Hypolipidemic Activity of Peony Seed Oil Rich in α‐Linolenic,is Mediated Through Inhibition of Lipogenesis and Upregulation of Fatty Acid β‐Oxidation

Peony seed oil (PSO) is a new resource food rich in α‐Linolenic Acid(ALA) (38.66%). The objective of this study was to assess the modulatory effect of PSO on lipid metabolism. Lard oil, safflower oil (SFO), and PSO were fed to wistar rats with 1% cholesterol in the diet for 60 d. Serum and liver lipids showed significant decrease in total cholesterol (TC), triglyceride (TG), and low density lipoprotein‐cholesterol (LDL‐C) levels in PSO fed rats compared to lard oil and SFO fed rats. ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), contents were significantly increased, whereas linoleic acid (LA), arachidonic acid (AA) levels decreased in serum and liver of PSO fed rats. Feeding PSO increased ALA level and decreased n‐6 to n‐3 polyunsaturated fatty acid (PUFA) ratio. The hypolipidemic result of PSO indicated that PSO participated in the regulation of plasma lipid concentration and cholesterol metabolism in liver. The decreased expression of sterol regulatory element‐binding proteins 1C (SREBP‐1c), acetyl‐CoA carboxylase (ACC), and fatty acid synthase (FAS)‐reduced lipid synthesis; Activation of peroxisome proliferator–activator receptor (PPARα) accompanied by increase of uncoupling protein2 (UP2) and acyl‐CoA oxidase (AOX) stimulated lipid metabolism and exerted an antiobesity effect via increasing energy expenditure for prevention of obesity.     

牡丹籽油化学成分GC-MS分析

牡丹种籽经石油醚-乙酸乙酯(7:1)索氏提取,三氟化硼甲醇甲酯化后,用气相色谱-质谱联用技术对牡丹籽油组分进行分析;共鉴定37种成分,主要为亚麻酸、油酸、亚油酸、棕榈酸和硬脂酸,其中不饱和脂肪酸占总量83.42%,饱和脂肪酸占14.662%。     

牡丹籽油的脂肪酸组成及理化特性分析

实验在分析测定牡丹籽油的理化特性指标的基础上,采用气相色谱仪分析了牡丹籽油的脂肪酸组成含量,其不饱和脂肪酸含量高达92.00%。这些不饱和脂肪酸主要以油酸、亚油酸、亚麻酸为主,含量分别为23.92%、27.58%、40.50%;采用棒状薄层色谱-氢火焰离子化检测器测得牡丹籽油中除游离脂肪酸外,含有95.89%的甘三酯和4.11%的甘二酯;猪胰脂酶水解分析牡丹籽油的Sn-2脂肪酸组成,结合1,3-随机-2-随机分布学说计算出牡丹籽油甘三酯组成。牡丹籽油中主要是以油酸、亚油酸和亚麻酸为主的甘三酯,其中三不饱和脂肪酸甘三酯的含量达到71.00%以上,一饱和二不饱和脂肪酸甘三酯含量大于15.00%;高压液相色谱法测定牡丹籽油中维生素E总含量为0.56 mg/g;Rancimat法测定的氧化稳定性结果为110℃,2.85 h。为牡丹籽油的进一步研究和深度开发利用提供参考依据。     

超临界CO2流体提取洛阳牡丹籽油工艺研究

采用单因素和正交试验法讨论超临界CO2 萃取牡丹籽油过程中萃取温度、压力、时间及CO2 的流量因素对牡丹籽油脂的萃取率及不饱和萃取液中脂肪酸的含量的影响。并采用GC-MS 技术对油脂成分进行分析。结果表明,采用超临界CO2 流体技术可以萃取牡丹籽中的油脂成分,其最佳工艺条件为压力30MPa、萃取温度40℃、萃取时间2.5h、二氧化碳流量25kg/h。此时油脂的萃取率为30.7%,萃取液中不饱和脂肪酸的相对含量可达70.81%。     

Relationships of Sensory Bitterness in Lager Beers to Iso‐α‐Acid Contents

Iso‐α‐acids and their chemically modified variants play a large role in evoking the bitter sensory attributes of lager character, but individual consumers may vary in their perception of bitterness. Sixteen lagers were scored in rank‐rating for bitterness by 14 trained assessors and the concentrations of the six bitter components in these beers were determined by high performance liquid chromatography. Relationships between bitterness intensity and the bitter components were modelled well using partial least square regression with a correlation value of 0.92. When 8 assessors carried out time‐intensity scoring of bitterness, profiles for single products were very different. However, single assessor profiles for multiple products showed qualitative similarities but quantitative differences. That individual assessors perceived bitter characters differently in relation to time has implications for new product development.     

牡丹籽油亚临界流体萃取工艺优化

采用亚临界流体技术萃取牡丹籽油,通过正交试验对制油工艺进行优化,并对此法所得牡丹籽油的脂肪酸
组成及理化性质进行分析。结果表明,最优萃取工艺条件为萃取温度50 ℃、萃取压强0.5 MPa、每次萃取30 min、
萃取3 次,该条件下牡丹籽出油率达24.16 %。所得牡丹籽油共鉴定出12 种脂肪酸,主要为亚麻酸（45.412 2%）、
亚油酸（38.119 9%）、棕榈酸（11.124 6%）和硬脂酸（3.648 9%）。其理化指标为：相对密度0.901 3、折光指数
1.474 2、酸值3.25 mg KOH/g、碘值175 g I2/100 g、皂化值176 mg KOH/g、过氧化值1.48 meq/kg。     

牡丹籽油的精炼及理化特性变化分析

本实验主要探讨了牡丹籽油的精炼过程及精炼过程中理化特性的变化。实验结果表明,牡丹籽油经水化脱胶和碱炼脱酸后,胶体含量和酸价明显降低,经测定脱胶油中的磷脂含量为0．017g／100g,脱酸油的酸价为0．33mgKOH／g。牡丹籽油采用活性白土二次脱色效果较好,脱色率高,所得产品油透明澄清、颜色为淡黄色,并且脱色过程使过氧化物含量降低,同时也使磷脂含量降到很低水平。油脂精炼过程中碘价、皂化价和折光指数基本不变,对脂肪酸组成成分及含量影响不大。     

不同预处理方式对牡丹籽毛油出油率及品质影响

以油用牡丹籽为原料,探究未处理、微波、烘烤、炒籽四种预处理方式对牡丹籽毛油出油率、理化性质及脂肪酸组成含量的影响。研究结果表明,四种预处理方式对牡丹籽出油率有显著性影响(P<0.05),其中微波处理80?s时的出油率最高,为(23.34±0.02)%。四种预处理方式得到的牡丹籽毛油酸价、过氧化值、皂化值及碘值均有显著性差异(P<0.05);脂肪酸种类相同,但相对含量差异显著(P<0.05)。总之,不同预处理方式对牡丹籽毛油出油率及品质影响显著,其中微波处理是一种高品质的预处理方式,能够保留较高含量的亚油酸、亚麻酸等多不饱和脂肪酸。     

高温加热对牡丹籽油脂肪酸和理化性质的影响

通过研究牡丹籽油经不同温度（90、120、150、180、210、240 ℃）加热30 min后脂肪酸组成、含量以及 理化性质的变化,探究高温加热对牡丹籽油品质的影响。结果表明：牡丹籽油在高温加热后会生成脂肪酸异构体、 环状脂肪酸以及中、短碳链脂肪酸,且温度越高种类越多。虽然上述高温加热后牡丹籽油各理化指标均符合食用油 标准,但是随着温度的升高,牡丹籽油不饱和脂肪酸含量下降,富含营养价值的α-亚麻酸含量在温度超过180 ℃时 迅速下降。可见,在理化指标上牡丹籽油具有良好的热稳定性,但是从营养角度其不适合用于高于180 ℃的高温煎 炸等烹调方式。     

Inhibitory activities of kaempferol,galangin, carnosic acid and polydatin against glycation and α‐amylase and α‐glucosidase enzymes

The activities of four natural phenolics, kaempferol, galangin, carnosic acid and polydatin in scavenging free radicals, inhibiting advanced glycation end‐product (AGE) formation, α‐amylase and α‐glucosidase and trapping methylglyoxal (MGO), were evaluated in this study. Carnosic acid and galangin had the highest activity in scavenging free radicals. Kaempferol and galangin had the greatest activity in preventing bovine serum albumin (BSA) against glycation and reducing glycated proteins. Polydatin had the greatest performance in trapping MGO to reduce glycation reaction. However, there was no significant difference for kaempferol, galangin and carnosic acid in inhibiting AGE formation by BSA‐MGO reaction. Kaempferol, galangin and carnosic acid were the competitive inhibitors for α‐amylase, while kaempferol and carnosic acid were noncompetitive inhibitors for α‐glucosidase. However, polydatin showed as a mixed noncompetitive inhibitor for both α‐amylase and α‐glucosidase. The results indicated that the four natural phenolics have potential in inhibiting AGE production and the digestive enzymatic activity with different mechanisms.     

牡丹籽油超临界CO2萃取工艺优化及抗氧化活性的研究

以牡丹籽为原料,利用超临界CO2萃取法提取牡丹籽油。采用单因素试验对影响牡丹籽油萃取率的3个因素(温度、压力和时间)进行了考察;以萃取率为响应值,以温度、压力和时间3个主要影响因素设计正交实验(L9 33),对提取条件较为温和、对油脂抗氧化性成分破坏较小的超临界提取工艺进行了优化;采用DPPH法和亚铁离子(Fe2 )诱导的过氧化体系法,以油酸和亚油酸为对照,研究了压榨法和超临界CO2萃取法两种工艺提取的牡丹籽油清除DPPH自由基和抗脂质过氧化能力的差异。结果表明,萃取时间对萃取率影响最大,其次为萃取温度,萃取压力对萃取率影响最小;超临界CO2萃取法提取牡丹籽油的优化工艺条件为：温度35℃、压力30 MPa、时间60 min,牡丹籽油的萃取率为28.86%;牡丹籽油的抗氧化性质与脂溶性抗氧化剂类似;超临界油清除DPPH自由基的能力明显高于压榨油,而经Fe2 诱导的脂质过氧化程度则低于压榨油,说明超临界CO2提取的牡丹籽油品质优于压榨油,建议采用超临界CO2萃取技术提取高附加值牡丹籽油。     

Extraction,optimisation and characterisation of phenolics from Thymus vulgaris L.: phenolic content and profiles in relation to antioxidant,antidiabetic and antihypertensive properties

The objectives of this study were to examine varying extraction conditions of Thymus vulgaris L. as related to phenolic content and profiles of the extracts and their antioxidant, antihypertensive and antidiabetic properties. Phenolics were extracted under various conditions pertaining to free and bound phenolics, solvent type and combination of extraction time and temperature, and these extracts were evaluated in terms of their antioxidant activities and inhibitory activities of angiotensin‐converting enzyme (ACE), α‐glucosidase and α‐amylase. The acetone–water solvent mixture (1:1; v/v) produced the extract with the greatest phenolic content, antioxidant activity and inhibitory activities of ACE and α‐glucosidase. The optimal extraction temperature for maximum phenolic content and antioxidant activity associated with methanol extraction was 60 °C, whereas a lower temperature at 40 °C was required to maximise inhibitory activities for ACE, α‐glucosidase and α‐amylase. An inverse relationship was seen between antioxidant and glucosidase inhibitory activities vs. the ACE and α‐amylase inhibitory activities, which suggests the need for extractions to be directed to specific bioactivities of thyme extracts. Generally, the results indicate major differences in phenolic profiles among the tested extraction conditions with thymol as the predominant phenolic seen in most extractions, while gallic acid, rosmarinic acid or diosmin also predominated in other extracts. Extracts with the same predominant phenolic compound and similar phenolic content showed major disparities in their ACE, glucosidase and α‐amylase inhibitory activities, indicating that the major phenolic profiles of thyme extracts may not be necessarily related to the degree of inhibition of ACE, glucosidase and α‐amylase enzymes.     

Functional and bioinformatic characterisation of sequence variants of Fad3 gene from flax

BACKGROUND: Desaturases are enzymes that drive the multi‐step fatty acid biosynthetic pathway. As evident from directed mutagenesis, single base changes in their polypeptide can potentially alter their structure and may result in altered substrate specificity, regioselectivity and even loss of function. The authors have previously isolated several sequence variants of Δ15 desaturase from flax while attempting to clone that gene. The aim of the present study was to analyse these gene variants for their functionality and to predict the tertiary structure of the protein in order to correlate the functional differences with the protein structure. RESULTS: The variants differed in the rate at which they could convert linoleic acid to α‐linolenic acid. The highest conversion rate was 7.03%, while the lowest was 2.39%. The overall shape of the predicted 3D model of the protein is a compact cylinder containing α‐helices and β‐sheets. The Ramchandran plot of this model revealed that 98.5% of the residues are located in allowed region, which denotes a stable structure. CONCLUSION: Although the structures of the variants are apparently similar, subtle changes account for variation in their activity. Besides, these substitutions may alter their cross‐talk with other proteins and thus differentially influence their specificity, localisation and stability, which in turn may explain the diversity in their function. Copyright © 2011 Society of Chemical Industry     

南瓜的感官品质、质构及生化分析

在对127份南瓜材料进行感官鉴定的基础上,选取10份口感明显不同的南瓜材料为研究对象,分别测定其质构指标及生化指标,并分析感官属性和质构指标以及感官属性和生化指标的相关性。结果表明：南瓜的感官属性可以分为3个主成分,第1主成分为粉质、干湿情况和甜度,第2主成分为面度和纤维度,第3主成分为硬度和脆性;南瓜的质构指标也分为3个主成分,第1主成分为硬度、回复性和剪切力,第2主成分为内聚性,第3主成分为黏附性和弹性。感官属性与质构指标及理化指标不同项目之间具有不同的相关性。南瓜感官评价的关键指标为粉质,干湿情况和甜度。     

Chemical composition and functional characterisation of commercial pumpkin seed oil

BACKGROUND: Pumpkin (Cucurbita pepo L.) seed oil is a common product in Slovenia, Hungary and Austria and is considered a preventive agent for various pathologies, particularly prostate diseases. These properties are related to its high content of carotenoids and liposoluble vitamins. In this study the carotenoid (lutein and zeaxanthin), vitamin E (α‐ and γ‐tocopherol) and fatty acid contents of 12 samples of commercial pumpkin seed oil were investigated together with the composition of the volatile fraction resulting from the roasting process. RESULTS: The aromatic profile obtained from the commercial samples was directly related to the intensity of the roasting process of the crushed pumpkin seeds. The roasting temperature played a crucial role in the concentrations of volatile substances originating from Strecker degradation, lipid peroxidation and Maillard reaction. CONCLUSION: The findings suggest that high‐temperature roasting leads to the production of an oil with intense aromatic characteristics, while mild conditions, generally employed to obtain an oil with professed therapeutic characteristics, lead to a product with minor characteristic pumpkin seed oil aroma. The nutraceutical properties of the product are confirmed by the high content of α‐ and γ‐tocopherol and carotenoids. © 2012 Society of Chemical Industry     

Chemical Constituents of Gold‐red Apple and Their α‐Glucosidase Inhibitory Activities

Ten compounds were isolated and purified from the peels of gold‐red apple (Malus domestica) for the 1st time. The identified compounds are 3β, 20β‐dihydroxyursan‐28‐oic acid (1), 2α‐hydroxyoleanolic acid (2), euscaphic acid (3), 3‐O‐p‐coumaroyl tormentic acid (4), ursolic acid (5), 2α‐hydroxyursolic acid (6), oleanolic acid (7), betulinic acid (8), linolic acid (9), and α‐linolenic acid (10). Their structures were determined by interpreting their nuclear magnetic resonance and mass spectrometry (MS) spectra, and by comparison with literature data. Compound 1 is new, and compound 2 is herein reported for the 1st time for the genus Malus. α‐Glucosidase inhibition assay revealed 6 of the triterpenoid isolates as remarkable α‐glucosidase inhibitors, with betulinic acid showing the strongest inhibition (IC₅₀ = 15.19 μM). Ultra‐performance liquid chromatography‐electrospray ionization MS analysis of the fruit peels, pomace, flesh, and juice revealed that the peels and pomace contained high levels of triterpenes, suggesting that wastes from the fruit juice industry could serve as rich sources of bioactive triterpenes.     

35个栽培牡丹品种油用特性的评价研究

对35个栽培牡丹品种的籽油超临界CO2萃取后,使用气质联用色谱法(GC-MS)分析其脂肪酸成分,采用内标法对其主要脂肪酸进行定量分析,以单株种子产量、种仁出油率、籽油α-亚麻酸含量为指标,对35个牡丹品种进行了聚类分析。结果表明,不同牡丹品种的单株种子产量、种仁出油率、籽油α-亚麻酸含量等存在明显差异。其中,长茎紫、鸦片紫、墨池金辉、蝴蝶报春、罗春刺、天香紫、冰凌子、胭红金波、层中笑可以作为油用兼观赏的牡丹品种。如花似玉、擎天粉、琉璃冠珠、满园春光可以作为培育高α-亚麻酸含量油用牡丹品种的重要亲本。