气相色谱法测定鱼油软胶囊中二十碳五烯酸和 二十二碳六烯酸的柱前衍生化方法改进

目的建立柱前衍生-气相色谱法测定保健食品中二十碳五烯酸(eicosapentaenoic acid,EPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)含量的分析方法。方法鱼油软胶囊经皂化后用1%的硫酸-甲醇甲酯化,用气相色谱法测定,FID检测器检测,色谱柱为DB-FFAP(30 m×0.25 mm,0.25μm),进样口温度250℃,检测器温度260℃,柱温215℃,直接进样,外标法定量。结果 EPA和DHA在0.05~5 mg/mL范围内线性良好(r_(EPA)=0.9999,r_(DHA)=0.9999),EPA和DHA的回收率分别为93.1%~102.3%和92.2%~103.9%,EPA和DHA的相对标准偏差均小于3%。结论该方法操作简便、快捷,避免了有毒试剂的使用,定量准确,重现性好,适合大批量样品的快速检测。     

气相色谱法同时测定保健食品中的5种 不饱和脂肪酸

目的建立气相色谱法同时测定保健食品中亚油酸、α-亚麻酸、二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳六烯酸(docosahexaenoic acid,DHA)和二十二碳五烯酸(docosapentaenoic acid,DPA)的含量。方法样品先采用氢氧化钾甲醇溶液进行皂化处理,再用三氟化硼甲醇溶液甲酯化,经HP-FFAP色谱柱(30m×0.53 mm,1.0μm)分离测定。结果 EPA甲酯、DHA甲酯、DPA甲酯、亚油酸甲酯、α-亚麻酸甲酯分别在0.03927~1.178、0.04200~1.260、0.03449~1.035、0.08368~1.255、0.08482~4.241 mg/mL的浓度范围内线性关系良好,相关系数r均大于0.999;检出限分别为0.0039、0.0042、0.0034、0.0042、0.0042 mg/mL;加标回收率在91.1%~109.3%之间,相对标准偏差均小于5%。结论该方法操作简单快捷,适用于保健食品中亚油酸、α-亚麻酸、EPA、DPA和DHA的测定。     

气相色谱法测定鱼油微胶囊中EPA和DHA的含量

鱼油富含ω-3不饱和脂肪酸,主要包括二十碳五烯酸(Eicosapentaenoic acid,EPA)和二十二碳六烯酸(Docosahexaenoic acid,DHA).本文主要研究了用气相色谱内标法测定鱼油微胶囊产品中的EPA和DHA的含量.在充氮保护下,采用氢氧化钾-甲醇酯化法将鱼油微胶囊中的脂肪酸快速、有效地转化成脂肪酸甲酯,以二十一碳脂肪酸甲酯为内标,建立了EPA和DHA的定量分析法.使用HP-INNVOWAX毛细管柱(30m×0.25mm×0.25μm),载气为氦气,其流速为1.8mL/min,检测器温度为280℃.该方法对EPA和DHA定量分析的相对标准偏差分别为1.09%和1.05%,平均回收率分别为99.5%和99.3%.此检测方法简便快速、准确度高,适合于对大量样品的分析.     

气相色谱法多重检验海豹油中二十碳五烯酸、 二十二碳五烯酸和二十二碳六烯酸方法研究

目的建立多重检验海豹油中二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳五烯酸(docosapentenoic acid,DPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)的气相色谱法。方法用氢氧化钾甲醇溶液将样品中EPA、DPA和DHA甲酯化,气相色谱程序升温同时分析3个ω-3多不饱和脂肪酸,分别用外标法和内标法进行定量。结果 3个ω-3多不饱和脂肪酸的外标法定量线性范围为50~5000μg/m L,相关系数均0.999,精密度相对标准偏差均10%,回收率均90%;内标法定量的精密度相对标准偏差均10%,回收率均85%;外标法和内标法对3个ω-3多不饱和脂肪酸的结果比较,CV%均小于10%。结论该方法操作简单快捷,适用于进口海豹油中EPA、DPA和DHA的含量简便和准确的测定。     

气相色谱法测定乙酯型鱼油微胶囊产品中EPA乙酯和DHA乙酯含量

建立了气相色谱法测定乙酯型鱼油微胶囊产品中EPA乙酯和DHA乙酯含量的方法。样品经盐酸溶液溶解、破壁,再经异辛烷萃取净化,采用气相色谱法分析测定,内标法定量(二十三烷酸甲酯为内标)。结果表明:EPA乙酯和DHA乙酯含量在150~3 000μg/m L范围内,该方法的线性关系良好,相关系数分别为0.999 6和0.999 8,EPA乙酯和DHA乙酯最低检出限分别为8.8、16.5μg/m L;加标回收率分别为98.5%~99.0%、98.2%~100.5%,相对标准偏差(RSD)分别小于等于0.7%、0.9%。该方法分析时间短,重现性好,灵敏度高,可用于乙酯型鱼油微胶囊产品中EPA乙酯和DHA乙酯含量的测定。     

气相色谱内标法测定鱼油保健品中的EPA和DHA含量

采用气相色谱内标法测定鱼油保健品中的EPA和DHA含量,用酯交换法对样品进行处理,对程序升温条件进行优化,通过考察线性关系、精密度、重复性和稳定性、加标回收等对已建立的方法进行验证,并对市售10个不同厂家生产的鱼油保健品进行EPA和DHA含量评价。结果表明:EPA和DHA分别在5. 57～278. 50μg/m L和6. 97～348. 50μg/m L质量浓度范围内与峰面积呈良好的线性关系(相关系数分别为0. 999 6和0. 999 1),精密度(相对标准偏差(RSD)分别为0. 43%和1. 05%)、重复性(RSD分别为1. 04%和1. 62%)、稳定性(RSD分别为1. 48%和1. 27%)、准确性(平均回收率分别为100. 47%和101. 43%)良好。10个鱼油保健品样品质量参差不齐,需要完善的质量规范。所建立的检测方法准确性好、精密度高,可用于鱼油保健品中EPA和DHA含量的检测与质量控制。     

高效液相色谱/质谱联用直接测定鱼油中EPA/DHA含量

建立快速、简单、准确测定鱼油样品中EPA和DHA两种ω-3 PUFA含量的高效液相色谱/电喷雾质谱联用(HPLC ESI/MS)分析方法.鱼油经2 mol/L NaOH乙醇溶液皂化、3 mol/L HCL酸化后,使用Waters液相色谱仪、SymmetryC8柱(2.1×150mm),以甲醇一水为流动相、十七酸为内标,利用质谱定性定量测定EPA/DHA含量.质谱在电喷雾负离子模式下,对m/z 301、m/z 327和m/z269进行选择离子监测.该方法下EPA、DHA分别在5.55～55.50μg/mL和0.90～9.00μg/mL范围内峰面积和浓度呈良好的线性关系,相关系数REPA=0.999 5、RDHA=0.999 3;EPA、DHA的回收率分别为98.63%～99.23%、97.12%～99.17%.EPA、DHA的相对标准偏差分别为1.57%、1.20%(n=5).此方法流动相简单,分析时间短且无需衍生处理,不受色谱分离度的限制并可实现对样品的重复分析,能准确快速测定鱼油中EPA和DHA含量.     

HPLC法测定海鲈鱼鱼油中EPA和DHA的含量

设计建立测定海洋鲈鱼鱼油中EPA (二十碳五烯酸)和DHA (二十二碳六烯酸)含量的方法,并测定尿素包合前后鱼油中EPA和DHA含量变化。采用Agilent色谱柱型号XDB (C_(18)),设置柱温38℃、检测波长220 nm、恒定流速1 mL/min,流动相乙腈-水梯度洗脱。结果表明, EPA甲酯和DHA甲酯的检测线性范围分别为0.059～5.9和0.094～9.4μg (R~2_(EPA)=0.999 6, R~2_(DHA)=0.999 9),检出限分别为0.5和0.9μg/mL。在精密度试验中, EPA甲酯和DHA甲酯的RSD分别为0.29%和0.34%。在加样回收率试验中,分别设计了6个加标浓度做检测, EPA甲酯和DHA甲酯的平均回收率分别为99.29%～99.87%(平均99.52%)和99.59%～101.48%(平均100.22%),平均RSD分别为0.24%和0.83%。尿素包合前,原料鱼油中EPA和DHA的含量分别为1.23%和2.52%;尿素包合后,含量分别为5.66%和12.34%。建立的HPLC法稳定、快捷、重复性好,适用于海鲈鱼下脚料鱼油中EPA和DHA含量测定。尿素包合后EPA和DHA的含量显著增长,达到包合前的4.8倍。     

气相色谱法测定海豹油中EPA、DPA、DHA含量的方法学研究

目的：建立气相色谱检测海豹油中EPA、DPA和DHA的方法。方法：采用氢氧化钾-甲醇酯化法将海豹油中的脂肪酸快速、有效的转化成脂肪酸甲酯,并通过方法学实验验证其可行性。结果：EPA、DPA和DHA甲酯含量在10～2000μg/mL范围内,峰面积与EPA、DPA和DHA甲酯含量呈良好线性关系;加样回收率在96.93%～103.38%之间,相对标准偏差小于2%;结论：该方法可以快速、准确地同时测定EPA、DPA和DHA含量。     

鱼油精制过程中邻苯二甲酸酯类化合物分析及变化规律

建立了气相色谱-质谱法检测鱼油样品中的邻苯二甲酸酯类化合物(phthalate acid esters,PAEs)的方法,并研究PAEs在鱼油精炼过程中的变化规律。研究表明,16种PAEs标准物质在20min内实现有效分离,在0.05~1.0μg/m L浓度范围内呈现出良好的线性关系(R20.998 3),加标实验回收率为82.1%~107.4%,相对标准偏差(RSD)为0.8%~12.9%,检出限为0.08~0.30 mg/kg。同时,毛油中3种塑化剂(DIBP,DBP和DEHP)含量分别为0.06、0.05和0.04 mg/kg,且随着精炼工艺的进行呈上升趋势,成品油中的含量分别为0.19、0.24和0.06 mg/kg。精炼工艺中所使用的化学助剂是造成鱼油中3种塑化剂含量增加的主要因素。     

Bioavailability of Eicosapentaenoic and Docosahexaenoic n-3 Polyunsaturated Fatty Acids in Salmon Patties Compared with Capsules

ABSTRACT This sequential treatment trial compared the bioavailability of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from salmon patties fortified with fish oil (DHA:EPA ratio = 1.8, total DHA + EPA about 2.2 g), unfortified salmon patties (DHA:EPA ratio = 1.9, total DHA + EPA about 1.1 g), and fish oil capsules (DHA:EPA ratio = 1.6, total DHA + EPA = 500 mg) in healthy older adults. Fortified salmon patties produced a significantly higher mean incremental area under the curve (AUC_{fasting-9 h}) than unfortified patties for plasma EPA (37.6 in contrast to 12.9 μg·h/mL, p = 0.017), for plasma DHA (103.7 in contrast to 40.8 μg·h/mL, p = 0.035) and for plasma EPA + DHA (141.2 in contrast to 53.7 μg·h/mL, p = 0.031). Plasma EPA and DHA responses were larger with the fortified than the unfortified patties, indicating that fish oil incorporated into the salmon patties was bioavailable.     

Comparison of Infrared Spectroscopy and Nuclear Magnetic Resonance Techniques in Tandem with Multivariable Selection for Rapid Determination of ω-3 Polyunsaturated Fatty Acids in Fish Oil

This study investigated the potential of using four spectroscopic techniques including visible–short-wave near infrared, long-wave near infrared (LNIR), mid-infrared, and nuclear magnetic resonance (NMR) spectroscopy in tandem with multivariable selection and calibration for rapid determination of three important ω-3 polyunsaturated fatty acids (PUFA), namely eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA) in fish oil. Quantitative models were established between the spectral data and reference PUFA contents of samples based on partial least squares regression (PLSR) algorithm. Successive projections algorithm (SPA) and uninformative variable elimination (UVE) were used to select the most important variables for prediction. The average decrements of 23.20 % for root mean square error of cross-validation (RMSECV) and 64.90 % for the absolute value between root mean square error of calibration and RMSECV (AV_RMSE) in all 12 cases achieved after over 90 % variables were eliminated. UVE was also found to be helpful to improve the efficiency of SPA’s variable selection in 8/12 cases. The best predictions for EPA, DHA, and DPA were all achieved by NMR spectroscopy (determination coefficients of cross-validation (r _CV ² ) of 0.970, 0.982, and 0.983 and the RMSECV of 11.48, 4.73, and 0.77 mg/g for the EPA, DHA, and DPA predictions, respectively). LNIR spectra also did good predictions similar to NMR. The results demonstrated that the laborious and time-consuming gas chromatography method could be replaced by spectroscopic techniques in tandem with PLSR modeling and variable selection in order to provide a rapid and reliable inspection of PUFA in fish oil.     

毛细管气相色谱内标法同时测定奶粉中亚麻酸、ARA、EPA和DHA

建立了以二十一烷酸甲酯为内标物,同时测定奶粉中亚麻酸ARA、EPA和DHA的毛细管气相色谱方法。试样经氢氧化钾-甲醇甲酯化后、生成相应的脂肪酸甲酯,再经气相色谱分析、内标法定量。结果表明,奶粉中亚麻酸、ARA、EPA、DHA和内标物均获得良好的分离;4种被测组分色谱峰面积与其质量浓度有良好线性关系,相关系数均大于0.998;样品加标回收率为95.4%～104.7%,变异系数为2.168%～4.368%,检出限为1.0mg/100 g。该方法操作简便、快速、准确,适合批量奶粉中亚麻酸、ARA、EPA和DHA的测定。     

Short communication: docosahexaenoic acid promotes vaccenic acid accumulation in mixed ruminal cultures when incubated with linoleic acid

Previous studies found that feeding dairy cows a blend of fish and soybean oils enhanced milk vaccenic acid (VA) and conjugated linoleic acid (CLA) concentrations more than when the oils were fed separately. In these studies, the authors concluded that a component in fish oil was stimulating ruminal VA production from other sources of unsaturated fatty acids; however, that component was not identified. The objective of this study was to determine whether docosahexaenoic acid (DHA), an omega-3 fatty acid (FA) in fish oil, is the active component that promotes trans-C18:1 FA, VA in particular, accumulation using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of DHA (DH), control plus 30 mg of soybean oil (SBO), and control plus 5 mg of DHA and 30 mg of SBO (DHSBO). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the level of trans-C18:1 FA (14.1 and 11.7 mg/culture) and VA (13.0 and 10.2 mg/culture) increased more with added DHA than with added SBO, respectively. Combining DHA and SBO yielded higher quantities of trans-C18:1 FA (21.3 mg/culture) and VA (19.8 mg/culture) in the cultures than either fat source alone. These data suggest that DHA is the component in fish oil that promotes VA accumulation when incubated with linoleic acid.     

HPLC测定海豹油软胶囊中3种多不饱和脂肪酸含量

目的建立测定海豹油软胶囊中有效成分二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)、二十二碳五烯酸(DPA)含量的方法。方法以氰基柱色谱柱为分析柱,乙腈-水(90∶10)为流动相,检测波长220 nm。结果 EPA甲酯、DHA甲酯和DPA甲酯线性范围分别为0.6～3.6μg,0.6～3.6μg,0.3～1.8μg,加样回收率分别为99.75%,100.37%,100.35%,RSD分别为1.19%,0.87%,1.22%。结论本方法简便、快速、稳定、重复性好,可用于海豹油软胶囊的质量控制。     

Stability of docosahexaenoic acid and eicosapentaenoic acid in breads after baking and upon storage

Wholemeal bread and white bread were prepared by substituting shortening with refined menhaden fish oil (0.5%, 1.0% and 1.5% w/w). The stability of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were evaluated over 5 days of storage through gas chromatography (GC) analysis along with peroxide and anisidine value determinations. Sensory analysis was also performed by evaluating the fishy flavour, palatability and palatability differences compared to the control bread upon storage. The recoveries of EPA and DHA in breads after baking were 68.7%–72.8% with no further significant changes (P < 0.05) upon storage for both types of breads. Results from GC analyses correlated well with peroxide and anisidine value analyses, which showed relatively low values throughout the storage time. Omega‐3‐fatty acids from Menhaden fish oil can be incorporated into breads by substituting the shortening at a fish oil level of 0.5% (w/w) with acceptable palatability even after a 3‐day storage period.     

POSITIONAL DISTRIBUTION OF FATTY ACIDS IN TRIACYLGLYCEROLS OF SEAL BLUBBER OIL

The positional distribution of long-chain ω3 polyunsaturated fatty acids namely eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in the triacylglycerol (TAG) molecules of seal blubber oil was determined and compared with that of commercially available menhaden oil via stereospecific analysis. In seal blubber oil, EPA, DPA and DHA occurred mainly in the sn-1 and sn-3 positions of the TAG molecules. The amounts were EPA, 8.36 and 11.2; DPA, 3.99 and 8.21; and DHA, 10.5 and 17.9%, respectively. In menhaden oil, DPA and DHA occurred mainly in the sn-2 position of the TAG at 3.11 and 17.2%, respectively. However, EPA was equally distributed in the sn-2 and sn-3 positions and was present only in minute amounts in the sn-1 position.     

直接进样串联质谱法快速筛查水产副产物中ω-3脂肪酸链磷脂

建立自下而上快速筛选含二十碳五烯酸（eicosapentaenoic acid,EPA）、二十二碳五烯酸（docosapentenoic acid,DPA）和二十二碳六烯酸（docosahexaenoic acid,DHA）链磷脂的新方法。通过针泵注射进样,以m/z 301、329和327为特征碎片离子峰进行母离子扫描（precursor ion scan,PreIS）,采用去簇电压－100 V和碰撞电压－40 V,质谱扫描范围设定为350～1?150?Da,得到含EPA、DPA和DHA链磷脂质谱全谱图。经结构鉴定和归一法含量计算,结果表明：水产品加工副产物中磷脂种类丰富,共鉴定50?种EPA、DPA及DHA磷脂分子,其sn-1位置的脂肪酸链主要以C16:0、C18:1和C18:0为主,部分磷脂脂肪酸链不饱和度极高,如磷脂酰丝氨酸20:5/22:6和磷脂酰肌醇22:6/22:6等,以水产品加工副产物为原料开发ω-3脂肪酸链磷脂保健功能产品潜力较大。方法经验证,特征磷脂分子相对标准偏差不高于7.3%,PreIS模式下质谱数据稳定性较好。本方法可一步快速筛查样品中含ω-3脂肪酸链磷脂,理论上同样适用于其他生物样品,可为探索与发现磷脂新资源提供一定理论支持。     

鱼粉加工副产物中鱼油的精炼及其脂肪酸组成分析

对鱼粉加工副产物中鱼油的精制进行研究,得到鱼粉加工副产物中鱼油精炼的最佳工艺：添加1%磷酸（体积分数60%）脱胶,3% NaOH（质量分数12%）溶液脱酸以及15%活性炭脱色,在85 ℃条件下减压蒸馏脱臭10 min。在精炼过程中,鱼油中饱和脂肪酸含量下降,其他脂肪酸含量变化较小。所制备鱼油的理化指标均达到精制鱼油一级要求,其中多不饱和脂肪酸总含量达到0.69 g/mL,二十二碳六烯酸和二十碳五烯酸含量分别为0.229 g/mL和0.121 g/mL。