关于锌强化营养盐内在含量稳定性的探讨

在生产中锌强化营养盐内在锌含量极易不合格,论述了如何能保证锌强化营养盐内在含量稳定,加强锌强化营养盐生产过程控制,达到产品内在含量的稳定。     

生物强化富锌食品研究进展

锌元素在人体内具有不可或缺的作用,然而世界范围内均存在锌摄入不足的问题。通过生物强化富锌可使无机锌转化为人体易于吸收的有机锌或生物锌,以此方式生产出的富锌食品稳定安全、价格低廉且营养价值高。目前生物强化富锌食品主要包括真菌类如食用菌与酵母菌,植物类如果蔬、谷物、茶叶和芽苗菜等。富锌豆类芽苗菜因其成本低、周期短、种植简单易控、无季节性及可通过萌发降低植酸含量从而提高锌的生物利用性等优势,具有更为重要的应用价值。文章通过分析缺锌现状、原因和解决方法及生物强化富锌食品研究进展,表明生物强化富锌食品尤其是富锌豆类芽苗菜具有广阔的发展前景,为富锌食品的开发提供理论参考和研究方向。     

高锌牛乳的研究开发

研究了以生鲜牛奶为原料,以乳酸锌进行营养强化的高锌乳制品。通过实验确定了锌源,生产工艺和配方,结果表明,产品安全,性能稳定,乳制品锌含量为0．01g/L。     

强化锌食品对改善儿童锌营养状况效果观察

本文介绍从某幼儿园随机抽取68名4-6岁健康儿童分为两组,对比观察强化锌食品的食用效果。实验后强化组血清锌、发锌含量上升,身高、体重增长值显著高于对照组。提示,适量的锌营养强化对儿童生长发育,改善锌营养状况有良好效果。     

强化锌面粉的研究与开发

探讨了开发强化锌面粉的必要性和可行性，以及研发和生产强化锌面粉的工艺技术等问题     

锌强化大米的研究开发

营养元素锌是人体必需的微量元素之一，对人体的生长发育起着重要的作用。该文探讨了大米中强化锌的可行性和必要性，论述了锌强化剂的选择、强化的标准、锌强化大米的生产工艺等技术问题。     

富锌茶的锌浸出率及其饮用安全性研究

本文对利用茶树的生物富集作用制得的富锌茶的锌浸出率、饮用的营养价值及安全性进行了分析研究，结果表明：富锌茶的锌浸出率为47．1％～51．1％，茶叶锌浸出率主要与加工方法等有关，而与锌含量无关；经粉碎加工的袋泡茶浸出率高于炒青。第一泡浸出的锌为两次浸泡锌总浸出量的80％左右，饮茶时一次冲泡即可获取茶叶中的大部分可浸出锌，通过饮用富锌茶可获取10％～15％的锌营养，并不会造成锌过量。利用生物转化生产富锌茶的农残及铅铜含量符合国家茶叶卫生标准。该富锌茶是一种安全有效的补锌饮料。     

强化锌面粉的研究开发

针对儿童缺锌问题，开发研制了强化锌面粉，并对强化剂的选择、用量及工艺、安全性等进行研究，提供了一条安全、经济的补锌途径。     

锌强化营养小麦粉开发的实证研究

营养元素锌是人体必需的微量元素之一,对人体的生长发育起着重要的作用。分析了在小麦粉中强化锌的可行性和必要性,阐述了针对营养强化小麦粉的锌强化剂选择、强化标准、锌强化营养小麦粉的生产工艺等技术问题。     

锌与人体

锌的吸收和代谢 锌在人体的含量仅次于铁．而且锌的含量随着年龄的变化而不同。通常，新生儿的含量较高．随着生长发育过程而迅速下降．青年、中年时期回升老年又趋于下降。     

加锎液体培养灰树花富集有机锌的研究

灰树花是药食两用真菌,富含多糖、氨基酸和多种矿物元素.利用灰树花将无机锌转化为有机锌,能为人体补锌提供一条新的有效途径.稀土元素对生物的生长代谢具有促进作用.为了研究镧和锌元素存在时灰树花液体培养富集锌的能力,设计了四因素四水平的正交试验方案.其因素和水平分别为硝酸镧浓度50、100、150、200(mg/L培养基),1 L培养基中碳源马铃薯/葡萄糖150/18、200/24、250/30、300/36(g/g),氮源麸皮20、25、30、35(g/L培养基)和7水硫酸锌浓度100、600、1300、2000(mg/L培养基).分别以干菌丝有机锌含量、25 ml培养基有机锌产量和锌的转化率3个指标进行了分析,并分别给出了其最优培养条件,以用于指导灰树花液体培养基的设计.以25 ml培养基有机锌产量为指标时,得到优化培养基为1 L培养基中含ZnSO4·7H2O 2000 mg、麸皮35 g、La(NO3)3 50 mg、马铃薯300 g、葡萄糖36 g.优化培养基下有机锌的产量为1.472 mg/25ml,即58.88 mg/L培养基.     

酵母锌和硫酸锌对肉仔鸡微量元素沉积的影响

将140只1日龄艾维茵商品代肉仔鸡,随机分为7组。试验采用2×3因子设计,另设一个对照组,共7个处理,每个处理4个重复,每个重复5只鸡。在基础日粮中分别添加40、80和120mg/kgZn,分别来自酵母锌和硫酸锌。饲喂21d,取肝脏、肾脏、胫骨、胸肌,测定铁、铜、锌、锰浓度。试验结果表明:酵母锌组的胫骨锌(P<0.05)、肝脏铜(P<0.05)和肝脏铁浓度(P<0.01)明显高于硫酸锌组,说明酵母锌能明显提高胫骨锌浓度,对铜、铁吸收的抑制作用小于硫酸锌。     

食品级丙酸锌的合成工艺研究

以丙酸钙和硫酸锌为原料，经分解反应合成了一种新型食品添加剂－丙酸锌，此反应的优化条件是：n(丙酸锌）:n(硫酸锌）＝1.16:1，c(丙酸钙）＝1.075mol/L,c（硫酸锌）＝1.239mol/L，反应温度为80℃，反应时间为40min，丙酸锌产率可达93.6%，其各项技术指标经检测符合同类产品食品级标准要求。     

Effect of Zinc Chloride or Zinc Sulfate Treatment of Protein Supplement on Milk Production

Production response to protein supplements treated with Zn salts to increase rumen escape was evaluated with 27 lactating Holstein cows in a switchback design trial with three treatments. Pelleted supplements fed with corn silage as total mixed rations were: 1) 18% protein, untreated, 2) 15% protein, treated with .5% zinc chloride, and 3) 15% protein, treated with .65% zinc sulfate. Corresponding total mixed rations (TMR) fed ad libitum contained 15, 12.6, and 13% crude protein. Each cow was offered 2.3 kg of alfalfa-orchardgrass hay daily. Dry matter intake (DMI) 17.2, 16.8, 17.0 kg/d), DMI as percent of body weight (2.74, 2.68, 2.73%), and milk total solids (10.8, 10.7, 10.6%) were similar, although low for TMR 1 to 3, respectively. Daily milk production and fat percentage were 26.4, 26.5, and 26.2 kg and 3.16, 3.21, and 3.26%, respectively. Plasma and milk Zn concentrations (1.15, 1.35, 1.33: 3.68, 4.37, 4.17 ppm) were relatively normal despite dietary concentrations of 135, 1386, and 1264 ppm. Body weight change, total milk yield, fat percent, FCM, milk protein yield, and SNF produced were similar among treatments. Dietary crude protein intake was highest for total mixed ration 1 but was lower than recommended on all diets as a result of low DMI.     

锌失衡与人体健康

锌是人体必需的营养元素,本文探讨了锌的生理功能以及锌缺乏与锌过量对人体健康的影响。     

加镧液体培养灰树花富集有机锌的研究

灰树花是药食两用真菌,富含多糖、氨基酸和多种矿物元素。利用灰树花将无机锌转化为有机锌,能为人体补锌提供一条新的有效途径。稀土元素对生物的生长代谢具有促进作用。为了研究镧和锌元素存在时灰树花液体培养富集锌的能力,设计了四因素四水平的正交试验方案。其因素和水平分别为:硝酸镧浓度50、100、150、200(mg/L培养基),1L培养基中碳源马铃薯/葡萄糖150/18、200/24、250/30、300/36(g/g),氮源麸皮20、25、30、35(g/L培养基)和7水硫酸锌浓度100、600、1300、2000(mg/L培养基)。分别以干菌丝有机锌含量、25ml培养基有机锌产量和锌的转化率3个指标进行了分析,并分别给出了其最优培养条件,以用于指导灰树花液体培养基的设计。以25ml培养基有机锌产量为指标时,得到优化培养基为1L培养基中含ZnSO4·7H2O2000mg、麸皮35g、La(NO3)350mg、马铃薯300g、葡萄糖36g。优化培养基下有机锌的产量为1.472mg/25ml,即58.88mg/L培养基。     

Zinc binding in bovine milk

About 90% of the Zn in bovine skim milk was sedimented by ultracentrifugation at 100,000 g for 1 h. About half of the non-sedimentable Zn was non-dialysable, indicating that it was associated with protein, probably non-sedimented casein micelles. Casein micelles incorporated considerable amounts of Zn added to skim milk as ZnCl2, and at Zn concentrations greater than or equal to 16 mM coagulation of casein micelles occurred. Ca was displaced from casein micelles by increasing ZnCl2 concentration and approximately 40% of micellar Ca was displaced by 16 mM-ZnCl2. Micellar Zn, Ca and Pi were gradually rendered soluble as the pH of milk was lowered and at pH 4.6 greater than 95% of the Zn, Ca and Pi were non-sedimentable. These changes were largely reversible by readjustment of the pH to 6.7. About 40% of the total Zn in skim milk was non-sedimentable at 0.2 mM-EDTA and most of the remainder was gradually rendered soluble by EDTA over the concentration range 1-50 mM. This indicates that there are two distinct micellar Zn fractions. No micellar Ca or Pi was solubilized at EDTA concentrations up to 1.0 mM, indicating that both colloidal calcium phosphate (CCP) and casein micelles remained intact under conditions where the more loosely bound micellar Zn fraction dissolved. Depletion of casein micelles of colloidal Ca and Pi by acidification and equilibrium dialysis resulted in removal of Zn, and in colloidal Pi-free milk non-dialysable Zn was reduced to 1.2 mg/l (approximately 32% of the original Zn). Thus, approximately 32% of the Zn in skim milk is directly bound to caseins, while approximately 63% is associated with CCP. Over 80% of the Zn in colloidal Pi-free milk was rendered soluble by 0.2 mM-EDTA, indicating that the casein-bound Zn is the loosely bound Zn fraction in casein micelles. A considerable fraction of the Zn in acid whey (pH 4.6) co-precipitated with Ca and Pi on raising the pH to 6.7 and heating for 2 h at 40 degrees C, indicating that insoluble Zn phosphate complexes form readily under these conditions. Studies on dialysis of milk against water, or dilution of milk or casein micelles with water, showed that CCP and its associated Zn is very stable and dissolves only very slowly at pH 6.6. The nature of Zn binding in casein micelles may help to explain the lower nutritional bioavailability of Zn in bovine milk and infant formulae compared with human milk.     

莼菜富集锌的能力及其锌的分布探讨

用原子吸收分光光度法测定同一土壤栽培的5种作物及其环境（土壤，灌溉水）的锌含量，经方差分析和多生比较，玉米，马铃薯和两种水稻籽粒的锌含量彼此间无显著差异，均低于土壤背景值；而莼菜锌含量极显著地高于土壤背景值和另外4种作物，显示出莼菜对环境中的锌有很强的富集能力。采用先分离再测定的方法，进一步探索锌在莼菜各器官的几种大分子中的积累分布规律，结果表明，各器官均积累有锌，锌的分布量依次为：叶＞主根＞须根＞茎；莼菜富集锌的70％以上结合于有机化合物中，在几种生物大分子中的锌含量依次为；蛋白质＞水溶性多糖＞碱溶性多糖。     

液体培养富锌金针菇锌源与锌添加量的研究

对液体培养富锌金针菇的锌源与锌添加量进行了研究,结果发现:在600、700、800、900、1000 mg/kg的浓度梯度内,提高Zn~(2+)浓度,会增加菌丝体富锌量。800 mg/kg Zn~(2+)浓度对菌丝体促长作用极显著(P<0.01);900 mg/kg时,促长作用有消退现象;1000 mg/kg时,菌丝体生长受抑显著(P<0.05)或极显著(P<0.01)。③在800 mg/kg Zn~(2+)浓度时,Zn(CH_3COO)_2、ZnSO_4、ZnCl_2、Zn(NO_3)_2之间对菌丝体生物量的影响差异不显著(P>0.05),但菌丝体对Zn(CH_3COO)_2的富集能力最好,富锌量达42.43 mg/g,与其他3种锌源富锌效果差异极显著(P<0.01)。