土壤中总铬测定方法的比较研究

采用国标GB/T 17137-1997和GB/T 17141-1997中规定的两种方法即H2SO4-HNO3-HF、HNO3-HF-HClO4法对土壤样品进行消解处理,筛选了HNO3-HF-HClO4消化体系并进行改进,再运用火焰原子吸收分光光度法测定样品中总铬（Cr）的含量。结果表明：土壤总Cr测定中的3种预处理方法的测定结果存在明显差异,改进后的HNO3-HF-HClO4法优于原国标方法,该方法消解速度快（3 ~ 4 h）且完全,大大缩短了实验时间;该方法灵敏度高（最低检出限0.04 mg/L）、准确度高（相对误差在1.3% ~ 5.0%）、加标回收率高（94.6% ~ 108.7%）,精密度好（相对标准偏差小于5.7%）,是值得推广的土壤Cr消解方法,可应用于农业环境土壤质量样品的检测。     

复合酶料添加剂对蓝狐育成期营养物质消化、代谢的影响

为探讨不同剂量的复合酶添加剂对蓝狐育成期营养物质消化、代谢的影响,选用72只65日龄健康蓝狐(公、母各半)进行单因子饲养试验和消化代谢试验.结果表明:复合酶添加剂能增强育成期仔狐的食欲,增加采食量.在日粮中添加0.6%的复合酶添加剂,可显著提高粗蛋白(CP)的表观消化率和代谢率(P＜0.05),分别高出对照组13.05%、10.82%;同对照组相比,净蛋白的利用率提高18.92%(P＜0.01);能显著提高无氮浸出物(NFE)的消化率(P＜0.05).在日粮中添加0.4%的复合酶添加剂,可有效提高粗脂肪(EE)及粗纤维(CF)的消化率,同对照组相比,EE的消化率提高8.98%(P＜0.05),CF的消化率提高21.62%(P＜0.01).     

微波消解-氢化物发生原子荧光法测定鲜肉中汞的研究

建立了一种微波消解样品、氢化物发生原子荧光光度法测定鲜肉中汞含量的方法。研究了酸消解体系、酸度、硼氢化钾浓度、载气流量、灯电流等因素对测定的影响,在优化条件下,汞的检出限为0.068μg/L。比较了湿法消化、微波消化两种试样前处理方法回收率的差异,两种前处理方法的回收率分别为77.8%￣85.9%和97.2%￣103.4%,微波消化的回收率明显高于湿法消化法。     

阿维菌素在沙糖桔和土壤中的消解动态研究

利用高效液相色谱法建立了沙糖桔和土壤中的阿维菌素残留量分析方法,并研究了阿维菌素的动态消解过程并拟合了消解曲线方程,全果中消解动态方程为：y=0.2559e-0.214t,R2 = 0.969,T1/2=4.36d,果皮中消解动态方程为：y = 0.222e-0.14t,R2 = 0.9695,T1/2=4.27d,土壤中效解动态方程：y = 0.3601e-0.228t,R2 = 0.9763,T1/2=3.67d。通过对比分析动态消解方程表明,阿维菌素在土壤中消解速率优于果实中。     

丙酮酸钙对山羊瘤胃消化代谢的影响

为探讨丙酮酸钙对山羊瘤胃消化代谢的影响。利用气相色谱法测定挥发性脂肪酸(VFA)含量;采用酚-次氯酸比色法测定NH3-N活性;考马斯亮蓝(G250)比色法测定瘤胃微生物粗蛋白(MCP)含量。结果发现动物试验和体外试验结果基本一致,丙酮酸钙不影响山羊瘤胃内环境pH值,提高乙酸含量(56.91±0.68vs61.68±0.79,P<0.01)降低瘤胃液中NH3-N浓度(3.620±0.24vs3.540±0.13,mM/L),促进蛋白质的生成(1135.81±34.92vs1225.05±49.47,mg/L)。所以添加丙酮酸钙对瘤胃的代谢有显著的促进作用。     

不同粗蛋白水平精料对梅花鹿仔鹿消化代谢的影响

试验选择4只梅花鹿仔鹿,按4×4拉丁方设计,进行消化代谢试验。研究了不同粗蛋白水平精料对梅花鹿仔鹿的干物质消化率、蛋白质消化代谢率、中性洗涤纤维消化率和钙磷代谢率的影响。结果表明,随着日粮蛋白质水平的提高,仔鹿对蛋白质的采食量(r=0.98)、蛋白质消化率(r=0.97)、可消化蛋白质(r=0.99)、尿蛋白排出量(r=0.93)以及沉积量(r=0.94)呈上升趋势,其中蛋白质采食量和可消化蛋白质极显著地增加(p<0.01);对干物质表观消化率、中性洗涤纤维消化率和钙、磷消化率无显著性影响(p>0.05)。     

Use of two varieties of hard-to-cook beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata) in the processing of koki (a steamed legume product)

Koki is a nutritious cowpea-based food product usually processed by steam cooking whipped cowpea (Vigna unguiculata) paste mixed with spices and palm oil. A study was carried out to investigate the effect of the partial replacement of cowpeas (CP) with hard-to-cook (HTC) beans on the chemical, nutritional and sensory characteristics of koki. Towards this objective, two varieties of beans – Phaseolus vulgaris (red kidney beans – RKB and mottled brown beans – MBB), each with the HTC defect, were separately incorporated into cowpea paste in the following Bean:CP ratios 0:100, 20:80, 30:70, 40:60, 50:50, 60:40 and processed into koki. Incorporation of dry HTC beans into cowpeas in the making of koki affected the bulking properties of the uncooked paste, the nutrient composition, essential amino acid content, antinutritional factors, digestibility as well as the sensory attributes of cooked koki. Sensory tests showed that a highly acceptable, nutritious and digestible koki can be processed from cowpeas partially replaced with dry HTC bean paste up to levels of about 40–50% depending on the variety of dry bean used.     

3种红枣消解方法的对比研究

[目的]推荐实用、准确、高效、方便、快捷的消解预处理方法。[方法]采用3种消化方法处理同一红枣样品,利用火焰原子吸收法测定样品中Fe、Zn、Ca的含量。[结果]3种消化方法对测定结果的影响不大。[结论]非完全消化法是值得推广的样品消解方法。     

不同能量水平日粮对中卫山羊泌乳母羊消化率的影响

选择10只胎次相近,出生时间相近,健康母羊和羔羊的平均体重差异不显著(P>0.05),随机分为二组,每组5只。分为泌乳前后两个时期以不同能量水平日粮饲喂各组母羊,结果表明:第一组试验羊的能量和后期蛋白质消化率稍高于第二组试验羊,第一组试验羊前期的蛋白质消化率稍低于第二组。     

Ingestion and digestion of 10 species of microalgae by winged pearl oyster Pteria sterna (Gould, 1851) larvae

Ten species of microalgae were tested for ingestion and digestion in Pteria sterna larvae using epifluorescence microscopy to choose an appropriate diet. An experiment was conducted using 2, 4, 5 (straight-hinge) 10 and 22 (umbo stage) day old larvae. Larvae were stocked in 150 ml flasks at 30 ml⁻¹ and fed 100,000 algal cells ml⁻¹ of each species individually. Larvae were fed for 1 h and then were observed under the microscope to detect ingestion; larvae were then sieved and placed in flasks containing filtered seawater and were observed after 1 and 2 h to analyse digestion for the microalgae ingested. Out of the 10 species administered, only Nannochloris sp., Pavlova lutheri and Isochrysis aff. galbana (T-ISO) were ingested, and only the last two species were digested. No ingestion of Phaeodactylum tricornutum, Chaetoceros muelleri, Ch. calcitrans, Thalassiosira weisflogii, Dunaliella salina, Tetraselmis tetrathele and T. suecica was evident at any stage of larval development tested. Only T-ISO and P. lutheri should be used for larval rearing of P. sterna until other species are identified as suitable (ingested and digested) for this species.