不同采收期对中华寿桃贮藏生理和品质的影响

以中华寿桃果实为试材,在(1±0.5)℃、相对湿度(90±5)％条件下对4个不同成熟度果实贮藏7周,通过对果实硬度、可溶性固形物、可滴定酸、乙烯生成速率、呼吸速率、细胞膜透性、褐变度等生理指标研究和果实感官品质评价,以确定适于低温冷藏的中华寿桃最佳采收期.结果表明:不同采收期对果实硬度、可溶性固形物含量和可滴定酸的保持,呼吸速率、乙烯释放及果实褐变度等方面的影响具有明显的差异,10月25日采收的果实贮藏效果明显优于其它处理.贮藏后期果实品质感官评价结果表明,低温冷藏条件下不同采收期对中华寿桃果实品质的影响依次是10月25日＞10月20日＞10月30日＞10月15日.     

三种树形对中华寿桃生长及果实品质的影响

对中华寿桃V字形、改良纺锤形和自然开心形3种树形的长、中、短果枝和果实进行对比试验研究,得出不同树形对果枝、生长势、花芽量及果实的硬度、着色率和可溶性固形物含量等质量指标的影响。     

中华寿桃果实褐心病的发生及预防措施

河北省衡水市从20世纪90年代中后期引进栽培中华寿桃,曾遭遇两次严重冻害,目前尚存66.7hm2.该品种产量高,666.7m2产量可达2000～3000kg,但果实在成熟期易发生褐心病.发病果果核附近果肉变褐色,含水量和含糖量均降低,食之不脆且略带苦味,但与缺硼、缺钙症状有别.采后贮藏运输过程中,病果褐变部分继续向周围果肉组织蔓延,降低商品价值,甚致不堪食用.为找出褐心病病因,笔者2005年9～10月对武强县、饶阳县约10hm2中华寿桃进行了调查,并提出了防治措施.     

中华寿桃果实“褐心病”发病原因及解决办法

河北省衡水市从20世纪90年代中后期开始引入中华寿桃,现栽培面积60余hm2。目前该品种在成熟期易发生“褐心病”,即果核附近果肉褐变,降低了商品价值。为找出中华寿桃褐心病的发病原因,我们于2005年9月25日至10月20日对武强县、饶阳县的42户果农约15hm2中华寿桃果园进行了详细调     

几种防褐变剂对去皮切片马铃薯贮藏的影响

几种防褐变剂对去皮切片马铃薯的贮藏试验表明,采用３００ｍｇ／Ｌ的亚硫酸钠液处理,能有效抑制马铃薯组织中多酚氧化酶的活性,防褐变效果佳,维生素Ｃ损失少。     

三种树形对中华寿桃生长及果实品质的影响

对中华寿桃V字形、改良纺锤形和自然开心形3种树形的长、中、短果枝和果实进行对比试验研究，得出不同树形对果枝、生长势、花芽量及果实的硬度、着色率和可溶性固形物含量等质量指标的影响。     

香蕉采后不同处理对果实品质和褐变染病的影响

对采后香蕉果实进行蜂蜜、茶树油、苯扎氯铵、邻苯基苯酚、CPPU及草酸等31组不同的处理,在(25±2)℃室温,RH 85%～95%的环境下贮藏,并定期取样进行观察测定。结果表明:1∶5(v/v)蜂蜜、0.1%及0.5%茶树油、10mg/L CPPU及10mg/L CPPU与10mg/L BA及50mg/L GA3组合、20mmol草酸等处理具有较好的保鲜效果;以CPPU系列处理测定呼吸变化,可明显抑制呼吸强度(对照:157.79±8.46mg·kg-1·h-1;10mg/L+10mg/L BA处理后为132.56±6.48mg·kg-1·h-1),延后了呼吸峰的出现。且以上处理对延缓果实衰老及成熟软化、保持色泽变化、显著抑制果皮褐化,有效降低果实真菌侵染等均有较好的效果。     

贮藏温度对鲜切嘎啦苹果褐变的影响

研究了鲜切嘎啦苹果在常温、2、6、10℃下贮藏的褐变情况及相关酶活性,以探索低温贮藏对鲜切嘎啦苹果采后保鲜的效果及适宜的贮藏温度.结果表明:低温冷藏可有效抑制多酚氧化酶(PPO)和过氧化氢酶(POD)活性,延缓鲜切苹果的褐变和衰老;同时冷藏抑制了总酚含量的上升,降低苯丙氨酸解氨酶(PAL)的活性,保持鲜切苹果较高品质.但由于2℃条件下贮藏鲜切苹果会出现低温冷害,所以选择在6℃条件下贮藏鲜切嘎啦苹果较为适宜.     

应用永富复合氨基酸液肥提高中华寿桃果实品质的试验初报

中华寿桃采收前30天和15天各喷一次600倍和800倍永富复合氨基酸液肥，并以清水作对照，结果表明，喷布600倍永富液肥，单果重比对照增加40g、红色果率增长25.2%、可溶性固形物含量增加6.5%，总糖增加5.8%，还原型Vc增加0.97mg/100g。     

不同处理对采后“南果梨”贮藏期间果皮钙形态及褐变的影响

以"南果梨"为试材,研究2%氯化钙处理、0.2%壳聚糖涂膜处理及2%柠檬酸处理对果实贮藏期间果皮褐变及钙形态的影响。结果表明:贮藏期间,氯化钙处理、壳聚糖涂膜处理、柠檬酸处理与对照相比显著提高了果皮中总钙含量,延缓了总钙含量的下降;果胶酸钙是果皮中的主要钙形态,约占全钙的53.4%~75.1%;氯化钙处理、壳聚糖涂膜处理和柠檬酸处理显著抑制了果皮中水溶性钙、果胶酸钙下降,促进草酸钙的增加;贮藏末期,氯化钙处理"南果梨"果皮褐变指数为5.556%、壳聚糖涂膜处理果皮褐变指数为16.667%、柠檬酸处理果皮褐变指数为25.000%,对照果皮褐变指数高达88.889%。相关性分析表明,果皮褐变与水溶性钙、果胶酸钙和草酸钙呈显著负相关,与磷酸钙呈显著正相关;氯化钙处理、壳聚糖涂膜处理和柠檬酸处理等3种处理都能通过控制可溶性钙向难溶性钙转变,抑制了果皮褐变的发生,其中以氯化钙处理效果最好。     

果实套袋提高中华寿桃质量的试验初报

中华寿桃套袋能增加果实着色度，使果面洁净，鲜艳，明显降低裂果率。套内黑，外深红褐色和内黑，外浅黄褐色的纸袋，果实不仅外观品质好，而且可溶性固形物含量下降幅度小，分别只比不套袋果低0．2和0．1度。     

套袋黄冠梨黑点病与钙素营养和果实衰老的关系

为探明套袋黄冠梨果实黑点病发病原因,从采后生理、矿质营养水平、酚类物质酶促褐变和果实衰老等方面对套袋黄冠梨果实黑点病进行了研究。结果表明:套袋果呼吸强度显著高于不套袋果;套袋果Ca含量仅为不套袋果的49%-63%,果皮钙素含量未套袋果>套袋健康果>套袋病果,套袋病果与不套袋果果皮N/Ca比值分别为9.8和6.1,K/Ca比值分别为17.6和8.8;果皮和果心酚类物质含量及多酚氧化酶活性(PPO)呈套袋病果>套袋健康果>未套袋果的趋势;套袋病果果皮丙二醛(MDA)含量及电导率显著高于未套袋果;果皮钙素含量与其PPO活性、多酚及丙二醛含量、电导率呈高度负相关。初步分析黄冠梨果实黑点病病因为缺钙性生理衰老。     

不同纸质果袋对湖景蜜露桃果实品质的影响

为探索提高桃果实品质的适宜果袋,以6年生湖景蜜露桃为试材,选用橘红色袋、黄色袋、白色袋和报纸袋等4种不同纸质的果袋对果实进行套袋处理,以不套袋作对照,研究了不同纸质果袋对成熟果实外观和内在品质特性的影响。测定了果重、可溶性固形物、可滴定酸含量、果实色差等物理性状和果实糖、有机酸、花青苷、香气物质的含量。结果表明,白色袋能提高糖和香气物质含量的积累,增加果实风味,但果实外观暗红并涉及果肉;报纸袋果实外观粗糙,不清洁,且香气和酸含量低;黄色袋果实综合品质性状优于报纸袋和白色袋;橘红色袋能改变果实果皮底色,加快花青苷降解,使果实外观光亮(L值大),高雅美观,糖、酸及香气物质等品质指标也相对较高。     

Effect of calcium dissolved in slightly acidic electrolyzed water on antioxidant system,calcium distribution,and cell wall metabolism of peach in relation to fruit browning

To improve storage of peach fruit, the effect of slightly acidic electrolyzed water (SAEW) dissolved without and with Ca(NO₃)₂ (at concentrations of 0.5, 1, and 2%) on fruit browning, antioxidant system, tissue Ca²⁺ content and distribution, metabolism of cell wall polysaccharides, and related modifying enzymes was evaluated at 25°C for 8 d. Results showed that Ca(NO₃)₂ and SAEW had synergistic effects on reducing ethylene production, respiration rates, and browning index; inhibiting the accumulation of free radicals and lipid peroxidation, and polyphenol oxidase activity; maintaining fruit firmness and higher levels of phenolic compounds, enzymatic and non-enzymatic antioxidants; increasing tissue Ca²⁺ content and distribution; and delaying the disassembly of cell wall polysaccharides and activities of cell wall-modifying enzymes. These results revealed that 1% Ca(NO₃)₂ in SAEW treatment has potential as a commercial cleaning process to extend fruit life, through suppressing browning and solubilization of pectin, protecting the antioxidant system, and facilitating Ca²⁺ absorption.     

姬松茸加工过程中防褐变的研究

根据姬松茸酶促褐变的机理,研究了姬松茸加工过程中防褐变的有效方法。以处理后菇片中多酚氧化酶的残存活性及视觉观察菇片放置8h不褐变为指标,确定每种方法的最适参数。结果表明,防止姬松茸褐变有四种方法:沸水热烫10min,0.7％亚硫酸钠溶液浸泡,直接添加0.7％VC或添加0.5％亚硫酸钠与0.3％VC。     

The effect of preharvest calcium sprays on quality attributes,physicochemical aspects of cell wall components and susceptibility to brown rot of peach fruits (Prunus persica L. cv. Andross)

This study was planned to evaluate the effect of preharvest calcium sprays on physicochemical aspects of cell wall components, activity patterns of pectin-modifying enzymes and susceptibility to brown rot (Monilinia fructicola) of peach fruits (Prunus persica L. cv. ‘Andross’). Six or 10 preharvest calcium sprays were applied with two different formulas (calcium chloride and an ethylenediamine tetraacetic acid (EDTA) chelated calcium form) in equimolar calcium concentration (0.12% Ca, w/v). After harvest, peach fruits were cold stored (0 °C, 95% R.H.) up to 4 weeks. Calcium content increased significantly in the calcium-sprayed peaches both in the peel (25–42%) and in the flesh (11–17%), 1 d after harvest. Calcium chloride sprays were more effective than those of chelated calcium, whereas the increase of calcium content in the fruits seems to be unaffected by the 6 or 10 calcium sprays. The increase of cell wall calcium corresponded to increase of calcium in the insoluble pectin fraction, whereas no differences were detected in the calcium of water-soluble pectin fraction. Ethylene production, respiration rate, uronic acid content and activity of pectin-modifying enzymes did not indicate substantial differentiations by preharvest calcium sprays as ripening progressed after harvest or cold storage. Calcium sprays resulted in significant decrease of brown rot development, although no effect on disease incidence was recorded.     

Relationships between strawberry fruit quality attributes and crop load

Crop load can influence fruit quality in several horticultural species. The aim of the present study was to determine the effect of different concentrations of calcium on crop quality traits in three short-day strawberry (Fragaria × ananassa Duch.) cultivars (‘Ventana’, ‘Camarosa’ and ‘Candonga’) and to assess the relationships between crop load and quality parameters. The studies were conducted using a hydroponic system in a greenhouse. Calcium was added as Ca(NO₃)₂ at 2 mM, 3 mM, 4 mM and 5 mM. A completely randomized block design (4 Ca concentrations × 3 cultivars) with three replicates was used. Each replicate consisted of 12 plants grown in polyethylene bags (100 cm × 18 cm × 3 cm) filled with coconut peat. Titratable acidity, total soluble solids and firmness were measured throughout the experimental period. Calcium application had no effect on fruit quality attributes but the genotype effect was clear. At the end of the experiment (28th May, 2008), titratable acidity was positively related to the fresh weight of above-ground biomass and number of leaves respectively in the ‘Ventana’ and ‘Camarosa’ cultivars. Higher values of total soluble solids were found at low crop load in ‘Ventana’ but in ‘Camarosa’ this relation was not found. In ‘Candonga’, higher total soluble solids were linked to crop load. In ‘Ventana’, titratable acidity significantly decreased as crop load increased, and in ‘Camarosa’ high values of titratable acidity were found at different values of crop load. ‘Ventana’ seemed to be more sensitive to the effects of crop load patterns. Genotype was an important factor in determining fruit quality parameters.     

不同品种菊芋总酚含量、PPO活性、POD活性及其与褐变的关系

对5个菊芋品种的总酚含量、PPO活性、POD活性与褐变强度进行了测定。结果表明：不同菊芋品种的总酚含量、PPO活性、POD活性与褐变强度差异显著,其中3个北方品种的各项指标均高于2个南方品种。相关性分析显示,4个外形呈不规则瘤形品种的PPO活性与褐变强度之间呈显著正相关,相关系数r=0.982。褐变主成分分析表明：PPO活性、POD活性和总酚含量这3个变量共同影响菊芋的褐变。     

莲藕在不同贮藏温度下的褐变生理研究

试验研究莲藕在不同贮藏温度下褐变相关酶的活性变化.结果表明低温能显著抑制多酚氧化酶、过氧化物酶和淀粉酶活性,在4℃和10℃下贮藏3种酶的活性始终维持在较低状态,20℃、30℃下贮藏2 d后,过氧化物酶和多酚氧化酶活性急剧上升,淀粉酶活性表现为随温度升高而增强,其中温度达到20℃后酶活急剧上升.     

Effect of pruning intensity on peach yield and fruit quality

Light, medium and heavy pruning treatments were used with one unpruned as check (control) in Flordasun, Flordaking and Saharanpur Prabhat peaches. Fruit yield decreased with the increase in severity of pruning in Flordaking and Saharanpur Prabhat peaches, whereas, medium pruning treatment gave highest yield in Flordasun peach. Pulp weight, stone weight, pulp-stone ratio, ascorbic acid, sugar acid ratio and moisture content were not affected by pruning levels. However, fruit weight, size, TSS, sugar and acid content were significantly increased by pruning in Flordasun peach. Almost all the physico-chemical characters were significantly affected by pruning in Flordaking and Saharanpur Prabhat peaches, in which medium and heavy pruning treatments performed better, respectively.