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微波技术在化学领域中的应用及其机理探讨 总被引:3,自引:0,他引:3
微波对物质的作用机理及微波合成反应技术是目前微波化学研究的重点。主要从有机化学、高分子化学及其它化学领域中对微波这一新型合成技术的应用进行了综述,并探讨了微波对物质的内加热效应及非热效应的作用机理。 相似文献
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《食品科学》2020,(15)
干燥均匀性及微波能利用率是评价物料微波能吸收与利用的重要指标,干燥均匀性、干燥过程微波能利用率分别是影响产品品质、加工成本的主要因素。为提高微波泡沫干燥均匀性及微波能利用率,以树莓浆果为实验原料,采用数值模拟分析料层电场强度、温度及微波能吸收分布规律;运用理论分析和单因素试验研究微波强度、料层厚度及循环干燥时间对泡沫果浆干燥特性、干燥均匀性(温度均匀性及含水率均匀性)及微波能利用率的影响规律。结果表明:随微波强度增加,料层电场分布均匀性显著提高(P0.05),料层电场均匀性及物料吸收特性对温度及含水率分布均匀性影响显著(P0.05);在微波强度2~6 W/g、料层厚度3~7 mm、循环干燥时间2~6 min条件下,随微波强度增加,干燥均匀度呈逐渐上升的变化趋势,随料层厚度增加和循环干燥时间延长,干燥均匀度呈逐渐下降的变化趋势;随微波强度、料层厚度增加及循环干燥时间延长,泡沫果浆微波能利用率均呈先升高后降低趋势。研究结果可为高品质、高能效的微波干燥浆果果粉工艺研究提供理论参考。 相似文献
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目的确定茶叶内质成分保留量最佳的微波杀青工艺参数及干燥方式。方法以夏秋茶鲜叶为研究对象,以茶多酚、咖啡碱、叶绿素、儿茶素保留量为考量指标,研究微波干燥、微波-远红外干燥、热风干燥对夏秋茶叶内质成分的影响,并对微波杀青工艺进行参数优化。通过对微波杀青时间、投叶量及微波功率进行单因素试验;并在此基础上进行L9(33)正交试验,运用方差、极差分析确定最佳微波杀青工艺参数。结果微波杀青时,投叶量50 g、微波功率800 W及微波杀青时间150 s,茶叶中内质成分保持最佳;比较三种干燥方式,得出微波干燥对茶叶内质成分在总体水平上保留效果最好。结论本研究建立的实验室微波干燥茶鲜叶方法可以为实验室微波固样方法提供参考,为工厂微波杀青及干燥提供一定的理论依据。 相似文献
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微波技术在食品工程中的新应用展望 总被引:5,自引:2,他引:5
微波强化萃取、微波真空干燥及微波浓缩是微波能在食品工程中的先进应用技术、有广泛的应用前景,对食品、制药、生物化工等行业的生产过程将产生较大的变革和影响,能提高生产效率及产品质量。 相似文献
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微波联合干燥即微波干燥与其他干燥方法的联合应用。例如微波热风干燥,微波真空干燥,微波冷冻干燥及微波喷动床干燥等。随着人们对干燥产品的品质提出了更高要求,各种联合干燥方法应运而生。微波联合干燥以其如下几方面的优点倍受研究者的青睐:大量缩短干燥时间,提高产品干燥质量,灵活生产出各种类型的干燥产品。简要阐述了微波干燥的基本原理,概述了微波联合干燥在果蔬干燥方面的研究状况及不同联合干燥方法的特点及其试验设备,为缩小实验室研究和工业生产之间的差距提供参考。 相似文献
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开发一款具有滋肾养肺、增加免疫力、补血黑发、降糖降脂、益气强身等功效的黑木耳瘦肉红枣粥。探究了黑木耳瘦肉红枣粥的最佳优配方及其工艺参数,利用单因素试验得到的最佳配比为:黑木耳90g、新鲜瘦猪肉300g、红枣70g、大米200g。按照这一配方,制作出的黑木耳瘦肉红枣粥口感香甜,质地细嫩,清脆爽滑,品质营养最佳。 相似文献
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浓香型产区烟叶主要化学成分与风格品质特色及其关系研究 总被引:2,自引:0,他引:2
收集主要浓香型产区烟叶,测定其化学成分并对其风格品质特征进行评定,研究了产区间烟叶的差异及烟叶化学成分与风格品质特色的关系。结果表明,烟碱、总糖、糖碱比对烟叶感官品质特征的影响较大。劲头的强弱与还原糖和总糖的含量呈极显著的负相关关系,而与烟碱和总氮的含量呈极显著的正相关关系。烟叶的甜感、香气质、香气量、余味均与还原糖、总糖呈正相关关系,而与烟碱和总氮呈负相关关系,随着钾含量的增加,烟气的细腻度、余味评分有增大趋势,刺激性也会变小。烟气的刺激性随氯含量的增加有变大的趋势。烟气的香气质、细腻度、余味均与糖碱比呈极显著的正相关关系,而刺激性与其呈负相关关系。 相似文献
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制约我国乳业实现跨越式发展的主要问题 总被引:5,自引:2,他引:5
通过比较我国乳业与发达国家乳业存在的差距和不足,讨论了加入WTO后,要实现我国乳品企业的跨越式发展应具备的条件。提出我国孔业在奶质量、奶源基地的建设、奶牛单产、原料乳成本、乳品结构等方面与国外相比存在很大的差距;并讨论了我国乳业管理体制、建立奶牛风险基金、高新技术在乳品工业的应用、技术创新体系建设和设备制造技术等问题,得出我国乳业要在管理方面、企业经营规模和效益方面、乳业的管理体制和政策方面、乳品加工技术的创新及体系方面需加强和提高,从而实现我国乳业的跨越式发展。 相似文献
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施智杰 《纺织高校基础科学学报》2008,21(4):393-397
给出内正则duo序半群的刻划,证明一个序半群S是内正则duo的当且仅当它是单且左单且右单的半群半格.特别地,S是单且左单且右单的序半群链当且仅当S是内正则duo的且S的所有理想关于集合的包含关系构成链. 相似文献
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M.C. Tirado M.J. Cohen N. Aberman J. Meerman B. Thompson 《Food research international (Ottawa, Ont.)》2010,43(7):1729-1744
More than one billion people are suffering hunger and malnutrition in 2009. Food security has deteriorated since 1995 and reductions in child malnutrition are proceeding too slowly to meet the Millennium Development Goal (MDG) target of halving hunger by 2015. Three major challenges threaten current and future efforts to overcome food insecurity and malnutrition: climate and global environmental change and the consequent loss of ecosystems’ services, the growing use of food crops as a source of fuel and the food and financial crises. This paper reviews and analyses the current and projected effects of climate change and bioenergy on nutrition and proposes policy recommendations to address these challenges. The first section of the review lays out the public health and socio-economic consequences of malnutrition and explores causes and costs. The paper then analyses the implications of climate and global environmental change and biofuel production for food security and nutrition, addressing strategies for adaptation and mitigation. This analysis includes a number of important socio-economic factors, besides climate change and biofuel production, that are currently impacting food and nutrition security, and that will likely contribute to future effects. The paper concludes with a series of policy proposals and recommendations to adapt to and mitigate the impacts of climate and global environmental change placing human rights in the centre of decision making. These proposals include a number of options for improving sustainability and food and nutrition security while addressing the links between climate change and bioenergy demand. 相似文献
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油脂是人体最主要的营养物质之一,其消化吸收主要发生在肠道,而肠道内存在种类繁多的菌群,可以直接参与人体的消化吸收、脂质代谢、能量供应等。油脂的消化吸收可能与多种代谢紊乱和肠道疾病、糖尿病、肥胖等慢性疾病存在联系,而食用油脂摄入不平衡会影响肠道菌群组成和代谢,破坏肠道稳态,进而可能导致上述疾病的发生。综述了油脂的脂肪酸组成、功能性伴随成分及其对人体健康的影响,分析了近年来油脂对肠道菌群组成及其代谢产物影响的研究,并对未来的研究方向进行了展望,这对进一步开展油脂营养特性及其对肠道健康影响的研究以及合理膳食保障人体健康具有积极意义。 相似文献
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Composite diets served to patients at the University College Hospital, Ibadan were collected and analysed for their concentration of zinc, copper, iron, manganese and cadmium. Data collected indicate that the concentration of zinc for breakfast foods was highest in bread and fried egg and lowest in bread alone. Copper was highest in yam and corned beef stew but not detected in any of the bread-containing breakfast foods. Iron and manganese were highest in hot pap and moinmoin and lowest in yam, stew and meat.For lunch and dinner diets, the concentration of zinc was highest in dodo, stew and meat and lowest in dodo alone; copper was highest in eba, melon soup and meat and was non-detectable in jollof rice and meat, pounded yam, melon soup and meat. Iron was highest in amala, melon soup and meat and lowest in dodo alone. Manganese was highest in agidi, vegetable soup and fish and was non-detectable in pounded yam, okro soup and fish. The levels found appear sufficient to meet daily dietary requirements. 相似文献
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研究者和生产者一直试图通过育种、饲料组分功效量化、饲养方案优化、加工工艺调整和贮藏条件改善等来提升肉及肉制品的产量和品质,而肉及肉制品的质量属性检测分析是衡量肉及肉制品营养价值、安全性、生产能力和市场接受性的重要途经,也是研究者和生产者开展生产和产品市场定位等的重要依据之一。目前肉及肉制品质量属性的检测方法,主要包括通过凯氏定氮法测定蛋白质含量、采用色谱法测定胆固醇含量、色谱法对脂肪酸组分的测定分析和色谱法测定氨基酸组分等对常规营养属性的分析、采用味觉识别系统、质谱分析技术、颜色分析系统对味觉、风味和颜色等感官品质进行的分析等。肉及肉制品质量属性评价方法的完善和改进不仅能够促进肉制品加工产业的发展,还能够更好的促进消费,鉴于此,本文对肉及肉制品质量属性评价方法及其创新进展进行了概述,对肉及肉制品质量安全属性评价方法目前面临的挑战进行了分析,以期为肉制品产业发展和科研提供参考。 相似文献
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我国常见家畜胴体分割及分级技术发展 总被引:2,自引:1,他引:1
牛、猪、羊为我国主要家畜品种。改革开放以来,我国牛、猪、羊胴体分割、分级技术水平有了一定的提升,关于家畜胴体分割、分级技术的发展过程及其标准的研究不断完善。本文概述了我国牛、猪、羊胴体分割、分级技术相关标准规定,阐述了常见家畜胴体分割、分级技术的发展历程,并对胴体分割、分级技术存在的问题提出意见,旨在为我国家畜屠宰企业进行牛肉、猪肉和羊肉分割、分级提供参考,促进肉质提高及分割肉的增值,推动我国畜肉产业健康、持续、稳定、快速发展。 相似文献
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Tremblay CL Letellier A Quessy S Boulianne M Daignault D Archambault M 《Journal of food protection》2011,74(10):1639-1648
This study was conducted to characterize the antimicrobial resistance determinants and investigate plasmid colocalization of tetracycline and macrolide genes in Enterococcus faecalis and Enterococcus faecium from broiler chicken and turkey flocks in Canada. A total of 387 E. faecalis and E. faecium isolates were recovered from poultry cecal contents from five processing plants. The percentages of resistant E. faecalis and E. faecium isolates, respectively, were 88.1 and 94% to bacitracin, 0 and 0.9% to chloramphenicol, 0.7 and 14.5% to ciprofloxacin, 72.6 and 80.3% to erythromycin, 3.7 and 41% to flavomycin, 9.6 and 4.3% (high-level resistance) to gentamicin, 25.2 and 17.1% (high-level resistance) to kanamycin, 100 and 94% to lincomycin, 0 and 0% to linezolid, 2.6 and 20.5% to nitrofurantoin, 3 and 27.4% to penicillin, 98.5 and 89.7% to quinupristin-dalfopristin, 7 and 12.8% to salinomycin, 46.7 and 38.5% (high-level resistance) to streptomycin, 95.6 and 89.7% to tetracycline, 73 and 75.2% to tylosin, and 0 and 0% to vancomycin. One predominant multidrug-resistant phenotypic pattern was identified in both E. faecalis and E. faecium (bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, tetracycline, and tylosin). These isolates were further examined by PCR and sequencing for the genes encoding their antimicrobial resistance. Various combinations of vatD, vatE, bcrR, bcrA, bcrB, bcrD, ermB, msrC, linB, tetM, and tetO genes were detected, and ermB, tetM, and bcrB were the most common antimicrobial resistance genes identified. For the first time, plasmid extraction and hybridization revealed colocalization of tetO and ermB genes on a ca. 11-kb plasmid in E. faecalis isolates, and filter mating experiments demonstrated its transferability. Results indicate that the intestinal enterococci of healthy poultry, which can contaminate poultry meat at slaughter, could be a reservoir for quinupristin-dalfopristin, bacitracin, tetracycline, and macrolide resistance genes. 相似文献