钢铁企业余热余能回收利用措施研究

为实现钢铁企业中的余热余能回收再利用,达到良好的节能环保效果,并进一步提升钢铁企业自身的经济效益,本文以某钢铁企业为例,对其生产过程中的余热余能回收及其再利用措施进行研究.文章主要分析了余热余能回收与再利用的影响因素、回收利用中的关键技术以及某钢铁企业余热余能回收利用措施.希望通过本次的研究与分析,可以为钢铁企业中的余...     

Invited review: Sustainable forage and grain crop production for the US dairy industry

A resilient US dairy industry will be underpinned by forage and crop production systems that are economically, environmentally, and socially sustainable. Land use for production of perennial and annual forages and grains for dairy cattle must evolve in response to multiple food security and environmental sustainability issues. These include increasing global populations; higher incomes and demand for dairy and other animal products; climate change with associated temperature and moisture changes; necessary reductions in carbon and water footprints; maintenance of soil quality and soil nutrient concerns; and competition for land. Likewise, maintaining producer profitability and utilizing practices accepted by consumers and society generally must also be considered. Predicted changes in climate and water availability will likely challenge current feed and dairy production systems and their national spatial distribution, particularly the western migration of dairy production in the late 20th century. To maintain and stabilize profitability while reducing carbon footprint, particularly reductions in methane emission and enhancements in soil carbon sequestration, dairy production will need to capitalize on genetic and management innovations that enhance forage and grain production and nutritive value. Improved regional and on-farm integration of feed production and manure utilization is needed to reduce environmental nitrogen and phosphorus losses and mitigate greenhouse gas emissions. Resilient and flexible feed production strategies are needed to address each of these challenges and opportunities to ensure profitable feeding of dairy cattle and a sustainable dairy industry.     

果蔬冷链过程中多尺度热质传递的研究进展

果蔬冷链过程由于管控粗放、损耗大等问题易造成果蔬内部结构损伤,引起品质劣变;同时,果蔬内部的水分和热量会发生动态迁移,不利于果蔬的贮藏和销售。因此,明确果蔬冷链过程多尺度热质传递机理是目前该领域亟待解决的问题。本文阐述了用于果蔬多尺度建模的数值成像技术,探讨果蔬冷链过程热质传递机理的多尺度计算流体动力学建模方法,以及建模中存在的基本问题和解决方案,并优化现有的热质传递模型,设计更高效合理的冷却系统,以期为果蔬冷链过程多尺度热质传递机理研究和减损保鲜提供理论依据。     

饲料标签中存在的问题及对策

饲料标签是饲料生产企业展示产品质量和标示其他信息的一种重要途径,也是使用者选择和正确使用饲料产品的重要依据。饲料标签不仅标示产品的各项指标,也是体现一个企业的社会责任,对客户、对产品的态度。近年来,随着人们对畜禽产品和饲料质量安全的日益关注,对饲料标签的关注度也日益提高,正确标示和使用标签尤为重要,但由于部分饲料生产企业经验不足,法律意识淡薄,对标准的解读不透彻,造成了部分饲料标签的标示不规范,从而对饲料产品的质量安全以及政府监管带来诸多不便。本文列举了饲料质量安全监管过程中发现的饲料标签存在的问题,从生产企业、消费者和监管部门等多方面对问题存在的原因进行综合分析,并对标签制定和管理提出合理化的建议和改进措施,从而使标签的制定逐渐规范化、标准化。     

黑木耳瘦肉红枣粥的研制

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。     

Percentage Ether Extractable Fat and Moisture Content of Beef Longissimus Muscle as Related to USDA Marbling Score

Percentage fat and moisture values for beef longissimus steaks (trimmed completely of all subcutaneous fat, epimysium, and peripheral muscles) from 518 steer and heifer carcasses of A and B maturity over a wide range in marbling were as follows: Moderately Abundant = 10.42 and 68.14, Slightly Abundant = 8.56 and 69.56, Moderate = 7.34 and 70.35, Modest = 5.97 and 71.35, Small = 4.99 and 72.36, Slight = 3.43 and 73.61, Traces = 2.48 and 74.29, and Practically Devoid = 1.77 and 75.37.     

活化、催化过氧化氢漂白与脱木素体系的研究进展

采用过氧化氢活化剂能活化或催化过氧化氢漂白与脱木素,进一步提高试剂与木素及其发色基团的反应活性,从而提高其漂白效率与效果.文章简要介绍了近年来新型高效过氧化氢/活化、催化漂白/脱木素新体系的发展状况.     

金丝肉卷加工技术探讨

金丝肉卷(豆皮肉卷)是一种兼具中西式做法和风味的便携食品。目前,在北方地区市场上占有极高的销售量,深得消费者喜爱。产品配方为:精猪肉80kg、鸡胸肉20kg、鸡皮10kg、水12kg、淀粉6kg、大豆蛋白3kg、食用盐3.8kg、绵白糖0.2kg、食用大豆油2kg、红辣椒0.5kg、豆皮25kg、姜1.2kg、胡椒粉0.6kg、山梨酸钾0.15kg、异Vc-钠0.15kg、味精0.2kg、乳酸链球菌素0.1kg、亚硝酸盐0.015kg、脱氢乙酸钠0.01kg、5'-呈味核苷酸二钠0.4kg、乳酸钠0.15kg、六偏磷酸钠0.1kg、焦磷酸钠0.15kg、三聚磷酸钠0.05kg、红曲粉0.10kg。叙述了产品批量生产的加工工艺和操作要点,以便为该产品的批量加工开辟新思路。     

Effect of pasteurization and fat,protein, casein to serum protein ratio,and milk temperature on milk beverage color and viscosity

Our goal was to determine the effect of pasteurization-homogenization, fat and protein concentration, proportion of milk protein that is casein and serum protein, and temperature on sensory and instrumental measures of viscosity and color of milk-based beverages. A second goal was to use instrumental measures of whiteness and yellowness to predict sensory measures of whiteness and yellowness. A complete balanced 3 factor (fat, true protein, and casein as a percentage of true protein) design was applied with 3 levels of fat (0.2, 1.0 and 2.0%), 4 levels of true protein (3.00, 3.67, 4.34, and 5.00%) within each fat level, and 5 levels of casein as a percentage of true protein (CN%TP; 5, 25, 50, 75, and 80%) within each protein level for beverage formulation. Instrumental color and viscosity, and visual sensory color analyses were done on each beverage formulation. For unpasteurized beverages across 3 fat levels (0.2, 1, and 2%), changes in CN%TP had the largest effect on L values, sensory whiteness, opacity, color intensity, and yellowness, whereas changes in fat concentration had a stronger influence on a and b* values. Increasing CN%TP from 5 to 80% increased L values, sensory whiteness, and opacity, and decreased sensory color intensity and yellowness. The a and b* values increased with increasing fat concentration. For unpasteurized milk protein beverages within each fat level, variation in CN%TP dominated the changes in L values, sensory whiteness, and opacity, and decreased a and b* values, sensory color intensity, and yellowness. The effect of heat (pasteurization and homogenization) and its interaction terms had the second largest effect on color of milk protein beverages with respect to instrumental color data and sensory appearance attributes. Heat increased L values, sensory whiteness, and opacity, and decreased a and b* values, sensory color intensity, and yellowness. Increases in temperature decreased instrumental viscosity and changes in protein concentration and CN%TP had a greater effect on instrument viscosity data within each temperature (4, 20, and 50°C) than fat. Sensory perception of yellowness was not highly correlated with b* values. Multiple linear regressions of L, a, and b* values produced more robust predictions for both sensory whiteness and yellowness than simple linear regression with L and b* values alone, and may be a useful instrumental approach for quality control of sensory whiteness and yellowness of milk protein beverages.     

Bioaccessibility of Se, Cu, Zn, Mn and Fe, and heme iron content in unaged and aged meat of Hereford and Braford steers fed pasture

The content and the bioaccessibility of Se, Cu, Zn, Mn, and Fe were determined in unaged and aged meat (14days) from the Psoas major (PM), Gluteus medius (GM) and Longissimus dorsi (LD) muscles of Hereford (H) and Braford breed (B) steers fed pasture. Furthermore, the content of heme-Fe was determined in the same muscles. The H had a lower content of Cu and a higher content of Fe. Also, H had more heme-Fe than B. The bioaccessibility in unaged meat for Se, Cu, Zn, Mn and Fe ranged between 75 and 91%, 30 and 45%, 40 and 68%, 55 and 95%, and 60 and 70%, respectively. After aging, the bioaccessibility for the same minerals ranged between 58 and 80%, 30 and 48%, 40 and 58%, 75 and 95%, and 59 and 70%, respectively. Aging affected negatively the Se content and its bioaccessibility, in the two breeds. Also, the heme-Fe content was negatively affected by aging in all muscles and breeds.     

短波紫外线处理对鲜切果蔬品质及抗氧化活性的影响研究进展

鲜切果蔬因具有营养、便利、新鲜、可食率达100%等特点,越来越受到人们的关注。但鲜切果蔬由于受到机械损伤,其品质下降、易被微生物污染。短波紫外线作为一种非热力杀菌技术,近年来被研究者们用于鲜切果蔬保鲜,得到了良好的效果。本文介绍了鲜切果蔬及短波紫外线技术的特点,综述了短波紫外线处理对鲜切果蔬安全品质、营养品质及感官品质的影响及短波紫外线处理对鲜切果蔬抗氧化物质及抗氧化活性的作用,并讨论短波紫外线技术在鲜切果蔬中的应用前景,为短波紫外线处理鲜切果蔬的深入研究和推广应用提供重要的理论依据和参考。     

Composition and microbiological profile of two Moroccan traditional dairy products: raib and jben

Forty two samples each of raib (Moroccan traditional fermented milk) and jben (Moroccan traditional fresh cheese) were examined for their chemical composition and their microbiological profile. The average composition of raib and jben was respectively 10.7and37.5%solids, 2.22and 16.47%fat, 3.1and 15.8%protein, 4.2and4.1%lactose, 0.17 and 0.5% chloride and 0.54 and 1.26% ash. Both products had a low pH (4.2 and 4.1, respectively) and a high lactic acid content (0.67 and 1.04%, respectively). Their microbiological profiles were characterized by the predominance of lactic acid bacteria and high coliform counts.     

中上层鱼类及加工副产品高值化利用的研究进展

中上层鱼类及加工副产品的高效利用是我国海洋鱼类资源综合开发利用的重要研究方向,中上层鱼类产量巨大、营养丰富,从不同领域研发中上层鱼类及副产品,具有重要的经济价值和实践意义。目前,主要从中上层鱼类及加工副产品中营养成分的角度出发,加工优化食用制品以及提取利用其中的蛋白质、脂肪、矿物质等,从而研发营养功能制品、医药品及调味品等。本文从鱼糜及鱼糜制品、生物医药及制品、鱼油提取及制品、调味品、休闲食品以及其他制品等方面,综合论述了中上层鱼类及加工副产品高值化利用的研究进展,并展望了中上层鱼类及加工副产品广阔的研究方向及发展趋势,旨在有效提高中上层鱼类及加工副产品的附加值,为其更深入的研究利用提供参考。     

Adverse effect of beta-carotene in diet on fertility of dairy cows

A total of 155 high yielding dairy cows were used to study the effect of dietary beta-carotene (carotene) on fertility. The diet of group 1 was supplemented with 69 mg retinyl acetate per cow daily before calving and 96 mg retinyl acetate after calving: diet of group 2 was supplemented with 500 mg carotene per cow before calving and 96 mg retinyl acetate after calving; and that of group 3 with 500 mg carotene before and 700 mg after calving. Conception rates were 53.9, 42.2, and 27.9% for cows of groups 1, 2, and 3. Days open were 110 and 112 for young (second and third lactation) and old (fourth and later lactations) cows of the group 1; 130 and 129 for young and old cows of group 2; and 133 and 166 for young and old cows of group 3. Number of inseminations per conception was 1.8 and 1.8, 2.2 and 2.2, and 2.5 and 3.4 for the same groups, respectively. Within group 3 the percent of cows pregnant 120 d after calving was 57 and 20 for the young and old cows. Correlation coefficients between plasma carotene of 53 old cows of all groups 4 and 8 wk after calving, and the number of open days and the number of inseminations per conception were significant. The intake of high carotene may have adverse effects on the fertility of dairy cows.     

Chemical analysis and sensory evaluation of mahi-mahi (Cryphaena hippurus) during chilled storage

Biogenic amines, total volatile base-nitrogen (TVB-N), and sensory evaluation are some of the indicators used for fish quality determination. Our objective was to evaluate the relationship among histamine, cadaverine, putrescine, TVB-N, and sensory evaluation as quality assessment tools. Two groups of six mahi-mahi fillets were refrigerated at 7 degrees C and sampled on days 0, 2, 4, 6, 8, and 10. On day 3, histamine, cadaverine, and putrescine levels reached 5, 3, and 0.5 mg/100 g, respectively, whereas TVB-N reached 30 mg/100 g. Sensory scores were 6 to 6.5 (10 very fresh and 1 very spoiled) for odor, appearance, texture, and color. Correlations were 0.78 and 0.72 between histamine and cadaverine and histamine and putrescine, 0.74 and 0.80 between TVB-N and cadaverine and TVB-N and putrescine, and 0.75 and 0.78 between odor and putrescine and odor and cadaverine. AromaMaps showed distinct trends for deteriorating mahi-mahi (Coryphaena hippurus) quality.     

浅谈节能减排政策与立体式污染防治体系

随着我国工业活动强度的加大,节能减排政策与污染防治措施的结合日益紧密.本文阐述了节能减排政策与立体式污染防治措施的重要意义,并提出了五点节能减排政策合理推进污染防治的工作措施,形成立体式污染防治体系,以供相关工作人员借鉴分析.     

我国不同生态区云烟87烟叶主要化学成分及感官风格差异

为明确我国不同生态区云烟87烟叶主要化学成分及感官风格差异,采用描述性统计、方差分析和简单相关分析法对西南高原、黔桂山地、武陵秦巴和南岭丘陵4个生态区共288个云烟87烟叶样品进行了对比分析。结果表明,西南高原生态区上部叶“高糖低碱”、中下部叶“高糖中碱”,特征香韵为清甜香且与总糖相关系数（0.679）最大,余味好,刺激性和杂气小;黔桂山地生态区上部叶“高碱低钾”、中下部叶“高糖低氮”,特征香韵为正甜香且与总氮相关系数（0.503）最大,香气质和香气量高;武陵秦巴生态区上部叶“高碱中糖”、中下部叶“高糖高碱”,特征香韵为正甜香且与总糖相关系数（0.455）最大,香气质、香气量、浓度、劲头和余味均较小;南岭丘陵生态区上部叶“高碱高钾低糖”、中下部叶“高钾低糖”,特征香韵为焦甜香且与还原糖相关系数（0.529）最大,浓度高、劲头大。     

Moisture, Fat and Cholesterol Content of Some Raw; Barbecued and Cooked Organ Meats of Beef and Mutton

The effect of barbecueing and conventional cooking methods on moisture, fat and cholesterol content in brain, heart, kidney, liver, and tongue of local Iraqi; beef and mutton were studied. Moisture, fat and cholesterol content differed significantly (P ≤ 0.05) between raw and barbecued samples and between raw and cooked samples of both beef and mutton organ meats, except for those mentioned. The lower moisture in barbecued and cooked samples probably caused a relative increase in fat and cholesterol content. Minor differences were observed in raw, barbecued and cooked organ meats between beef and mutton in terms of moisture, fat and cholesterol content at similar animal ages.     

果蔬在生产环节的质量安全问题探讨

概述了一些在生产环节影响果蔬质量安全的因素,探讨了一些控制措施. 影响因素包括生产者的产品质量安全意识淡薄、违规使用高毒农药、常用农药的直接污染和间接污染造成农药残留超标. 控制措施包括加强果蔬产品质量安全的宣传,推广应用无害化防治技术,研发高效、低毒、低残留农药,科学合理使用农药,制定和完善果蔬生产技术标准,按照标准进行果蔬生产与监管.