由虾壳制备的蛋白水解物-柠檬酸钙的复合钙粉的生物利用率研究

目的:评价从虾壳中制取的蛋白水解物-柠檬酸钙复合钙粉（PHC-Ca）的生物利用率。方法:选择4周龄体重无显著性差异的SD大鼠60只,随机分为6组,在自由进食低钙饲料的基础上分别以PHC-Ca、碳酸钙（Ca CO3）、柠檬酸钙、葡萄糖酸钙以及虾壳细粉灌胃饲养,每日灌胃剂量为66.5 mg Ca/（kg·d）（以钙剂量及大鼠体重为计算指标）。喂养至4周末进行3 d代谢实验,测定钙表观吸收率、储存率。继续喂养至8周末,观察大鼠体格增长并测定血清碱性磷酸酶、骨钙素水平以及股骨相关指标。结果:低钙对照组大鼠各项体生长指标均显著低于除碳酸钙组外的其他组（p<0.05）;PHC-Ca能显著提高大鼠钙表观吸收率、钙储存率,且能降低血清碱性磷酸酶、骨钙素水平（p<0.05）;摄食PHC-Ca、葡萄糖酸钙的大鼠,其血清钙水平无显著性差异（p>0.05）且高于其他组;PHC-Ca组大鼠股骨钙、股骨长、股骨干重指标高于葡萄糖酸钙组、柠檬酸钙组、虾壳粉组（p<0.05）。结论:从虾壳中制取的PHC-Ca有促进钙吸收的效果,其生物利用率优于相同钙含量的柠檬酸钙以及虾壳粉,可作为一种良好的膳食钙补充剂。      

含锌乳粉的生物利用率研究

本文以硫酸钾溶液为标准,对含锌乳粉中锌离子在家兔体内的生物利用度进行研究。结果表明,硫酸锌组和含锌乳粉组血锌浓度的达峰时间、峰浓度、平均滞留时间及曲线下面积均无显著差异,说明两组锌盐在家兔体内的代谢过程基本一致。含锌乳粉组的相对生物利用度为112．9%,说明锌盐与赖氨酸、牛乳粉同服能提高其生物利用度。研究结果认为,鉴于人工乳粉中锌含量相对偏低,在本市售普通乳粉中添加适量硫酸锌,使之达到FAD/WHO的规定值,是合理、可行的。     

类胡萝卜素的生物利用率

论述了作为VA前体的类胡萝卜素在体内的吸收代谢过程、类胡萝卜素生物利用率的定义、影响生物利用率的因素以及测定新方法。     

虾壳钙蛋白的生物利用率研究

采用酸处理虾头，壳粉，可获得蛋白质含量７６．５５％，钙含量１５．２０％，磷含量５．２８％的优质钙磷蛋白。其必需氨基酸组成与牛乳极为近似，含量占４８．４５％。饲喂大鼠的试验结果表明，虾钙蛋白能极地显著地提高大鼠的增理率，饮料利用率，体钙储留率和骨钙含量。     

体外模拟法研究生物利用率的影响因素

体外模拟法是目前常用的研究胃肠道营养素的生物利用率的方法。其方法简单,成本低,时间短、效果好、因而应用很广。总结了体外模拟时需考虑的各项因素,包括胃的消化和胰的消化、pH调节、蠕动频率、膜的渗透等;同时概述了目前存在的问题并对以后的发展方向进行了展望。     

类胡萝卜素的生物利用率

本文论述了作为维生素A前体的类胡萝卜素在体内的吸收代谢过程、类胡萝卜素生物利用率的定义、影响生物利用率的因素以及测定新方法。     

杨梅果汁蛋白粉稳定性及其花色苷生物利用率

杨梅货架期短,富含花色苷,豌豆蛋白营养丰富不含致敏原。该研究以豌豆蛋白为壁材,经高压均质和喷雾干燥技术将杨梅果汁包埋加工成杨梅-蛋白粉固体饮料。通过扫描电镜、傅里叶红外分析(Fourier transform infrared spectrometry, FTIR)、热重分析(thermogravimetric analysis, TG)、粒度测定和电位分析对杨梅-蛋白粉的包埋特性、稳定性进行表征。同时利用体外模拟消化对杨梅-蛋白粉中花色苷的生物利用率进行分析。结果表明,杨梅-蛋白粉形貌圆润,与豌豆蛋白粉相比粒径更小且均匀。FTIR分析表明,制备杨梅-蛋白粉对豌豆蛋白的二级结构有一定的影响(α-螺旋下降1.22%,β-折叠下降1.98%,β-转角上升3.72%,无规则卷曲下降0.52%),TG分析表明杨梅-蛋白粉较好地保留了豌豆蛋白热稳定性。杨梅-蛋白粉饮料Zeta电位为-45 mV,显著高于豌豆蛋白(-18 mV),具有更高的稳定性。体外模拟消化结果表明,在胃液中消化30 min后,果肉、果汁和杨梅-蛋白粉中花色苷的生物利用率分别为91.23%、99.31%和74.98%,120 m...     

番茄红素生物利用率的研究进展

番茄红素具有很强的抗氧化活性,能有效降低癌症、心血管病的发病率,可以作为一种功能性色素广泛应用于功能食品、药品和化妆品中。与其他类胡萝卜素相比,它具有更强的抗氧化能力,但其在正常生理功能条件下营养素进入体循环,达到作用部位的比例即生物利用率较低,且易受多种因素的影响。本文简要综述了番茄红素生物利用率的研究状况及影响因素。     

体外消化过程中影响类胡萝卜素生物利用率的因素

类胡萝卜素是存在于很多水果蔬菜中的天然色素,具有VA原活性、抗氧化等特性,在维持人体健康方面发挥重要作用。从食物基质中释放的脂溶性类胡萝卜素包裹在脂滴中被运送到小肠,与胆盐、脂类等形成水溶性胶束,随后被小肠上皮细胞吸收并进一步代谢。在体外消化实验中,影响类胡萝卜素生物利用率的因素很多,类胡萝卜素种类及结构、食物基质、脂类、样品加工处理方法、消化模型、细胞模型、检测方法及指标等的不同都会造成最终的生物利用率评估值的不同,另外不同因素对生物利用率的影响因类胡萝卜素种类而异,且各因素间可能存在协同效应。     

In vitro availability of minerals from oat products

The content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals. © 2002 Society of Chemical Industry     

酶解动物蛋白制备抗氧化多肽研究进展

动物蛋白资源丰富,酶法水解动物蛋白制备的抗氧化多肽具有多种生理机能,成为研究的热点。综述了酶解动物蛋白制备抗氧化多肽的研究现状,为提高畜禽副产品附加值提供了理论依据。     

动植物复合蛋白酸乳的研制

以大豆、花生、骨素、牛奶为主要原料,经乳酸菌发酵制成一种具有营养保健功能的动植物复合蛋白酸乳。对各原料间的配比、乳酸菌的接种量等工艺条件进行了研究,采用了3因素3水平的正交实验,通过风味感官评价得出最佳产品配方。     

Effect of processing and cooking on the content of minerals and protein in pasta containing buckwheat bran flour

Research was conducted to determine the effect of processing and cooking on the ash content and mineral composition and on protein content and amino acid composition of spaghetti that was fortified with 250 g kg^?1 buckwheat bran flour (BBF). Extrusion and drying temperature had little or no effect on ash and mineral content of spaghetti containing BBF. Drying temperature did not affect protein content; however, a 31% reduction in lysine content was observed in spaghetti containing BBF dried at 90 °C. Cooking spaghetti fortified with BBF reduced ash content by 28%. Reduction in ash content was reflected by an average decrease in potassium of 62%, in copper of 45%, and in zinc of 11%. Cooking had little or no effect on content of calcium, iron, magnesium, or manganese. As a result of material leaching from spaghetti during cooking, the protein content and content of each amino acid (db) were greater in cooked than uncooked spaghetti. Copyright © 2007 Society of Chemical Industry     

Effect of Heat Treatment Upon the Chemical Composition of Cottonseed Meal and Upon the Reactivity of Cottonseed Condensed Tannins

The effects of heat treatment on the chemical composition of cottonseed meal (CSM), with or without the addition of cottonseed hulls (containing condensed tannins; CT), and upon reactivity of the CT were studied. Heat was applied in a forced draught oven at 100°C for 2 h. Fluorodinitrobenzene (FDNB)-available lysine, free gossypol, extractable- and bound-CT concentrations, in vitro total nitrogen (N) solubility and the in vitro rumen degradation of the two major seed proteins (52 and 48 kDa) present in cottonseed kernel (which does not contain CT) were determined. The reactivity of CT was assessed by determining N solubility and rumen degradation of cottonseed kernel proteins in the presence or absence of polyethylene glycol (PEG; molecular weight (MW) 3500), which binds and inactivates CT. Heat treatment reduced the concentrations of free gossypol and FDNB-available lysine by small amounts, reduced measurable total CT content by 13%, reduced the solubility of total N, and reduced potential degradability of the 52 and 48 kDa cottonseed storage proteins by mixed rumen microorganisms. Addition of hulls further depressed solubility of total N and ruminal degradation of the two major storage proteins in cottonseed kernel. The action of PEG in vitro indicated that only part of the depression caused by hull addition could be explained by the presence of CT in the hulls, and that the effects of CT upon N solubility and potential degradability in heated CSM were similar to that in unheated CSM. Addition of hulls also substantially reduced FDNB-available lysine. In commercially produced materials, CSM from the Brisbane mill had a lower total CT content, lower N solubility and lower ruminal protein degradation rate than CSM from the Narrabri mill, but a similar level of FDNB-available lysine. Although application of heat inactivated 13% of the total CT, such that it could no longer be extracted and detected with butanol/HCl, it did not seem to change the overall effects produced by CT in reducing N solubility and protein degradation. The effect of hull addition in reducing available lysine has considerable relevance for feeding CSM to monogastric livestock. Interactions involving heat, hulls and CT need to be further studied.     

三聚磷酸钠改性花生蛋白的研究

采用三聚磷酸钠对花生蛋白进行化学改性,探讨了改性中三聚磷酸钠的添加量、反应温度、时间、pH等因素对花生蛋白化学改性的影响。实验结果表明,通过化学改性使花生蛋白的溶解性达到2.01g/mol,乳化度为56.98%,乳化稳定性为55.54%,高于原料花生蛋白的水平。     

Effect of extrusion cooking on structure and functional properties of pea and kidney bean proteins

Pea (Pisum sativum L cv Ballet) and kidney bean (Phaseolus vulgaris L cv Pinto) seeds were extruded at 148 and 156 °C respectively. Protein solubility at various pH values and in various solvents was determined and analysis of protein fractions was carried out by SDS‐PAGE. Also, sulphhydryl and disulphide groups, water‐holding capacity (WHC), water solubility index (WSI) and oil absorption capacity (OAC) were determined. No changes in total nitrogen content of pea and kidney bean seeds occurred as a result of thermal treatment. Protein solubility from raw and extruded legumes was significantly higher in saline solutions than in water in the pH range 2–10. The solubility of proteins from extruded pea and kidney bean flours was greatly decreased with respect to native flours when extraction was in buffer (pH 7.0) alone. Extraction with buffer containing 2‐mercaptoethanol (2‐ME) or sodium dodecyl sulphate (SDS), alone or in combination, greatly increased protein extractability. As a result, the relative solubility was nearly 100% in buffer with SDS and 2‐ME for both raw and extruded samples. Total and free sulphhydryl group and disulphide contents decreased significantly (P < 0.05) after extrusion cooking. Moreover, extrusion treatment caused major changes in the band patterns of the albumin and globulin fractions obtained by SDS‐PAGE. WHC and WSI of extrudates increased significantly in both peas and kidney beans. A significant reduction in OAC was observed in extruded kidney bean flour. © 2000 Society of Chemical Industry     

婴儿配方羊奶粉对幼龄动物生长发育的影响及其蛋白质体内消化研究

以全脂羊奶粉和婴儿配方牛奶粉为对照,通过体内消化实验和幼龄动物生长实验,测定了婴儿配方羊奶粉中蛋白质的体内消化率,实验组SD大鼠的体重、身长、脏器的重量,奶粉的热能效率、蛋白质功效比及食物利用率。研究结果表明:婴儿配方羊奶粉中蛋白质的体内消化率在灌食后4h时显著高于婴儿配方牛奶粉组和全脂羊奶粉组(p<0.05),最终消化率均达到95%以上;婴儿配方羊奶粉组SD大鼠各内脏器官发育基本正常,实验结束时该组SD大鼠体重和身长分别为216.47g和23.56cm,均显著高于其他两个对照组(p<0.05);婴儿配方羊奶粉的热能效率、蛋白质功效比以及食物利用率分别为3.27g/418.4kJ、1.26和17.03%,各指标均显著高于其他两个对照组(p<0.05)。由此说明,婴儿配方羊奶粉中蛋白质能较快地被机体吸收利用,该奶粉能够有效地促进幼龄动物的生长,具有较高的营养价值。      

New approach for the quantification of processed animal proteins in feed using light microscopy

A revision of European Union's total feed ban on animal proteins in feed will need robust quantification methods, especially for control analyses, if tolerance levels are to be introduced, as for fishmeal in ruminant feed. In 2006, a study conducted by the Community Reference Laboratory for Animal Proteins in feedstuffs (CRL-AP) demonstrated the deficiency of the official quantification method based on light microscopy. The study concluded that the method had to be revised. This paper puts forward an improved quantification method based on three elements: (1) the preparation of permanent slides with an optical adhesive preserving all morphological markers of bones necessary for accurate identification and precision counting; (2) the use of a counting grid eyepiece reticle; and (3) new definitions for correction factors for the estimated portions of animal particles in the sediment. This revised quantification method was tested on feeds adulterated at different levels with bovine meat and bone meal (MBM) and fishmeal, and it proved to be effortless to apply. The results obtained were very close to the expected values of contamination levels for both types of adulteration (MBM or fishmeal). Calculated values were not only replicable, but also reproducible. The advantages of the new approach, including the benefits of the optical adhesive used for permanent slide mounting and the experimental conditions that need to be met to implement the new method correctly, are discussed.     

茶多酚对大豆蛋白溶解性影响

茶多酚是茶叶所含多羟基酚类化合物总称,具有很多生理活性。该实验就茶多酚对大豆蛋白溶解性影响进行研究,以蛋白质溶液吸光度值作为溶解蛋白质评价指标,在单因素试验基础上,用响应面实验方法确定茶多酚在大豆分离蛋白溶液中最佳添加量及添加条件为:浓度为1%SPI溶液中茶多酚浓度0.088%,混合温度为21.6℃,pH值为4.85。在此条件下,上层清液吸光度预测值为0.1867,做验证试验得到上层清液吸光度为0.1898;同样条件下,不添加茶多酚时,上层清液吸光度值为0.04352,说明在此条件下蛋白质溶解性得以提高。