Reducing the potential for processing contaminant formation in cereal products

Processing contaminants may be defined as substances that are produced in a food when it is cooked or processed, are not present or are present at much lower concentrations in the raw, unprocessed food, and are undesirable either because they have an adverse effect on product quality or because they are potentially harmful. The presence of very low levels of processing contaminants in common foods is becoming an increasingly important issue for the food industry, as developments in analytical techniques and equipment bring foods under closer and closer scrutiny. This review considers the formation of lipid oxidation products, hydrogenation of polyunsaturated fatty acids to prevent lipid oxidation and the associated risk of trans fatty acid formation. The formation of acrylamide in the Maillard reaction is described, as well as the genetic and agronomic approaches being taken to reduce the acrylamide-forming potential of cereal grain. The multiple routes for the formation of furan and associated chemicals, including hydroxymethylfurfuryl, are also described. The evolving regulatory and public perception situations for these processing contaminants and their implications for the cereal supply chain are discussed, emphasising the need for cereal breeders to engage with the contaminants issue.     

长期接触有机磷农药的农民体内自由基含量的调查报告

[目的]调查长期接触有机磷农药的农民体内自由基的含量。[方法]随机抽取豫北农村地区长期接触有机磷农药的农民790人,分别检测其体内MDA、SOD、GSH-PX、LPO含量。[结果]接触有机磷农药10年以上的农民体内自由基含量明显增加,但增加量无年限差异。[结论]农民长期接触有机磷农药会引起体内自由基含量增加。     

不同钼水平对山羊红细胞膜自由基代谢及其酶活性的影响

本研究旨在观察不同钼水平对山羊红细胞膜自由基代谢及其酶活性的影响。选用27头健康山羊随机分成3组，选用七钼酸铵（[（NH4）6Mo7O24·4H2O]）作为本试验口服钼源，采用（NH4）6Mo7O24·4H2O水溶液对实验山羊每d1次的方式进行灌服。对照组灌服相应剂量蒸馏水，高钼组山羊按每公斤体质量15mg和45mg（以钼计）灌服（NH4）6Mo7O24·4H2O水溶液（15mg Mo·kg^-1·BW组（Ⅱ组）和45mgMo·kg^-1·BW组（Ⅲ组））。试验为期50d，并于第0、10、20、30、40、50天采血，测定红细胞膜中自由基含量和酶活性变化。结果显示，组内比较，Ⅱ组、Ⅲ组GSH—Px、T—AOC、CAT、GST、T—AOC、ATPase和AKP活性在试验前期（0～30d）差异不显著（P〉0．05），试验后期（40～50d）与前期比较下降，差异显著（P〈0．05）；MDA含量、XOD和LDH活性在实验前期（0～30d）差异不显著（P〉0．05），后期（40～50d）与前期（0～30d）比较升高，差异显著（P〈0．05）；组间比较，Ⅱ组、Ⅲ组GSH—Px、T—AOC、CAT、GST、T—AOC、ATPase和AKP活性在实验前期（0～30d）与对照组比较差异不显著（P〉0．05），后期（40～50d）与对照组比较降低，差异显著（P〈0．05）；MDA含量、XOD和LDH活性前期（0-30d）与对照组比较差异不显著（P〉0．05），后期（40～50d）升高，差异显著（P〈0．05）。由此可见，摄入过量的钼会导致山羊红细胞膜抗氧化功能降低、自由基含量升高和能量代谢障碍。     

Closantel缓释剂对实验感染肝片吸虫山羊机体自由基影响的研究

选用5只实验感染肝片吸虫山羊研究Closantel缓释剂对机体抗氧化功能的影响，实验用山羊每只一次性口服肝片吸虫囊蚴150个，感染后第15周随机将山羊分成对照组（n=2）和驱虫组（n=3），驱虫组每羊口服两颗Closantel缓释剂，每周定时采集颈静脉血液，检测血清抗氧化酶的变化，观察服用Closantel缓释剂对其的影响。结果表明投药后山羊血清中GSH－Px、CAT均有不同程度的升高，SOD变化不显著，而脂质过氧化产物MDA含量则下降，提示Closantel的缓释剂型对实验感染肝片吸虫山羊机体的抗氧化产生了影响，对机体有一定保护作用。     

Physiology Mechanism of Metabolisms in the Middle Scales of Lilium davidii var. unicolor Bulbs Stored at Low Temperature for Dormancy-Release

Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10℃ in moist sawdust were studied. The results indicated that as the storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreased markedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increased sharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealed that the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase and phenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level of arginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and path analysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middle scales may be mainly regulated by endogenous GA3.     

肝片吸虫感染对山羊机体自由基代谢影响的研究

实验选择9只健康、6－10月龄雄性白山羊，经粪便学检查和Dot-ELISA检测，确认无肝片吸虫感染，随机分成感染组（n=5)和对照组（n=4)，试验组每只1次口服接种150个肝片吸虫囊蚴，每周定时从颈静脉采集感染前（0周）和感染后15周血液1次分离血清。测定血清谷胱甘肽过氧化物酶（GSH－Px)活性、超氧化物歧化酶（SOD）活性、过氧化物酶（CAT）活性、丙二醛（MDA）和一氧化氮含量的变化，结果表明肝片吸虫感染后血清中GSH－Px活性除第8周试验组显著高于对照组，其他各周无显著差异；在整个实验期间，试验组山羊血清中SOD活性在1－5周呈波动状，以后两组基本处于同一水平；试验组山羊血清CAT活性在感染后第3周显著低于对照组，第6－15周时，试验组始终高于对照组，但各周差异均不显著；试验组山羊血清中MDA含量在整个实验期间始终呈波动状，而在第8、9周试验组显著高于对照组，中周与对照组相比无显著差异；感染后试验组血清中NO开始下降，并且显著低于对照组，至第3－6周时试验组显著高于或低于对照组，第6－15周，试验组一直高于对照组，并在第7、10周时显著地高于对照组。提示山羊感染肝片吸虫后，机体发生多种功能的改变，机体的自由基产生与清除处于相互对抗之中，机体的自由基代谢参与了肝片吸虫病的发展过程。     

48小时母仔分离对自由哺育或控制哺育母兔性能的影响

本试验估测了48小时母仔分离（Doe-Litter Separation,DLS)对不同哺育方式（自由或控制）的母兔进行周期发情的效果。结果表明：控制哺育相对于自由哺育来说，可提高哺育母兔繁殖率（68．62％和46．00％，P＜0．01），降低1－9日龄期间仔兔死亡率（8．00％和10．74％，P＜0．05），同时也提高了母兔淘汰率（67．92％和56．41％，P＜0．05）和乳房炎的发病率（15．09％和11．11％，P＜0．05）。当母仔分离的方法使用在自由哺育方式中时，母兔的发病率和繁殖率均能得到极显著的改善（74．18％和53．72％，P＜0．01；69．23％和46．00％，P＜0．01）。然而，当母仔分离的方法使用在控制哺育方式中时，母兔的发情率和繁殖率的改善不及自由哺育中的应用效果（73．35％和58．47％，P＜0．05；77．77％和69．62％，P＞0．05）。48小时母仔分离时自由或控制两种哺育方式来说，均能显著降低哺乳期间仔兔的死亡率（18．69％和22．35％，P＜0．05；15．47％和19．52％，P＜0．05），尤其是9－42日龄期间仔兔的死亡率（8．15％和14．29％，P＜0．01；8．57％和11．98％，P＜0．01）。哺育方式和母仔分离对哺乳母兔窝产仔数、窝产活仔数、断奶个体重和断奶前日增重均无明显影响。     

Astragalus polysaccharides protects against free fatty acid-induced human vascular endothelial cell dysfunction via AMPK-eNOS pathway

AIM: To study the protective effect of Astragalus polysaccharides (APS) on free fatty acid-induced injury in human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs were divided into control group, APS group [APS (200 mg/L) treated for 24 h], free fatty acid group [free fatty acid (0.25 mmol/L) treated for 24 h], free fatty acid plus APS group [free fatty acid (0.25 mmol/L) and APS (200 mg/L) treated for 24 h], and compound C group [free fatty acid (0.25 mmol/L) and APS (200 mg/L) and AMPK inhibitor compound C (10 μmol/L) treated for 24 h]. The cell viability was detected by MTT assay. Nitric oxide (NO) content in the medium was determined by nitrate reductase assay. The protein levels of total adenosine monophosphate-activated protein kinase (AMPK), phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK), endothelial nitric oxide synthase (eNOS) and phosphorylated endothelial nitric oxide synthase (p-eNOS) were measured by Western blot. RESULTS: No significant difference of all indexes between APS group and control group was observed. The cell viability in free fatty acid group decreased significantly compared with control group. The cell viability in free fatty acid plus APS group was significantly improved as compared with free fatty acid group. The cell viability in compound C group was almost the same as that in free fatty acid group. The No content and protein levels of p-AMPK and p-eNOS in free fatty acid group decreased obviously as compared with control group, while the NO content and protein levels of p-AMPK and p-eNOS in free fatty acid plus APS group increased obviously compared with free fatty acid group. No significant difference of the p-AMPK and p-eNOS protein levels between free fatty acid plus APS group and free fatty acid group was observed. No significant difference of the AMPK and eNOS protein levels in all groups was found. CONCLUSION: APS attenuates the free fatty acid-induced injury, and its mechanism is related to the AMPK-eNOS signal pathway.     

自由基清除剂的保护作用与甘蔗的抗旱性

用半胱氨酸、二苯胺、巯基乙醇，苯甲酸钠和α-生育酚等五种化合物作为外源自由基清除剂，研究自由基清除剂的保护作用与甘蔗抗旱性的关系。结果表明，外源自由基清除剂预处理降低了水分胁迫下甘蔗叶片细胞的膜脂过氧化程度和膜透性增加的程度，并延缓 甘蔗叶片叶绿素和可溶性蛋白含量的下降。这些结果说明外源自由基清除剂在     

水稻籽粒蛋白质、游离氨基酸含量的配合力与杂种优势分析

利用两组5×5双列杂交,以 Griffing模型Ⅰ分析籽粒蛋白质、游离氨基酸含量的配合力与杂种优势表现。结果表明:1.蛋白质、游离氨基酸含量均受加性和非加性基因效应的共同作用,但蛋白质以加性效应为主,游离氨基酸以非加性效应为主;2.蛋白质不存在显著的胞质效应,而游离氨基酸则存在极显著的胞质效应;3.蛋白质杂种优势较小,其最强的组合超中亲优势值仅为13.75％,而游离氨基酸存在强大的杂种优势,最高的组合可达155.17％;4.蛋白质、游离氨基酸一般配合力间存在极显著线性关系,在一般配合力改良上可同步进行; 5.京香1号、培矮64、IR58、Mcp231-2具有较高的一般配合力和较大的特殊配合力方差,可作为优良亲本利用。