转基因大豆DNA检测芯片的研究

为提高对转基因大豆的监督检测能力，研制了转基因大豆DNA检测芯片。根据转基因大豆(Roundup Ready)中所转入的外源基因，选择CaMV35S启动子、NOS终止子、NOSIEPSPE基因和内源Lectin基因设计特异性引物，采用多重PCR法对待测样品进行扩增，通过缺口平移法合成DIGdUTP标记杂交探针，并制备基因芯片。在对PCR反应和扩增产物与芯片杂交条件进行优化的同时，比较了芯片检测的特异性和重复性，并对检测的灵敏度进行测试。结果表明，该方法具有较好的特异性和重复性，检测灵敏度可达0．5％，由于采用了多重PCR技术，一次可同时检测多个基因，提高了检测的准确性和效率。     

发酵液中透明质酸含量快速检测方法研究

对十六烷基三甲基溴化铵(CTAB)溶液与透明质酸(HA)溶液反应体系进行了全波长扫描,绘制了不同波长下的标准曲线,并对反应时间和温度对反应体系的影响分别进行了比较。研究表明,随着反应时间延长,反应体系的吸光度逐渐升高,但当反应时间固定后,在可见光区反应体系能较好的遵循朗伯-彼尔定律,并且不受温度的影响。依据此原理,建立了发酵液中HA含量的快速测定方法,即CTAB比浊法,并与Bitter-Muir法进行了比较。结果表明,CTAB比浊法的准确度、精确度、灵敏度均优于Bitter-Muir法,并且具有快速、安全等特点。反应体系中除了蛋白质以外,葡萄糖、KH2PO4、MgSO4对CTAB比浊法测定的影响很小,因此,应尽量减少反应液中蛋白质的含量,以提高测定准确度,而上述杂质对Bitter-Muir法测定HA含量均有较大影响。     

用于农残快速检测的离心式微流控芯片研制

基于酶抑制原理结合光度分析方法,研制一种预存储生化试剂的离心式微流控芯片。设计制作的一次性微流控CD芯片集成进样、酶抑制反应、显色反应及检测单元,结合自行研制的便携式分析装置,可以同时检测12个样品,能够实现对大批量农产品中有机磷和氨基甲酸酯类农药残留进行现场、快速、高通量检测。结果表明:与传统农残快速测定仪比较,微流控芯片农残速测系统操作单元集成度高,可以实现农残检测流程的自动化,样品及试剂消耗量降至传统速测方法的约1/20,同时检测灵敏度、重复性和准确性整体优于传统农残快速测定仪,可以满足基层非专业人员针对大批量样品农药残留的筛查需求。     

等温扩增技术在食品中沙门氏菌检测中的应用

目的针对沙门氏菌肠侵袭蛋白基因设计适合交叉引物等温扩增法及环介导等温扩增法的特异性引物及探针,并进行应用评估。方法用19株沙门氏菌,35株近源菌进行特异性试验;通过定量DNA、纯菌液计数检测进行检测低限验证,与环介导等温扩增法进行比较;对6类18种食品根据ISO 5725-2:1994标准要求,以现行国家标准为基准方法对2种等温扩增法进行灵敏度、特异性、假阳性率、假阴性率及相对准确度等5方面验证。结果交叉引物等温扩增法与环介导等温扩增法具有相同的特异性,检测灵敏度较高于环介导等温扩增法,与基准方法比较的各项性能指标符合ISO的要求。结论该方法不需要复杂仪器,可作为食品中沙门氏菌快速定性检测方法使用,对口岸快速筛查、基层或偏远经济不发达地区顺利开展检测具有实际意义。     

膜芯片用于肉制品中动物源性成分检测的研究

目的研究膜芯片技术检测肉类及其制品中动物源性成分,验证该技术的准确性及可行性。方法利用膜芯片检测肉制品中的动物源性成分,对样品中猪、牦牛、驴及羊源性成分的灵敏度、检出限进行相关实验,并就实际样品的检测与国家标准进行比较。结果该技术用于动物源性成分检测特异性良好,4种动物源性检测的灵敏度为0.1 ng,检出限为0.1%(w:w),适用的样品种类较广,实际样品的检测结果与国家标准荧光PCR法一致。结论该技术可作为快速筛选的方法,为肉制品的动物源性成分鉴定和掺假检测提供理论依据。     

蛋白质芯片技术在食品安全检测中的应用

近年来,蛋白质芯片因其具有平行性、高通量、灵敏度高、样品用量少及检测速度快等优点而引起人们的高度关注.对蛋白质芯片技术及其目前的研究进展进行了简要综述,并在此基础上初步探讨了其在食品安全检测中的应用.     

食用植物油快速检测方法灵敏度研究

目的:研究快速检测方法对食用植物油的检测精确度,为其推广应用提供科学依据。方法:采用快速检测方法、国标法进行食用植物油检测的对照研究。结果:快速检测法对食用植物油的检测合格率为97.9%,与国标组无统计学差异,并且快速检测法与国标组符合率为97.9%,灵敏度为97.9%。结论:快速检测法与国标组的符合率较高,重复性较好,灵敏度较高,能够满足现场监督检测的需要,具有在现场监督和重大活动保障中推广的潜力。     

反转录-环介导等温扩增技术快速检测志贺氏菌

建立了反转录-环介导等温扩增技术的志贺氏菌快速检测方法。针对志贺氏菌特异保守基因ipa H设计多套引物,建立优化了的反应体系,并评价其准确性、特异性、灵敏度。以人工污染脱脂乳样品比较RT-LAMP与RT-PCR的灵敏度。结果表明,在65℃等温条件下,RT-LAMP反应可在30 min内完成。在活菌/损伤菌模型中,该方法表现出比国标法更好的准确性。在23株细菌标准菌株中仅对4株志贺氏菌有特异性检出。志贺氏菌RNA模板的检测灵敏度为7 fg/μL。人工污染脱脂乳样品检测灵敏度达到40 CFU/g,比RT-PCR方法高出2个数量级。表明所建立的志贺氏菌RT-LAMP扩增方法可以准确的检测志贺氏菌,同时具有快速、特异、灵敏的优势,可用于志贺氏菌的快速筛查和现场监控。     

普通PCR法、荧光定量PCR法及微流控芯片法检测大豆产品中外源基因灵敏度的比较

目的:为提高食品中转基因成分检测的灵敏度,将微流控芯片仪应用到转基因检测中.方法:将微流控芯片法与普通PCR法、荧光定量PCR法进行灵敏度比较;检测高温、高压处理过的转基因大豆粉.结果:荧光定量PCR法的灵敏度明显高于普通PCR法,但在较极端高温、高压处理(高压灭菌121℃/30min)及转基因成分含量较低(1%)的情况下,采用荧光定量PCR法未能检测到外源基因,而微流控芯片法能检测到相应的峰值,前提是在未添加内标(Marker)的情况下.若添加内标,在内标峰和目的峰区分开的条件下,有损检测灵敏度.结论:微流控芯片在转基因检测中具有高效率、高灵敏度的特点,但该方法有待完善.     

表面等离子体共振技术在纺织等消费品检测中的应用

表面等离子体共振(SPR)生物传感技术是一种具有良好发展前景的新兴生物化学检测技术,具有灵敏度高、快速、无需标记等优点,广泛应用于材料化学、医药检测、环境监测和食品安全等领域。文章对SPR生物传感器进行了简要介绍,并着重对其在有毒有害残留检测中的应用进行了分析,最后对SPR生物传感技术在消费品检测领域的研究前景进行了展望。由于SPR技术检测过程方便快捷、灵敏度高,且只要更换不同的修饰特异性匹配芯片,一台仪器便可实现无机和有机类危害因子的筛查检测,因此SPR技术在消费品检测中有很好的发展前景。     

An analysis of the etiology of anemia and iron deficiency in young women of low socioeconomic status in Bangalore, India

BACKGROUND: Anemia and iron deficiency are significant public health problems in India, particularly among women and children. Recent figures suggest that nearly 50% of young Indian women are anemic. OBJECTIVES: Few studies have comprehensively assessed etiologic factors contributing to anemia and iron deficiency in India. Hence, this study assessed the relative importance of various factors contributing to these problems in young women of low socioeconomic status in Bangalore, India. METHODS: A random sample of 100 nonpregnant, nonlactating women 18 to 35 years of age, selected from among 511 women living in a poor urban settlement, participated in this study. Data were obtained on demography, socioeconomic status, anthropometry, three-day dietary intake, blood hemoglobin, hemoglobinopathies, serum ferritin, serum C-reactive protein, and stool parasites. RESULTS: The prevalence rates of anemia and iron deficiency were 39% and 62%, respectively; 95% of the anemic women were iron deficient. The mean dietary iron intake was 9.5 mg per day, predominantly from the consumption of cereals, pulses, and vegetables (77%). The estimated bioavailability of nonheme iron in this diet was 2.8%. Dietary intakes were suboptimal for several nutrients. Blood hemoglobin was significantly correlated with dietary intake of fat, riboflavin, milk and yogurt, and coffee. Serum ferritin was significantly correlated with intake of niacin, vitamin B12, and selenium. Parasitic infestation was low. CONCLUSIONS: An inadequate intake of dietary iron, its poor bioavailability, and concurrent inadequate intake of dietary micronutrients appear to be the primary factors responsible for the high prevalence of anemia and iron deficiency in this population.     

Iron-Fortified Infant Cereals

Infants are particularly susceptible to iron deficiency and related anemia due to their high growth rates and the low iron content of breast milk and most unfortified weaning foods. Cows' milk also is poor in iron, and certain forms of cows' milk cause blood and thus iron loss from the gastrointestinal tract. Iron-fortified cereal-based complementary foods – infant cereals – are recommended to supply the iron needs of older infants. Fortified infant cereals contain much more iron than other fortified cereal products – up to ten or fifteen times as much. Highly or slightly soluble iron salts have excellent bioavailability, but affect color and reduce chemical stability, so these iron salts are not commonly used to fortify infant cereals. Insoluble sources of iron, such as the iron phosphates, were used historically to fortify infant cereals, but these sources have very poor bioavailability. Infants depending on these cereals for iron suffered from high rates of iron deficiency and anemia.

Elemental iron of small particle size, particularly electrolytic iron, currently is the generally accepted vehicle for infant cereal fortification. Iron-fortified cereal made with electrolytic iron reduces iron deficiency and related anemia in several settings but unfortunately is not fully protective in all. Ascorbic acid is a known enhancer of iron bioavailability but ascorbic acid is heat-labile and ascorbic activity declines rapidly during storage. Nonetheless, adding ascorbic acid during processing appears to improve the availability of electrolytic iron and thus the reliability of iron-fortified infant cereal as a means of preventing iron deficiency in older infants.     

Effect of oilseed protein concentrates and exogenous amino acids on the dialysability of iron and zinc

Iron deficiency anaemia and zinc deficiency have been persistent public health problems worldwide. Both deficiencies are attributed to poor bioavailability of minerals. The investigation was undertaken to study the effect of oilseed protein concentrates and exogenous amino acids on the dialysability of iron and zinc. Corn flour matrices with 10–20 g protein/100 g were formulated using groundnut and sesame protein concentrates. Dialysability of iron and zinc in natural and mineral fortified matrices was analysed. The effect of exogenous cysteine, histidine, glycine and lysine on mineral dialysability was analysed in groundnut and sesame protein concentrates. Dialysability of iron was enhanced with increasing protein concentration in matrices with groundnut protein but decreased in matrices with sesame protein. Dialysability of zinc increased with increasing protein concentration with both the protein concentrates. Among the amino acids, histidine enhanced dialysability of iron in natural groundnut and sesame protein concentrates, glycine in fortified groundnut and lysine in fortified sesame protein concentrates to a considerable extent. Dialysability of zinc was enhanced in natural groundnut, natural and fortified sesame protein concentrates by all amino acids. Amino acids definitely promotes the dialysability of iron and zinc, but its enhancing ability is highly specific to the food matrix.     

Infection and anemia in Canadian aboriginal infants.

The prevalence of anemia in Aboriginal children is high, but, given the high burden of infection in these children, the extent to which anemia is due to iron deficiency and/or infection is unclear. To determine the contribution of iron deficiency to anemia, we screened 144 Aboriginal infants (70 boys, 74 girls) who were free from infection. The prevalence of anemia (hemoglobin <105 g/L) was 18.8%; caregivers reported that 53.5% of infants had had an infection in the two weeks before screening. Anemic infants were more likely than non-anemic infants to have had an infection before screening (74.1% versus 48.7%, p = 0.02), and anemic infants had a higher prevalence of iron deficiency revealed by low serum iron concentrations (<7 micromol/L) (73.7% versus 38.3%, p <0.01). Iron deficiency measured using serum ferritin concentration tended to be less marked in infants who had had an infection (13% versus 30.3%, p = 0.06); this is probably because serum ferritin is a positive acute-phase protein. This study indicates the difficulty of isolating the contribution of infection to anemia from the separate effects of dietary iron deficiency.     

某养血口服液改善缺铁性贫血的实验评价

为评价某养血口服液改善动物营养性贫血的作用 ,采用实验性缺铁性贫血模型大鼠观察对血液细胞学、血液生化学指标的影响。试验结果表明实验期间各组动物体重增加 ,3个剂量组的血红蛋白、血清铁、血清铁蛋白和HCT、MCV、MCH及MCHC均明显高于阴性对照组 (P <0 0 5 ,P <0 0 1) ,红细胞内游离原卟啉含量明显低于阴性对照组 (P <0 0 5 ,P <0 0 1) ,由此可见受试物具有改善动物营养性贫血的作用     

Iron and energy supplementation improves the physical work capacity of female college students

A nutritionally controlled study was conducted on two groups of 15 female college students aged 16 to 20 years, selected from Punjab Agricultural University, Ludhiana, Punjab, India. The girls were either anemic (hemoglobin 7.7 g/dl) but energy adequate (AEA), or anemic (hemoglobin 7.4 g/dl) and energy deficient (AED). The AEA group was given iron supplementation (60 mg iron/day) for 6 to 9 months along with 100 mg of ascorbic acid, and the AED group was given iron as well as energy supplementation for 3 months. There was a significant (p < .01) increase in weight, body mass index, mid-upper-arm circumference, and body fat in the AED group after iron-energy supplementation. Hemoglobin, serum iron, transferrin saturation, total iron-binding capacity, and unsaturated iron-binding capacity were below normal in both groups; however, after iron and iron-energy supplementation, there was a significant (p < .01) increase, and these indices were in the normal range. There was a significant (p < .01) increase in exercise time and maximum work load tolerance after iron and iron-energy supplementation. Combined energy and iron deficiency had a greater adverse effect on physical work capacity than energy or iron deficiency alone.     

铁蛋白铁释放机理的研究进展

铁蛋白是一种广泛存在于生命体中的铁贮藏蛋白,具有调节机体铁代谢平衡和去除二价铁毒性的双重功能。缺铁严重影响着全球近一半人的健康,研究表明,铁蛋白具有良好的补铁活性而且安全、高效,能够取代具有毒副作用的传统补铁试剂。因此,寻求并开发以铁蛋白为原料的新型补铁功能食品已成为一种趋势。为了更科学地应用于实践和开发,对铁蛋白理化性质及其生物学功能的阐明显得颇为重要。目前,关于铁蛋白铁释放机理的研究分为体外和体内两个方面,体外机理涉及还原剂和螯合剂的共同作用,而体内机理主要涉及降解途径和酶介导的还原释放途径。综述了国内外有关铁蛋白铁释放机理的研究进展,以期为新型补铁功能食品的开发提供理论依据。     

Preparation of succinylated sodium caseinate–iron complex by adopting ultrafiltration technology: A novel food fortificant

Iron has several functions in the human body and its deficiency leads to severe health problems. Food fortification is considered as the most acceptable strategy to combat iron deficiency, but the fortification of soluble iron salts induces many technological problems. Succinylated milk proteins can bind sufficient amount of iron. Many varieties of iron protein succinylates are also available in the market as iron supplements, not as food fortificants. Therefore, the present study was intended to prepare succinylated sodium caseinate (succ. NaCas)–iron complex suitable for food fortification purposes by adopting ultrafiltration technology. Level of iron required for the preparation of complex was standardized on the basis of maximum iron binding ability of succ. NaCas. Diafiltration carried out during the manufacturing process not only removed free iron but also reduced excess succinic acid from the complex. The obtained complex also showed better stability under different conditions encountered during processing.Industrial relevanceCentrifugation and ultrafiltration (UF) technologies were adopted in the study, the former used to remove the insoluble iron and latter was used to remove free iron. The presence of both insoluble and free iron may be unacceptable for the food processing. The freeze drying technology was also used to facilitate the availability of iron protein succinylate in the powder form for wide range of food application. The proposed method will help industries to adopt the suitable conditions to produce a novel food fortificant commercially.