海藻多糖用于食品涂膜保鲜的研究现状

海藻多糖具有抑菌、抗病毒和抗氧化等多种生物活性,可用于食品的涂膜保鲜。本文概述了海藻多糖的生物活性及其保鲜机理,并将目前已发现的具有活性的海藻多糖种类及其在食品涂膜保鲜中的应用现状、保鲜效果等进行综述,同时对其未来发展趋势进行展望。     

新型种衣剂对玉米苗期病虫害及瘤黑粉病的防治效果

对3种不同种衣剂不同剂量组合设计9个处理进行大田药效对比试验,明确其不同抗病虫效果、使用安全性及其对玉米营养生长的影响,为玉米生产中种衣剂的选择提供科学依据。试验表明,种衣剂处理(70%噻虫嗪悬浮种衣剂200g+28%灭菌唑200mL+35g/L咯菌·精甲霜100mL)/100kg种子能提高玉米出苗率7.7%;对苗期烂根病的防效为57.1%;对地下害虫的防效为33.3%;对瘤黑粉病防治效果为52.6%;对玉米株高,茎粗,根系数,叶片数,根鲜重和植株鲜重有较好的促进作用,增产幅度19.1%,对玉米生长安全。     

Roughness of biopores and cracks in Bt‐horizons assessed by confocal laser scanning microscopy

In structured soils, water and reactive solutes can preferentially move through larger inter‐aggregate pores, cracks, and biopores. The surface roughness of such macropores is crucial for describing microbial habitats and the exchange of water and solutes between macropores and the soil matrix together with other properties. The objective of this study was to compare the roughness of intact structural surfaces from the Bt‐horizons of five Luvisols developed on loess and glacial till and to test the applicability of confocal laser scanning microscopy. Samples of 5 to 10 cm edge length with intact structural surfaces including cracks with and without clay‐organic coatings, earthworm burrow walls, and root channels were prepared manually. The surface roughness of these structures was determined with a confocal laser scanning microscope of the type Keyence VK‐X100K. The root‐mean‐squared roughness (R_q) the curvature (R_cu) and the ratio between surface area and base area (R_A) were calculated from selected surface regions of interest of 0.342 mm² with an elevation resolution of 0.02 µm. The roughness was smaller for coated as compared to uncoated cracks and earthworm burrows of the Bt‐horizons. This reduction of roughness by the illuviation of clayey material was similar for the structural surfaces of the coarser textured till‐Bt and the finer‐textured loess‐Bt. This similarity suggested a dominant effect of pedogenesis and a minor effect of the parent material on the roughness levels of structural surfaces in the Bt‐horizons. An expected “smoothing” effect of burrow wall surfaces by earthworm activity was not reflected in the roughness values compared to those of uncoated cracks at the chosen spatial scale. However, for root channel walls from one loess‐Bt, the roughness was reduced as compared to that of other structures. These results suggest that the surface roughness of the structural surface types should separately be considered when describing preferential flow and macropore‐matrix exchange or analysing root growth, microbial habitats, and colloidal transport in structured soils. The confocal laser scanning microscopy technique was found useful for characterizing the roughness of intact structural surfaces.     

纳米植物糖原改造壳聚糖膜工艺研究

以壳聚糖为基料,加入纳米植物糖原、甲基纤维素等来改善膜的性能。通过测定膜的透水率、透光率、溶解率、抗菌性,分析膜组分中的各物质对成膜效能的影响。结果表明,在植物糖原纳米保鲜剂中,植物糖原对透水率溶解率、透光率的影响最大。此外,通过正交试验对膜进行优化,得出在60 m L 2%的乙酸水中植物糖原为0.3 g,壳聚糖为0.5 g,氢氧化钙为0.7 g,甲基纤维素为0.9 g时,成膜效能最好,此时,透水率为33.1%,溶解率为3.361%,透光率为12.19%。     

复合涂膜处理对火龙果常温贮藏品质的影响

以新鲜红肉火龙果为试材,分别用不同浓度的蔗糖基聚合物和海藻酸钠复配涂膜液浸泡处理1 min,于常温(29~31℃)下贮藏11 d,研究不同浓度复合涂膜液处理对火龙果常温贮藏品质的影响。结果表明,各涂膜处理组均能有效减缓果实水分的蒸发、降低失重率、延缓可溶性固形物、可滴定酸、可溶性糖、可溶性蛋白质含量的下降。在常温贮藏条件下,火龙果能存放8~9 d,比对照(清水处理)可延长2~4 d。其中,5%蔗糖基聚合物+1%海藻酸钠处理的保鲜效果最佳,贮藏7 d后才出现腐烂果,比对照推迟了4 d。     

生物质炭对砖红壤pH及养分含量影响研究

为提高软木地板表面的物理性能,采用弹性漆对软木地板表面进行涂饰处理,研究不同弹性漆的涂漆量、油漆固化温度对软木地板表面耐磨、耐冲击性、表面色度学特性的影响。结果表明：与对照相比,软木地板表面漆膜具有优良的耐磨性、表面磨耗值随着弹性漆涂漆量的增加而降低,表面磨耗值为0.015 6～0.031 0 g/100 r;弹性漆对软木地板表面抗冲击改善幅度较大;油漆固化温度和涂漆量对软木地板表面颜色影响较小。     

带菌豇豆种子包衣效果试验

采用 6种不同种衣剂对带菌的豇豆种子进行包衣育苗及直播栽培试验。结果表明 :种衣剂不仅提高了豇豆的出苗率 ,促进了幼苗的生长 ,而且对豇豆种子本身所带的炭疽病和土传的猝倒病、枯萎病均有明显的防效。从综合效果看 ,合肥丰乐营养包衣剂和ZBS菜豆包衣剂较其他种衣剂效果更好     

瘤胃保护性氨基酸制备工艺及包被效果的研究

试验以棕榈油脂肪粉为包被壁材,研究了先制粒后底喷流化床包衣工艺制备瘤胃保护性赖氨酸及蛋氨酸的主要工艺参数,以人工唾液释放率为评价指标对适宜包被比例(芯材:壁材)进行了筛选。结果发现,在理想制粒及包衣工艺参数条件下,赖氨酸和蛋氨酸的适宜包被比例(芯材:壁材)分别以40:60和50:50为宜。     

竹叶抗氧化物浸泡结合乳清分离蛋白涂膜对冷藏富硒虹鳟食用品质的影响

为延长冷藏富硒虹鳟的货架期,实验以3种浓度的竹叶抗氧化物溶液(AOBS,质量浓度分别为0.5%、1.0%和1.5%)分别浸泡富硒虹鳟鱼块,再进行乳清分离蛋白溶液(WPIS)涂膜,(25±1)°C下鼓风吹干表面水后置于4°C冰箱贮藏1、4、7、10和13 d,测定鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数、结合水分含量和水分状态,分析涂膜对冷藏富硒虹鳟鱼块品质的影响。结果显示,随着冷藏时间的延长,鱼块的pH值、TVB-N值、K值、菌落总数和嗜冷菌数显著增加,水分含量显著降低,结合水和不易流动水向自由水迁移。其中,1.0%AOBS+WPIS组的pH值、TVB-N值、K值、菌落总数和嗜冷菌数的增加速率和水分含量的减少速率最慢,结合水与不易流动水的比例最高。1.0%竹叶抗氧化物浸泡结合乳清分离蛋白涂膜,提升了乳清分离蛋白涂膜的保鲜效果,可有效抑制富硒虹鳟冷藏过程中品质的劣变,延长货架期。根据TVB-N值、K值和菌落总数,1.0%AOBS+WPIS组可延长富硒虹鳟货架期3 d。本研究可以为富硒虹鳟的低温贮藏技术提供科学指导。     

高寒退化草地恢复中种子包衣对出苗的影响

采用植物性吸水材料对垂穗披碱草(Elymus nutant)和山野豌豆(Vicia amoena)种子进行包衣处理,在模拟高寒草地条件下观察包衣种子的出苗,同时测定包衣混合物的持水力.结果表明,最适条件下两种牧草种子的出苗率分别为86%和88%;在模拟条件下,种子的出苗率分别为38%和24%.经过包衣处理后,种子的出苗...