叶类蔬菜硝酸盐与矿质元素含量及其相关性研究

对重庆市 2 3种叶类蔬菜NO-3 和部分矿质元素含量及其相关性研究结果表明 ,不同蔬菜、同一蔬菜不同品种NO-3 和矿质元素含量差异很大 ,除莴笋、西生菜和瓢儿白 (卷心 )鲜菜食用安全外 ,其他均有不同程度污染 ,且以芹菜食用安全性最差。不同叶类菜矿质元素间多数相关性很好 ,尤以N、P、K(除个别元素外 )与其他矿质元素呈显著或极显著正相关 ;叶类菜鲜样中NO-3 含量与K、Na、Ca和Fe呈显著或极显著正相关 ,叶类菜干样中NO-3 与P、S、Mn、Zn、B和Mo呈负相关 ,且与B、P达显著负相关     

芦笋矿质元素吸收特性研究

研究了芦笋不同生长时期干物质积累和矿质元素吸收特性。结果表明,芦笋在采笋期干物质积累占全年总积累量的26.2%。嫩茎为该时期的干物质积累中心,积累量占采笋期积累量的69.7%。母茎生长期干物质积累占全年总积累量的73.8%,母茎为该时期的干物质积累中心,积累量占这一时期积累量的70.9%。在各种矿质元素中,芦笋植株吸收钾最多,其次为氮。对氮、磷、钾、钙、镁的吸收比例为3.33︰1︰4.77︰0.52︰0.23。钾在采笋期和母茎生长期的积累量基本相同;氮、铜、锌主要在采笋期积累;磷、钙、镁、铁、锰则主要在母茎生长期积累。根据芦笋矿质元素吸收特性提出了芦笋不同生育阶段的施肥建议。     

河北省主栽山药品种矿质养分累积及矿质营养品质差异

  【目的】  比较河北省主栽山药品种的矿质养分累积特性及营养品质的差异,以期为山药生产提质增效制定科学的养分管理措施。  【方法】  田间试验在河北省蠡县进行,供试山药(Dioscorea oppositifolia L.)品种包括棒药、大和白玉、紫药和小白嘴,山药4个品种的施肥量和施肥方法均一致。在成熟期,取样测定了山药地上部、根茎生物量,以及9种矿质元素(氮、磷、钾、钙、镁、铁、锰、铜和锌)含量和累积量。  【结果】  4个主栽山药品种根茎的鲜生物量表现为大和白玉>棒药>紫药>小白嘴,而干生物量表现为紫药>大和白玉>小白嘴>棒药。大和白玉根茎的氮、钙、镁、锰、铜、锌累积量最高,且钾、钙、镁、锰、铜、锌分配系数最高,紫药根茎的磷、钾累积量最高,且氮分配系数较高,磷分配系数最高,棒药根茎的铁累积量及分配系数均为最高。4个山药品种形成1000 kg产量对大量营养元素的需求量均表现为钾>氮>磷,对中量营养元素的需求量均表现为镁>钙,对微量营养元素的需求量均表现为铁>锌>锰>铜。以《中国食物成分表》(标准版)中山药的9种矿质营养品质指标作为参比,对4个供试山药品种的9个矿质营养品质指标进行主成分分析,提取出特征值大于1的主成分3个,累计贡献率为96.77%。其中,第1主成分贡献率为56.45%,主要受钾、锌的影响;第2主成分的贡献率为29.09%,主要受镁、锰的影响;第3主成分的贡献率仅为11.22%,主要受铁的影响。矿质营养品质综合评价结果为大和白玉最优,其次是棒药,小白嘴和紫药分列第3和第4位,但4个品种矿质营养品质均优于《中国食物成分表》(标准版)中的山药品质。  【结论】  大和白玉为矿质营养品质最优品种,且为高锌品种,棒药为高钙、铁品种,土壤中钾、镁、铁、锰和锌含量是影响山药根茎矿质营养品质差异的主要元素。山药生产中,矿质肥料的施用要考虑土壤中矿质元素含量与不同品种的矿质元素需求,进行科学的养分管理,以进一步提升山药矿质营养品质。     

新疆灰枣园土壤养分与枣果矿质元素关系的多元分析

为了研究新疆灰枣园土壤养分与枣果矿质养分间的复杂关系,制定土壤养分因子的优 化方案,从而为新疆枣园的科学施肥与精准化管理提供参考依据和技术指导。对新疆 9 个灰枣 主产县市的 20 个枣园的枣果矿质元素含量和土壤养分含量进行测定,运用 R 语言和 SIMCA 多 元统计软件分析并筛选出影响枣果矿质养分的重要土壤养分因子,并利用 Lingo 软件建立线性 规划方程,探明枣果矿质养分最优时土壤养分因子的优化方案。结果表明,研究区的枣园土壤 皆为碱性土壤,各样点间土壤有机质、碱解氮、有效磷含量具有极显著性差异;各样点间土壤 速效钾含量具有显著性差异;各样点间土壤交换性钙、交换性镁、有效硫、有效硼、有效锌含 量具有极显著性差异;各样点间土壤有效铁、有效锰、有效铜含量具有显著性差异。枣果矿质 营养是土壤养分因子共同作用的结果。偏最小二乘回归分析结果表明,土壤养分影响枣果中的 氮、磷、钾、钙、镁、硫、硼、铁、锰、锌、铜含量最大的指标分别为土壤速效钾、有效硼、 碱解氮、有机质、有效硼、有效铁、有效硼、有效锰、有机质、pH 值、有效锌,同一土壤养 分指标影响着不同的果实矿质元素含量,且果实一种矿质元素受不同土壤养分影响皆不同,其 中土壤有机质和有效硼含量对果实矿质元素影响较大。新疆灰枣园土壤养分的最优方案为:当 灰枣园土壤 pH 值为 7.30 ～ 8.46,有机质为 23.24 ～ 59.73 g/kg,碱解氮大于 63.75 mg/kg,有效磷 为 92.40 ～ 164.67 mg/kg, 速 效 钾 为 223.25 ～ 372.47 mg/kg, 交 换 性 钙 为 437.00 ～ 1392.00 mg/kg, 交换性镁为 124.87 mg/kg,有效硫为 412.66 mg/kg,有效硼为 1.66 ～ 6.05 mg/kg,有效铁为 12.21 ～ 16.15 mg/kg,有效锰为 8.88 mg/kg,有效锌为 0.45 ～ 1.41 mg/kg,有效铜为 2.35 ～ 3.86 mg/kg 时,灰枣 果实的矿质元素含量最优。在对新疆灰枣枣园的施肥管理中,应注重水肥管理的科学性,适时增 施有机肥,调节土壤 pH 值,提高土壤中交换性钙、交换性镁、有效锰和有效锌含量,因地制宜, 选择科学的施肥配比。     

豫北地区小麦籽粒矿质元素含量分析

为了解豫北地区小麦籽粒中矿物元素的含量,指导小麦区域种植,本研究采集了河南安阳、鹤壁、新乡等3个地市9个粮食主产县区的81份小麦籽粒样品,并分析其钙、铁、锌、硒、铜、镁、钠、钾、铬等9种元素含量。结果表明,豫北地区小麦籽粒中铜、铬元素含量均符合国家相关标准要求,锌元素存在少量超标样品,被测元素除镁、铬元素可满足一般人群的每日摄入量外,其余元素均需通过食用其他食品补充人体矿质元素营养需求。豫北地区矿质元素呈不均一分布,鹤壁市淇滨区周边小麦籽粒中锌含量较高,新乡市市区周边的硒含量较高,铁元素含量较高地区为安阳市内黄县、滑县东部,硒元素含量较低地区为安阳市滑县、新乡市延津县。本研究结果为保障豫北地区消费者营养元素均衡摄取提供了数据参考。     

南阳烤烟矿质元素及化学成分次适宜因子与土壤生态因子的典型相关分析

为了解南阳烤烟矿质元素及主要化学成分次适宜因子及其与土壤生态因子的关系,选取代表南阳不同生态类型的13个样点的土壤样品和烟叶样品,以及2个津巴布韦、14个巴西的优质烟样,测定烟样矿质元素及化学成分与土壤生态因子.对优质烟与南阳烤烟间矿质元素及主要化学成分指标的比较表明,南阳烤烟矿质元素及主要化学成分次适宜因子为磷、钾、钙、钠、烟碱、总糖、还原糖、淀粉.对次适宜因子与土壤生态因子进行典型相关分析的结果表明,在一定范围内,随着土壤锌含量提高,烟叶还原糖呈显著增加趋势而烟碱呈显著减少趋势:土壤氨化菌数减少、硝化菌数增加,烟叶烟碱显著增加而总糖、淀粉、磷含量显著减少;随土壤放线菌数减少、解钾菌数增加,烟叶还原糖含量增加;随土壤铜含量提高,烟叶钙、钠含量减少;随土壤硝化菌数减少、真菌数增加,烟叶钙含量呈增加趋势而钠含量呈减少趋势.改良土壤特别是改良土壤微生物性状可望改善烟叶质量.     

木芙蓉营养生长旺期主要矿质元素的吸收与分布特征

木芙蓉是一种观赏和药用价值较高的多年生木本花卉。在大田条件下,研究营养生长旺期木芙蓉主要矿质元素的含量与分布特征,可为其科学施肥提供技术支撑。以营养生长旺期的两个木芙蓉品种(早花品种"牡丹红"和晚花品种"醉芙蓉")为研究对象,称量根、茎、叶等器官的生物量,测定其中氮、磷、钾、钙、镁、铁、锰、锌元素含量。结果表明:(1)在营养生长旺期,"牡丹红"和"醉芙蓉"整株生物量无差异,但前者茎的比重大于后者,后者根的比重大于前者。(2)磷在木芙蓉不同器官含量无差异,叶片中其他矿质元素含量显著高于茎和根;对于相同器官,早花品种叶片中钙的含量低于晚花品种,其余元素含量无差异。(3)木芙蓉不同器官的养分吸收累积量与含量类似,除磷、钾、镁、铁以外,其余元素在叶中积累量高于根和茎;早花品种整株氮、钙和铁的积累量低于晚花品种。(4)早花品种氮、磷、钾、钙、镁、铁、锰、锌养分累积量分别为4.34、0.87、4.99、3.12、1.44、0.15 g·株^-1和8.50、5.86 mg·株^-1,晚花品种累积量分别为5.92、1.11、5.71、4.35、1.74、0.22g·株^-1和12.52、7.52 mg·株^-1。因此,木芙蓉生长阶段不仅需要施用氮、磷、钾大量元素,还要注意中微量元素的补充。种植年限相同的晚花品种施肥量稍高于早花品种,但不同养分施用比例的规律类似,营养生长旺期两者氮、磷、钾、钙、镁、铁、锰、锌养分吸收比例平均为1∶0.20∶1.06∶0.73∶0.31∶0.04∶(2.04×10–3)∶(1.31×10–3)。然而,木芙蓉整个生育期肥料施用数量和时期有待进一步研究。     

铁和不同形态氮素对玉米植株吸收矿质元素及其在体内分布的影响——Ⅰ.对氮、磷、钾、钙、镁等营养元素的影响

用营养液培养方法研究了铁和两种形态氮素(NO3--N和NH4+-N)对玉米植株吸收氮、磷、钾等大量元素和钙、镁等中量元素及其在体内分布的影响。结果表明:与NO3--N相比,供应NH4+-N促进了玉米对氮的吸收,在缺铁条件下,降低了对磷、钾、钙及镁的吸收。铁和NH4+-N都显著提高了玉米植株各器官中氮的含量。与NH4+-N处理相比,NO3--N处理的新叶中磷含量显著增加,但铁的供应对植物体内磷的含量无显著影响。使用NO3--N显著提高了玉米新叶和老叶中钾的含量,根和茎中钾的含量无明显影响。铁的供应降低了新叶和老叶中钾的含量。供铁时,NH4+-N处理的玉米新叶中钙和镁的含量显著低于NO3--N处理,而在缺铁时则无显著差异。     

陇薯系列马铃薯品种营养品质评价及相关性分析

为了解陇薯系列马铃薯块茎的主要营养品质状况,对甘肃省农业科学院马铃薯研究所自主选育的14个品种(系)马铃薯块茎的干物质、淀粉、还原糖、维生素C和粗蛋白含量等主要品质性状和钾、钙、铁、锌、硒等矿质元素含量进行了测定和相关性分析,并利用隶属函数法对各品种(系)主要营养品质进行了综合评价。结果表明,马铃薯块茎主要品质性状和矿质元素含量在品种间差异较大,品质性状中还原糖含量的变异系数最大(101.30%),干物质含量变异系数最小(11.64%);矿质元素中硒含量的变异系数最大(29.78%),钾含量变异系数最小(7.62%)。马铃薯块茎中干物质含量与淀粉含量、粗蛋白含量与干物质含量和淀粉含量均呈极显著正相关,维生素C含量与还原糖含量呈显著正相关,粗蛋白含量与还原糖含量和维生素C含量分别呈极显著和显著负相关,其他品质性状间的相关性均未达到显著水平;钾含量与淀粉含量呈极显著正相关,钾含量与干物质含量、钙含量与粗蛋白含量呈显著正相关,其他矿质元素与品质性状间的相关性均未达到显著水平。利用隶属函数法,将参试的14个马铃薯品种(系)的营养品质从优到劣进行排序,依次为陇薯8号陇薯14号LY08104-12LZ111陇薯9号陇薯7号陇薯12号陇薯10号陇薯3号陇薯6号陇薯11号LK99陇薯13号陇薯5号。本研究不仅为合理应用陇薯系列马铃薯品种提供了科学依据,也为选育不同用途马铃薯新品种提供了一定的理论参考。     

番茄对氮磷钾及中微量元素的吸收规律研究

通过田间试验研究了番茄生长过程中对氮、磷、钾及中微量元素的吸收分配规律。通过试验,测定番茄各个时期根系、茎秆、叶片、果实中氮、磷、钾、钙、镁、铁、锰、铜、锌的含量,旨在发现番茄各时期矿质元素的吸收规律。研究表明:随番茄生长发育的进行,氮、磷、钾及中微量元素在根、茎、叶中的分配率均呈降低的趋势,而果实中各元素分配率持续提高。至番茄成熟期果实中氮、磷、钾分配率分别达44.89%、56.73%、54.25%,钙、镁分配率分别达19.9%、53.9%,铁、锰、铜、锌分配率分别达31.8%、19.0%、27.8%、9.0%。番茄全生育期吸收钾最多,氮次之,磷最少,全生育期对氮、磷、钾吸收比例为3.0∶1.0∶4.7;对钙、镁吸收比例为8.1∶1;番茄全生育期对铁需求较大,锌、锰次之,铜最少,吸收比例为38.6∶2.9∶1∶2.0。     

Antioxidant and antiproliferative activities of common vegetables

Epidemiological studies have shown that consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Increased consumption of fruits and vegetables containing high levels of phytochemicals has been recommended to prevent chronic diseases related to oxidative stress in the human body. In this study, 10 common vegetables were selected on the basis of consumption per capita data in the United States. A more complete profile of phenolic distributions, including both free and bound phenolics in these vegetables, is reported here using new and modified methods. Broccoli possessed the highest total phenolic content, followed by spinach, yellow onion, red pepper, carrot, cabbage, potato, lettuce, celery, and cucumber. Red pepper had the highest total antioxidant activity, followed by broccoli, carrot, spinach, cabbage, yellow onion, celery, potato, lettuce, and cucumber. The phenolics antioxidant index (PAI) was proposed to evaluate the quality/quantity of phenolic contents in these vegetables and was calculated from the corrected total antioxidant activities by eliminating vitamin C contributions. Antiproliferative activities were also studied in vitro using HepG(2) human liver cancer cells. Spinach showed the highest inhibitory effect, followed by cabbage, red pepper, onion, and broccoli. On the basis of these results, the bioactivity index (BI) for dietary cancer prevention is proposed to provide a simple reference for consumers to choose vegetables in accordance with their beneficial activities. The BI could be a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.     

Determination of total content of phenolic compounds and their antioxidant activity in vegetables--evaluation of spectrophotometric methods

This research studies in detail the contents of phenolic compounds determined by the Folin-Ciocalteu reagent and the antioxidant activities determined by the TEAC (Trolox equivalent antioxidant capacity), DPPH (using diphenyl-p-picrylhydrazyl radical), and FRAP (ferric reducing antioxidant power) methods, and their correlations for used standards with these methods (catechine, gallic acid, caffeic acid, ferulic acid, Trolox, ascorbic acid, and ferrous sulfate) and extracts from several species of commonly consumed vegetables were studied in detail. The comparison of absolute values of absorption coefficients for used standards and for individual methods allows one to choose optimal common standards for methods to be compared. The procedures applied for the same sets of the extracts using identical calibration procedures and common standards allowed better comparison of the results obtained by the TEAC, DPPH, and FRAP methods. The values of content of phenolic substances and total antioxidant activity of the sets of samples correlate very well for all used methods. The very high values of antioxidant activity were found in intensely colored vegetables (red cabbage, red onion, etc.), and the values were very low in watery vegetables such as potato, marrow, and cucumber.     

Antioxidant activity of dietary fruits, vegetables, and commercial frozen fruit pulps

Fruits, vegetables, and commercial frozen pulps (FP) consumed in the Brazilian diet were analyzed for antioxidant activities using two different methods, one that determines the inhibition of copper-induced peroxidation of liposome and another based on the inhibition of the co-oxidation of linoleic acid and beta-carotene. The anthocyanin-rich samples showed the highest, concentration-dependent, antioxidant activities in both systems. In the liposome system, at both 10 and 50 microM gallic acid equivalent (GAE) addition levels, the neutral and acidic flavonoids of red cabbage, red lettuce, black bean, mulberry, Gala apple peel, jambolao, acai FP, mulberry FP, and the acidic flavonoids of acerola FP showed the highest antioxidant activities (>85% inhibition). In the beta-carotene bleaching system, the samples cited above plus red guava gave inhibition values >70%. On the other hand, some samples showed pro-oxidant activity in the liposome system coincident with a low antioxidant activity in the beta-carotene system. There was no relationship between total phenolics content, vitamin C, and antioxidant activity, suggesting that the antioxidant activity is a result of a combination of different compounds having synergic and antagonistic effects.     

兰州土壤-蔬菜系统铅污染特征及全钾速效钾与pH对其富集特性影响

通过野外调查取样与实验测定相结合的方法,对兰州市农业生态系统土壤-蔬菜体系49个样点进行研究,分析探讨了研究区蔬菜与土壤的铅污染水平以及蔬菜铅富集效应特性。结果表明：①蔬菜种植地土壤铅平均含量为26.30 mg.kg-1,合格率为93.62%,在不同县区存在显著差异,其大小顺序为红古区〉榆中县〉永登县;②蔬菜铅平均含量为0.59 mg.kg-1,合格率为60.78%,在不同县区存在显著差异,其大小顺序为永登县〉榆中县〉红古区;③蔬菜铅富集系数为（1.69±2.99）%,永登县蔬菜的铅富集能力显著高于榆中县和红古区,不同种类蔬菜铅富集能力在不同县区具有差异性;④土壤全钾除与白菜和甘蓝有正相关性以外,与其他蔬菜均为负相关性,其中与白菜、番茄、土豆显著相关,与胡萝卜为极显著相关;⑤土壤速效钾与各种蔬菜的铅富集能力均为正相关性,其中与胡萝卜、甜菜、甘蓝为显著正相关,与番茄、土豆、菜花为极显著正相关;⑥土壤pH值与胡萝卜、甜菜铅富集系数呈显著负相关,与菜花呈极显著负相关。研究表明,兰州市不同蔬菜产区的各类蔬菜对土壤铅的富集具有明显的差异性,同时不同形态的钾元素及土壤pH值对蔬菜铅富集能力具有显著的影响。     

榨菜(Brassica juncea)和紫甘蓝(Brassica oleracea)种间周缘嵌合体光合特性研究

对榨菜和紫甘蓝种间嫁接嵌合体的光合作用、叶绿素荧光、叶绿素含量、Rubisco的活性以及Rubisco酶大亚基和小亚基基因的转录水平等进行了测定分析。研究发现,种间周缘嵌合体TCC(茎尖分生组织细胞层LI-LII-LIII=TCC,T代表榨菜,C代表紫甘蓝;)的净光合速率为18.09μmol CO2·m-2·s-1,与亲本榨菜相当,但比亲本紫甘蓝高出24.8%。嵌合体的气孔导度和胞间CO2浓度显著高于2个亲本。叶绿素荧光参数中光系统II的实际电子传递量子效率(ФPSⅡ)和光化学猝灭系数(qP)在榨菜中最高,而嵌合体和紫甘蓝的这2个参数基本一致。对叶绿素含量测定后发现,嵌合体的叶绿素a、b及总含量与榨菜比较接近,比紫甘蓝高97%。TCC嵌合体Rubisco酶的初始活性和总活性处于榨菜(最高)和紫甘蓝(最低)之间,为1.76和3.75μmol CO2·g-1·min-1。而TCC嵌合体的Rubisco酶大亚基和小亚基基因的mRNA转录丰度与榨菜和紫甘蓝相比明显增高。以上结果说明,与TCC嵌合体光合机构的层源亲本——紫甘蓝相比,其叶绿素含量升高、Rubisco酶的活性以及其大小亚基基因的转录水平的增强可能是导致其净光合速率提高的原因。可见,TCC嵌合体的异源表皮(来自榨菜)对改善其内部光合组织(来自紫甘蓝)的光合能力有很大的促进作用。     

Carotene, tocopherol, and ascorbate contents in subspecies of Brassica oleracea

Cruciferous vegetables contain high levels of vitamins that can act as antioxidants, compounds that may protect against several degenerative diseases. The edible portions of 50 broccoli and 13 cabbage, kale, cauliflower, and Brussels sprouts accessions were assayed to determine variation in alpha-carotene, beta-carotene, alpha-tocopherol, gamma-tocopherol, and ascorbate contents within and between subspecies of Brassica oleracea. Ascorbate content was estimated in fresh samples using HPLC. Tissues for carotene and tocopherol analysis were lyophilized prior to extraction. Carotene and tocopherol concentrations were simultaneously measured using a reverse phase HPLC system. Results indicate that there is substantial variation both within and between subspecies. Kale had the highest levels of vitamins, followed by broccoli and Brussels sprouts with intermediate levels and then by cabbage and cauliflower, with comparatively low concentrations. Variability in vitamin content among the broccoli accessions suggests that potential health benefits that accrue with consumption are genotype dependent.     

Content of glucosinolates in cruciferous vegetables grown at the same site for two years under different climatic conditions

Individual glucosinolates (GLS) were determined in vegetables of three Cruciferae species: Brassica oleracea L. (white cabbage, red cabbage, Savoy cabbage, Brussels sprouts, cauliflower, kale, kohlrabi), Brassica rapa L. (turnip), and Raphanus sativus L. (red radish, black radish, and white radish) produced in two years. The cultivars were compared for the contents of total-, indole-, and aliphatic GLS. In both years, the total content of GLS was highest in black radish, and all examined R. sativus vegetables contained the greatest amount of aliphatic GLS. Neither the level nor the identity of GLS differentiated among the vegetables of the other cultivars grown in the same year. Comparison of the GLS contents of the same cultivar in two production years, which differed in temperature and rainfall rate, showed that low average 10-day rainfall and high average temperature during the vegetation period significantly increased the GLS content of vegetables. This suggests that the year x cultivar interaction modified the GLS content of vegetables.     

Simultaneous extraction and quantitation of carotenoids, chlorophylls, and tocopherols in Brassica vegetables

Brassica oleracea vegetables, such as broccoli (B. oleracea L. var. italica) and cauliflower (B. oleracea L. var. botrytis), are known to contain bioactive compounds associated with health, including three classes of photosynthetic lipid-soluble compounds: carotenoids, chlorophylls, and tocopherols. Carotenoids and chlorophylls are photosynthetic pigments. Tocopherols have vitamin E activity. Due to genetic and environmental variables, the amounts present in vegetables are not constant. To aid breeders in the development of Brassica cultivars with higher provitamin A and vitamin E contents and antioxidant activity, a more efficient method was developed to quantitate carotenoids, chlorophylls, and tocopherols in the edible portions of broccoli and cauliflower. The novel UPLC method separated five carotenoids, two chlorophylls, and two tocopherols in a single 30 min run, reducing the run time by half compared to previously published protocols. The objective of the study was to develop a faster, more effective extraction and quantitation methodology to screen large populations of Brassica germplasm, thus aiding breeders in producing superior vegetables with enhanced phytonutrient profiles.     

Synergistic, additive, and antagonistic effects of food mixtures on total antioxidant capacities

Different foods possess different bioactive compounds with varied antioxidant capacities. When foods are consumed together, the total antioxidant capacity of food mixtures may be modified via synergistic, additive, or antagonistic interactions among these components, which may in turn alter their physiological impacts. The main objective of this study was to investigate these interactions and identify any synergistic combinations. Eleven foods from three categories, including fruits (raspberry, blackberry, and apple), vegetables (broccoli, tomato, mushroom, and purple cauliflower), and legumes (soybean, adzuki bean, red kidney bean, and black bean) were combined in pairs. Four assays (total phenolic content, ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl, radical scavenging capacity, and oxygen radical absorbance capacity) were used to evaluate the antioxidant capacities of individual foods and their combinations. The results indicated that within the same food category, 13, 68, and 21% of the combinations produced synergistic, additive, and antagonistic interactions, respectively, while the combinations produced 21, 54, and 25% synergistic, additive, and antagonistic effects, respectively, across food categories. Combining specific foods across categories (e.g., fruit and legume) was more likely to result in synergistic antioxidant capacity than combinations within a food group. Combining raspberry and adzuki bean extracts demonstrated synergistic interactions in all four chemical-based assays. Compositional changes did not seem to have occurred in the mixture. Results in this study suggest the importance of strategically selecting foods or diets to maximum synergisms as well as to minimum antagonisms in antioxidant activity.     

蔬菜有机磷农药多残留检测中的样品基质干扰及检测方法的适宜性

为研究NY/T 761-2004(农业行业标准)用于蔬菜有机磷农药多残留检测中的样品基质干扰问题,根据NY/T 761-2004分析众多蔬菜样品,结合气质联用技术,评估蔬菜样品基质对有机磷农药多残留分析的干扰。结果表明,用NY/T 761-2004检测蔬菜有机磷农药多残留时,绿叶菜类、白菜类、瓜类、茄果类、豆类、薯芋类和根菜类蔬菜几乎没有样品杂质峰,有机磷农药测定不受干扰;甘蓝类蔬菜(如紫甘蓝、甘蓝和西兰花等)有显著的样品杂质峰,敌敌畏、甲胺磷、甲拌磷和甲基毒死蜱等测定常受干扰;葱蒜类蔬菜(如蒜、葱和韭菜等)有较强的样品杂质峰,有机磷农药多残留测定无法进行。