谷物和种子介电特性的研究及应用进展

为了更好地研究农业物料介电特性,总结了国内在应用介电特性测量谷物的含水率、种子的介电分选,以及种子电致生物效应等方面的研究进展。     

干酪介电特性研究进展

结合干酪介电特性的国内外研究现状,介绍干酪介电特性测试相关参数,以及微波频率下干酪介电特性的测定方法,分析成熟期内干酪成分与介电特性参数的关系,为进一步研究介电特性在干酪品质评定中的应用提供参考。     

棉花种子介电特性的试验研究

将棉花种子简化为一种复合介质模型,通过试验测试种子的介电常数,探讨种子的介电特性,分析频率、湿度与种子介电特性的关系,得出介电常数随各参数变化的规律,为合理地确定介电式种子分选机的结构参数和工况参数提供理论依据。对外表完整与表面破裂的种子进行吸湿性的对比试验研究,从而为提高介电式种子分选机的分选效果创造条件。     

农业物料介电特性的测试及影响

在进行农业物料相关品质检测与加工时,往往需要测定其许多参数,其中介电特性随物料种类的不同而体现出差异性,可以根据这一特性对不同物料的物性进行表达。此外,同种物料本身的介电特性又与许多因素有关,利用影响因素与介电特性的相关性,可以对物料的品质因素进行判定,对加工过程进行实时监测和优化控制。综述分析了国内外农业物料介电特性的相关研究,介绍了生物电学模型及介电特性的各种测试方法,并概括了各种测试方法的优缺点,总结了不同方法的适用条件以及受约因素。综述农业物料(特别是果蔬)的介电特性受到电磁场参数、温度、物料外形参数以及水和离子行为的影响,为研究果蔬介电特性在果蔬干燥、保鲜、品质检测等方面的应用提供参考。     

食品介电特性参数试验机理分析

分析了食品介电特性参数的理论基础,结合试验研究的现状,探讨了介电特性参数的物理意义和使用条件。指出以测量食品等效电容对应食品其他性质的方法而得出结论的重复性和可验证性较差;食品介电特性研究需同时指出测量的频率,甚至需要通过介电常数频谱测量,找出测量该物料复介电常数的最佳频率;复介电常数测量受到夹持物料应力大小的影响。     

甜玉米安全优质高效生产技术

<正>甜玉米集中了水果和谷物的优质特性,是我国近年来新兴起的兼具休闲型与保健型的现代食品。甜玉米根据遗传类型和胚乳特性可分为三种:普通型甜玉米、超甜型甜玉米(又称水果甜玉米)和加强型甜玉米。笔者从2008年开始在山东烟台市夹河绿色农业园引进试种甜玉米,至今已引进试验国内外品种四十多个,筛选出了一系列适合生产发展的品种,     

发展农大超甜1号玉米前景诱人

甜玉米作为特用玉米的一种,它富含蛋白质、多种维生素、膳食纤维、胡萝卜素、亚油酸等营养成分,集中了水果和谷物的优质特性.甜玉米具有独特的营养价值、良好的口感和加工性能,经济价值较高.     

基于介电特性在农产品品质无损检测中的应用研究

近年来,随着人们对农产品品质的重视,关于农产品品质的无损检测新技术研究尤为迫切。主要从介电特性的基本原理、主要的测定方法、影响介电特性的主要因素3个主要方面进行了介绍,详细了解该方法在农产品无损检测中的最新应用,并为新技术在新疆特色农产品品质检测的应用提供理论依据。     

基于介电特性小粒咖啡含水率的检测研究

为了研究带壳咖啡豆介电特性与含水率之间的关系,利用LCR测试仪研究频率信号(1~1 000 k Hz)、温度(20~45℃)和含水率(11.18%~43.69%)对带壳咖啡豆介电特性的影响。结果表明,在1~1 000 k Hz频段内,相对介电常数(ε')随着频率的增大单调减小,却随着含水率的升高而增大;温度对相对介电常数(ε')基本没有影响,介质损耗因数(ε')随频率增大先递减后增大;当温度和含水率升高,介质损耗因数(ε')呈增大趋势。在500 k Hz下建立相对介电常数(ε')预测带壳咖啡豆含水率(W,%)的模型,该模型R2=0.987 5;制作了20个样本,将测量值与模型计算值进行比较,发现其绝对误差范围为-3.07%~2.47%,说明所建立的模型可行。此项研究对了解带壳咖啡豆的介电特性,以及开发带壳咖啡豆含水率检测仪有一定的指导意义。     

检测谷物及淀粉糊化特性的旋转式粘度仪的研制

论述了检测谷物及淀粉糊化特性的方法和电子旋转式粘度仪的总体结构、工作流程、设计要点和实验。研究表明:该仪器测定谷物及淀粉粘度性状,采用非牛顿流体粘度测量方法 (旋转式粘度),全面真实地反映谷物及淀粉糊化的实际情况,为GB/T 14490-2008《粮油检验谷物及淀粉糊化特性测定粘度仪法》的执行提供技术手段。     

Study of pomegranate ripening by dielectric spectroscopy

Pomegranate (Punica granatum L.) is one of the fruits most recently studied for its many health benefits and its high antioxidant capacity and total phenolic content. Currently, the industry uses destructive methods to ensure the quality standards demanded by consumers. In this context, dielectric spectroscopy is presented as an interesting technique to monitor, on-line, fruit quality standards and ripening changes. The aim of this study is to analyze the effect of the major components of pomegranate and its structure on the dielectric spectrum between 500 MHz and 20 GHz. Some physical, chemical and dielectric measurements were carried out in the arils, spongy white tissues and peel. A maturity index was defined based on dielectric properties of fruit at two different frequencies, 2.4 and 1.2 GHz. The results demonstrated the utility of this index for pomegranate.     

套袋与采后涂膜对红富士苹果果实贮藏效果的影响

以长富2号红富士苹果为试材,在实验室条件下观察了套袋与采后涂膜处理对红富士苹果果实贮藏效果的影响。试验结果表明,苹果果实套袋可使果实表面蜡质减少,角质层变薄且疏松,呼吸强度增大,贮藏期更容易失水,从而导致耐贮性能下降。而将套袋果实进行单果涂膜处理,可抑制其在贮藏过程中的呼吸强度与失水程度,从而延缓红富士苹果果实衰老进程及改善贮藏性能。     

不同品种夏橙品质的评价分析

为了提高夏橙品系品质性状的选择效率,为夏橙的品质优化提供理论依据,以湖北宜昌秭归地区9个夏橙品系为材料,分析其物理特性（单果重、果形指数、果实硬度、果皮厚、果皮颜色、果汁颜色、水分）和化学特性指标（果实纤维、可溶性固形物、可滴定酸、固酸比和维生素C）之间的关系。结果表明,物理特性中单果重、果实硬度、果皮厚的变异系数较大,果汁颜色、果性指数变异系数较小;化学特性中果实纤维、水分、可溶性固形物、可滴定酸的品系间变异系数较大。9种品种间单果重、硬度和果实纤维差异显著,其余指标变化均不显著。主成分分析表明这16项指标反映的夏橙品质可用4个主成分来表示(累计贡献率达93.37%),并且各性状的贡献率集中。不同品种夏橙品质差异为夏橙品质选择改良提供了很好的借鉴作用,并为人们日常生活中合理消费夏橙提供理论依据。     

不同品种番木瓜果实后熟及贮藏特性的比较研究

研究比较了5个品种番木瓜果实采后生理、品质变化等贮藏后熟特性,结果表明,穗选1号（P2）和穗优2号（P3）两个品种的果实采后后熟进程较慢,呼吸和乙烯高峰相对较低,峰值出现时间也较迟,果实硬度保持较好,在20℃条件下贮藏20天好果率仍达80%以上,是比较耐贮运的番木瓜品种;夏选1号（P4）次之;白皮日升（P1）和穗黄（P5）两个品种果实后熟软化速度最快,贮藏后期病害发生严重,果实容易腐烂变质,不耐贮藏。     

草莓果实主要数量性状变异及相关性研究

以露地栽培的82份草莓品种(系)为材料,对其主要数量性状的变异、分布规律及相关性进行了研究和分析。结果表明,草莓果实硬度、可溶性固形物、平均单果重、最大单果重和单株产量基本呈正态分布,不同性状的变异不同;果实硬度与平均单果重、单株产量分别呈显著正相关和极显著正相关,平均单果重与最大单果重及单株产量均呈极显著正相关,最大单果重与单株产量呈极显著正相关。此研究为草莓育种的亲本选配和杂交后代预先选择提供了依据。     

Comparative studies on nanostructures of three kinds of pectins in two peach cultivars using atomic force microscopy

Firmness is an important postharvest quality property of fruit. To investigate the reasons for firmness differences between soft and crisp fruit cultivars, two peach (Prunus persica L. Batsch) cultivars (soft and crisp) were selected to compare the nanostructures of pectins. Water-soluble pectin (WSP), chelate-soluble pectin (CSP) and sodium carbonate-soluble pectin (SSP) were extracted and nanostructures were conducted and analyzed using atomic force microscopy (AFM). The results show that SSP chain lengths were different between the two cultivars with average SSP lengths of 249 nm and 57 nm for fruit of the crisp and soft cultivars, respectively, while the WSP and CSP chain lengths were not much different. There were no statistical differences for chain heights and widths in the three kinds of pectins between fruit of the two cultivars. All the chain heights were about 1–5 nm. The results indicate that neutral sugar-rich pectins from the primary cell wall of peach flesh might be the cause of the main differences in pectin nanostructures between the two cultivars. The neutral sugar-rich pectins in primary cell walls of peach might also be the reason for firmness differences.     

香梨杂种后代营养枝叶片与果实性状的相关性研究

为研究香梨杂交后代叶片性状与果实性状的相关性,通过叶片性状对香梨杂交后代进行早期预选。对香梨12个杂交组合的杂交后代的营养枝不同部位叶片、枝条性状和果实性状之间的相关性进行分析。结果表明：香梨杂交后代果实单果重、纵横径、果形指数等性状之间具有显著或极显著的正相关性。营养枝基部、中部和顶部叶片性状之间的相关性有所不同。基部叶片叶形指数与单果重、果实横径具有显著的正相关;中部叶片叶面积与果心大小呈极显著的负相关,与纵径呈显著的正相关;叶宽与果心大小呈极显著的负相关。顶部叶叶面积、叶宽与果心大小具有显著的负相关性。营养枝节间长度与果实单果重、纵横径呈显著正相关,可利用回归方程进行苗期或幼树期的预测。     

Phenotypic diversity and relationships of fruit quality traits in peach and nectarine [<Emphasis Type="Italic">Prunus persica</Emphasis> (L.) Batsch] breeding progenies

Agronomic and fruit quality traits were evaluated and compared for three consecutive years on 1,111 seedlings coming from 15 peach and nectarine breeding crosses, grown under a Mediterranean climate. Significant differences among and within the different progenies were found for most of the traits analyzed. The breeding population segregated for several Mendelian characters such as peach or nectarine fruit, round or flat fruit, yellow or white flesh and freestone or clingstone. In addition, aborting fruit and flat fruit trees were found in our progeny, and our data seem to support multi-allelic control of both flat shape and aborting fruit. The variation within the progenies of some traits such as blooming and harvesting date, yield, fruit weight and SSC was continuous, suggesting a polygenic inheritance. Relationships between qualitative pomological traits and these agronomic and fruit quality parameters were also found. Valuable correlations among agronomic and fruit quality parameters were found, although coefficients of variation depending on the progeny should be considered. In addition, principal component analysis (PCA) revealed several relationships among quality traits in the evaluated progenies. Based on this evaluation, 26 outstanding genotypes were pre-selected from the initial breeding population for further studies.