利用生化指标预测苎麻产量品质的研究

1984～1987年对10个苎麻当家品种的过氧化物酶同工酶和酯酶同工酶,以及果胶和可溶性糖含量进行了研究,根据苎麻根中过氧化物酶同工酶电泳图谱中主酶带SS和FF的表现特征,把苎麻品种分为三种类型:类型I的苎麻品种为低质类型;类型I的苎麻品种为优质类型;类型I的苎麻品种为中质类型,酯酶同工酶中兵有强活性的5C酶带或4C和5C酶带是高产苎麻品种的特征,苎麻叶中果胶,可溶性总糖和非还原塘含量与苎麻产量呈显著或极显著正相关。     

Fruit yield and quality of strawberry plants transformed with a fruit specific strawberry pectate lyase gene

Two transgenic strawberry lines (Pel 1 and Pel 3) containing the open reading frame of a fruit specific strawberry pectate lyase gene (FaplC) under the control of the CaMV35S promoter have been obtained to evaluate the role of this gene on fruit softening. Ripen fruits from both lines showed a significant down-regulation of FaplC, being the percentage of silencing of 84 and 71% on Pel 1 and Pel 3, respectively. The agronomic behaviour of transgenic plants was evaluated during two consecutive years. Fruit set increased in the two transgenic lines when compared with control plants, although Pel 1 showed a significant reduction on fruit weight. Firmness of full ripen fruits from Pel lines was significantly higher than control fruits, while color and soluble solids were not affected. The increase of firmness in Pel lines was maintained when ripe fruits were stored for 3 days at 25 °C. Histological analysis of ripe fruits showed lower intercellular spaces and a higher degree of cell to cell contact area in transgenic fruits when compared with controls. Altogether, these results suggest a direct relationship between pectate lyase gene expression and strawberry fruit softening.     

蚕沙中叶绿素铜钠盐和果胶的提取工艺

[目的]研究从蚕沙中提取叶绿素铜钠盐和果胶的方法,以综合利用蚕沙资源,变废为宝。[方法]以蚕沙为原料,采用有机溶剂提取法提取叶绿素铜钠盐,用活性炭对果胶脱色。[结果]蚕沙中叶绿素铜钠盐的最佳提取条件为:预处理好的蚕沙50 g采用95%乙醇作为提取剂,500 ml 8%NaOH溶液于70℃水浴中浸提5 h;提取果胶的最佳条件为:在恒温水浴60℃的情况下脱色120 min,沉析时的pH为3.5,沉析温度为50℃,HCl用量为1.5～2.0 ml。[结论]得到的叶绿素铜钠盐和果胶的主要技术指标符合国家标准。     

从不同原料中提取果胶工艺的研究综述

简述了果胶的结构和化学性质以及主要提取方法,并对近几年来国内外从不同原料中提取果胶工艺条件的研究进行综述。     

梨果实成熟生理特性的研究

对鸭梨、酥梨果实的呼吸强度、乙烯生成量、果胶酶活性、果实硬度等进行了测定,结果表明:鸭梨、酥梨果实均可在树上通过呼吸跃变而成熟,分期采收的果与树上留果在盛花后155d 即9月18日通过呼吸高峰,跃变时有超前的果胶酶活性峰、超前或平行的乙烯生成峰,但酥梨没有检测到乙烯。另外,晚采的果实比早采的果实较快地进入呼吸跃变。     

叶面喷施Ca( NO3) 2 和GA 对‘糯米糍’荔枝裂果的影响

 以果实易裂品种‘糯米糍’荔枝为材料, 研究叶面喷施Ca (NO₃) ₂ 和GA 处理对其裂果的影响。结果表明: Ca (NO₃) ₂和GA 处理均能使裂果率明显降低。果实发育初期, 果皮中原果胶和水溶性果胶的含量均有所升高, 且原果胶含量的增高幅度明显; 随着果实的成熟, 可溶性果胶含量有所降低, 原果胶含量大幅度提高。此外, 除果实成熟期外, 果皮内果胶脂酶(PE) 和多聚半乳糖醛酸酶(PG) 的活性一直有上升趋势, 且PG的活性与水溶性果胶的含量有极显著正相关, 而纤维素酶(CX) 在整个果实发育期都表现出较高的活性且有两次明显的高峰。     

苹果双向变动气调贮藏初步研究

 将苹果贮藏在不同温度和不同气体成分组合条件下，定期测定果实的品质和生理生化变化。结果表明，贮藏期间（150-180天）同时变动温度和气体成分，温度从10-15℃降至0℃，CO#-2从12-15%降至6-8%，O#-2为3%，获得很好的保鲜效果。这种处理中果实硬度保持在12磅/厘米#+2以上，显著抑制了果实内乙烯生成和果胶水解。这类贮藏技术建议称为“双向变动气调贮藏”。     

低温贮藏对菠萝细胞壁降解的影响

菠萝在贮藏过程中PG、PE活性升高 ,水溶性糖醛酸含量增加 ,硬度降低 ,同时果肉组织细胞表现为细胞壁微纤丝层次性排列被破坏 ,中胶层电子密度降低。低温可延缓水溶性糖醛酸含量的增加和硬度的下降 ,抑制PG和PE活性 ,从而抑制细胞壁的降解。     

Isolation and partial characterization of a pectic polysaccharide from the fruit pulp of Spondias cytherea and its effect on peritoneal macrophage activation

The total carbohydrate content of the intact pulp of Spondias cytherea was 41%. Polysaccharides were obtained via hot aqueous extraction after defatting with organic solvents. The aqueous extract was treated with excess ethanol to form a precipitate, which was then solubilized in water. The material precipitated upon acidification when HCl was removed. The resulting supernatant fraction was submitted to freeze-thawing treatment yielding a soluble fraction (sFTS). This fraction had Ara, Rha, Gal and GalA in its structure as determined by GC-MS. 13C NMR analysis showed signals assigned to alpha-L-Araf, beta-D-Galp, alpha-D-GalpA and alpha-L-Rhap units, in addition to galacturonic acid units, which were present also as methyl ester. These results suggest a type I rhamnogalacturonan with arabinogalactan branches. Cell eliciting activity in a dose-depending pattern was observed in vitro on peritoneal macrophages treated with sFTS.     

热水萃取法生产澄清香蕉汁的研究

基于热处理可能诱导香蕉果肉中果胶和蛋白质形成水不溶物的理论,研究了热水萃取温度对香蕉汁澄清度、可溶性固形物含量、多酚氧化酶（PPO）和色泽的影响。结果发现,热水温度对香蕉果肉中果胶和蛋白质形成水不溶性聚合物的能力有显著的影响,其中75℃的热水萃取诱导香蕉果肉中果胶和蛋白质形成水不溶物的能力最强,获得香蕉汁的澄清度最高,其透光率（660 nm）接近90%;75℃热水萃取获得的香蕉汁的果胶和蛋白含量最低,分别低于每100 ml 香蕉汁7.3和12.9 mg。由于香蕉果肉中 PPO耐热性强,75℃的热水萃取难以将其完全失活,为防止在香蕉果肉中的 PPO在香蕉汁打浆期间引起酶促褐变,需添加0.05%的 L-半胱氨酸或抗坏血酸进行护色。