Establishment of reliable methods of in vitro pollen germination and pollen preservation of Brassica rapa (syn. B. campestris)

A simple and reliable method for evaluating the viability of Brassica pollen was established in which the in vitro germination rate of pollen was adopted as the index of the viability of pollen grains. Pollen grains were preincubated in an atmosphere in which the relative humidity (RH) was fixed to 52% or 66% at 20 °C for 5 hours. They were cultured for 16 hours at 25 °C in a liquid Kwack's medium (1964) supplemented with 20% sucrose, and the pH was adjusted to 8.0. They were then observed under a microscope and the number of germinating and unchanged pollen grains were counted. The germination rate of pollen was improved and stabilized by preincubation and the use of a high pH medium. More than 90% of the freshly harvested pollen grains of Brassica rapa (syn. B. campestris) germinated constantly in these conditions Undehisced anthers were collected from flowers at anthesis and dehydrated by incubation at 20 °C for 16–24 hours in an atmosphere where the RH was fixed to 15% or 32%. They were put into a plastic vial and preserved in a freezer at -20 °C. The germination percentage of the preserved pollen was scored at intervals during preservation. The germination rate of the pollen grains preserved at -20°C for 1 year was higher than 50% and the pollen proved to be efficient for seed set. Most of the seeds germinated normally. This revised version was published online in August 2006 with corrections to the Cover Date.     

枇杷采后生理变化与贮藏保鲜技术

阐述枇杷采后主要生理变化,并对采后贮藏保鲜技术处理作逐一介绍.     

国内外果蔬生物保鲜方法的研究现状与展望

概述果蔬生物保鲜方法的种类、原理和技术,同时对现阶段生物保鲜技术在果蔬贮藏保鲜中的应用进行综述,最后对生物保鲜技术存在的问题和未来研究方向进行展望.     

国内外果蔬鲜切加工及保鲜技术研究现状

随着工作节奏的加快,方便快捷食品需求的增强,鲜切加工产品越来越受到关注。阐述了鲜切产品的加工过程、原料来源及选择,清洗、去皮、切分、护色、包装和贮藏等各项技术,论述和比较了鲜切产品的保鲜技术包括冷藏保鲜、保鲜剂保鲜、MAP保鲜及冷杀菌保鲜等,分析了加工过程中需要注意的问题,最后对鲜切加工技术的发展提出了展望。     

壳聚糖-山梨酸复合涂膜对宣城圆枣保鲜效果的影响

针对鲜食红枣成熟后贮藏期短,商品性会随贮藏期延长而降低等问题,以宣城圆枣为试材,采用5个浓度(0.1%、0.25%、0.5%、1.0%、1.5%)壳聚糖与浓度为0.1%的山梨酸混合,配制成复合保鲜液,对其进行涂膜保鲜处理。结果表明:在4℃条件下,壳聚糖-山梨酸复合涂膜处理在一定程度上能延缓宣城圆枣果实失重率与腐烂率上升的速度,同时抑制硬度及VC含量的下降,从而延缓果实的成熟衰老进程,提高贮藏品质,延长货架期。通过对各项果实品质指标数据的综合分析得出,复合涂膜溶液的最佳使用浓度为0.25%壳聚糖+0.1%山梨酸。     

温度处理在柑橘果实采后保鲜中的应用研究进展

柑橘采后贮藏过程中存在营养物质易流失、果实易腐烂、易受病原菌侵染等问题,从而导致极大的采后损失。温度是影响柑橘采后贮藏品质的主要因素之一,合适的温度处理不仅能够使果实在贮藏过程中保持营养价值和风味品质,还能给予果实良好的外观颜色,提高果实的抗病能力。综述了不同温度处理方式对柑橘果实采后生理生化和抗病能力的影响,以期为柑橘采后绿色贮藏技术的研究提供理论参考。     

几种可食膜在杭晚蜜柚柚瓣保鲜中的应用研究

采用3种可食性复合涂膜剂对杭晚蜜柚柚瓣进行涂膜保鲜,同时以不做任何处理的柚瓣为对照,研究常温货架期间蜜柚柚瓣的失重率、可溶性固形物含量、有机酸含量、VC含量、乙醇含量、粒化指数、硬度、菌落总数等指标的变化。结果表明：与对照组相比,涂膜能减少货架期间蜜柚柚瓣的水分损失,抑制VC含量的下降,保持较高的可溶性固形物和有机酸含量,延缓粒化发生,延长货架期。其中,以葡甘聚糖复合膜的保鲜效果较好。     

杏鲍菇冷链综合保鲜技术应用

介绍了我国杏鲍菇工厂化栽培现状、销售方式及存在的问题,综述了真空预冷、防雾薄膜、纳米保鲜薄膜、减压贮藏等技术在杏鲍菇保鲜上的应用,构建了杏鲍菇综合协同保鲜成套技术,以期为杏鲍菇贮藏保鲜提供一定的技术支持。     

不同保鲜剂喷雾处理对冰箱贮藏期间西兰花保鲜效果的影响

以西兰花为试材,在冰箱贮藏条件下(温度(5±1)℃、相对湿度76%±10%),通过测定失重率、VC含量、多酚氧化酶(PPO)、过氧化氢酶(CAT)、脂氧合酶(LOX)活性等指标,研究丙酸钙和纳他霉素喷雾处理对西兰花品质和相关酶活性的影响。结果表明,与对照相比,3.0 g/L丙酸钙和1.2 g/L纳他霉素喷雾处理均能有效保持冰箱贮藏期间西兰花的感官品质、硬度、VC含量和CAT活性,并且减少失重,抑制PPO活性和LOX活性的升高,其中丙酸钙喷雾处理的保鲜效果优于纳他霉素。     

双孢蘑菇液氮保藏菌株的遗传稳定性分析

双孢蘑菇As2796、As3003、As4607、As4580等4个菌株经4年的液氮保藏,菌种解冻后进行成活率的测定,恢复生长的菌种在粪草培养基上进行不同温度、不同含水量及不同酸碱度的走菌试验,同时进行纤维素酶活力的测定、同工酶谱检测、RAPD检测及出菇栽培等试验。试验结果表明：双孢蘑菇菌种在液氮中经过4年的保藏,液氮保藏菌种的菌丝生长速度、纤维素酶活力与对照菌株相同,同工酶电泳酶谱和RAPD扩增条带保持不变,栽培出菇仍保持着原有的生长特性与产质量性状,液氮保藏方法可以长期保持双孢蘑菇菌种的稳定性。