超声波法制备蛋壳柠檬酸钙的工艺研究

为充分利用鸡蛋壳丰富的钙资源,通过单因素与三元正交多项式回归设计相结合的研究方法,构建出超声波法高效制备蛋壳柠檬酸钙的三元正交多项式回归模型,并优化出最佳工艺条件为：蛋壳粉颗粒细度180 目、料液比1:60、超声功率700W、超声时间25min、柠檬酸与蛋壳粉的质量比2:1、柠檬酸钙得率可达90.83%。超声波法与传统方法相比,不但提高了蛋壳柠檬酸钙产品得率,而且还克服了柠檬酸钙在制备过程中的凝聚沉淀现象。     

鸡蛋壳低温直接制备柠檬酸钙

运用容量分析的方法测定出脱膜后的鸡蛋壳中含有93.5%的碳酸钙.将鸡蛋壳洗涤后用氢氧化钠水溶液脱去内膜,干燥后磨成粉末,然后与柠檬酸溶液直接反应,在较低温度下,可以有效地生成食品添加剂柠檬酸钙.鸡蛋壳脱膜的最佳条件是,氢氧化钠水溶液的浓度为5.5%(质量分数),脱膜温度为95℃,经15 min时间,蛋壳基本完全脱膜.柠檬酸钙的生成反应条件为,蛋壳粉的细度为300目,反应温度为65℃,柠檬酸过量25%,柠檬酸溶液的浓度为20%,柠檬酸钙的最高产率可以达到99%以上.     

利用鸡蛋壳中碳酸钙制备高纯度乙酸钙的工艺条件优化

利用鸡蛋壳粉与乙酸溶液直接反应,制取产品乙酸钙。采用四因素二次通用旋转组合试验设计得出乙酸与蛋壳粉反应的回归方程,探讨各因素间的相互作用,并对有交互作用的乙酸浓度和反应温度、乙酸浓度和反应时间与乙酸钙产率的关系进行响应面分析,得出蛋壳粉与乙酸反应的最佳条件为乙酸浓度6mol/L、反应温度79.38℃、反应时间5.98h、料液比1:5,实际产率98.48%。通过正交试验优化除镁工艺,最佳工艺参数为温度65℃、时间15min、CaO 添加量0.5g,除杂后纯度达99.79%,X- 射线衍射对产品进行鉴定,确定为乙酸钙。     

以贝壳为钙源一次煅烧法制取柠檬酸钙

本论文采用一次煅烧法,研究了以贝壳为钙源制备柠檬酸钙的工艺条件。通过综合利用单因素实验、正交实验对影响反应的各因素进行分析,得出制备柠檬酸钙的最佳条件是:1g煅烧后的贝壳粉加10mL水,用2mol/L的柠檬酸15mL在70℃条件下中和反应,制得柠檬酸钙的产率为73.36%,纯度为93.8%。     

利用蛋壳生产柠檬酸钙的初步研究

为充分利用蛋壳中的CaCO3，采用中和法制备柠檬酸钙，使其中的无机钙转化为有机钙，进行了煅烧条件、原料配比、反应物浓度、温度、时间等因素对产物收率和纯度的影响实验研究。结果表明：最适宜工艺条件分别为：蛋壳在900℃煅烧分解1-2h,CaO收率为95％以上。中和反应条件：石灰乳浓度5％，柠檬酸浓度50％，反应温度60℃，反应时间1h，产品收率高、质量好、安全无毒。     

二次回归正交设计优化鸡蛋壳制备柠檬酸—苹果酸钙工艺研究

我国拥有丰富的鸡蛋壳资源,而对蛋壳的相关开发研究却很少,未利用的蛋壳被成批地抛入垃圾堆,不仅造成了环境的污染,同时也是资源的浪费。蛋壳是一种很好的钙源,主要成分为碳酸钙,其含量在93%以上,且因为蛋壳是生物组织、无毒,因此是制备柠檬酸—苹果酸钙良好的钙原料。因此,本文以鸡蛋壳为钙源,以柠檬酸—苹果酸钙的溶解量为评价指标,考虑1mol·L-1柠檬酸的用量(mL)、1.5mol·L-1L-苹果酸的用量(mL)、反应温度(℃)三个因素,运用二次回归正交设计对柠檬酸—苹果酸钙的制备工艺进行优化。结果表明,当1mol·L-1柠檬酸溶液用量为30mL、1.5mol·L-1L-苹果酸溶液用量为30mL(即体积比为1∶1)、反应温度为44.6℃时,柠檬酸—苹果酸钙的溶解量达到最大,此时制得的柠檬酸—苹果酸钙的溶解量达0.356mol·L-1。     

鸡蛋壳超微粉粉体性质及其对谷氨酸螯合钙制备的影响

考察蛋壳超微粉粉体性质并优化以原料谷氨酸螯合钙制备工艺。在蛋壳超微粉和粗粉粉体性质及单因素对比试验的基础上,采用响应面法优化蛋壳超微粉制备谷氨酸螯合钙最佳工艺。结果表明:蛋壳超微粉的填充性、水溶性、电导率均优于蛋壳粗粉,超微粉碎4 min蛋壳粉的各项品质特性最佳;蛋壳超微粉制备谷氨酸螯合钙的螯合率较蛋壳粗粉提高了12.57%,蛋壳超微粉较粗粉提高了谷氨酸的利用率,减少了能量的消耗;响应面法优化蛋壳超微粉制备谷氨酸螯合钙的最佳条件为蛋壳粉与谷氨酸物质的量比1∶2.0、pH 7、螯合时间59 min、螯合温度60℃。在最优条件下,蛋壳超微粉制备谷氨酸螯合钙的螯合率为81.12%。     

蛋壳粉咀嚼片的研制与溶解性研究

以蛋壳粉和麦芽糊精为主料,添加辅料糖(葡萄糖和白砂糖质量比1︰2)、柠檬酸、硬脂酸镁和VC制备蛋壳粉咀嚼片。通过正交试验进行配方优化,并采用EDTA法比较4种粒度(≤25μm,≤48μm,≤75μm和≤150μm)蛋壳粉在模拟胃环境中的溶解性,确定适合人体吸收的粒度,研制一种补钙咀嚼片。结果表明,蛋壳粉与麦芽糊精比例1︰1,混合糖和柠檬酸分别为蛋壳粉和麦芽糊精预混料总质量的30%和1.25%时,蛋壳粉咀嚼片口感最佳,其硬度为175.6 N。超微蛋壳粉咀嚼片(粒度≤25μm)在胃环境中溶解性最好,溶解度为88.5%,溶解钙为7.65%。     

超声波辅助优化鸭蛋壳中碳酸钙制取丙酸钙工艺研究

利用废弃鸭蛋壳为原料,在超声波辅助条件下,与丙酸制备丙酸钙。考察了稀释比、蛋壳粒度、反应时间、反应温度和超声波功率对蛋壳转化率和丙酸钙纯度的影响,采用二次回归正交组合实验优化工艺。结果表明:实验最佳工艺条件为稀释比1∶9.4,反应温度61℃,超声波功率352W,蛋壳粒度50目,反应时间2h。在此条件下,蛋壳转化率达93.91%,产品中丙酸钙纯度达95.47%。     

鸡蛋壳制备高水溶性果法钙的研究

研究了利用鸡蛋壳和水果汁为原料制备高水溶性果汁钙的方法.鸡蛋壳经高温煅烧咸蛋壳粉,再与酸性果汁进行中和反应,最后烘干得到固体果汁钙产品.与其它常见钙制剂比较,制备出的果汁钙具有优良的水溶性,并达到较高的钙含量.     

乳钙和干酪素磷肽的钙强化功能

<正> 钙是非常重要的营养素,能够预防骨质疏松症。但是,据有关研究显示,全球各地尤其是亚洲地区的居民,普遍存在缺钙的情况,大大影响了其国民的身体素质。有鉴于此,营养权威专家正积极讨论和复审膳食钙的需求量(RDA),并制定新的推荐钙摄入量(RDI),例如,美国最近就提高了其推荐钙摄入量的新标准,其他国家也将仿效这种做法。 为人体补充钙的有效方法,是在我们日常进食的食品中进行钙强化。提取自牛奶的乳钙,具有优良的感官性质,而且极具营养性,是理想的天然食品级钙源。另一方面,营养科学界普遍认为,钙源的溶解性决定了钙能否良好地被人体吸收,干     

含乳(钙奶)饮料中钙含量的测定

目前对含乳饮料中钙含量的测定一般采用GB12398-90<食物中钙的测定方法>,有原子吸收分光光度法和EDTA滴定法.     

Intravenous calcium infusion in a calving protocol disrupts calcium homeostasis compared with an oral calcium supplement

Hypocalcemia is a common postpartum condition in dairy cows, which negatively affects health and production. Intravenous Ca infusions are commonly included in calving protocols to prevent or mitigate the effect of hypocalcemia in multiparous cows. Thus, we sought to contrast the effect of intravenous Ca infusion against voluntary oral Ca intake on Ca metabolism. Serum total Ca (tCa) and whole-blood ionized Ca (iCa) were monitored in 24 multiparous Holstein cows after parturition. Precalving diets were formulated with a positive dietary cation-anion difference of 172 mEq/kg of DM and contained 4.1 g of Ca/kg of DM. At parturition, cows were blocked by calving sequence and calcemic status as either normocalcemic (cutoff threshold of iCa ≥1.10 mmol/L) or hypocalcemic (cutoff threshold of iCa <1.10 mmol/L). Cows in each block were randomly assigned to 1 of 2 treatments: either an oral source of Ca (Ca-Oral; n = 12) or an intravenous source of Ca (Ca-IV; n = 12). Cows in the Ca-Oral group were offered a 20-L commercial Ca suspension (48 g of Ca) for voluntary consumption. The supplement contained Ca carbonate, Ca formate, Ca propionate, and other minerals and vitamins (Farm-O-San Reviva, Trouw Nutrition, Amersfoort, the Netherlands). Cows in the Ca-IV group received a 450-mL intravenous Ca solution (13 g of Ca) that contained 298 mg/mL of Ca gluconate, 33 mg/mL of magnesium chloride, and 82 mg/mL of boric acid (AmosCAL, Kommer-Biopharm BV, Heiloo, the Netherlands). Both treatments were initiated within 25 ± 10 min after calving. The oral Ca suspension was offered to cows in a 25-L bucket and was available for 10 min. All cows in the Ca-Oral group voluntarily consumed the entire 20 L of the Ca suspension within 5 min. Blood samples for Ca analyses were collected at 0 (before treatment initiation), 1, 3, 10, and 18 h relative to treatment, and at 0700 and 1900 h for the next 2 consecutive days, to represent the 24-, 36-, 48-, and 60-h sampling time points. In Ca-IV cows, both iCa and tCa concentrations peaked at 1 h (1.54 mmol/L for iCa and 2.85 mmol/L for tCa) and declined to a nadir at 24 h following treatment initiation (0.94 mmol/L for iCa and 1.74 mmol/L for tCa). Although whole-blood iCa and serum tCa were higher at 1 and 3 h in Ca-IV cows, concentrations of iCa were greater for Ca-Oral cows at 18, 24, and 36 h and for tCa at 24 and 36 h. Our data indicate that intravenous Ca infusion immediately induced a state of hypercalcemia followed by lower whole-blood iCa and serum tCa concentrations 24 h later compared with oral Ca.     

Effect of calcium carbonate,calcium citrate,tricalcium phosphate,calcium gluconate and calcium lactate on some physicochemical properties of soymilk

Soymilk fortified with 25 mm Ca (Ca carbonate, Ca citrate, triCa phosphate, Ca gluconate or Ca lactate) was compared with the properties of unfortified soymilk (control). Calcium carbonate, Ca citrate and triCa phosphate did not significantly affect [Ca²⁺], absolute viscosity and particle size of soymilk, but Ca gluconate and Ca lactate significantly increased these properties. The pH of soymilk was significantly increased by adding Ca carbonate but significantly reduced by adding Ca gluconate and Ca lactate. Dry sediment of soymilk increased significantly with the addition of all Ca salts excluding triCa phosphate. Freezing point depression increased significantly only for Ca gluconate and Ca lactate, mainly owing to their higher solubility.     

钙强化剂和钙强化食品的研究进展

综述了钙吸收机理,钙营养强化剂与钙强化食品的研究现状.     

微囊乳钙补钙剂的测定研究

微囊乳钙是以乳清为原料,经去除部分蛋白质、乳糖成分后得到乳矿物盐,再采用微胶囊技术包埋制成的高效补钙剂.文中采用扫描电镜、红外光谱仪、X-射线衍射光谱仪、X-射线荧光光谱仪等仪器和方法,测定一种进口的微囊乳钙产品的结构与性质.结果表明,微囊乳钙颗粒表面凹凸,大小不均,粒径在2～100μm-间;主要成分为磷酸钙盐,灰分含量约78.5％～78.9％,蛋白质1.93％,样品可溶于中酸性至强酸性溶液中.     

Effect of calcium and fat intake on calcium metabolism in calves

Ten male Holstein calves were fed diets with or without 5% added animal fat in combination with low and high dietary calcium (.15 or .98%) for 4 wk. After 3 wk, the animals were orally dosed with calcium-45. One week later they were killed and tissue samples taken. Except for lower calcium-45 in bile, added dietary fat had no marked influence on calcium metabolism. Net absorption of calcium-45 (not excreted in feces) ranged from 82% for calves fed low calcium to 53% for those given high calcium. Calcium-45 in bone was substantially higher in calves fed .15% calcium. Tailbone biopsies revealed rapid uptake of calcium-45 with approximately as much incorporated during the 1st d as in the following 6 d. Calcium-45 in blood peaked 24 h following dosing. Calves fed .15% calcium had higher calcium-45 in blood and bile than those receiving .98% calcium. Calcium-45 values in soft tissue were low and did not differ materially among treatments. The decreases in radioactive calcium absorption and bone deposition with higher dietary calcium indicated that variable absorption was a major factor in calcium homeostasis. Added fat did not materially effect calcium metabolism with either low or high dietary calcium.     

离子选择性电极法测定味精生产中的钙含量

拟定了以钙离子选择电极为指示电极，饱和甘汞电极为参比电极，EGTA标准溶液为滴定荆的电位滴定法测定味精生产过程中钙含量的分析方法。该方法的测定结果与原子吸收法基本一致，标准偏差在0．018～0．025之间，相对标准偏差在1．00％～2．12％之间，回收率在95．0％～102．3％范围内。     

硫酸钙在膳食钙中的应用现状及优势

中国式补钙的背后,国内外营养学界普遍建议,通过高钙食物来补充钙,减少补充剂摄入量。通过探讨在膳食中较为常用的硫酸钙、碳酸钙、氯化钙和磷酸钙4种无机钙盐在食品中的应用及其优缺点,最终认为天然、无毒、高性价比的硫酸钙在膳食钙的应用中更胜一筹。     

生物活性肽促钙吸收机制与钙离子通道

近年来,第4代补钙产品——促钙吸收肽(如酪蛋白磷酸肽)的研究已成为热点,其主要是通过钙离子通道发挥促钙吸收作用。钙离子通道是一组跨细胞膜的蛋白质,它控制着Ca~(2+)进入细胞的过程,TRPV6和Cav1.3是钙在肠道跨膜吸收的2种重要钙离子通道。TRPV6是TRPV离子通道家族成员中高选择性的Ca~(2+)转运通道,由钙结合蛋白D9k(Calbindin-D_(9k))和维生素D共同参与调节。Cav1.3在去极化条件下被激活,从而发挥重要的促钙吸收作用,但其不依赖于Calbindin-D_(9k)和维生素D的调控。小肽转运蛋白是一种低亲和力、高容量的协同转运载体,其不仅可以消除氨基酸之间的相互竞争,加速蛋白合成,也可促进动物对矿物质的吸收与利用。本文概述了生物活性肽通过其与2种最常见的钙离子通道(TRPV6、Cav1.3)的作用及小肽转运系统(Pep T1转运)转运,以促进钙的高效吸收,旨在阐明活性肽的高效促钙吸收机制。