利用扇贝壳制备胶原螯合钙的研究

为了有效利用废弃扇贝壳,提高贝类加工废弃物的附加值,采用双酶法水解猪皮制得胶原多肽,并利用灰化的扇贝壳制备胶原螯合钙。优化的胶原螯合钙制备条件是:pH8,胶原多肽与氯化钙的比为0.3g∶7mL,反应时间50min。经95%乙醇沉淀得到胶原螯合钙产品。用红外光谱法对胶原螯合钙进行表征,结果表明胶原多肽的氨基和羧基都参与了与Ca2+的配位,找到Ca-N伸缩振动峰,说明经酶水解得到的胶原多肽成功螯合了贝壳中的钙离子,使该产品既具有胶原多肽增加骨胶原韧性的作用又具有补钙的特性。     

正交试验优化胶原多肽螯合钙的制备工艺

以胶原多肽及氯化钙为原料制备胶原多肽螯合钙并确定其最佳制备工艺,结果表明：胶原多肽螯合钙最适的螯合条件为钙元素和胶原多肽的质量比为13:100、pH6.0、时间30min、温度30℃。在该最佳螯合条件下得到的胶原多肽螯合钙的螯合率达到77.7mg/g。傅里叶变换红外光谱分析结果表明胶原多肽螯合钙是一种新的物质,后期的动物实验也证明了胶原多肽螯合钙具有增加骨密度的功能。     

猪皮胶原多肽螯合钙的制备及其结构表征

以猪皮明胶复合酶解胶原多肽和葡萄糖酸钙为原料,多肽钙螯合率为指标,在一定条件下制备多肽螯合钙。通过Plackett-Buiman(PB)和中心组合设计(CCD),考察胶原多肽/水料液比、多肽/葡萄糖酸钙质量比、p H、反应温度、反应时间、搅拌时间、搅拌速度等因素对多肽螯合率的影响。结果表明:通过PB设计筛选出多肽/葡萄糖酸钙质量比、p H和反应时间为多肽钙螯合主要影响因素,经CCD优化确定最佳螯合工艺为多肽/葡萄碳酸钙质量比5.5∶1,p H6.0,反应时间130 min,胶原多肽/水料液比1.5∶100,反应温度60℃,搅拌速度30 r/min,搅拌时间20 min。在此条件下,多肽螯合率达78.3%。采用紫外光谱、红外光谱、扫描电镜、X衍射等手段,研究了猪皮胶原多肽螯合钙的结构,结果表明猪皮胶原多肽与钙形成了螯合物,且胶原多肽的氨基和羧基均与Ca2+发生了螯合反应。     

胶原多肽螯合钙的研究进展

目前我国居民钙摄入量不足,普遍存在缺钙现象,传统的补钙制剂存在缺陷,将逐步被新型钙制剂所取代。胶原多肽螯合钙作为新型生物钙制剂,具有吸收效率高、无副作用、服用方便等特点,是一种良好的补钙产品。近些年来,许多学者研究胶原多肽螯合钙,为补钙产品提供了新思路。胶原多肽作为其原料的一部分,与钙螯合后可以帮助钙的转运和吸收,被一起摄入后兼补了两种营养素。从一些动物加工的副产物中可以提取胶原多肽和钙,利用他们为原料制备胶原多肽螯合钙有利于副产物的高值化,也为副产物的利用提供了新途径。本文主要对胶原多肽螯合钙的原料制备、螯合工艺、螯合效果的影响因素、发展前景进行了概述。     

鮟鱇鱼骨胶原多肽螯合钙的工艺优化

为减少水产品加工过程中副产物对环境的污染与资源的浪费、提高水产品的附加值,对鮟鱇鱼骨制备胶原多肽螯合钙的工艺进行优化。以鮟鱇鱼骨为原料,在适宜条件下制备小分子胶原多肽,并与鱼骨钙提取液进行螯合,制成胶原多肽螯合钙,分别考察螯合温度、鱼骨胶原多肽与鱼骨浸提液的质量比、时间、pH值对螯合率和螯合物中钙含量的影响。根据单因素试验结果,对胶原多肽螯合钙工艺进行四因素三水平正交试验,得到鮟鱇鱼骨胶原多肽螯合钙的最佳工艺参数为螯合温度30℃、时间50 min、鮟鱇鱼鱼骨胶原多肽与钙浸提液质量比2∶1、pH 6,此条件下的螯合率和螯合物中的钙含量分别为98.00%和21.29%。对螯合钙进行氨基酸组成成分分析,其中,具备典型的胶原多肽氨基酸的含量占总氨基酸含量的17.37%。     

补钙面条加工技术研究

对添加胶原多肽螯合钙的补钙面条加工技术进行了研究。以猪皮明胶为原料,制备胶原多肽螯合钙,并对其结构进行了表征。添加胶原多肽螯合钙、猪皮明胶、复合磷酸盐和食盐对面条品质进行改良,通过感官评价对补钙面条的加工条件进行优化。试验结果表明,补钙面条的最佳配方为:胶原多肽螯合钙添加量为2%,猪皮明胶添加量为1.5%,复合磷酸盐添加量为0.8%,食盐添加量为1.5%,小麦粉94%。面条产品弯曲断条率为0,熟断条率为0,干物质失落率为6.9%,蒸煮吸水率为167.5%,面汤浊度为0.104。经感官评价,面条得分为88.7分。通过添加胶原多肽螯合钙,补钙面条中强化钙量为143.6 mg/100 g。补钙面条外观色泽良好,风味较好,食用营养价值高。     

鮰鱼骨胶原多肽-钙螯合物的制备及结构表征与稳定性研究

为制备一种人体易吸收的钙制剂，并提高鮰鱼加工副产物鱼骨的附加值，以钙结合活性为评价指标，通过单因素试验得到鮰鱼骨胶原多肽的最佳酶解工艺，然后采用Sephadex G-25凝胶柱分离纯化钙结合活性高的胶原多肽。运用红外光谱、扫描电镜和能谱分析对鮰鱼骨胶原多肽-钙螯合物进行结构表征，最后评价鮰鱼骨胶原多肽-钙螯合物的热稳定性、酸碱稳定性和体外消化稳定性。研究表明，以碱性蛋白酶制备的胶原多肽的最佳酶解工艺为料液比1∶13(g∶mL),酶添加量4%,pH 8.0,酶解时间2 h,酶解温度40℃,其钙结合能力达29.37 mmol/L,分子质量为195～1 967 Da的胶原多肽约占鮰鱼骨胶原多肽整体的77.73%。经Sephadex G-25分离纯化得到3个不同分子质量的肽组分，其中F₃组分的钙结合活性最佳。红外光谱、扫描电镜和能谱分析表明，鮰鱼胶原多肽的氨基、羧基和酰胺键为Ca²⁺的主要结合位点，螯合之后，其光滑的平面变为粗糙、疏松、多孔的形状，钙含量明显增加。稳定性分析发现，鮰鱼骨胶原多肽-钙螯合物具有一定的耐热性、耐弱碱性和消化稳定性，胃肠道消...     

白鲢鱼骨胶原多肽螯合钙的工艺优化

为减少淡水鱼加工过程中副产物对环境的污染和资源的浪费、提高淡水鱼的附加值,对白鲢鱼骨制备胶原多肽螯合钙的工艺进行研究。以白鲢鱼骨和氯化钙为原料,在一定条件下制备胶原多肽螯合钙,考察温度、鱼骨胶原多肽与氯化钙的质量比、时间、pH值对螯合率和螯合物中钙含量的影响。根据单因素试验结果,对胶原多肽螯合钙工艺进行四因子二次正交旋转设计优化,得到鱼骨胶原多肽螯合钙的最佳工艺参数为温度42 ℃、时间38 min、鱼骨胶原多肽与氯化钙的质量比2.1∶1、pH 6.8,此条件下的螯合率和螯合物中的钙含量分别为80.4%和12.1%。对螯合钙进行氨基酸组成成分分析,其总氨基酸含量为61.03%,且具备典型的胶原蛋白氨基酸组成特征。红外光谱扫描和电镜扫描观察表明：钙离子与胶原多肽发生了螯合反应,结合方式有离子结合、配位结合和吸附作用。     

林蛙皮胶原多肽螯合钙的制备及表征

为了有效利用林蛙资源,以林蛙皮胶原多肽和氯化钙为原料,多肽螯合率为指标,在一定条件下制备胶原多肽螯合钙。首先通过正交试验,中性蛋白酶进行酶解,以水解度为指标,确定最佳水解条件为:温度45℃、pH7、水解时间2 h、加酶量1.7%,该条件下水解度为18.21%。得到的林蛙皮胶原多肽与CaCl_2进行螯合,通过单因素响应面试验,以螯合率为指标,确定螯合的最优条件为:螯合时间40 min、温度40℃、钙肽比1.5:1、无水乙醇添加倍数为8,该条件下螯合率为79.43%。采用傅里叶红外光谱仪、扫描电镜和X射线衍射等手段,研究了胶原多肽和多肽螯合钙的结构,结果表明林蛙皮胶原多肽与钙形成了新的螯合物。     

胶原多肽螯合钙螯合工艺研究

试验以螯合率为指标,研究肽钙添加比例、温度、p H和时间四因素对猪皮胶原多肽螯合钙螯合效果的影响。通过设计单因素和正交试验对螯合效果进行优化,得到优化的螯合工艺的主要参数:肽钙比例3︰1、p H 7、温度50℃、螯合时间30 min。并对所制备的胶原多肽螯合钙粉末进行傅立叶红外光谱和紫外吸收定性检测,发现均发生不同程度的峰移动,证明螯合前后胶原多肽-化学结构上发生了一定的变化,确定有新的螯合物生成。     

Effect of dietary fat and calcium source on insoluble soap formation in the rumen

Diets with and without added fat and with different amounts of soluble and insoluble calcium were fed to rumencannulated cows to determine roles of fat and calcium in formation of insoluble calcium soaps in the rumen. Percent of total fatty acids in soap was increased only by addition of soluble calcium (CaCl2). The amount of fatty acid in soap was highly dependent on amount of fat in the rumen and was not changed by calcium addition. Concentration of ionized calcium in rumen content was halved by fat addition and was inversely correlated with rumen pH, whereas proportion of fatty acid in soap was directly related to pH. Rumen pH was lower 8 to 12 h postfeeding when calcium was added to the diet, which was related nonsignificantly with total volatile fatty acid concentration. Addition of fat to diets tended to lower the ratio of acetic to propionic acids in the rumen; this trend was reversed by calcium addition. Beneficial effects of added calcium in high fat diets were not caused by increased calcium soap formation in the rumen.     

不同钙片产品体外快速持钙活性与原子吸收法测定含钙量的比较研究

酪蛋白磷酸肽(CPP)是从牛乳酪蛋白中水解分离所得到的一种生物活性肽,具有很强的促钙吸收活性。本实验考察CPP抑制磷酸钙/碳酸钙沉淀的产生,来表征CPP的持钙效果。对市售三种钙片体外持钙活性进行了体外快速演示实验和利用原子吸收法测定含钙量的比较和研究,结果表明含CPP的钙片具有较明显的持钙优势,阻止磷酸钙/碳酸钙聚沉时间可达30 min以上。在相同钙片重量和相同钙含量的情况下,加有CPP的钙片在水中溶解后的沉淀明显少于另外两种钙片产品,上清液加入碳酸钠溶液中,沉淀明显较多于另外两种钙片,表明了CPP具有明显延长持钙时间、有效抑制碳酸钙沉淀生成的作用。这一研究发现为市场上钙片产品补钙效果提供了有理有据的科学支撑,对保健品行业健康稳健的发展具有重大指导意义。     

Effect of pH on the taste of alkaline electrolyzed water

ABSTRACT:  The pH dependence of the taste of alkaline electrolyzed water (AEW) made by electrolyzing bottled mineral waters was examined by sensory evaluation. For water with a calcium concentration of 79 or 93 mg/L, the taste of AEW with a pH of 9.5 was considered better than that of the unelectrolyzed water. In contrast, for water with a calcium concentration of 10 mg/L, the taste of the unelectrolyzed water was preferred to that of AEW with a pH of 9.5. Electrolysis reduced the calcium concentrations in waters with calcium concentrations of 79 or 93 mg/L, but did not change the calcium concentration in water with a calcium concentration of 10 mg/L. Electrolysis probably improved the taste of water with a higher calcium concentration by reducing the calcium concentration; however, the effect of electrolysis on water with a calcium concentration of 10 mg/L is likely to be the result of the pH increase alone.     

四种食用菌菌丝体富集有机钙能力的研究

目的:从硫磺菌、茯苓、红曲和蜜环菌中筛选富钙率和钙有机化程度高的食用菌,并研究富钙高的硫磺菌液体培养时富钙对主要活性成分齿孔酸含量的影响。方法:采用生物富集方法研究无机钙的添加对四种食用菌生长的影响,采用静置浸出法分析菌丝体钙有机化程度,并用高效液相色谱法（High Performance Liquid Chromatography, HPLC）分析硫磺菌主要活性成分齿孔酸的含量。结果:固态培养时,在适宜的加钙量下,硫磺菌的生长均优于茯苓、蜜环菌、红曲。液态培养在加钙量为100 mg/L时,硫磺菌的富钙率显著高于茯苓、蜜环菌和红曲。硫磺菌液态培养加钙量为100 mg/L时,可以达到93.51%的富钙率、85.85%的钙有机化程度和18.34 mg/g的齿孔酸含量,因此硫磺菌具有成为功能性新型补钙产品开发利用的潜质。     

桑叶粉中钙的含量测定及生物利用

目的:以四川大竹县所产桑叶为研究材料,对桑叶粉中钙含量进行测定,并对生物利用性进行探究。方法:对桑叶粉中总钙含量及氨基酸种类和含量进行测定,并对不同形态的钙含量进行测定;通过模拟胃部及肠道消化法研究桑叶粉的生物利用性。结果:样品中含钙量达到1614.85 mg/100 g,其水溶性钙、果胶钙和碳酸钙接近钙总含量的60%;桑叶粉可在胃酸作用下缓慢释放钙离子,与碳酸钙和葡萄糖酸钙相比,可减轻对胃的刺激,在肠道中其钙透过率显著(p<0.05)高于碳酸钙和葡萄糖酸钙;桑叶粉中氨基酸种类丰富,比例适当,EAA/TAA=40.79%,EAA/NEAA=68.88%,接近FAO/WHO标准模式。结论:桑叶粉中含有多种形态的钙且总钙量丰富,桑叶粉中的钙质更易被人体吸收。     

不同烹调方法对骨汤中钙含量的影响

为寻找适合大众需要的膳食钙源,用原子吸收光谱仪分析了不同烹调方法烹制的骨汤中钙含量,并探讨烹调时间对骨汤中钙含量的影响。结果显示,常用的烹调方法（包括家用压力锅和瓦堡）熬出的猪骨汤中钙含量极低,平均10～1．2mg／100ml,作为人体的钙营养补充意义不大。但加入食醋后,骨汤中钙含量明显增加（P＜0．01）,钙浓度达1780±11．6mg／100ml,且随着烹调时间的延长。汤中钙含量也显著增加（P＜0．01）,可作为一种丰富的膳食钙源。     

Effect of Molar Substitution (MS) on Calcium Binding by Hydroxypropyl Rice Starches

Unisolated rice starch was obtained by wet milling of broken milled rice grains. Hydroxypropyl rice starches of different level of molar substitution (MS) were prepared and characterized. Both native and modified starches were treated with calcium carbonate at various calcium: starch ratios. Binding was markedly influenced by the calcium concentration in the reaction mixtures. Native starch binds less calcium than modified starch. Ability to bind calcium decreased with increasing calcium concentration in both native and modified starches. A parallel increased in calcium binding was observed as MS increased to the value of 0.09 and thereafter reversed. Increased level of substitution depressed the optical rotation and electrical conductivity of starch-calcium complex.     

Soluble, Dialyzable and Ionic Calcium in Raw and Processed Skim Milk, Whole Milk and Spinach

Chemical availability of calcium was measured with and without simulated digestion to determine processing effects. Available calcium was low in spinach and significantly higher in skim milk and whole milk, consistent with their known bioavailabilities. In nondigested processed milk it was significantly higher for whole milk than for skim milk. However, available calcium in digested whole milk was lower than in digested skim milk. Digestion increased available calcium in skim milk, dialyzable and ionic dialyzable calcium in whole milk and ionic calcium in spinach. Soluble and ionic soluble calcium were lowered in whole milk during digestion due to soap formation. Effects on % calcium were slight, but available calcium in nondigested skim milk was significantly lowered by processing.     

Calcium ions enclosed in casein phosphopeptide aggregates are directly involved in the mineral uptake by differentiated HT-29 cells

Casein phosphopeptides (CPPs) display the ability to form aggregates with calcium and promote the mineral uptake in models of intestinal cells. The present study aimed to clarify which fraction of calcium, CPPs – bound or free, is directly involved. A commercial preparation of calcium enriched CPPs was employed. The free intracellular calcium was monitored at the single cell level by fura-2 fluorescence. Results showed that calcium enriched CPPs formed aggregates and promoted mineral uptake by the cells at a stable level regardless of the amount of extracellular calcium, indicating that the fraction of calcium bound to CPPs was responsible of the bioactivity. The decalcified CPPs bind free calcium available in solution, form aggregates and promote the mineral uptake by the cells, but are dependent on extracellular calcium.