气相色谱—质谱联用法测定植物油和鸡肉中抗氧化剂BHA BHT和TBHQ

建立了气相色谱质谱联用(GC-MS)技术测定植物油和鸡肉中BHA,BHT和TBHQ的分析方法。GC-MS测定结果显示,BHA,BHT和TBHQ的线性相关系数均大于0.999,定量下限为别为3,2,5μg/kg;此方法的精密度和加标回收率良好。结果表明,该方法可以用植物油和鸡肉中3种抗氧剂同时分析。     

茶多酚棕榈酸酯和迷迭香提取物复合抗氧化剂对葵花籽油的抗氧化效果研究

研究比较了天然抗氧化剂(茶多酚棕榈酸酯和迷迭香提取物)与人工合成抗氧化剂(BHA、BHT、TBHQ)在葵花籽油中的抗氧化能力,并优化茶多酚棕榈酸酯、迷迭香提取物比例,制备天然复合抗氧化剂。发现当茶多酚棕榈酸酯0. 45 g/kg、迷迭香提取物0. 15 g/kg时,其协同抗氧化性最强。在最佳添加量条件下,复合天然抗氧化剂在减缓酸值、过氧化值方面优于BHT、BHA,与TBHQ相近。但在减缓丙二醛含量上升速率的能力优于TBHQ。因此复配抗氧化剂有其明显的优势,可为葵花籽油储存过程中添加天然抗氧化剂提供参考。     

气相色谱法同时测定食品接触材料纸制品中6种抗氧化剂

建立了气相色谱法同时测定食品接触材料纸制品中双酚A,丁羟基茴香醚(BHA)、特丁基对苯二酚(TBHQ)、2,6-二叔丁基对甲酚(BHT)、2,4,6-三异丁基苯酚(TTBP)、2,2′-亚甲基双(4-乙基-6叔丁基酚)(AO425)共6种抗氧化剂的分析方法。纸制品加水浸泡,然后用乙酸乙酯—正己烷混合溶剂匀浆提取,考察了提取溶剂、提取方法对抗氧化剂提取效率的影响。提取液经毛细管气相色谱柱DM-5(30 m×0.25 mm×0.25μm)分离,氢火焰检测器(FID)检测,外标法定量。结果表明,在抗氧化剂添加量为10.0～50.0 mg/kg范围内,双酚A,BHA,TBHQ,BHT,TTBP和AO425在纸制品中的平均添加回收率分别为82%～104%,82%～103%,83%～102%,85%～104%,85%～104%,84%～104%,相对标准偏差(RSD,n=10)分别为5.3%～6.8%,4.9%～6.7%,4.6%～6.6%,53%～6.9%,4.7%～6.6%,4.5%～6.9%,BHA,BHT,TBHQ,TTBP,双酚A,AO425测定低限(信噪比>10)为10.0mg/kg,线性范围1.0～100.0 g/mL,相关系数大于0.999。     

即食辣椒萝卜中抗氧化剂的应用研究

为了防止即食辣椒萝卜中的油脂在贮藏过程中发生氧化,而使产品品质下降,往辣椒萝卜中加入适量的BHA,BHT,TBHQ,PG和VC,在室温下贮存60d后,对其过氧化值(POV)和酸价(AV)进行测试和分析,并比较它们在即食辣椒萝卜中的抗氧化效果。从过氧化值和酸价指标综合看来,同时添加BHT0.075g/kg,BHA0.06g/kg和TBHQ0.04g/kg,对辣椒萝卜中油脂的抗氧化具有较好的效果。     

气相色谱法测定植物油中的抗氧化剂BHA BHT与TBHQ及不确定度评定

建立了气相色谱法同时测定植物油中抗氧化剂BHA,BHT与TBHQ含量的方法,重点考察了方法的检出限、线性范围、重复性、回收率等。针对测量数学模型建立了气相色谱法测定植物油中TBHQ含量不确定度的评定方法。通过不确定度来源分析,建立不确定度的数学模型,并考察了测定中的各种影响因素。     

气相色谱法测定食品中BHT BHA TBHQ三种抗氧化剂

对比了气相色谱法测定食品中丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)和特丁基对苯二酚(TBHQ)残留量的2种前处理分析方法。一种是提油脂法,样品先用石油醚浸泡过夜,减压蒸发溶剂后,油脂用甲醇反复提取,最后氮吹浓缩;另一种是直接处理法,样品直接用正己烷溶解,甲醇反复提取,氮吹浓缩。3种抗氧化剂在5~200μg/m L质量浓度范围内呈现良好的线性关系,相关系数R~2均大于0.999 9。提油脂法的检出限、定量限较低,回收率也大于直接处理法。因此,提油脂法可作为这3种抗氧化剂检测的有效技术手段。     

食品抗氧化剂在焙烤葵花子中的应用效果研究

通过BHA,BHT,TBHQ三种抗氧化剂的单独和两两复配实验,同时考虑柠檬酸的协同增效作用,寻求最佳的抗氧化方案,从达到延长葵花子货架期的目的。实验结果表明,抗氧化效果最好的是单加TBHQ,随着TBHQ添加量的不断增大,抗氧化的效果差异不明显,添加量为0.04%(按水质量计)较适宜;其次是TBHQ与BHT的复配组合,随着TBHQ添加比例的增加,抗氧化效果增强;在葵花子中,柠檬酸对TBHQ抗氧化效果的增效作用不显著。     

气相色谱法同时测定食品接触材料纸制品中6种抗氧化剂

建立了气相色谱法同时测定食品接触材料纸制品中双酚A,丁羟基茴香醚(BHA)、特丁基对苯二酚(TBHQ)、2,6-二叔丁基对甲酚(BHT)、2,4,6-三异丁基苯酚(TTBP)、2,2’-亚甲基双(4-乙基-6叔丁基酚)(AO425)共6种抗氧化剂的分析方法.纸制品加水浸泡,然后用乙酸乙酯一正己烷混合溶剂匀浆提取,考察了提取溶剂、提取方法对抗氧化剂提取效率的影响.提取液经毛细管气相色谱柱DM-5 (30 m×0.25 mm×0.25 μm)分离,氢火焰检测器(FID)检测,外标法定量.结果表明,在抗氧化剂添加量为10.0～50.0 mg/kg范围内,双酚A,BHA,TBHQ,BHT,TTBP和A0425在纸制品中的平均添加回收率分别为82％～ 104％,82％～ 103％,83％～ 102％,85％～ 104％,85％～104％,84％～ 104％,相对标准偏差(RSD,n=10)分别为5.3％～6.8％,4.9％～6.7％,4.6％～6.6％,53％～6.9％,4.7％～6.6％,4.5％～6.9％,BHA,BHT,TBHQ,TTBP,双酚A,AO425测定低限(信噪比＞10)为10.0 mg/kg,线性范围1.0～100.0 g/mL,相关系数大于0.999.     

一种同时测定鱼腥草中百草枯和乙草胺残留方法探讨

采用高速匀浆提取,固相萃取(SPE)净化,三重四级杆气相色谱质谱联用仪(GC-MS/MS)检测,建立了鱼腥草中两种除草剂农药残留的分析方法。在0.02~0.50 mg/L范围内,目标物的峰面积与其质量浓度的线性关系良好(R20.99);在0.02、0.10、0.50 mg/kg的添加水平,样品添加回收率为73.5%~81.2%,相对标准偏差(RSD)为3.43%~4.49%;乙草胺方法检出限为0.2μg/kg,定量限为0.80μg/kg,百草枯方法检出限为1.40μg/kg,定量限为5.00μg/kg。该方法具有高灵敏度、快速、准确度高、线性范围宽等优点,可满足鱼腥草中农药残留检测的要求。     

国际油脂制品法规委员会 关于色素、抗氧化剂、抗氧化增效剂添加量的最新规定

国际油脂制品法规委员会于1987年2月在伦敦召开会议,作出了油脂中色素、抗氧化剂和抗氧化增效剂的添加量的最新规定:色素的最高限量为β-胡萝卜素25mg/kg,胭脂树籽红色素20mg/kg,姜黄素5mg/kg,角黄素25mg/kg,胡萝卜酸甲酯或乙酯25mg/kg;抗氧化剂的最高限最为:棓酸丙酯100mg/kg,BHT75mg/kg,BHA175mg/kg,TBHQ120mg/kg,天然或合成生育酚500mg/kg,山梨酸硬脂酸酯500mg/kg,硫代二丙酸肉桂酯200mg/kg;抗氧化增效剂的最大允许添加量是:柠檬酸,柠檬     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.