热处理对轻度加工葡萄呼吸强度和内源激素的影

为探索热处理对轻度加工葡萄衰老软化机制及贮藏保鲜效果的影响,以红地球葡萄为试验材料,研究了热空气55℃、5min和热水45℃、8min处理对其衰老过程中呼吸强度和内源激素含量的影响.结果表明,热处理显著地抑制了轻度加工葡萄的呼吸强度;热处理葡萄中IAA(生长素)和GA_3(赤霉素)的含量与果实的腐烂率呈显著的线性负相关性(P<0.05),其相关系数r分别为0.903 5和0.841 6;轻度加工葡萄中ABA(脱落酸)含量变化呈抛物线形变化,热处理可以推迟ABA高峰期并降低峰值;热处理对诱导ZR(细胞分裂素)的产生效果不明显.各处理葡萄中ZR的含量变化无明显规律.     

Effects of seed maturity,seed storage and pre-germination treatments on seed germination of cleome (Cleome gynandra L.)

The influence of seed maturity, seed storage and germination pre-treatments on seed germination of cleome (Cleome gynandra L.) were investigated. Seed maturation studies showed that capsules harvested at 18 days after anthesis possessed the highest dry weight with 19.2% moisture and 1% germination. Development of fresh-ungerminated seed was observed with increasing maturity of fruit, suggesting that cleome exhibited forms of seed dormancy. Storing mature seed at 15 °C and at room temperature for 5 months showed that seed dormancy was broken after 3 months under both storage regimes. When mature seeds were subjected to different treatments including various levels of GA₃, KNO₃, leaching, pre-chilling, soaking and pre-heating at different temperatures, it was found that pre-heating at 40 °C for period of 1–5 days was the most effective method in breaking dormancy in cleome.     

猕猴桃幼果期钙处理对果实贮藏和品质的影响

以中华猕猴桃品系湘酃８０－２为试材,在幼果期进行浸钙处理。结果表明：不同钙处理能不同程度地延长猕猴桃果实贮藏期,其中以０.５％Ｃａ_２（ＮＯ_３）_２处理对果实贮藏与品质的综合效果最好;０．５％Ｃａ（ＮＯ_３）_２＋ １００ ｍｐ·ｌ~(－1)萘乙酸能显著提高果实硬度与贮藏性能。     

SO2对贮藏龙眼果皮酶促褐变的影响

以‘石硖’龙眼为材料,研究了ＳＯ２抑制贮藏期间龙眼果皮酶促褐变的机理。结果表明：ＳＯ２通过降低果皮细胞质的ｐＨ值,抑制多酚氧化酶酶活性,保存游离酚和总酚含量,保护还原型抗坏血酸等作用抑制了龙眼果实贮藏期间的褐变。     

莴苣种子贮藏条件研究

运用适当的种子起始含水量、贮藏温度和包装方式,可经济有效地保持种子的发芽率。种子的生活力与超氧化物歧化酶、酸性磷酸酶的活性呈正相关。     

多花野牡丹种子萌发和贮藏特性的研究

对多花野牡丹(Melastoma affine D.Don)种子的好光性、不同贮藏温度和时间、发芽适温以及种子活力做了研究,结果表明:光对多花野牡丹种子萌发有促进作用;多花野牡丹种子发芽最适温度为26℃;种子25℃短期贮藏可有效提高发芽率和发芽整齐度,长期贮藏温度以5℃较为合适;赤霉素(0.01mmol)对种子发芽有一定的促进作用,发芽率最高;种子活力测定显示种胚细胞的呼吸强度极微弱,呈现出休眠状态,多花野牡丹具有后熟期。     

套袋对嘎拉苹果贮藏品质的影响

以不套袋果实为对照,研究了套袋嘎拉在冷藏期间主要生理指标的变化规律。结果表明:嘎拉苹果套袋果实与不套袋果实在贮藏过程中主要生理指标具有相似的变化趋势。与对照果实相比,套袋果实的失重率高、硬度略低、可溶性固形物含量低、乙烯高峰和呼吸高峰均提前20d,进入衰老。     

不同贮藏处理对‘槜李’果实采后生理特性的影响

本研究以‘槜李’果实为材料,分别进行外源乙烯、减压浸钙和低温贮藏处理,研究各处理条件下‘槜李’果实成熟软化过程中硬度、乙烯释放量、ACS和ACO活性等指标的变化。结果表明:‘槜李’果实软化过程中,硬度逐渐降低,乙烯释放量和ACS活性的峰值同时出现在软化后期;外源乙烯(0.5μl·L^-1)处理后,果实硬度迅速下降,乙烯跃变提前,乙烯释放量增大,ACS活性增强,促进果实迅速软化;用2%CaCl2溶液浸泡处理显著减缓果实软化,降低乙烯释放速率;低温贮藏显著抑制果实硬度下降,表明一定条件的低温贮藏对乙烯释放速率及其相关酶活的控制效果极为显著。     

Evaluation of partial-vacuum baking for gluten-free bread: Effects on quality attributes and storage properties

The purpose of this study was to evaluate the impact of partial-vacuum baking on the quality and storage properties of gluten-free bread (GFB). Conventional (180°C-30 min at atmospheric pressure) and partial-vacuum (180°C-15 min at atmospheric pressure and at 180°C-15 min at 60 kPa vacuum pressure) methods were conducted to bake GFB. Quality attributes (specific volume, colour, texture, total water loss) were assessed, DSC and SEM analyses were carried out to understand the effect on the bread's microstructure when using vacuum during baking. No significant differences (p > 0.05) were observed in the hardness and specific volume of the partial-vacuum baked GFB; however, changes in the total water loss and in the total colour change were statistically significant (p < 0.05). The DSC, SEM and XRD results showed that more crystalline structure and different starch crystal types formed after partial-vacuum baking. Storage properties were also investigated over a 3-day period. Partial-vacuum baking significantly affected the total water loss and the texture parameters (p < 0.05) during storage. Partial-vacuum baked samples were softer and had a tendency to become stale more slowly than the control. The findings indicate that the partial-vacuum baking method increases the shelf life of gluten-free products by modifying the microstructure of the bread.     

6种杜鹃属花粉形态及活力研究

为了解不同杜鹃花属植物花粉的形态、活力和寿命,观测映山红、迎红杜鹃、满山红、密枝杜鹃、高山杜鹃和白花杜鹃花粉形态结构,采用TTC染色法测定6种杜鹃花粉贮藏活力,研究不同杜鹃花粉活力随贮藏时间的变化规律。6种杜鹃花粉均为四合体复合花粉,呈球形四面体结构,不同花粉四合体的直径28.0~55.0 μm,花粉由大到小依次为高山杜鹃>迎红杜鹃>映山红>白花杜鹃>满山红>密枝杜鹃。不同杜鹃花粉大小差异极显著。6种杜鹃花粉贮藏7天,生活力为62.4%~72.9%,花粉生活力由高至低依次为白花杜鹃>高山杜鹃>映山红>密枝杜鹃>迎红杜鹃>满山红,不同种之间差异显著。随贮藏时间延长,不同杜鹃花粉生活力呈不同程度下降,下降速度由慢到快依次为白花杜鹃<映山红<迎红杜鹃<满山红<密枝杜鹃<高山杜鹃。6种杜鹃间的花粉生活力随储藏时间变化差异极为显著。贮藏期7~21天的花粉生活力,白花杜鹃>映山红>迎红杜鹃>满山红>密枝杜鹃>高山杜鹃。不同贮藏期之间,花粉生活力差异极显著。6种杜鹃花粉形状结构基本一致,花粉大小存在差异。白花杜鹃花粉活力高,失活慢;高山杜鹃花粉采集后7天内保持较高的活力,随后快速失活,花粉寿命短;映山红亚属较杜鹃亚属的杜鹃花粉失活速度慢。