贮藏温度对蒲公英采后生理和品质的影响

研究贮藏温度对蒲公英采后生理指标和品质的影响,探索适宜的贮藏温度,为蒲公英贮运技术的发展与延长供应期提供指导。设置25,10,2,-18℃4种贮藏温度,测定了蒲公英在贮藏过程中外观、营养成分含量和采后生理指标的变化。结果表明:采后蒲公英随着贮藏天数的增加,叶片逐渐黄化,粗纤维的含量升高,维生素C和绿原酸含量下降,硝酸盐含量先升高后降低;2℃下贮藏能够使采后蒲公英具有较高的叶绿素、维生素C、绿原酸,较低的硝酸盐和粗纤维含量,较低的细胞膜渗透率、MDA含量和较高的SOD活性,显著地延缓其衰老进程,延长贮藏寿命。     

中国和越南大豆种质资源贮藏蛋白亚基组成的鉴定

利用聚丙烯酰胺凝胶电泳法(SDS-PAGE)对收集于中国、越南的850份大豆资源贮藏蛋白的亚基组成进行分析。在222份中国栽培大豆品种中检测到14粒7S球蛋白b-亚基少型种子。在黑农35、黑农38和黑农41中筛选到11S球蛋白A3–、A4–亚基缺失或减少的类型。另外,利用越南b-少型种质选育到一个‘b-少’品系。两个越南渭公河流域的野生大豆不仅具有&;#61537;&;#61602;-及&;#61537;-亚基的缺失变异特性,还具有根瘤成瘤性高,豆荚抗食心虫的特性,是大豆品质改良育种的重要基础材料。     

兔出血症-巴氏杆菌病蜂胶二联灭活苗保存期试验

研制兔出血症-巴氏杆菌病蜂胶二联灭活苗2批，分别在4-8℃和室温条件下保存6个月、12个月后进行免疫保护试验。结果显示：蜂胶二联苗在4～8℃和室温条件下保存6个月、12个月，对兔出血症的保护率均为100％；4～8℃保存6个月对巴氏杆菌病的保护率为100％，保存12个月对巴氏杆菌病的保护率为90％；室温保存6个月对巴氏杆菌病的保护率80％，保存12个月对巴氏杆菌病的保护率为70％。据此可以确定蜂胶二联苗的保存期为4～8℃一年或室温半年。     

离体桑叶在贮藏过程中的生理变化

试验表明，不同叶位的桑叶随着贮藏时间的延长，叶片含水率与叶绿素含量持续下降；可溶性糖和粗蛋白含量在前36h左右略有升高然后逐渐下降；丙二醛（MDA）含量与过氧化物酶（POX）活性稳定升高；超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性渐渐降低。从而表明，离体桑叶在贮藏过程中的生理变化是叶片的衰老，这种衰老与叶片本身的老熟程度关系不大。     

不同温度对扬州盐水鹅品质的影响

[目的]为了保证扬州盐水鹅的卫生质量和品质。[方法]对扬州盐水鹅在不同保存温度下菌落总数、菌相和pH值的变化进行试验性观察。[结果]当菌落总数达到106 cfu/g、腿肌pH值为6.5以上时,均有异味产生;腐败过程中的优势菌种,37℃为肠球菌属和葡萄球菌属,20℃为变形杆菌属,4℃为假单胞菌属;对于当天制作并于中午出售的盐水鹅,其保存期限建议值为:37℃不超过7 h,20℃不超过24 h,4℃不超过6 d。[结论]该研究为建立健全可供盐水鹅新鲜度鉴定使用的卫生评价指标提供了依据。     

不同贮藏条件对辣椒花粉生活力的影响

试验研究了不同贮藏条件下辣椒品种(保加利亚尖椒-2)花粉的贮藏效果,以及不同吸湿方法对辣椒花粉染色效果的影响.研究结果表明,随着贮藏时间的增加辣椒花粉的生活力逐渐降低;在低温3℃干燥条件下最有利于保持辣椒花粉的生活力:在30℃高温环境下花粉的染色效果最为明显.     

Polygalacturonase and β-galactosidase activities in Hayward kiwifruit as affected by light exposure,maturity stage and storage time

Softening process and total antioxidant activity were evaluated in kiwifruit differently exposed to light intensity and harvested at two different times (October 10 and November 14). Fruit was stored for 2 months at 0 °C (S1) and then maintained for a week at ambient temperature (S2). The results showed that fruit harvested later presented a faster softening rate during storage than fruit harvested earlier, even if antioxidant activity did not change. Light-exposed fruit showed higher flesh firmness than that of shaded ones. Polygalacturonase activity was higher in kiwifruit maintained for a week at ambient temperature after cool storage and, in particular the highest value was recorded in fruit harvested later. The behaviour of β-galactosidase was different: it did not show changes in fruit harvested later and significantly decreased in light- and shade-exposed fruit harvested earlier.     

不同温度和CO_2体积分数对丰水梨采后生理指标的影响

为明确丰水梨采后适宜的贮藏温度和CO2体积分数,从果实硬度、膜透性、乙醇质量分数、总酚质量分数、PG活性、PPO活性及果心褐变等方面研究了不同温度和CO2体积分数对丰水梨果实的防褐保鲜效果。结果表明,-1.5℃明显降低果实腐烂率,维持较高的果实硬度,但果实发生不同程度冷害;5℃适合短期贮藏(<60d)。与CK相比,3%O2+1%CO2可较好保持果实硬度和风味,明显抑制PPO活性、乙醇产生和果心褐变,延缓酚类物质降解,较好保持细胞膜完整性;2%CO2防褐保鲜效果次之;3%～5%CO2防褐保鲜效果最差。     

Effect of set-size and storage temperature on bolting,bulbing and seed yield in two onion cultivars

The effects of three set-sizes (12.5, 17.5 and 22.5 mm in diameter) and seven storage temperatures (0, 5, 10, 15, 20, 25 and 30 °C) on bolting, bulbing and seed yield in two onion (Allium cepa L.) cultivars ‘Hygro’ and ‘Delta’ were investigated. The incidence of bolting increased linearly with set-size and curvi-linearly with decreasing storage temperature. Time to inflorescence emergence and floret opening showed a curvi-linear response to storage temperature with the earliest inflorescence emergence and floret opening occurring at 5 °C and the latest at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’. Seed yield per umbel also showed a curvi-linear response to storage temperature with the lowest seed yield occurring at 30 °C for ‘Hygro’ and at 25 °C for ‘Delta’ and the highest seed yield at 5 °C. For a seed crop, storage of large sets (22.5 mm) of these cultivars at 5 °C for 120 days appeared to be optimum with 5–12% higher seed yield per umbel than that of 90 days storage. Bulb yield showed a curvi-linear response to storage temperature with the highest bulb yield occurring at 25 °C and the lowest at 5 °C.     

Effects of ultrasound and high pressure argon on physico-chemical properties of white mushrooms (Agaricus bisporus) during postharvest storage

Effects of high pressure argon (H), ultrasound (U) and their combination treatments (UH) on physico-chemical characteristics of white mushrooms were studied during 9 d of postharvest storage at 4 °C. H treated samples exhibited the smallest weight loss and respiration rate compared to all other samples. Mass losses after 9 d of storage were 3.01%, 5.09%, 5.39% and 9.59% for H, UH, U and untreated mushrooms, respectively. Furthermore, U treated samples showed lower polyphenol oxidase activity (PPO, E.C. 1.14.18.1) during storage while UH treated samples showed a slight increase in antioxidant capacity during storage and also experienced reduced mass loss and respiration rate. In addition, treated samples were effective in retaining mushrooms colour changes compared to control. Physico-chemical properties of differently treated mushrooms (UH, H and U) stored at 4 °C were significantly different (p < 0.05) from control.