低聚木糖对大鼠粪钙、尿钙的影响

对大鼠进行正常饲料及低钙饲料中添加2%低聚木糖的喂养,喂养周期21d。测定大鼠钙摄入,粪钙、尿钙含量以及钙的吸收率。得出:低聚木糖能够有效提高大鼠对钙的吸收率,降低粪钙含量,并且,低聚木糖对低钙饲料组的影响比普通饲料组的影响大。在喂养1周之后低钙饲料+2%低聚木糖组的粪钙含量8.09mg,较相应对照组降低59.6%;普通饲料+2%低聚木糖组粪钙含量21.71mg,较相应对照组降低58.5%;低钙饲料+2%低聚木糖组的钙吸收率为94.84%;普通饲料+2%低聚木糖组的钙的表观吸收率为92.33%。另外,低聚木糖对尿钙影响不大。     

鳖甲超微细粉增加大鼠骨密度的研究

通过鳖甲超微细粉和相同剂量的碳酸钙的钙表观吸收率实验,证实鳖甲超微细粉的钙表观吸收率显著高于碳酸钙对照组（P<0.01）。并通过测量相应饲料喂养大鼠的身长和体重,以及股骨的长度、重量、骨密度、钙含量等指标,结果为：3个剂量水平鳖甲超微细粉实验组及2个剂量水平碳酸钙对照组大鼠的股骨长度、股骨干重、股骨骨密度、股骨骨钙含量以及身长显著高于低钙饲料对照组（P<0.01）。2个剂量水平鳖甲超微细粉实验组大鼠的股骨骨密度及股骨骨钙含量显著高于相同钙含量的2个剂量水平碳酸钙对照组（P<0.01）。结论为：鳖甲超微细粉具有增加骨密度的功能,在钙表观吸收率和提高股骨骨密度及股骨骨钙含量方面优于碳酸钙。     

牦牛骨粉对大鼠骨钙、骨密度及骨钙吸收率影响的研究

目的:研究牦牛骨粉钙吸收率及对大鼠骨钙、骨密度的影响。方法:清洁级雌性SD大鼠,70只,随机分为7组,即低钙对照组(饲料中含钙量为1180mg/kg),牦牛骨粉高、中、低三个剂量组(相当于人体推荐摄入量的5、10、20倍),实测值饲料中含钙量为1437、1852、2778mg/kg,另设与样品对照组剂量相对应的三个碳酸钙对照组。于实验第4w末进行三天的钙代谢试验。整个喂养时间为12w,实验结束日,测右侧股骨长度,干重,骨钙含量及骨密度。结果:牦牛骨粉10、20倍剂量组股骨钙含量、股骨骨密度高于低钙对照组,5、20倍剂量组钙表观吸收率高于相应剂量的碳酸钙对照组(p<0.05)。结论:牦牛骨粉不仅有增加骨密度功能,并具有较高的钙表观吸收率。     

乳清蛋白肽对去卵巢大鼠骨生物力学的影响

目的:利用6月龄SD去卵巢大鼠研究乳清蛋白肽(Whey protein peptide,WPP)对骨密度和骨强度的影响。方法:将40只患有骨质疏松症的SD大鼠,随机分为去卵巢对照组OVX-C和WPP低、中、高剂量组(WPP-L、WPP-M、WPP-H,分别为1%、5%、10%)各10只。10周后处死,取大鼠双侧股骨测干重、长度、骨密度和骨强度等指标。结果:低、中、高剂量乳清蛋白肽干预组大鼠体重较对照极显著增高;高剂量组大鼠股骨骨密度及矿物质含量较对照显著增加;乳清蛋白肽干预组大鼠股骨干重、长度大于对照组,但差异不显著;乳清蛋白肽干预组大鼠股骨结构力学指标和材料力学指标较对照组显著增加。结论:用乳清蛋白肽长期喂养大鼠,能明显增加其骨密度、骨矿物质含量和骨骼的承载能力,提高骨骼抵抗骨折的能力。     

复合L-氨基酸螯合钙对大鼠骨密度增加的影响

研究复合L-氨基酸螯合钙对SD大鼠骨密度的影响.将SD大鼠随机分成6组,分别喂养复合L-氨基酸螯合钙,"乐力"氨基酸螯合钙和低钙饲料,通过测量相应饲料喂养大鼠身长、体重、钙表现吸收率,股骨长度、质量、骨密度和股钙含量等指标,观察复合L-氨基酸螯合钙对SD大鼠骨密度的影响.结果表明:2种剂量的复合L-氨基酸螯合钙和"乐力"氨基酸螯合钙对大鼠的身长和体重、股骨质量、骨密度、钙含量和钙表观吸收率显著高于低钙饲料组﹙P＜0.01﹚,两种剂量水平的氨基酸螯合钙对大鼠骨密度、股骨钙含量和钙表观吸收率差异显著﹙P＜0.01﹚,复合L-氨基酸螯合钙具有增加大鼠骨密度的功能.     

酶解骨钙粉细粉与普通酶解骨钙粉增加骨密度功能比较

目的:分析比较酶解骨钙粉细粉与普通酶解骨钙粉增加大鼠骨密度功能和对钙吸收率的影响。方法:SPF级4周龄雌性SD大鼠100只,随机分为10组,即酶解骨钙粉细粉和普通酶解骨钙粉低、中、高剂量组,相应剂量碳酸钙对照组(低、中、高剂量组饲料钙含量分别为216.7、283.3、550.0mg/100g),以及低钙对照组(饲料钙含量为150mg/100g)。喂养13周,检测钙表观吸收率、骨钙含量、骨密度、骨长和骨恒质量。结果:酶解骨钙粉细粉组股骨骨密度明显高于低钙对照组且不低于相应剂量碳酸钙对照组(P>0.05);普通酶解骨钙粉组股骨三点骨密度均明显高于低钙对照组,但低剂量组股骨钙含量和远心端股骨密度均低于碳酸钙对照组(P<0.05)。酶解骨钙粉细粉和普通酶解骨钙粉相应剂量组的钙表观吸收率、骨钙含量、骨密度、骨长、总食物利用率和喂养13周时的体质量均无明显差异(P>0.05);酶解骨钙粉细粉中剂量组骨恒质量高于普通酶解骨钙粉中剂量组(P<0.05)。结论:酶解骨钙粉细粉具有增加骨密度的作用,不能判定普通酶解骨钙粉具有增加骨密度的作用。酶解骨钙粉细粉在增加骨密度功能方面优于普通酶解骨钙粉。     

三文鱼骨胶原低聚肽钙增加SD大鼠的骨密度

以三文鱼骨为原料制备三文鱼骨胶原低聚肽,与钙离子螯合为三文鱼骨胶原低聚肽钙并作为受试物,以低中高剂量作用SD大鼠,并设置空白组和碳酸钙阳性对照组,检测体重、钙吸收率与储留率、股骨干重、股骨长、骨密度等重要指标,评价三文鱼骨胶原低聚肽钙的增加骨密度功能。结果显示,螯合物的总蛋白含量为65.37%,螯合率为52.56%,螯合物得率为43.12%;各试验组体重无显著性差异(p>0.05),中、高剂量组和碳酸钙组的钙吸收率分别为39.18%、40.52%、38.38%,储留率分别为38.80%、39.27%、37.58%,显著高于空白对照组36.31%,35.91%(p<0.05),且高剂量组明显优于同等钙含量的碳酸钙组(p<0.05);另外高剂量组的股骨干重、股骨中点直径分别为0.57(g)和2.40(mm),股骨近端、远端和中点密度分别为0.19、0.22、0.17(g/cm2),均高于空白组(p<0.05),与碳酸钙组无显著性差异。表明三文鱼骨胶原低聚肽钙具有良好的促钙吸收效果和增加骨密度的功能,为相关新型功能性食品的开发利用奠定良好的理论基础。     

乳清蛋白肽对幼年大鼠生长发育的影响

目的：探讨乳清蛋白肽对幼年大鼠体格、长骨发育及血液参数的影响。方法：40 只雄性断乳SD 大鼠随机分为1 个阴性对照组和低(0.225%)、中(0.45%)、高(1.35%)3 个乳清蛋白肽干预组,每组10 只动物。连续喂养42d,期间每周测量体重和身长一次,计算食物利用率,实验结束时对每只大鼠进行血液常规和生化标检测,并测定股骨长度、直径、骨矿物质含量和密度。结果：中、高剂量乳清蛋白肽干预组大鼠体重及食物利用率较对照显著增高;高剂量组大鼠股骨近端骨密度及矿物质含量较对照显著增加;乳清蛋白肽干预组大鼠股骨干重、长度和直径较对照有增加趋势,但尚未见统计学差异;中、高剂量组大鼠血肌酐和血尿酸含量较对照组显著降低。结论：一定剂量的乳清蛋白肽能够促进幼年大鼠体格发育和增加长骨矿物质密度。     

比较不同来源钙剂对大鼠骨密度的影响

目的:研究纳米碳酸钙、微晶体羟磷灰钙、乳钙对大鼠骨密度和钙表观吸收率的影响。方法:SPF级4周龄雌性SD大鼠90只,随机分为9组,即纳米碳酸钙、微晶体羟磷灰钙、乳钙低、高剂量组和相应剂量碳酸钙对照组(低、高剂量组饲料钙含量分别为500mg/100g和1000mg/100g),以及低钙对照组(饲料钙含量为150mg/100g)。喂养13周,测钙表观吸收率、骨钙含量和骨密度。结果:不同钙剂组大鼠骨密度均明显高于低钙对照组(P0.05);不同钙剂低剂量组大鼠钙表观吸收率介于52.96%～68.16%之间,高剂量组吸收率介于41.78%～61.30%,均明显低于低钙对照组(P0.05)。结论:与低钙对照组相比,纳米碳酸钙、微晶体羟磷灰钙、乳钙均可明显改善大鼠的骨密度。     

添加牛奶碱性蛋白牛奶对大鼠骨密度的影响

探讨添加牛奶碱性蛋白(MBP)牛奶对正常大鼠骨密度的影响。将50只SD大鼠分为低钙对照组、碳酸钙、低、中、高5个剂量组。分别采用含钙40,80,96mg/kg及含3.3,6.7,8mg牛奶碱性蛋白,检测体质量、骨密度、骨钙以及钙吸收率等指标。结果表明,各剂量组对大鼠体质量在3个月中未见显著差异;各剂量组大鼠股骨干重、股骨远心端骨密度、股骨中点骨密度、骨钙质量分数均明显高于低钙对照组;高剂量组的钙表现吸收率明显高于碳酸钙对照组。根据《保健食品检验与评价技术规范》推断,添加牛奶碱性蛋白的牛奶产品对大鼠具有增加骨密度作用。     

钙与补钙

就目前我国人口普遍存在的缺钙问题提出了科学补钙的方法,并介绍了钙的生理功能、吸收机理及影响因素、常用钙制剂等。     

不同钙补充剂对体外胃酸消耗及大鼠胃液分泌的影响

比较柠檬酸苹果酸钙、碳酸钙、牦牛骨粉、L-天门冬氨酸钙这四种钙补充剂溶解后对胃酸的消耗情况,及对大鼠胃液分泌的影响,为消费者选择合适的钙剂提供参考。通过体外模拟人工胃环境,测定四种钙剂在人工胃液中释放钙离子所消耗的胃酸量;使用大鼠幽门结扎法建立大鼠胃液分泌模型,观察不同钙剂对大鼠胃液量、胃酸酸度及胃酸分泌量的影响。实验表明柠檬酸苹果酸钙溶解后使人工胃液中氢离子含量显著增加(P0.01),碳酸钙、牦牛骨粉和L-天门冬氨酸钙溶解后则使人工胃液中氢离子含量显著降低(P0.05);大鼠体内实验中,柠檬酸苹果酸钙组和牦牛骨粉组大鼠的胃液量、胃酸酸度及胃酸分泌量均显著减少(P0.01),L-天门冬氨酸钙组大鼠的胃液量、胃酸酸度及胃酸分泌量均显著增多(P0.01),碳酸钙组大鼠的胃液量、胃酸酸度、胃酸分泌量与正常对照组大鼠相比无显著性差异(P0.05)。     

菊糖对大鼠钙吸收利用的影响

菊糖是从菊芋中提取的一种水溶性天然多糖,在中性和弱碱性的环境下可提高钙的溶解度和钙溶液的稳定性。取SD大鼠16只,分成对照组和实验组两组,对照组喂予基础饲料;实验组为基础饲料并灌胃2mL菊糖液(150mg/mL),喂养2周,并进行4天钙代谢试验。结果表明:实验组的钙吸收率比对照组提高10·60%,差别有显著性意义,血钙含量无显著差异。     

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。     

补钙与钙营养强化剂CCM

阐述了钙在人体中的重要作用与补钙的必要性以及选择钙营养强化剂应考虑的原则,介绍了CCM作为钙营养强化剂的优良特性。     

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。     

Field trial of 2 calcium supplements on early lactation health and production in multiparous Holstein cows

Our objectives were to measure serum Ca concentrations in the first 48 h postpartum in cows supplemented with oral Ca or subcutaneous Ca and nonsupplemented cows and evaluate the effect of these treatments on the incidence of metritis, displaced abomasum, mastitis, and early lactation disease (any of the diseases milk fever, retained placenta, metritis, or displaced abomasum), removal from the herd, pregnancy to first insemination, and average daily milk yield for the first 10 wk of lactation. We conducted 2 experiments on 1 commercial herd in New York State. In experiment 1, multiparous Holstein cows (n = 30) were blocked by parity (2 and ≥3) and sequentially assigned at calving to nontreated control (CON, n = 10), subcutaneous administration of 500 mL 23% Ca gluconate at calving (SC, n = 10), or administration of an oral Ca bolus containing 43 g of calcium at calving and again 12 h later (OB, n = 10). Blood was collected before treatment and at 1, 2, 4, 8, 12, 24, and 48 h thereafter for measurement of serum total Ca concentration. In experiment 2, 1,478 multiparous Holstein cows were sequentially assigned by calving date to the same 3 treatments (CON, n = 523; SC, n = 480; OB, n = 475). In experiment 1, SC cows had greater Ca concentrations from 1 through 12 h post-treatment and OB cows had greater Ca concentrations at 1 and 24 h post-treatment compared with CON cows. We found no difference in risk of metritis, displaced abomasum, early lactation disease diagnosis, or pregnancy to first insemination among treatments. Treatment with SC or OB had no effect on average daily milk yield compared with CON cows (CON = 46.7 kg; SC = 47.1 kg; OB = 47.0 kg). Cows treated with SC or OB that had a high relative herd milk rank in the previous lactation were almost half as likely to be diagnosed with mastitis in the first 60 DIM compared with CON cows [risk ratio (RR)_SC = 0.57, RR_OB = 0.54]; however, we found no difference in risk of mastitis among treatments for cows with low relative herd milk rank. Second-parity cows fed a negative prepartum dietary cation-anion difference ration and treated with SC or OB were more likely to be removed from the herd than CON cows (RR_SC = 3.91, RR_OB = 4.72); this difference was not observed in second-parity cows fed a neutral prepartum dietary cation-anion difference ration or in parity ≥3 cows. Although Ca supplementation increased serum Ca, this effect did not greatly improve milk production or health and reproductive outcomes.     

离子选择性电极法测定食品中钙的含量

对4 0 2型钙离子选择性电极的性能进行了测试,此电极对钙离子浓度在1 0 -4～1 0 -4mol/L范围内有较理想的能斯特响应,斜率为- 2 9.2 5mV/pCa(2 0℃) ,重现性与选择性较好,应用此电极测定食品中钙的含量,精密度和准确度较理想,结果与EDTA滴定法基本吻合。     

Changes in the proportions of soluble and insoluble calcium during the ripening of cheddar cheese

In cheese, the concentration and form of residual Ca greatly influences texture. Two methods were used to determine the proportions of soluble (SOL) and insoluble (INSOL) Ca in Cheddar cheese during 4 mo of ripening. The first method was based on the acid-base buffering curves of cheese and the second was based on the extraction of the aqueous phase ("juice") of cheese under high pressure and determining the concentration of SOL Ca in the juice using atomic absorption spectroscopy. When cheese was acidified there was a strong buffering peak at pH approximately 4.8, which was due to the solubilization of residual colloidal calcium phosphate (CCP) of milk that remained in cheese as INSOL Ca phosphate. The area of this buffering peak in cheese was expressed as a percentage of the original area of this peak in milk and was used to estimate the concentration of residual INSOL Ca phosphate in cheese. There were no significant differences between the 2 methods. The proportions of INSOL Ca in cheese decreased from approximately 73 to approximately 58% between d 1 and 4 mo. These methods will be useful techniques to study the role of Ca in cheese texture and functionality.