas Chromatography — Mass Spectroscopy (GC — MS). The two oils contained five similar fatty acids in almost the same ratios. Arachidic acid was the most abundant fatty acids (greater than forty per cent) in both oils. Other fatty acids in the oils were behenic, stearic, palmitic and linoleic acids. The sixth fatty acid inP. bicolor was an odd number of carbon atom and un unsaturated fatty acid (C₂₀H₃₇COOH) named bicolargic acid. The oils were also found to be non toxic.     

Oil extraction from coriander fruits by extrusion and comparison with solvent extraction processes

The aim of this work was to optimise a single-screw extruder dedicated to coriander production and to investigate the effects of screw configuration, nozzle diameter and nozzle/screw distance. On the other hand, the coriander fruit was extracted using soxhlet methods, the results were compared with mechanical screw press methods.Maximum yield was obtained with single screw extruder for a configuration allowing the strongest oil expression (nozzle/screw distance: 3 mm, nozzle diameter: 9 mm).Comparing with mechanical press, the maximum yield was obtained by the soxhlet extraction with 21.25%.The effect of the operating parameters on oil quality was not important. In all the experiments tested, the oil quality was very good. The acid value was below 1.8 mg of KOH/g of oil and iodine values were tolerable (44 mg of iodine/100 g of oil).Nine fatty acids were identified, with petroselinic acid accounting for 74-77% of the total fatty acids, followed by linoleic, oleic and palmitic acids, accounting for 12-13%, 4-6% and 3%, respectively, of the total fatty acids.β-Sitosterol was the major sterol in all oils with 28% of total sterols of all oils. The next major sterols in all oils were stigmasterol (24-27% of total sterols) and Δ⁷-stigmasterol (14-18% of total sterols).     

Lipid Indexes and Quality Evaluation of Omega-3 Rich Oil from the Waste of Japanese Spanish Mackerel Extracted by Supercritical CO2

Japanese Spanish mackerel (JSM) (Scomberomorus niphonius) is a marine fish species containing health-beneficial polyunsaturated fatty acids (PUFAs). In the present study, the quality of JSM by-products oils extracted by supercritical CO₂ (SC-CO₂) and organic solvent extraction was compared in terms of physico-chemical properties of the oils. Eicosapentaenoic acid (EPA) is one of the important polyunsaturated fatty acids present in SC-CO₂-extracted skin and muscle oil 5.81 ± 0.69% and 4.93 ± 0.06%, respectively. The amount of docosahexaenoic acid (DHA) in SC-CO₂-extracted skin and muscle oil was 12.56 ± 0.38% and 15.01 ± 0.28%, respectively. EPA and DHA are considered as important PUFAs for the development of brain function and the prevention of coronary heart diseases. Extracted oils showed considerable antioxidant activity. In the obtained oils, atherogenic index (AI) values varied from 0.72 to 0.93 and thrombogenic index (TI) ranged from 0.75 to 0.92, which is considered an acceptable level. Fatty acid composition, bio potentiality, thermogravimetric, and vitamin D analysis showed that oils extracted from JSM by-products can be a good source of oil for application in food, pharmaceutical and cosmetic industries. Therefore, the present research revealed the potentiality of green valorisation of S. niphonius by-products as a possible sustainable approach for targeting the era of zero waste.     

Marine bioactives as functional food ingredients: potential to reduce the incidence of chronic diseases

The marine environment represents a relatively untapped source of functional ingredients that can be applied to various aspects of food processing, storage, and fortification. Moreover, numerous marine-based compounds have been identified as having diverse biological activities, with some reported to interfere with the pathogenesis of diseases. Bioactive peptides isolated from fish protein hydrolysates as well as algal fucans, galactans and alginates have been shown to possess anticoagulant, anticancer and hypocholesterolemic activities. Additionally, fish oils and marine bacteria are excellent sources of omega-3 fatty acids, while crustaceans and seaweeds contain powerful antioxidants such as carotenoids and phenolic compounds. On the basis of their bioactive properties, this review focuses on the potential use of marine-derived compounds as functional food ingredients for health maintenance and the prevention of chronic diseases.     

Biotechnological production of oil: Fatty acid composition of microbial oil

The fatty acid profile and the fatty acid composition of microbial lipids obtained from molds revealed that oil from Aspergillus sydowii, Fusarium oxysporum and F. equisetti had a high percentage of unsaturated fatty acids, particularly oleic acid, and had a similarity to the edible oils, groundnut and palm oil. This study sheds light on the possibilities of exploring the use of these oils as supplement to other edible fats and for other non-edible industrial purposes.     

Complete and partial epoxidation of plant oils by lipase-catalyzed perhydrolysis

Epoxidation of unsaturated plant oils is industrially carried out by the Prileshajev-epoxidation using either preformed or in-situ-generated short chain peroxy acids. The need of a strong acid to catalyze peroxy acid formation in these processes often results in unsatisfactory selectivities. Chemo-enzymatic `self'-epoxidation by the lipase-catalyzed in-situ-formation of peroxy fatty acids is a highly selective method for the epoxidation of plant oils. Rapeseed, sunflower, soybean and linseed oil were epoxidized with selectivities and conversions well above 90%. Beside complete epoxidation the high selectivity of the chemo-enzymatic `self-'epoxidation renders an accurate prediction of iodine values and oxirane oxygen contents of partially epoxidized plant oils possible. Thus, it is possible to produce tailor-made partially epoxidized plant oil, e.g. a synthetic substitute for vernonia oil.     

乙醇水剂法提取武夷水仙茶叶籽油及其品质分析

以武夷水仙茶叶籽为原料,采用乙醇水剂法提取武夷水仙茶叶籽油,通过单因素试验考察了提取温度、料液比、乙醇浓度和pH对提取率的影响,并采用正交试验设计优化了提取工艺条件。结果显示,武夷水仙茶叶籽油最佳提取条件为乙醇浓度30%（V/V）、料液比1∶7、pH 9、提取温度60 ℃,在该条件下武夷水仙茶叶籽油提取率为93.61%。在提取的武夷水仙茶叶籽油中共检测到18种脂肪酸,以油酸（51.77%）、亚油酸（23.14%）为主,∑SFA∶∑MUFA∶∑PUFA=1∶2.64∶1.27,各项理化指标均符合国家标准。结果表明武夷水仙茶叶籽油是一种营养价值较高的植物食用油,研究结论可为武夷山茶产区茶叶籽油提取、品质评价提供理论依据。     

超临界CO2萃取斜叶黄檀精油工艺优化及精油成分分析

本研究采用超临界CO2萃取斜叶黄檀中的精油,并分析精油的挥发性成分,主要考察萃取压力、萃取温度和萃取时间对精油得率的影响,通过正交试验确定超临界CO2萃取精油的最佳工艺条件,并通过气相色谱-质谱联用（GC-MS）检测斜叶黄檀精油中的主要挥发性成分。结果表明:超临界CO2萃取精油的最佳工艺条件为萃取温度75℃,萃取压力35 MPa,萃取时间4 h,在此条件下精油的得率为4.7573%;从斜叶黄檀精油中共鉴定出13种挥发性组分,主要成分是榄香素和甲基丁香酚,分别占92.33%和3.18%。