野生毛花猕猴桃软熟期果实糖酸组分差异分析及品质评价

为探究野生毛花猕猴桃果实糖酸组分与含量及主要品质差异,以江西省南城县自然保护区境内采集的32份野生毛花猕猴桃果实为试验材料,采用HPLC技术对其软熟期果实糖酸组分与含量进行了测定,并利用主成分分析法对供试材料果实品质进行了评价。结果表明,所测野生毛花猕猴桃果实的主要糖组分中以果糖含量最高,葡萄糖次之,蔗糖最少。果糖含量最高达5.97 mg/g(MG24),最低为2.06 mg/g(MG3);葡萄糖含量最高为5.21 mg/g(MG24),最低为0.52 mg/g(MG11);蔗糖含量最高为2.49 mg/g(MG36),最低仅为0.29 mg/g(MG14);它们之间均存在显著性差异。总糖含量最高为12.14 mg/g(MG24),最低为3.01 mg/g(MG11),具有显著性差异。供试材料的主要酸组分为奎尼酸,其次为柠檬酸。奎尼酸含量最高可达1.17 mg/g(MG14、MG15),最低为0.39 mg/g(MG24);苹果酸含量最高为0.41 mg/g(MG12),最低为0.15 mg/g(MG17);柠檬酸含量最高为1.37 mg/g(MG6),最低仅有0.35 mg/g(MG...     

6个龙眼品种(品系)果实生长发育观察及果实品质比较

以石硖、桂明一号、越南迟熟、杂交1-3、杂交2-7和桂龙晚龙眼为材料,研究6个龙眼品种(品系)果实生长发育规律和果实品质,了解6个龙眼品种(品系)在贵港市农业科学研究所的引种表现。结果表明:(1)从6个龙眼果实纵径生长变化曲线可以得出:石硖、桂明一号、越南迟熟、杂交2-7龙眼果实纵径变化呈现"快-慢-快-慢"的规律,而杂交1-3则为"慢-快-慢",桂龙晚果实纵径变化为"慢-快-慢-快"的规律;石硖、桂明一号、越南迟熟、杂交1-3和杂交2-7龙眼的果实横径基本保持平稳的增长速率,而桂龙晚果实横径变化呈现"慢-快-慢-快"的规律;(2)6个龙眼品种果实品质方面,桂明一号果实纵横经和单果重最大,其次是杂交2-7,再者是越南迟熟和桂龙晚,四个品种果实均比石硖龙眼大,杂交1-3果实最小;在可食率方面杂交2-7最高,桂明一号、石硖居中,其余品种均比石硖的可食率低,越南迟熟可食率最低;在可溶性固形物方面杂交1-3最高、其次是石硖和杂交2-7,其余品种的可容性固形物含量不相上下;成熟期最早的是石硖龙眼,其次是杂交1-3和杂交2-7,再次是越南迟熟和桂明一号,桂龙晚表现特晚熟。     

提高龙眼果实品质的研究

本试验通过调查植株挂果量 ,在果期使用“营养丰产素”以及套袋等探讨提高龙眼果实品质的方法。1　“储良”龙眼植株挂果量调查　龙眼疏果存在一个量的问题 ,如何判断植株挂果量是否适中 ,是生产上亟待解决的问题。为探讨这个问题 ,我们于 1997年 7月 2 8日在电白县观珠镇 5年生储良龙眼园进行 ,先将果园中挂果均匀的植株分成 3类 :第一类是挂果较多 ,无夏梢长出的 ;第二类是有部分或少量夏梢长出的 ;第三类是有较多夏梢长出的。然后在每一类植株中各选出 10株树冠大小约 4ｍ ,生长正常的植株 ,调查其产量和果实品质。为保证挂果较多的植株…     

3个杨梅品种果实糖酸组分和含量分析

分析了浙江省3个杨梅主栽品种东魁、荸荠、晚稻果实糖、有机酸的种类和含量。结果表明,供试3个杨梅品种果实糖含量及组分差异较大,晚稻果实蔗糖含量最高,而荸荠果实葡萄糖和果糖含量最高;3个杨梅品种果实均以苹果酸含量最高,其次是琥珀酸和柠檬酸;果实可溶性固形物含量荸荠显著高于东魁、晚稻,可滴定酸含量东魁果实最高,其次为荸荠、晚稻;糖酸比:晚稻>荸荠>东魁,且品种间差异均达显著水平。     

套袋对石硖龙眼果实发育和品质的影响

以石硖龙眼为试材，研究了不同时期套袋对果实生长发育、病虫害及果实品质的影响。结果表明：套袋不影响果实的生长发育类型；套袋后果实的还原糖、总糖含量，单果重，果径，TSS和可食率与对照均没有显著差异；套袋使虫果率有所下降，但增加了落果率，且会使石硖龙眼出现较严重的日灼病。     

鲜食枣果实发育期糖酸组分含量及比例的变化

以新疆喀什地区3个鲜食枣(Zizyphus jujuba Mill.)品种果实为试材,采用高效液相色谱法(HPLC)对“冬枣”“伏脆蜜”“京沧1号”3个鲜食枣品种果实发育过程中糖类和有机酸类各组分含量进行测定,比较不同品种间的果实生长发育过程中糖酸积累差异,以期为揭示其动态变化规律提供参考依据。结果表明：3个鲜食枣品种果实中糖以蔗糖为主,且属蔗糖积累型果实,糖组分含量随果实发育呈整体上升趋势;有机酸以苹果酸为主,且属苹果酸型,酸组分含量随果实发育呈先增加后下降趋势;糖类和有机酸类各组分间各自存在一定相关性;蔗糖和苹果酸是3个鲜食枣品种果实全红期糖酸组分首要指标。     

龙眼新品种东良龙眼果实生长发育和果实性状

分析龙眼新品种东良果实生长发育特性和果实经济性状,并与珠三角主要栽培优质品种石硖龙眼进行对比。结果表明,东良花后32天左右开始长出半透明果肉,15～20天后包满种子。花后84天左右果肉开始快速生长,可溶性固形物含量快速增加。在果实接近成熟时,东良单果和果肉的重量还在快速增长;其果大,可食率高,味甜,肉质爽脆,品质好,可与石硖龙眼相媲美。     

几个早熟苹果品种果实糖酸组分及风味品质的评价

采用高效毛细管电泳仪分离测定了6个早熟苹果品种果实的糖酸组分,并对早丰甜、贝拉、辽伏3个品种可溶性糖、可滴定酸、糖酸比及主要香气成分含量与风味品质的关系进行了研究.结果表明,(1)所有参试品种均以果糖含量最高,品种间变异系数最小,仅为14.59%,但蔗糖和葡萄糖含量与果糖明显不同,在不同品种间存在较大差异,品种间变异系数分别为67.58%和29.94%,果糖和蔗糖含量是影响早熟苹果品种糖类总含量的主要因素.有机酸中苹果酸含量在不同早熟苹果品种也存在较大差异,最高为6.61 mg/g,最低仅为1.55 mg/g;(2)果实可溶性糖、可滴定酸、糖酸比及3种主要香气成分测定和官能鉴评结论在早丰甜、贝拉和辽伏3个品种间存在显著差异,官能鉴评的这种差异性与糖、酸及香气成分等成分测定结果基本一致,因此,在试验条件下,3个早熟苹果品种风味品质评价指标应包括可溶性糖含量、可滴定酸含量、糖酸比及1-丁醇、(E)-2-己烯醛和乙酸丁酯等3种主要香气成分的总含量.     

不同黄肉猕猴桃品种(系)果实品质及糖组分分析

以11个不同品种(系)的黄肉猕猴桃为研究材料,测定其不同品种(系)黄肉猕猴桃的可溶性固形物含量、干物质、可滴定酸、维生素C、糖组分等指标,为选育优良黄肉猕猴桃品种(系)提供依据.试验结果表明,所选11个品种(系)的黄肉猕猴桃单果质量为41.35～120.28 g;果形指数为0.73～1.33,平均值为1.19;可溶性固...     

Effects of bagging on fruit development and quality in cross-winter off-season longan

Clusters of cross-winter off-season longan (Dimocarpus longan Lour) cv. Chuliang were bagged with three types of bags: perforated translucent plastic bag (TPB), white adhesive-bonded fabric bag (WAFB) with about 70% light transmittance, and black adhesive-bonded fabric bag (BAFB) with <10% light transmittance. Bagging treatments began at 34 days after anthesis and continued until harvest. The results showed that bagging modified the microenvironment for fruit development. Bagging with TPB was most effective in increasing humidity, and air moisture within TPB maintained above 90% from 2 weeks after bagging. Bagging with BAFB or WAFB increased humidity most of the time, and the effect was more prominent when the weather was very dry (RH < 60%). All bag types tended to increase temperature and promoted fruit development, resulting in larger sized fruit. Bagging tended to promote early fruit drop but reduced late fruit drop, and the final fruit retention rate was not significantly affected by bagging. Bagging with different materials showed differential effects on incidence of fruit cracking. WAFB and BAFB reduced cracking incidence significantly as compared to the control (5.1% and 11.6% vs 32.8%). Sugar content was not significantly affected by bagging but organic acids including vitamin C (Vc) were considerably affected. Concentration of malic acid, the dominant organic acid in longan aril, was 605.6, 830.0, 1161.0 and 1428 μg/g FW in TPB, BAFB, WAFB and the control. Vc in the aril was significantly reduced by BAFB (108.4 μg/g FW), slightly increased by WAFB (183.9 μg/g FW) and significantly increased by TPB (264.5 μg/g FW) as compared with the control (174.7 μg/g FW). Pericarp of fruit bagged with TPB had a slightly higher content of Vc (1337 μg/g FW), while those bagged with BAFB (873.6 μg/g FW) and WAFB (787.4 μg/g FW) had significantly lower Vc contents than the control (1243 μg/g FW). The responses of oxalate and Vc contents in the aril and the pericarp to bagging treatments showed an opposite trend. The results suggested that WAFB increased fruit size and fruit retention rate while significantly reduced fruit cracking incidence and could be a promising practice for cross-winter longan production.     

翠冠与玉冠梨果实发育过程中色素、糖、酸累积特性研究

为进一步明确不同皮色梨品种果实色素、内在品质成分的变化特性,以褐皮梨新品系玉冠与绿皮梨品种翠冠为试材,测定了果实发育进程中纵横径、果皮与果肉色素含量的动态变化,以及在成熟至采收期间,可滴定酸、可溶性固形物、糖含量的变化特性。结果显示,2品种果实发育均呈"S"型曲线动态变化,果皮与果肉总叶绿素与类胡萝卜素含量及在测定期间的动态变化规律亦无显著差异。在成熟前14d至采收,果实生长趋缓,糖、酸含量急剧变化,2品种表现出各自特点,生产上应针对不同品种的内在品质形成特性,适期采收。     

Developmental problems in over-winter off-season longan fruit. I: Effect of temperatures

Fruit development was investigated in the field in over-winter off-season (bloomed in late November) and on-season (bloomed in mid April) longans (Dimocarpus longan Lour. cv. Chuliang) in 2004–2005 and 2007–2008 crops, and in potted trees grown in phytotrons set at cold (15/10 °C, day/night, simulating winter) or warm temperatures (28/23 °C, day/night) in 2008. Development of fruit in both on-season and off-season longans could be divided into two stages based on the pattern of fresh weight increase. Stage I was characterized by the slow fruit growth, and Stage II by rapid fruit growth with aril expansion. Off-season longan had a longer period of fruit development than on-season longan, chiefly due to a longer Stage I. The development of off-season fruit, especially in Stage I, was exposed to low and abruptly fluctuating temperatures. In contrast, the temperatures during on-season fruit growth were warmer and less fluctuating. Off-season fruit were smaller with a significantly higher fruit drop. Intensive fruit drop did not occur during cold period until temperature had risen. Fruit cracking in off-season longan was severe (27.6%) in 2004–2005 with a dry and cold winter, but negligible in 2007–2008 with a wet and cold winter. In phytotron experiment, trees exposed to the cold temperature regime during early fruit development produced significantly smaller fruit compared to those exposed to the warm temperature regime (6.2 g vs 7.3 g), while there was no significant difference in fruit drop rate and cracking incidence. The results suggested temperatures lower than 15 °C were stressful for the growth of young fruit and reduced the growth potential and thus fruit size. Severe fruit drop in over-winter off-season longan might be associated with stressful cold plus abrupt temperature fluctuations, while severe fruit cracking in over-winter off-season longan might be related to cold and dry weather in the winter.     

果实糖代谢与含量调控的研究进展

甜度作为水果风味的重要组成部分,在果实品质形成中扮演重要角色。糖含量和比例是影响果实风味与甜度的重要因素,在果实发育进程中受到糖转运和代谢的高度调控。因此,了解糖代谢与含量之间的关系,是提高果实品质的关键。植物中的碳水化合物不仅为体内代谢提供能量,而且可以作为响应环境的信号分子起关键作用。重点综述了糖代谢关键酶和相关基因在果实糖含量调控中的作用及糖信号响应不同环境变化的生理和生化过程,旨在为改良果实品质提供理论参考。     

杨梅果实发育与糖的积累及其关系研究

以东魁、荸荠种、水梅为试材,研究了杨梅果实发育与糖积累及其关系。根据杨梅果实大小的增加将果实发育大致分为3个阶段,呈双“S型”曲线动态变化:第1阶段(约盛花32d前)果实纵、横径增长最快;第2阶段(32-63d)果核发育硬化,果重增加明显;第3阶段(63d至成熟)果实进入快速增长高峰,果重迅速增加,光合产物在果实中迅速积累。杨梅果实中积累的糖主要是蔗糖,果糖和葡萄糖仅占总糖的1/4,蔗糖含量在发育初期和中期都较低,盛花52d后开始快速积累直至果实成熟,东魁高于水梅、荸荠种;葡萄糖和果糖变化大致保持同步,第1阶段较高,第2阶段降到最低,第3阶段迅速积累达到最高,与蔗糖积累基本保持一致,成熟时东魁与水梅较荸荠种高且相近。杨梅果实中酸性转化酶(Ivr)与中性转化酶(Nvr)活性变化趋势相同,幼果早期最高,中期降低后维持较低活性直至成熟。品种间pH值变幅相似,果实发育第1阶段最高,第2阶段降到最低,转色后上升。相关分析表明:果实发育动态与蔗糖、葡萄糖、果糖的积累存在着极显著的相关关系,其中果实横径的增加与果实糖积累组分中蔗糖的变化2者间相关性最大(r=0.93255**)。     

套袋对红地球葡萄果实发育过程中糖代谢及转化酶活性的影响

以红地球葡萄为试材,研究套袋对葡萄果实中糖代谢及转化酶活性的影响。结果表明:套袋果实在发育过程中蔗糖、葡萄糖、果糖含量和转化酶活性变化趋势与对照基本一致。果实成熟后套袋果的可溶性总糖含量明显高于对照。在果实发育前期,套袋明显提高了果实中蔗糖的相对含量及酸性转化酶活性。套袋可能主要是通过影响果实发育早期转化酶活性来影响果实糖分积累。     

水分胁迫对‘桂味’荔枝果实发育及糖代谢的影响

【目的】为研究水分胁迫对荔枝果实的生长发育、糖代谢及产量的影响,【方法】以15 a生‘桂味’荔枝(Litchichinensis Sonn‘Guiwei’)为试材,设以灌溉和水分胁迫2个不同的土壤水分处理。【结果】结果表明,水分胁迫下荔枝果实的大小、单果质量降低,果实发育受到抑制。水分胁迫的荔枝坐果率显著降低,同时导致最终产量的下降。对水分胁迫条件下糖积累的研究发现,‘桂味’荔枝前期以积累还原糖为主,果实发育后期主要积累蔗糖;胁迫处理的荔枝果实糖含量前期低于灌溉的,后期总糖、蔗糖及还原糖含量都高于灌溉处理的。在荔枝果实发育后期,分解蔗糖的酸性转化酶(AI)、蔗糖合成酶(SS)及合成蔗糖的蔗糖磷酸合成酶(SPS)的活性都为水分胁迫的高于灌溉处理的,这将有助于增加胁迫的果实库强及糖的积累。【结论】因此为使果实正常生长及提高产量和品质,生产上果实发育前中期应保持足量均衡的水分供应,后期不需要过多水分。     

杏果实发育过程中糖积累与蔗糖代谢相关酶的关系

以新世纪杏作为试材,在不同发育时期测定了果实中蔗糖、葡萄糖和果糖的质量分数以及蔗糖代谢相关酶的活性,对果实中糖积累与酶活性的关系进行了分析。结果表明,在果实发育过程中,蔗糖质量分数与蔗糖合成酶的合成方向和蔗糖磷酸合成酶呈极显著和显著相关,相关系数分别为0.934 9**和0.841 8*,而与中性转化酶活性呈显著负相关,相关系数为-0.842 5*。果实硬核期结束是果实中糖积累和蔗糖代谢相关酶的净活性变化的转折时期。硬核期结束之前果实中蔗糖代谢相关酶的净活性为负值,蔗糖积累缓慢;硬核期结束后进入着色期,蔗糖代谢相关酶的净活性转为正值,蔗糖积累迅速。     

不同微波渗糖工艺对低糖果脯维生素C保存的影响

研究了预处理方式、微波渗糖和干燥工艺等不同加工工艺对低糖果脯维生素C保存的影响,通过追踪测定各个工艺环节中维生素C保存的变化来寻求最佳微波渗糖工艺条件。结果表明,3种预处理方式在维生素C含量保存上以食盐预处理最好,微波预处理次之,热水漂烫预处理最差,质量分数2%的食盐溶液中浸泡30 min时果坯维生素C含量为1.083 0 mg.g-1,效果较好;微波渗糖时采用30%的微波火力渗糖20 min,后期干燥时选用60℃干燥6 h,与其他处理差异显著,果脯口感纯正,可以使多维营养得到最大程度的保存。