强冬性甘蓝型油菜种质资源的主要品质性状研究

为了探明强冬性甘蓝型油菜种质资源的品质特性,以109份强冬性甘蓝型油菜种质资源为材料,应用近红外光谱检测法,对油菜籽粒含油量、硫苷、蛋白质及脂肪酸组成进行检测,分析了主要品质性状的变异和相关性。结果表明,强冬性甘蓝型油菜种质资源含油量、硫苷、蛋白质质量分数平均值分别为43.44%、41.51μmol/g、25.33%。在脂肪酸组成中,油酸质量分数最高,平均为55.50%,亚油酸、亚麻酸、芥酸、饱和脂肪酸质量分数依次为19.97%、11.95%、7.41%、 5.34%,亚麻酸含量显著高于双低甘蓝型油菜。芥酸、硫苷含量材料之间差异明显,变异系数分别为89.11、71.97;油酸、亚油酸、亚麻酸、饱和脂肪酸变异系数分别为15.62、11.71、9.32、8.02;含油量、蛋白质变异较小,变异系数均为6.56。相关性分析表明,强冬性甘蓝型油菜的含油量、硫苷含量、亚麻酸、芥酸、油酸、亚油酸之间极显著相关(r=-0.92～0.82)。聚类分析将109份资源分为两大类,第Ⅰ大类为高硫苷、高芥酸、低含油量种质,第Ⅱ类群为低硫苷、高含油量种质。     

河北省核桃坚果蛋白质、脂肪及脂肪酸组成分析

目的:为深入了解河北省核桃资源现状,为优良核桃品种的选育和种质创新提供科学依据。方法:以河北省103份核桃资源为研究对象,对其蛋白质、脂肪及脂肪酸组分进行变异分析、相关性分析和聚类分析。结果:103份核桃资源脂肪、蛋白质的平均含量分别为62.15%、16.66%,油酸、亚油酸等不饱和脂肪酸的平均含量分别为17.31%、64.56%。各指标变异系数的变化范围为7.40%~31.41%,其中油酸的变异系数最大,亚油酸的变异系数最小;各指标的香农-威纳指数的变化范围为1.89~2.10,其中蛋白质的香农-威纳指数最高。相关性分析发现油酸含量与亚油酸、α-亚麻酸含量分别呈极显著负相关（P<0.01）,与花生烯酸呈极显著正相关（P<0.01）,且不饱和脂肪酸组分关联较紧密。聚类分析采用离差平方和方法,在欧氏距离D=9.75处可将103份核桃资源分为5个群组（I、II、III、 IV 和 V),各含有38、4、24、16和24个资源,其中群组Ⅱ为高蛋白、高脂肪、高亚油酸资源,群组Ⅴ为高油酸、低亚油酸资源。结论:本研究中,103份核桃资源的遗传多样性丰富,资源特色明显,王永久、史文海、王春安、早硕可作为高蛋白、高脂肪、高亚油酸资源进行研究,为河北省核桃特色油脂资源的开发利用和良种选育提供依据。     

摘薹对甘蓝型油菜籽粒品质性状的影响及其综合评价

为了探明摘薹对油菜籽粒品质性状的影响,本研究以21份甘蓝型油菜品系为材料,进行摘薹处理与正常收获,测定籽粒中饱和脂肪酸、不饱和脂肪酸、油份、蛋白质及硫苷含量变化。结果表明：摘薹后棕榈酸、硬脂酸、亚油酸、亚麻酸、蛋白质及硫苷含量表现为增加的趋势,油酸、油份含量表现为减少的趋势,芥酸、花生烯酸含量变化趋势并不明显。相关性分析表明,摘薹后油份与油酸呈极显著正相关,二者均与棕榈酸、硬脂酸、亚油酸、亚麻酸、蛋白质呈极显著负相关。主成分及隶属函数分析表明,摘薹后y15油菜品系籽粒综合性状最优良,y12、y10、y14、y6、y19、y11、y7、y13、y20、y3、y8品系次之,y4、y2、y9品系综合得分低于对照y21。     

国内亚麻育成品种品质性状的分析与评价

本研究测定了我国亚麻育成品种的主要品质性状,通过对我国亚麻育成品种品质性状进行综合评价与分析,为我国亚麻品质育种提供参考。结果表明：127份亚麻育成品种粗脂肪含量在34.86%～42.19%之间,平均37.22%;亚麻酸含量在39.8%～59%之间,平均49.04%;木酚素含量在5.34mg/g～10.99mg/g之间,平均8.84mg/g。品质性状变异系数在3.62%～14.62%之间,其中变异系数最大的是硬脂酸和木酚素,变异系数大于 10%;最小的是粗脂肪,为3.62%。相关分析表明,粗脂肪含量与木酚素、亚油酸极显著正相关,与棕榈酸极显著负相关,与油酸显著负相关,与亚麻酸和硬脂酸负相关;木酚素与棕榈酸、硬脂酸极显著正相关,与亚油酸极显著负相关,与亚麻酸、油酸负相关;亚麻酸与硬脂酸、油酸、棕榈酸极显著负相关。聚类分析把127份亚麻育成品种划分为4类,第Ⅰ类油酸含量最高,亚麻酸含量最低;第Ⅱ类木酚素含量最高,粗脂肪、亚油酸含量最低;第Ⅲ类粗脂肪、亚麻酸含量最高,油酸、棕榈酸含量最低;第Ⅳ类亚油酸含量最高,木酚素、硬脂酸含量最低。对我国亚麻育成品种品质的特征特性的研究,可为亚麻种质资源的利用和创新提供依据,为亚麻品种选育和遗传改良提供参考。     

芝麻籽中脂肪酸组成测定及相关性分析北大核心CSCD

对我国不同地区的46份芝麻籽样品进行脂肪酸组成测定,并分析了不同脂肪酸之间的相关性。亚油酸和油酸是芝麻籽中的主要脂肪酸,平均含量分别为45.40%和39.56%。芝麻籽中不饱和脂肪酸平均含量达到85.45%。亚油酸、油酸、棕榈酸和硬脂酸的含量分别为41.72%~48.51%,35.49%~43.60%、7.44%~10.39%和4.52%~6.00%。油酸含量与亚油酸含量呈极显著负相关,棕榈酸含量与硬脂酸含量呈显著负相关,与油酸、亚麻酸含量和花生酸含量呈极显著负相关,而与亚油酸含量呈极显著正相关。     

油菜籽成熟过程中主要营养成分变化研究

油菜籽品质的变化与其生育期密切相关。为获得优质油菜籽,以不同采收期的甘蓝型双低黄籽油菜籽为实验材料,对其含油量、蛋白质含量、以及多种脂肪酸含量等指标进行测定,及对各指标进行相关性分析。结果表明:供试的油菜籽在成熟过程中,含水量呈下降趋势,含油量在成熟中期上升较快,后期趋缓终花后32d达到35.33%;蛋白质含量变化较小,在成熟前期有一定上升,中后期变化平缓;总糖含量呈下降趋势,变化范围为13%~8%;油酸相对含量总体呈现缓慢上升趋势,最高值达56.99%;亚油酸和亚麻酸总体呈现缓慢下降趋势;棕榈酸和硬脂酸也有一定程度变化,但是变化幅度不大;油脂含量与蛋白质含量呈显著正相关,其与总糖含量呈极显著正相关;油酸的相对含量与亚麻酸的相对含量呈现显著负相关;亚油酸相对含量与亚麻酸相对含量呈现极显著的负相关;亚麻酸的相对含量与棕榈酸相对含量呈现显著正相关。综合考虑各物质的积累变化规律,在终花后的第29d至32d为最佳采收时间。     

芝麻籽中脂肪酸组成测定及相关性分析

对我国不同地区的46份芝麻籽样品进行脂肪酸组成测定,并分析了不同脂肪酸之间的相关性。亚油酸和油酸是芝麻籽中的主要脂肪酸,平均含量分别为45.40%和39.56%。芝麻籽中不饱和脂肪酸平均含量达到85.45%。亚油酸、油酸、棕榈酸和硬脂酸的含量分别为41.72%~48.51%,35.49%~43.60%、7.44%~10.39%和4.52%~6.00%。油酸含量与亚油酸含量呈极显著负相关,棕榈酸含量与硬脂酸含量呈显著负相关,与油酸、亚麻酸含量和花生酸含量呈极显著负相关,而与亚油酸含量呈极显著正相关。     

不同油梨种质资源果实脂肪酸分析及评价

为进一步探究油梨种质资源脂肪酸组分间关系,为其品种选育、构建油梨种质资源评价体系和综合利用提供参考,以23 份油梨成熟果为试验材料,采用气相色谱-质谱联用仪分析测定果实脂肪酸组分,通过相关系数、变异系数、多不饱和脂肪酸/饱和脂肪酸（polyunstaturated/saturated,P/S 值）、单不饱和脂肪酸/饱和脂肪酸值（monounsated/saturated,M/S 值）、致动脉粥样硬化指数（atherogentic index,AI 值）、高胆固醇指数（hypercholesterolaemic index,HI 值）、聚类分析指标综合评价油梨脂肪酸组分及其营养性。结果表明,不同油梨种质资源的脂肪酸组分之间存在差异性,果肉不饱和脂肪酸种类为6～15 种,占比为36.46%～66.39%;种子不饱和脂肪酸种类为2～11 种,占比为0%～65.26%。各脂肪酸之间普遍存在相关性,多为极显著正相关。变异系数在0.024～4.796,果肉、种子中的棕榈酸、硬脂酸、肉豆蔻酸、月桂酸4 种饱和脂肪酸变异系数均小于1,表现出遗传稳定性。油梨的M/S 值、P/S 值较高,AI 值、HI 值较低,具有较高的营养价值。以油梨果肉、种子脂肪酸组成为变量将23 份种质资源分为两类,南亚A、xx1、桂研1 号属于I 类,其油酸、棕榈油酸、亚麻酸、亚油酸含量显著高于另一类。桂研1 号果实的油酸、棕榈油酸、亚麻酸和亚油酸含量在23 份种质中最高,具有较大的开发潜力。由此可见不同油梨种质资源果实脂肪酸间存在差异性、相关性,脂肪酸组分分析对油梨的品种选育、种质资源评价和综合利用具有参考意义。     

高含油量油菜种子和果皮油份积累及主要脂肪酸的动态变化

以高含油量油菜品系为材料,研究角果发育过程中种子和果皮油份积累与主要脂肪酸的动态变化。结果表明：高含油量品种在角果发育早期油份的合成与积累较为缓慢,开花后20d种子含油率仅占成熟种子油份含量的8．35％～12．32％,角果发育中期是油份含量增加最快的时期,开花后40d种子含油率占成熟种子油份含量的72．89％。94．73％,籽粒成熟时油份含量达到最大值。果皮的油份积累与种子相反,随角果发育油份含量依次下降,两者呈极显著负相关,相关系数为-0．95。种子和果皮的二十碳烯酸、芥酸合成规律明显不同。种子的7种主要脂肪酸组成中芥酸和二十碳烯酸与16碳、18碳脂肪酸含量均呈负相关,亚麻酸和亚油酸与棕榈酸、硬脂酸和亚油酸含量均呈正相关,与油酸含量H2和H27为正相关,H1和H28为负相关。而油酸与其它脂肪酸的相关关系较为复杂,与棕榈酸、硬脂酸和亚油酸、亚麻酸的相关关系有正相关,也有负相关,可见油酸的合成与积累不仅与棕榈酸、硬脂酸有关,还会影响亚油酸和亚麻酸的含量,这是创新油菜高油酸材料的基础。     

不同杏品种果仁油脂的脂肪酸组成分析

为研究山西晋中地区不同杏品种果仁中脂肪含量与脂肪酸的组成特点,采用索氏提取、气相色谱分析法分析测定了15个杏品种果仁中的总脂肪含量及脂肪酸组成,结果表明:15个杏品种果仁中共检测出脂肪酸组分10种,总脂肪含量在28.11~53.15 g/100 g,其中不饱和脂肪酸占脂肪酸总含量的91.60%~95.15%,油酸与总脂肪含量之间呈极显著正性相关且油酸的偏相关系数最大;应用聚类分析可将其划分为"高含油率-高油酸-高亚麻酸""低含油率-高亚油酸""高含油率-高油酸-低亚麻酸"杏仁品种类型;根据主成分分析对杏仁的品质进行综合评价,扁杏综合评分最高。扁杏是高含油率-高油酸-高亚麻酸重要种质资源,该结果为杏栽培、育种及产业化的发展提供依据。     

Antityrosinase and antimicrobial activities of 2-phenylethanol, 2-phenylacetaldehyde and 2-phenylacetic acid

The inhibition kinetics of 2-phenylethanol, 2-phenylacetaldehyde and 2-phenylacetic acid on the enzyme activity of mushroom tyrosinase have been investigated. The results showed that these aromatic compounds can lead to reversible inhibition of the enzyme; furthermore, 2-phenylacetaldehyde and 2-phenylacetic acid are uncompetitive inhibitors and 2-phenylethanol is a mixed-type inhibitor. The inhibition constants have been determined and the inhibiting ability was: 2-phenylacetaldehyde > 2-phenylacetic acid > 2-phenylethanol, indicating that the functional group on the benzene ring group played an important role in the inhibition of the enzyme. In addition, 2-phenylacetic acid and 2-phenylethanol were found to have effective antibacterial activities, and 2-phenylacetic acid was more effective against Escherichia coli and Ralstonia solanacearum than 2-phenylethanol, but 2-phenylacetaldehyde lacked of antibacterial activity.     

用于亚硒酸钠检测的近红外荧光探针的设计合成及其应用研究

目的 建立一种基于荧光探针的亚硒酸钠检测方法。方法 基于荧光探针的构建方法, 在近红外荧光团中引入乙酰丙氨酸基对荧光团结构中羟基进行保护并淬灭荧光, 设计并合成荧光增强型近红外探针SeP1, 通过核磁氢谱(1Hydrogen-nuclear magnetic resonance, 1H NMR)、碳谱(13Carbon-nuclear magnetic resonance, 13C NMR)和高分辨质谱(High resolution mass spectrum, HRMS)的确证其化学结构, 通过荧光光谱法研究探针SeP1对亚硒酸钠的识别效果。结果 在多种分析物种,探针SeP1对亚硒酸钠具有高效专一的荧光选择性, 其最大荧光发射在近红外区(657 nm), 能够克服基质中常见背景荧光干扰, 在其他常见阴离子存在的情况下,具有较强的抗干扰能力并能够对亚硒酸钠实现裸眼识别。该探针对亚硒酸钠的最低检测限为0.068 μmol?L-1。进一步研究了探针对亚硒酸根的识别机理：当亚硒酸根离子与探针结构中乙酰丙基基团发生特异性反应后,使得探针结构中羟基脱保护重新生成带有羟基的化合物1,释放出强烈的荧光,通过高分辨质谱进一步确证了上述识别机理。结论 该探针对亚硒酸钠具有高效专一的识别能力, 并成功的应用于饮用水中亚硒酸钠加标回收检测, 具备较强的实用价值。     

固体酸催化大豆油脱臭馏出物甲酯化工艺研究

采用溶胶-凝胶和浸渍法制备了SO2-4/TiO2-SiO2固体酸催化剂,利用其对大豆油脱臭馏出物进行甲酯化。研究了TiO2-SiO2载体焙烧温度、浸渍用硫酸浓度、浸渍时间对催化剂活性的影响,以及催化剂用量、醇油比、反应温度和反应时间对酯化率的影响。得到了最佳反应条件为载体焙烧温度550℃,浸渍用硫酸浓度2.5 mol/L,浸渍时间12 h,催化剂用量5%(以大豆油脱臭馏出物质量计),醇油比1.5∶1(甲醇与大豆油脱臭馏出物体积质量比),反应温度65℃,反应时间4 h。在最佳条件下,酯化率达到96.5%。     

The effect of phytic acid on oxidative stability of raw and cooked meat

The effects of phytic acid addition (0.1, 1 and 5 mM) to pork and beef homogenates on TBARS and metmyoglobin levels in raw meat, and TBARS and heme iron contents in cooked meat during 3 days of storage at 4 °C were investigated. Also, the role of inositol as a potential synergist of IP₆ (phytic acid) was examined. IP₆ effectively decreased the TBARS accumulation in raw and cooked meat homogenates. The metmyoglobin formation was inhibited in raw beef by phytic acid in a dose-dependent manner. The effect of IP₆ was more pronounced in cooked meat than in raw and in cooked beef homogenates more than pork. Inositol did not enhance antioxidant action of phytic acid in minced meat.     

水稻中除草剂氯氟吡氧乙酸异辛酯和氰氟草酯的检测方法及其储藏稳定性研究

目的 探究26%氰氟草酯·氯氟吡氧乙酸异辛酯乳油在水稻上的残留行为, 对其储藏稳定性和膳食摄入风险进行评估。方法 待测试样经乙酸乙腈提取, N-丙基乙二胺(primary secondary amine, PSA)、C18和石墨化碳黑(graphitized carbon black, GCB)净化, 再经高效液相色谱-串联质谱法多反应监测模式扫描, 基质匹配标准曲线外标法定量。2018年在9地进行田间残留实验, 并且进行6个月的储藏实验, 获得氯氟吡氧乙酸、氰氟草酯和氰氟草酸在水稻上的残留实验中值、降解率, 对膳食摄入风险进行评估。结果 氯氟吡氧乙酸、氰氟草酯和氰氟草酸在加标浓度为0.05~0.5 mg/kg范围内具有良好的线性关系, 相关系数(r)为0.9984, 3种待测物在水稻中的平均回收率为76.4%~105.0%, 相对标准偏差(relative standard deviation, RSD)为1.2%~8.2%, 定量限为0.05 mg/kg。在6个月储藏实验期间, 3种待测物在稻谷及水稻植株的降解率低于30%。膳食风险评估表明: 普通人群氯氟吡氧乙酸异辛酯、氰氟草酯的国家估计每日摄入量分别为0.0596 mg和0.0120 mg, 膳食摄入风险评估分别为4.73%和1.90%。结论 该检测方法操作简便、前处理速度快、精密度高和灵敏度高, 可以满足对复合农药残留分析检测的要求。氯氟吡氧乙酸、氰氟草酯和氰氟草酸在-20 ℃冰箱6个月储藏稳定, 其在水稻上的残留对消费者不会产生不可接受的风险     

Glycosylation,amino acid analysis and kinetic properties of a major Kunitz-type trypsin inhibitor from Acacia victoriae Bentham seeds

An Acacia victoriae trypsin inhibitor (AvTI) was purified from the seeds of prickly wattle (A. victoriae Bentham) by salt precipitation, ion-exchange and gel filtration chromatography, and its degree of glycosylation, amino acid composition, and kinetic properties were determined. Gel electrophoresis revealed at least four glycoprotein bands in the crude extract, salt-precipitated and ion-exchange protein fractions, while the purified AvTI showed only one band and a degree of glycosylation of 2.06%. Glutamate (13.3%), aspartate (10.3%), leucine (7.62%) and lysine (7.01%) were the major amino acids in AvTI while the contents of sulphur-containing amino acids, cysteine (1.38%) and methionine (0.75%), as well as of tryptophan (1.17%) were low. Its dissociation constant (K_i) for the inhibition of bovine trypsin was found to be 1.06 × 10⁻⁸ M, indicating a high affinity between AvTI and this enzyme, and its role as a competitive inhibitor was confirmed by a double reciprocal plot. These results complement our earlier studies which indicated the presence of three isoforms of this Kunitz-type trypsin inhibitor in prickly wattle seed.     

Temperature and pressure stability of l-ascorbic acid and/or [6s] 5-methyltetrahydrofolic acid: A kinetic study

Processing (i.e. pressure and temperature) stability of l-ascorbic acid (l-AA) and/or [6S]-5-methy-ltetrahydrofolate ([6S]-5-CH₃-H₄folate) was studied on a kinetic basis using different vitamin and initial oxygen concentrations. Stability of both folate and l-AA was enhanced by increasing the vitamin concentration or by decreasing the oxygen concentration. Based on this study, it was concluded that (i) l-AA increased the folate stability during processing; (ii) the molar ratio between l-AA or folate and the initial oxygen content was an important parameter to determine the proportion of aerobic degradation; and (iii) the minimum concentration of l-AA needed to prevent the oxidation of folate was at least 2 times as high as the molar concentration of the initial oxygen content when l-AA exists as a single antioxidant in the system.     

氢核磁共振结合支持向量机鉴别蜂蜜植物源

目的建立基于氢核磁共振(1H nuclear magnetic resonance,1H NMR)结合支持向量机分类模型鉴别蜂蜜植物源的方法。方法采集荆条蜜、油菜蜜、洋槐蜜、葵花蜜4种不同植物源的蜂蜜共计122例样品的谱图信息,分全谱(δ0.10~δ9.50)、脂肪区(δ0.10~δ3.00)、糖类化合物区(δ3.00~δ6.00)、芳香区(δ6.00~δ9.50)4个不同积分区间建立分类模型,结合主成分权值系数筛选特征变量,进一步优化判别模型。结果基于主成分权值系数筛选变量范围δ3.40~δ3.90和δ4.60~δ4.70内共计267个积分变量,以该区域积分变量为输入变量建立的支持向量机分类模型,对训练集的判别正确率为97.53%,对测试集的判别正确率为100%。结论通过主成分权值系数能有效筛选特征变量,减少输入变量的同时提高模型稳健性与准确性,基于氢核磁共振结合支持向量机分类模型能有效鉴别不同植物源蜂蜜。     

液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量

目的 建立液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量的分析方法。方法 样品经氨化乙酸乙酯提取,通过DPC-2固相萃取柱净化,采用Poroshell 120 EC-C18柱分离,以10 mmol/L乙酸铵溶液-乙腈为流动相进行梯度洗脱,电喷雾正/负离子切换,多反应监测模式检测,同位素内标法定量。结果 氟苯尼考在0.2～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.05 μg/kg,回收率为85.5%~116.3%,相对标准偏差小于10%。氟苯尼考胺在1～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.3 μg/kg,回收率为85.6%~113.5%,相对标准偏差小于10%。结论 该方法快速、准确、灵敏, 适用于蜂蜜中氟苯尼考及其代谢物残留量的测定。     

Effects of folic acid and vitamin B12 supplementation on culling rate,diseases, and reproduction in commercial dairy herds

This study was undertaken to determine the effect of a combined folic acid and vitamin B₁₂ supplement given in early lactation on culling rate, metabolic disorders and other diseases, and reproduction in commercial dairy herds. A total of 805 cows (271 primiparous and 534 multiparous cows) in 15 commercial dairy herds were involved. Every 2 mo from February to December 2010 and within each herd, cows were assigned according to parity, previous 305-d milk production, and calving interval to 5 mL of either (1) saline 0.9% NaCl (control group) or (2) 320 mg of folic acid + 10 mg of vitamin B₁₂ (vitamin group). Treatments were administered weekly by intramuscular injections starting 3 wk before the expected calving date until 8 wk after parturition. A total of 221 cows were culled before the next dry period. Culling rate was not affected by treatment and was 27.5%; culling rate was greater for multiparous (32.2%) than for primiparous cows (18.8%). Within the first 60 d in milk (DIM), 47 cows were culled, representing 21.3% of total culling, and no treatment effect was noted. Ketosis incidence based on a threshold ≥100 µmol/L of β-hydroxybutyrate in milk was 38.3 ± 2.9% for the vitamin group and 41.8 ± 3.0% for the control group and was not affected by treatment. The combined supplement of folic acid and vitamin B₁₂ did not decrease incidence of retained placenta, displaced abomasum, milk fever, metritis, or mastitis. However, the incidence of dystocia decreased by 50% in multiparous cows receiving the vitamin supplement, although no effect was observed in primiparous cows. The first breeding postpartum for multiparous cows occurred 3.8 d earlier with the vitamin supplement compared with controls, whereas no treatment effect was seen for primiparous cows. Days open, first- and second-breeding conception rates, number of breedings per conception, and percentage of cows pregnant at 150 DIM were not affected by treatment. The reduced percentage of dystocia combined with the earlier DIM at first breeding for multiparous cows receiving the combined supplementation in folic acid and vitamin B₁₂ indicates that the vitamin supplement had a positive effect in older cows.