惰性粉处理稻谷防治锈赤扁谷盗的效果研究

研究了经食品级惰性粉处理的稻谷中锈赤扁谷盗的生存时间,并在实仓验证了散装稻谷仓粮堆表层应用惰性粉拌粮的防治效果。用纯惰性粉处理锈赤扁谷盗的生存时间为0.8 d,采用150 mg/kg惰性粉拌粮法处理的稻谷中锈赤扁谷盗生存时间为0.9 d;无惰性粉处理的活虫样和稻谷样中锈赤扁谷盗的生存时间分别为13.3 d和18.6d。研究表明,惰性粉拌粮对锈赤扁谷盗有显著的防治效果,实仓试验中应用惰性粉可以减少锈赤扁谷盗的数量,但其应用技术有待进一步研究。     

食品级惰性粉对储粮土耳其扁谷盗成虫的致死作用及体壁形态结构的影响

为明确食品级惰性粉对仓储害虫土耳其扁谷盗成虫的致死作用,采用拌粮法研究不同剂量食品级惰性粉对土耳其扁谷盗成虫的致死效果,结合扫描电镜观察惰性粉对其体壁形态结构的影响。结果表明,惰性粉对土耳其扁谷盗成虫有较强的致死作用,且随着使用剂量的增加和处理时间的延长,土耳其扁谷盗成虫的死亡率逐渐上升。当处理时间分别为24、48及72 h时,惰性粉的致死中量分别为8.3、5.6及4.1 mg/kg。扫描电镜观察结果表明,惰性粉能对土耳其扁谷盗成虫体壁形态结构造成明显的物理损伤。经惰性粉处理的土耳其扁谷盗成虫体表均匀粘附有惰性粉颗粒,体表刚毛出现损伤、缺失,体节及相关附肢关节,如头部与前胸、前胸与中胸、足的基节窝等处,发生明显的缢缩、间隙闭合。而对照组虫体体壁干净,各体节连接处舒展、正常。     

横向通风系统粮面施用惰性粉工艺效果研究

为解决横向通风系统粮堆覆膜前粮层表面惰性粉防护剂施用问题,通过收集粮面粉粒样本以及粮堆预埋试虫笼的方式,分析惰性粉气溶胶在横向通风系统覆膜前形成的斜向通风气流,在粮堆中扩散和分布特征。实验结果显示粮堆表面不同部位采集点粉粒沉降量无统计学差异,表明斜向气流不影响惰性粉在粮堆表面的均匀分布,可以满足横向通风系统覆膜后对粮堆表层膜下易生虫部位的防护要求。预埋虫笼以及实仓害虫密度监测结果显示对害虫防护效果良好。土耳其扁谷盗的死亡率达到100%,玉米象的死亡率为95%,仓内玉米象密度下降85%。     

实验室条件下惰性粉对海南地区高抗性扁谷盗系害虫的致死效应评价

本研究比较了惰性粉对7种海南地区高抗性扁谷盗系害虫的致死效果,并探讨了不同条件下惰性粉对海南地区扁谷盗系害虫的防治效果影响.结果表明:惰性粉对海南地区7种高抗性的扁谷盗系害虫的防治效果相近,均具有良好的杀虫效果;惰性粉含量的增加、环境温度的升高、环境湿度的的下降、粮食水分的下降都有利于提高惰性粉对7种高抗性扁谷盗系害虫...     

物理防治药剂惰性粉实仓防治效果初探

通过采用不同剂量物理防治药剂惰性粉,在仓房使用虫笼法进行害虫杀灭效果研究。结果表明:惰性粉对玉米象和赤拟谷盗等害虫具有较好的杀灭作用,同时具有一定的防治效果,可在实仓防治应用部分替代化学药剂。     

谷朊粉及其主要组分对果糖吸湿的抑制作用

为改善果糖因其强吸湿性而导致的结块和潮解现象,通过绘制吸湿曲线,吸湿等温线,宏观形态分析,接触角测定以及低场核磁等表征手段,考察谷朊粉（Wheat Gluten,WG）添加量对果糖冻干品吸湿特性的影响,并比较了谷朊粉中两种主要成分：麦醇溶蛋白和麦谷蛋白的作用差异。结果表明,谷朊粉显著降低了冻干果糖样品的平衡吸湿率（Equilibrium Moisture Content,EMC）,在25 ℃、75%相对湿度下果糖与谷朊粉比例为10:0、3:7、2:8的EMC分别为36.33%、16.00%、14.61%;随着谷朊粉比例的增加,样品的结块程度减弱,接触角由11.3 °增大到94.8 °。Peleg模型可以准确描述果糖-蛋白体系的水分吸附过程;相较于麦醇溶蛋白,添加麦谷蛋白的样品EMC更低,结块量更小,且麦谷蛋白的接触角（88.2 °）大于麦醇溶蛋白（64.6 °）;低场核磁结果显示,与麦醇溶蛋白相比,麦谷蛋白对降低水分自由度产生了更有效的影响。以上结果表明,谷朊粉及其主要组分对果糖的吸湿有显著的抑制作用,相较于麦醇溶蛋白,麦谷蛋白抑湿效果更突出。     

高大平房仓惰性粉防虫储粮试验

通过在高大平房仓中采取粮面施药的方式(粮面下50 cm处)将惰性粉均匀的施于粮堆表面,通过近一年对试验仓和对照仓储粮害虫及粮情数据的监测,惰性粉起到了良好的防治害虫作用,且未引起粮情的异常变化,达到了预期的目的,为采用惰性粉科学防治储粮害虫积累了数据.     

谷朊粉对冻干枣粉抑制吸湿作用研究

目的 研究谷朊粉对冻干枣粉吸湿特性的影响。方法 将谷朊粉与枣浆按不同比例均匀混合,真空冷冻干燥后粉粹,过60目筛制备不同配比的冻干枣粉。结果 谷朊粉显著降低了冻干枣粉的平衡含水率(equilibrium moisture content,EMC)。吸湿等温结果表明,红枣与谷朊粉质量比10:0、7:3、1:1、3:7样品的吸湿等温类型属“J”型增长,而0:10样品的属“S”型增长,表明谷朊粉的添加并未改变冻干枣粉吸湿等温类型;接触角随着谷朊粉的添加量的增大而增大,其值从31.22°增大到76.7°,说明谷朊粉可以减弱冻干枣粉的表面润湿性。从宏观和扫描电镜图中可知,冻干枣粉结块现象随着谷朊粉的添加量的增大而逐渐减轻。低场核磁结果显示,谷朊粉降低自由水的含量,减少水分向高自由度方向的迁移程度。结论 一定量的谷朊粉能够有效抑制冻干枣粉的吸湿,从而缓解结块的发生,保持流动性和分散性,进而提高冻干枣粉的品质。     

电子束辐照防治3种扁甲科储粮害虫及对小麦加工品质的影响

针对储粮害虫的磷化氢抗性问题,采用电子加速器对长角扁谷盗、锈赤扁谷盗和土耳其扁谷盗成虫及小麦进行辐照处理,研究了0-1000 Gy的电子束辐照对这三种害虫的致死效应,分析了它们对辐照的敏感性,并研究了0-5000 Gy剂量辐照下小麦的加工品质。结果表明,电子束辐照处理对三种害虫的致死规律大致相同,其对电子束的敏感性存在差异,但差异不显著。电子束辐照对小麦的出粉率、湿面筋含量影响不显著(p＞0.05),但面团的流变学特性变化明显。与对照相比,经3000 Gy及以上剂量辐照的小麦粉的面团形成时间和稳定时间显著下降(p<0.05)。因此,100-2000 Gy辐照剂量可以作为辐照防治扁甲科储粮害虫的适宜剂量。     

辣根素对长角扁谷盗和锯谷盗成虫的熏蒸活性

辣根素是一种潜在的替代溴甲烷的植物源熏蒸物质。为了进一步完善其杀虫谱,利用三角瓶密闭熏蒸法,研究了辣根素原油和无水乙醇以1∶9按体积比混配后分别在不同温度下对长角扁谷盗和锯谷盗成虫的熏蒸毒力。结果表明:在10、20、28℃下,辣根素对长角扁谷盗的LC50依次为1.40、1.13、0.87μL/L;对锯谷盗的LC50依次为10.06、6.88、5.81μL/L。在相同熏蒸温度下,长角扁谷盗成虫对辣根素的敏感性均较锯谷盗成虫高。辣根素对两种仓虫的熏蒸效果均随温度的升高而升高。     

砖圆仓惰性粉上下结合式施用工艺研究

选择砖圆仓进行上下结合式喷施惰性粉实验,采用粉尘采样法测定惰性粉分布情况,并通过预埋虫笼检查惰性粉气溶胶的直接杀虫效果,同时采用综合害虫监测方法对粮仓防虫效果进行评价。结果表明,上下结合式施用工艺能使惰性粉到达粮堆内部,并且在长达10个月的虫情监测中均处于基本无虫粮状态,无需采用磷化氢熏蒸杀虫。     

木材的水分与材性

本文着重介绍了木材吸湿、解湿特性对室内环境和木材干缩、湿胀特性对木制品形状与尺寸稳定性带来的重要影响，同时分析了木材中的水分对木材性质及加工利用的影响。     

Measurement and Modeling of Moisture Sorption Isotherm of Litchi (Litchi Chinensis Sonn.)

The equilibrium moisture contents of litchi (Litchi Chinensis Sonn.) were experimentally determined using the dynamic method at temperatures of 30, 40, and 50°C over a range of relative humidity values of 12 to 95%. Five models were tested to fit the experimental isotherm data of litchi. The GAB model fitted the best to experimental isotherm data. The agreement between experimental and predicted values of this model is excellent (RMSE 1.8 to 3.4%). The isosteric heats of sorption water were also determined from the equilibrium data using the Clausius-Clapeyron equation and it was found to be a function of equilibrium moisture content.     

Comparison of the Sorption Isotherm Characteristics of Two Cassava Products

The sorption characteristics of two cassava products were obtained using the gravimetric method at three temperatures, 20, 30, and 40°C. The GAB, BET, and the modified BET models were found to describe the data reasonably well. The heat of sorption, which varied from 39.47 kJ/mol at 1% moisture content to 4.92 kJ.mol^?1 at 20% moisture content dry basis, was calculated for the garified product. Similar values for the ungarified product were found to vary from 26.98 kJ/mol at 1% moisture content to 4.97 kJ/mol at 20% moisture content. The shelf-life for both products were estimated from sorption data and recommendations on their packaging and storage conditions given. The garified product was found to have a higher capacity for moisture adsorption and also potentially stores longer than the ungarified product.     

Moisture Sorption Isotherms for Un-Modified and Osan-Substituted Dextrin and Gum Acacia Used as Carrier Materials for Spray Dried Encapsulation of Flavoring Materials

Moisture sorption isotherms of ten un-modified and octenyl succinic anhydride substituted dextrin and gum acacia samples were determined gravimetrically via equilibration over saturated salt solutions (a_w ranged from 0.11 to 0.85) at 23 and 35°C. The degree of octenyl succinic anhydride substitution did not affect moisture sorption characteristics for dextrin samples. For gum acacia, increased levels of octenyl succinic anhydride substitution resulted in a decreased affinity for moisture in the range of 0.3 to 0.7 a_w. The sorption data were well described by the BET and GAB models.     

牛奶蛋白纤维与羊毛纤维吸湿性能对比分析

研究对比牛奶蛋白纤维与羊毛纤维吸放湿性能.对牛奶蛋白纤维在标准大气条件下的吸湿、放湿回潮率进行测定,描绘出吸湿放湿曲线,并与羊毛纤维进行了比较.根据吸湿放湿曲线,推导出标准状态下两种纤维的吸湿放湿速率回归方程.结果表明:牛奶蛋白纤维与羊毛纤维达到吸湿放湿平衡的时间及吸湿放湿曲线基本相似,吸湿过程中牛奶蛋白纤维和羊毛纤维达到平衡回潮率的时间几乎相同,而在放湿过程中牛奶蛋白纤维达到平衡的时间要低于羊毛.     

甘蓝型油菜籽的吸湿特性及其数学模型

油菜籽的吸湿特性影响油菜籽的收储工艺和储藏品质,为了给甘蓝型油菜籽收储工艺和管理提供基础依据,本文实验研究了甘蓝型油菜籽在温度为0~30℃,相对湿度为32%~88%的条件下的吸湿特性,比较了7种数学模型在甘蓝型油菜籽吸湿过程的适用性。结果表明:甘蓝型油菜籽的吸湿性受温度和相对湿度的影响很大,温度越高,达到吸湿平衡所需要的时间越短,相对湿度越大,平衡含水率值越大,达到吸湿平衡的时间越长;Peleg模型的相关系数为0.999,卡方为0.154和均方根误差为0.160,是描述油菜籽吸湿特性的最佳数学模型;随着温度的升高,甘蓝型油菜籽的临界相对湿度增大,降低储藏温度,可以有效降低油菜籽的的临界相对湿度;随着平衡含水率的增加,甘蓝型油菜籽的净等量吸湿热指数递减。     

Sorption isotherms and the state diagram for evaluating stability criteria of abalone

Water adsorption isotherms and the state diagram of abalone were developed to further investigate the connection between the two distinct criteria of food stability. The isotherms were measured at 23, 40 and 60 °C using an isopiestic method and they were treated with appropriate models available in the literature. The state diagram was developed using freezing points, as derived by the cooling curve method, and glass transition temperatures were measured by dynamic oscillation on shear. The limited glass transition process of the abalone network necessitated derivation of the mechanical glass transition temperature, since the transition could not be detected using MDSC. Results indicate that there is a considerable discrepancy in the temperature-related stability criteria predicted by the concepts of water activity (a_w) and the glass phenomenon (T_g). In contrast to the progressive deviation between a_w and T_g with increasing molecular weight reported earlier for a homologous family of materials, the effect of rising temperature produces a constant index of comparison between the two concepts.