日粮水平和饵料种类对真鲷能量收支的影响

以玉筋鱼为铒料生物,采用室内流水模拟实验法研究了摄食水平和饵料种类对真鲷能量收支各组分和能量收支分配模式的影响。结果表明,真鲷的生长量、总代谢量、排泄量及生态转换效率均随日粮水平升高呈减速增长趋势,二者之间的定量关系均可用对数曲线加以定量描述;不同生物饵料能造成真鲷摄食、生长、排泄和总代谢水平的显著差异,但却不能改变以比能值为单位的生态转换效率。依据各收支过程的量化结果,可得到真鲷的能量分配模式。     

Photoperiod influences the growth, food intake, feed efficiency and digestibility of red sea bream (Pagrus major)

Two consecutive trials were conducted to investigate the effects of photoperiod manipulation on growth rate, food intake and feed conversion efficiency (Trial 1), and the digestibility of nutrients and energy (Trial 2) in red sea bream, Pagrus major (body weight 19–120 g). Fish were exposed to four photoperiods (6L:6D, 12L:12D, 16L:8D and 24L:0D) with light intensity 1500 lx on the water surface. The fish were fed with a commercial diet to apparent satiation. In Trial 2, 0.5% chromic oxide (Cr₂O₃) was used as an inert marker. Significantly higher weight gain and specific growth rates were observed in fish exposed to a 24L:0D photoperiod followed by 16L:8D, 6L:6D and 12L:12D photoperiods (P < 0.05). Food intake and feed conversion efficiency (FCE) were also significantly higher in fish exposed to 24L:0D followed by 16L:8D, 6L:6D and 12L:12D photoperiods (P < 0.05). Fish exposed to 24L:0D and 16L:8D photoperiods showed significantly higher lipid and energy digestibility than those exposed to a 12L:12D photoperiod (P < 0.05). The results demonstrated that the enhancement of growth performances under 16L:8D and 24L:0D photoperiods were attributed to improved appetite, greater food intake and higher feed conversion efficiency as well as higher digestibility.     

高效液相色谱法测定食品中5种防腐剂和甜味剂

[目的]建立食品中5种防腐剂和甜味剂(苯甲酸、山梨酸、脱氢乙酸、安赛蜜、糖精钠)同时检测的高效液相色谱分析方法。[方法]对现行国标方法进行优化,采用ZORBAX SB-C18柱(5μm,4.6 mm×150 mm)分离,甲醇-0.02 mol/L乙酸铵为流动相等度洗脱,230nm波长下进行检测。[结果]试验显示,在高、中、低3个添加浓度下,样品的回收率在74.3%~105.6%,相对标准偏差(n=6)1.09%~6.88%。同时该方法通过基质适用性的研究。[结论]该试验建立的方法准确、高效,能够同时分析测定多种不同种类食品中的防腐剂、甜味剂。     

A test of the individual feeding activity and food size preference in rainbow trout using demand feeders

Feeding activity and food size preferences were investigated in three groups of rainbow trout with initial weights ranging from 200 to 1000 g. Fish were given the option of releasing food from either of two demand feeding devices that contained either 6 mm or 9 mm food pellets. Individual biting activity (to activate release of food) was continuously monitored using specially designed passive integrated transponders (PIT-tags). In each of the groups, biting activity was strongly influenced by three individuals, which accounted for 70–85% of the total. Thus, high bite activity by few individuals indicates the development of social dominance hierarchies. There was no statistically significant correlation between number of bites and growth rate, indicating that the fish that operated the demand feeders did not gain any growth advantage. Trout that dominated the actuation of the feeders were found among both medium- and large-sized fish. There was no evidence of active food size selection, and the fish that most frequently operated the feeders defended one area of the tank rather than preferring the trigger that would have delivered food of the optimal size.     

基于食品链视阈下的白酒质量安全控制

依据食品链含义,结合白酒产品形成的特点,确定白酒食品链构成及质量安全控制的关键环节,提出白酒企业实施良好操作规范应遵循的基本方法,为白酒企业实施良好操作规范并系统控制白酒产品质量安全提供参考依据。     

冬小麦节水与粮食安全关系的思考

简要阐述了自20世纪70年代以来河北省小麦生产的发展、小麦节水栽培技术的研究成就和历史沿革及农业对水资源利用的变化等特点。研究表明小麦用水量下降和产量提高呈协同发展变化模式。因此,通过综合节水技术的运用,在水分高效利用的前提下,可使小麦增产,实现节水和粮食安全双赢。     

大学生食品添加剂安全性认知研究

为了解食品添加剂及其安全性和可接受性,以及大学生对食品添加剂安全性的认知,为其今后发展提供相关理论和知识指导.调查结果显示,人们对于食品添加剂的安全意识还需加强,政府监管力度也需落实到位,同时也提出如何加强食品添加剂安全措施的建议.     

PBL教学法在高校食品专业文献检索课程中的应用研究

分析高校食品专业本科生文献检索课程教学中引进PBL教学模式的必要性及其教学特点,探讨该课程PBL教学模式的基本思路,提出PBL教学法在食品专业文献信息检索课程中应用的优点及在教学中应注意的问题。     

以“食品微生物学”为例探索基于工程认证的学生自主实践教学模式

针对"食品微生物学"实践教学,倡导以学生为中心、自主实践的教学理念,培养自主学习意识和科学素养,对实验课程的教学模式、考核评价等进行改革,优化考核评价体系,从而提高实验课堂效果,加强学生动手能力的培养。为解决复杂工程问题打下坚实的基础,有力支撑工程教育认证对课程教学指标点达成的要求。其他食品类基础实验也可借鉴"食品微生物学",不断完善食品科学与工程专业基础实验教学模式。     

月饼中安赛蜜、糖精钠、苯甲酸、山梨酸、脱氢乙酸检测方法的研究

建立了反相高效液相色谱法同时测定月饼中安赛蜜、糖精钠、苯甲酸、山梨酸、脱氢乙酸的检测技术。实验采用AQ-C18色谱柱(250 mm×4.6 mm),以0.02 mol/L的乙酸铵-甲醇(90∶10)为流动相,柱温25℃,二极管阵列检测器在波长23 0 nm处进行检测。整个分离过程在1 4m in内完成。上述5种物质的回收率为9 6.8%~1 0 2.1%,相对标准偏差小于1.21%。方法快速准确,适用于月饼的常规检测。