产蛋鸡饲料中钙颗粒大小的影响

饲料中各组分的颗粒大小,对于某些种类的动物至关重要。一般地说,增加石灰石或蚝壳的粉碎细度,有利于动物消化。但是,饲料中的这些钙组分,应以能向动物提供钙的最大生物学利用率的细度为宜。试验表明,产蛋鸡饲料中具有大颗粒(1400μm～5600μm)石灰石或蚝壳,能增加蛋壳强度。     

燕麦全麦粉中淀粉消化性的研究

研究了燕麦β-葡聚糖以及蛋白质对燕麦全麦粉中淀粉消化特性的影响,并对这一影响可能存在的机理进行了探索。燕麦通过磨粉,过筛后,按照颗粒大小分级成了不同的燕麦粉样品。检测表明,不同颗粒大小级别的燕麦粉具有不同质量分数的β-葡聚糖和蛋白质,不同的糊化特性,燕麦的消化速度则随着颗粒的增大而减小。蛋白酶预处理燕麦全粉提高了淀粉的水解速率,但外加β-葡聚糖到消化液中并没有对淀粉原有的消化特性产生显著影响。共聚焦显微镜结果显示,燕麦粉中蛋白质、β-葡聚糖和淀粉可能共同形成了一种聚合结构。因此,燕麦粉固有的β-葡聚糖可能与其他成分,如蛋白质交联而形成一定的空间结构,降低了消化酶与淀粉的接触度,从而延缓了燕麦粉中淀粉的消化。     

芒果中有机酸含量及对小鼠和大鼠消化功能的影响

研究不同成熟度芒果中有机酸含量变化规律及其对小鼠、大鼠消化功能的影响。用酸碱滴定法测定果实中有机酸含量,通过小鼠小肠运动实验、大鼠饲养实验及消化酶测定,评价不同成熟度或配伍使用的芒果果实对动物消化功能的影响。结果表明,生果、绿熟果和熟果中有机酸含量（以柠檬酸计）分别为1.02%、1.63%和0.12%。熟果对实验动物消化功能没有促进作用,生果和绿熟果都能促进实验动物消化功能,并且以绿熟果为最佳。绿熟果中配合加入栀子、芒果叶粉后,不仅可显著提高其对实验动物的胃肠动力、胃液量、胃蛋白酶活性及排出量,还可显著提高其总增重和食物利用率。     

影响乳液中β-胡萝卜素生物可给率的因素研究

为了明确影响乳液体系中β-胡萝卜素生物可给率的因素,作者通过构建体外消化模型及体外淀粉消化酶、脂肪酶及胆盐缺失3种特殊消化模型,对以辛烯基琥珀酸(OSA)改性淀粉为乳化剂的β-胡萝卜素乳液的生物可给率进行研究。结果显示,不同消化模型中β-胡萝卜素生物可给率的大小顺序为:完整消化模型淀粉消化酶缺失模型胆盐缺失模型脂肪酶缺失模型。因此,当乳化剂消化、油脂消化和胆盐胶束化中任一进程被抑制时,乳液中β-胡萝卜素的生物可给率均降低。且这三者对乳液中β-胡萝卜素生物可给率的影响程度如下:脂肪消化胶束化乳化剂消化。     

不同料形饲料对猪生产性能的影响

综述了膨化料和颗粒料的优缺点以及仔猪消化生理特点，并对不同料形饲料与仔猪、育成猪生产性能、猪体健康、猪胃肠道消化酶以及环境污染的关系进行了阐述。研究表明，颗粒料可以提高育成猪的平均日增重、营养物质在胃肠道的消化率，降低畜禽呼吸道疾病的发生率，减少环境污染。     

青梅提取物的制备及体内促消化功能研究

目的：探讨青梅促消化的功效。方法：以体内促消化能力大小为指标,对青梅促消化提取物用三氯甲烷、乙酸乙酯和水等不同极性溶剂萃取后的所得物,进行大鼠体质量、体质量增量、摄食量、食物利用率和消化酶的测定以及小鼠的小肠运动实验。结果：青梅乙酸乙酯提取物明显的改善了大鼠的摄食量,促进了大鼠胃液和胃蛋白酶的分泌,并且对墨汁在小鼠小肠的运动有明显的推进作用。结论：青梅的乙酸乙酯提取物有明显的促消化作用。     

益生素产品在反刍动物饲料中的作用

饲料中添加益生素主要作用在于益生菌在消化道内通过种群的竞争优势抑制病原菌的定殖;刺激提高宿主免疫系统的活力;吸附消化道内的病原菌和霉菌毒素;提高饲料的吸收利用效率,提高动物的生长率和健康水平;通过减少抗生素的使用以及毒素的污染从而保证动物产品的安全.对反刍动物而言,益生菌能促进瘤胃的发育,促进消化酶的分泌,减少氨、甲烷等有害气体的产生,提高营养物质的利用效率.     

国内外饲料粉碎机及其配套

概述在现代饲料工业中,几乎所有的饲料组分都要进行粉碎,以提高物料混合性能和有利于颗粒的压制,并改善动物对饲料的消化能力。因此,粉碎设备在现代饲料工业中占有重要地位,是饲料加工的关键设备之一。目前主要使用锤式粉碎机,其次是辊式磨粉机。     

犊牛代乳粉的开发和应用

犊牛代乳粉的开发和应用天津轻工业学院食品工程系赵征中国乳制品工业协会韩光烈乳牛属于反刍动物，幼龄犊牛的四个冒发育较差，与单胃动物一样主要靠真胃和肠道执行消化功能。开始采食饲料后，其余各胃才迅速发育，到达成熟期要６—９个月。早期断乳的犊牛因真胃消化酶和...     

饲料中添加酶也可提高生长肥育猪的饲养效果

仔猪饲料中添加酶正变得越来越普遍,许多试验表明:酶也能提高生长肥育猪的饲养效果。人们已经充分证明,初生仔猪消化器官不发达,产生消化酶的能力弱,仔猪断奶及其他应激因素能使消化酶的水平降低,使肠道粘膜形态发生变化,从而降低营养物质的消化和吸收。显而已见,饲料中添     

谷物淀粉在家禽日粮中的利用效率研究进展

本文综述了谷物淀粉结构、组成等理化性质，分析了淀粉理化性质、谷物细胞壁、抗营养因子、加工过程中淀粉的变化、动物消化道生理状态等因素对家禽日粮中淀粉利用效率的影响，为提高淀粉在家禽日粮中的营养价值提供理论参考。     

糙米酚类物质对淀粉消化特性的影响研究进展

糖尿病等慢性病是全球范围内重要的公共卫生问题。淀粉摄入是导致餐后血糖升高的主要原因之一。近年来研究表明，多酚类物质能够延缓淀粉的消化速率。糙米富含丰富的酚类物质，作为重要的全谷物来源，其营养健康功效在全世界得到广泛共识。糙米酚类物质特有基团如酚羟基对消化酶类产生一定的抑制作用，在加工过程中淀粉自身结构的改变也使消化酶类对其的作用减小，不仅能有效控制淀粉的消化速率及消化率，还能改善食品品质。本文从糙米中酚类物质及其抗氧化活性、淀粉消化过程、糙米多酚对淀粉消化特性的影响及其作用机制等几个方面进行综述，旨在阐明全谷物糙米酚类物质延缓淀粉消化的科学依据，为开发适用于慢性病人群、肥胖人群、超重人群、老年人群等的全谷物糙米基和淀粉基食品提供参考。     

The Role of Dietary Phenolic Compounds in Protein Digestion and Processing Technologies to Improve Their Antinutritive Properties

Digestion is the key step for delivering nutrients and bioactive substances to the body. The way different food components interact with each other and with digestive enzymes can modify the digestion process and affect human health. Understanding how food components interact during digestion is essential for the rational design of functional food products. Plant polyphenols have gained much attention for the bioactive roles they play in the human body. However, their strong beneficial effects on human health have also been associated with a negative impact on the digestion process. Due to the generally low absorption of phenolic compounds after food intake, most of the consumed polyphenols remain in the gastrointestinal tract, where they then can exert inhibitory effects on enzymes involved in the degradation of saccharides, lipids, and proteins. While the inhibitory effects of phenolics on the digestion of energy‐rich food components (saccharides and lipids) may be regarded as beneficial, primarily in weight‐control diets, their inhibitory effects on the digestion of proteins are not desirable for the reason of reduced utilization of amino acids. The effect of polyphenols on protein digestion is reviewed in this article, with an emphasis on food processing methods to improve the antinutritive properties of polyphenols.     

电火花沉积金属结合剂金刚石砂轮研究

采用电火花沉积法制备了金属结合剂金刚石砂轮。利用扫描电镜表征了沉积砂轮的显微结构和沉积层与金属基体的结合界面,考察了不同进刀量下电火花沉积的金刚石砂轮的磨削性能。结果发现,使用电火花沉积工艺可以制备出金属结合剂金刚石砂轮,沉积层与金属基体结合牢固,但沉积层中存在大量气孔;用电火花沉积工艺制备的金刚石砂轮,在进刀量为5μm/s时,其对硬质合金的磨耗比为37.2;工件表面粗糙度Ra为0.36μm,电镀砂轮加工工件的表面粗糙度Ra却为0.67μm。     

膳食多酚对淀粉消化吸收的影响

近年来基于食品成分之间相互作用调节食品质地与功能特性的研究成为食品学科的研究热点。多酚与淀粉的相互作用在食品中广泛发生,二者的相互作用对调控加工食品的风味和质地、提高多酚的生物利用度、抑制淀粉的老化以及降低淀粉的消化吸收速度等具有重要作用。综述了多酚与淀粉的复合作用、多酚对淀粉消化酶活性的抑制以及多酚对肠道葡萄糖吸收转运的抑制作用,为利用食物成分与淀粉的相互作用开发预防和控制高血糖症的新型食品提供了参考。     

Site of digestion of starch in the gastrointestinal tract of dairy cows and its effect on milk yield and composition.

Physical and chemical processing of feed ingredients and feeding management strategies are major instruments of manipulating amount and site of starch digestion in the gastrointestinal tract. Generally, as rumen escape of starch increases, postruminal starch digestion increases, and there does not appear to be a limitation to intestinal starch digestion. However, the efficiency with which postruminal starch is digested decreases, which represents a limitation that warrants investigation. Even though digestible dietary starch is presented to the intestine, there is no net glucose absorption at the portal vein, and plasma glucose levels remain relatively unaffected. This result may be associated with the large metabolic requirement for postruminally absorbed glucose, which is preferentially used for oxidative metabolism at the visceral tissue level. In addition, peripheral glucose concentration is highly regulated. A possible implication is that the exogenous glucose supply may spare endogenously synthesized glucose for gut metabolism, allowing more to be directed to the mammary gland. Amino acids also may be spared (less metabolism of dietary and tissue amino acids in the gut). Current production studies yield no clear evidence as to the benefits of postruminal digestion of starch to enhance milk yield or to change its composition. However, studies suggest that starch digested postruminally is used more efficiently for milk synthesis than that digested in the rumen.     

Characterization of Multisubstrate Processes during Membrane Digestion. (Data and hypotheses on the interactions and autoregulation of digestive and transport processes)

The regularities of interactions of the main groups of substrates during membrane digestion, their mechanisms as well as physiological and possible clinical significance are characterized. Mono-, bi- and multisubstrate processes of the hydrolysis of proteins, fats, carbohydrates and phosphoric esters have been investigated using new experimental models. The authors show that the activity of enzymes ensuring membrane digestion is affected by various food substrates which do not serve as substrates for a given enzyme. The inhibitory and stimulating effects have been observed in the process of interactions between different groups of food substrates (for example, lipids and peptides) as well as within a single group of food substrates (for example, between different peptides, peptides and amino acids etc.). The existence of species, ontogenetic and organ characteristics of the processes of interactions at the stage of membrane hydrolysis is shown. The analysis of the mechanisms of interactions permits us to conclude that a number of enzymes accomplishing membrane digestion are allosterically regulated systems. The possible alterations in the regulatory properties of digestive enzymes in pathology are considered.     

发酵过程中原花青素对大米淀粉多尺度结构及体外消化特性的调控

为了调控发酵米制品的消化性能,采用小角X射线散射、凝胶渗透色谱及体外模拟消化等多种现代分析技术,系统考察原花青素在大米淀粉发酵过程中对淀粉结构和消化性能的影响。研究表明,在发酵过程中原花青素与淀粉分子间存在相互作用,进而提高大米淀粉颗粒的抗消化性能,且在原花青素的添加量为8%时RS含量可达66.85%。在原花青素协同微生物发酵过程中,原花青素抑制微生物胞外酶活性并降低了淀粉分子被降解及聚集态结构无序化的程度;原花青素与淀粉分子形成淀粉分子-原花青素-淀粉分子的复合结构,促使淀粉半结晶层状结构中半结晶层厚度增大、无定型层厚度降低及聚集态结构紧密程度和表面短程有序化结构比例增加,且其在消化过程中释放原花青素并抑制淀粉酶活性,最终显著降低淀粉的消化性能。研究结果为发酵米制品消化性能的调控提供了依据。     

Effect of corn particle size on site and extent of starch digestion in lactating dairy cows

Two experiments were conducted to determine the effects of corn particle size (CPS) on site and extent of starch digestion in lactating dairy cows. Animals were fitted with ruminal, duodenal, and ileal cannulas. Dry corn grain accounted for 36% of dry matter intake. In experiment 1, 6 cows were used in a duplicate 3 x 3 Latin square design. Semiflint corn was used. Corn processing methods were grinding, medium rolling, and coarse rolling. The mean particle size of the processed corn was 730, 1807, and 3668 microm, respectively. Rumen digestibility of starch linearly decreased from 59% with ground corn to 36% with coarsely rolled corn. Similarly, small intestine digestibility linearly decreased with increased CPS, and consequently, the amount of starch digested in the small intestine was not affected by corn processing. In experiment 2, 4 cows were used in a 2 x 2 crossover design. Dent corn was used. Corn processing methods were grinding and coarse rolling. The mean particle size of the processed corn was 568 and 3458 microm, respectively. Rumen digestibility of starch decreased from 70% with ground corn to 54% with coarsely rolled corn. Small intestine digestibility of starch was not significantly affected by CPS, and the amount of starch digested in the small intestine tended to be greater for rolled than for ground corn. In both experiments, starch total tract digestibility decreased with increased CPS. In conclusion, CPS is an efficient tool to manipulate rumen degradability of cornstarch. In midlactation cows, the decrease in the amount of starch digested in the rumen between grinding and coarse rolling is partly compensated for by an increase in the amount of starch digested in the small intestine with dent genotype, but with semiflint genotype postruminal digestion is not increased and rumen escape starch is not utilized by the animal.     

不同添加量的氨基酸辅助干热处理对玉米淀粉理化和消化性质的影响（网络首发、推荐阅读）

以玉米淀粉为原料,通过氨基酸（天冬氨酸和赖氨酸）辅助干热处理对其改性,采用快速黏度仪、差式扫描量热仪、X射线衍射仪,对不同氨基酸添加量（0.5%、2%、4%和10%,w/w）的干热玉米淀粉的糊化特性、热特性、结构特性和消化性质进行了研究。结果表明,氨基酸添加量对干热处理玉米淀粉-氨基酸混合物的理化性质和消化性质有显著影响。随着两种氨基酸添加量的增多,淀粉的峰值黏度、回生值和糊化焓值降低,而相对结晶度和抗性淀粉含量升高;干热玉米淀粉-天冬氨酸混合物的糊化温度呈先升高而后降低的趋势,干热玉米淀粉-赖氨酸混合物的糊化温度呈升高趋势。提高氨基酸添加量能促进淀粉颗粒内部的晶体排列更紧密、有序,能更好地抑制淀粉的短期老化,降低淀粉的消化性能;可作为玉米淀粉改性的一种新方法,为生产改性淀粉提供参考。