成龄番木瓜的快繁技术

以番木瓜（泰国木瓜）的大田成龄植株之侧芽为材料，对取材的位置、外植体的消毒方法、继代增殖培养、催根及移栽等环节做了较系统的研究，从中找到了一套适合成龄番木瓜的侧芽的无性繁殖技术，为番木瓜良种的繁殖和种质的保存提供了一条有效的途径。     

The effect of cutting direction on aroma compounds and respiration rate of fresh-cut iceberg lettuce (Lactuca sativa L.)

The purpose of this research was to investigate whether cutting direction and storage temperature could influence aroma formation and respiration rates in minimally processed lettuce. Lettuce was cut both longitudinally and transverse to the mid-rib and stored at 6 and 10 °C for 4 and 5 days. The experiment was performed in January and March 2008. Changes in respiration rate were analyzed during storage, and aroma analysis was carried out after 4 and 5 days of storage in January and March, respectively. Respiration rates increased with increasing storage temperatures. Transverse cuts to the rib were strongly related with volatiles of the lipoxygenase (LOX) pathway i.e. cis-3-hexenal, cis-3-hexenol and trans-2-hexenol, while longitudinal cutting enhanced formation of volatiles from other metabolic routes. Aroma formation was also influenced by storage temperature, where higher storage temperatures resulted in increases in α-longipinene, 2-methylbutanal and 3-methylbutanal. Our results demonstrate that cutting the lettuce transverse to the mid-rib caused more severe damage to the tissue than longitudinal cutting, based on aroma production of LOX volatiles.     

木瓜籽精油的提取及其抗氧化活性研究

采用水蒸气蒸馏法提取木瓜籽精油(PSO),测定PSO的总抗氧化能力、羟基自由基和DPPH自由基清除能力,并应用GC-MS分析测定PSO的化学组成。结果表明,水蒸气蒸馏法提取木瓜籽精油最佳蒸馏时间是2.5 h,料液比和浸泡时间分别是1∶8(w∶V) 和1 h;与合成抗氧化剂相比,PSO的总抗氧化能力偏低,当PSO浓度达到5×10-5 mg/mL和8 mg/mL时,其清除羟基自由基和DPPH自由基的能力分别达到100%和70%以上;PSO化学成分主要是安息香醛、苯乙醛、苯乙腈和异硫氰酸苄酯,其中异硫氰酸苄酯的相对含量占98.28%。说明该方法可获得高纯度的异硫氰酸苄酯,可为工业上生产异硫氰酸苄酯提供一定的理论依据。     

鲜切莲藕微生物模型的建立及货架寿命预测

研究鲜切莲藕在不同贮藏温度下细菌生长趋势和感官质量的变化,建立微生物生长模型,预测鲜切莲藕的货架寿命;将莲藕切片经保鲜处理、包装后,置4、8和20℃贮藏温度下贮藏,测定贮藏期间鲜切莲藕中细菌总数,利用DPS软件,建立Gompertz模型;结果表明,试验中所建立的Gompertz模型能有效地拟合在不同贮藏温度下鲜切莲藕中细菌总数的动态变化;建立的微生物模型能预测不同贮藏温度下、不同贮藏时间内鲜切莲藕中的细菌总数,为快速、有效地评估鲜切莲藕的货架寿命和微生物安全性,提供了一个方便有效的方法。     

木瓜蛋白酶超声法提取工艺及其酶学性质

结果表明:最佳提取工艺条件为超声波功率300 W,超声处理时间200 s,果浆质量分数30%;经超声波强化提取,酶活力提高到原先的1.71倍;在以酪蛋白为底物、pH 7.5和40℃条件下,木瓜蛋白酶的Km值和Vm值分别为1.4709 mg.mL-1和5.5252μg.mL-1.m in-1;最适温度为70-80℃,最适pH值为5.4-6.6;该酶在40℃以下,pH为5.4-6.0时酶活力相对稳定;EDTA、Cys和Vc对酶活力具有激活作用,CuSO4和ZnC l2具有抑制作用,而KC l、NaC l、CaC l2、MgSO4对酶活力的影响不大.     

Karlheinz richter zum 65. geburtstag

Studies were carried out on spatio-temporal variations of arbuscular mycorrhizal (AM) fungi associated with Carica papaya L. growing in two different geographic localities in Goa, India – Western Ghats and coastal area, differing in soil characteristics and plantation status. The study recorded considerable variation in root colonization, spore density and distribution of AM fungi in the selected sites. The mean total root colonization was at a maximum in the month of July, while spore density was highest in April. The study recorded a total 33 species of AM fungi. Western Ghats recorded a relatively higher diversity of AM fungi compared to coastal area. Species richness of AM fungi was at a maximum in April and coincided with maximum mean spore density. Edaphic as well as climatic factors influenced the AM fungal parameters. The study recorded the existence of seasonality in AM fungi.     

Fe‐deficiency tolerance in papaya (Carica papaya L.): Ph reduction and chlorosis recovery in response to stress

The phenomenon of Fe‐stress response mechanism was examined using papaya as a test fruit plant species. This plant behaved like the many Fe‐efficient crop cultivars, reduced the pH of the minus Fe nutrient medium, followed by recovery from chlorosis. The response mechanism was observed in both the 2 cultivars, CO‐1 and CO‐3. Evidence obtained with this plant supports the widespread occurrence of the mechanism in diverse crop species ‐ grain, vegetable and fruit crop plants too.     

番木瓜生姜复合饮料配方及澄清工艺的研究

以番木瓜和生姜为主要原料．对番木瓜生姜复合饮料的配方及澄清工艺进行了研究。结果表明,番木瓜生姜复合饮料的优化配方为：番木瓜汁与姜汁的配比为3：2,白砂糖的添加量为5．0％,柠檬酸的用量为0．15％;采用0．15g·L^-1的硅藻土能明显提高番木瓜汁的澄清度,采用0．20g·L^-1的果胶酶能明显提高姜汁的澄清度。将两种清汁复合加工而成的番木瓜生姜复合饮料具有浓郁的番木瓜果香、淡淡的生姜芳香及良好的澄清度,透光率可达86．2％。     

一氧化氮处理对采后番木瓜果实乙烯生物合成的影响

为了解一氧化氮(N0)处理对番木瓜果实乙烯生物合成的影响,采用60 μL/L NO熏蒸处理采收成熟度为果皮浅绿并微带黄色痕迹的番木瓜果实3h,然后在20C和相对湿度为85％条件下贮藏20 d.研究NO对番木瓜乙烯、1-氨基环丙烷-1-羧酸(ACC)、丙二酰-1-氨基环丙烷-I-羧酸(MACC)、ACC合成酶(ACS)和ACC氧化酶(ACO)及CpA CS2和CpA C01基因表达的影响.结果表明,NO处理降低了番木瓜果实乙烯释放量、ACO的活性及CpA C0l基因的表达,导致贮藏过程果实ACC和MACC的积累,但对ACS的活性及CpA CS2基因的表达无显著抑制作用.     

木瓜果浆微波辅助泡沫干燥工艺

以番木瓜(Carica papaya L.)为原料,采用微波辅助泡沫干燥法制备番木瓜粉,考察单甘酯和大豆分离蛋白对果浆的起泡特性的影响,研究微波干燥特性并优化微波泡沫干燥工艺参数,确定起泡剂的最佳配方和番木瓜粉的干燥工艺。结果表明:在木瓜果浆中添加6.83%的单甘酯和6.56%的大豆分离蛋白,果浆泡沫膨胀率最大,且泡沫的稳定性好。木瓜果浆微波泡沫干燥的最优工艺条件为微波功率578 W,物料厚度4.90 mm,干燥时间6.65 min。