“风味2号”甜瓜果实成熟过程中的品质变化

以60Coγ射线育出甜瓜新品种"风味2号"为材料,研究其果实发育和品质形成的动态变化。结果表明,从授粉后第5天开始果实快速膨大,第30天时鲜重达最大。从授粉后第29天开始,果肉可溶性糖含量迅速增加,其后保持稳定,至第34天显著降低。可滴定酸含量随果实的发育逐渐增加,糖酸比的高峰出现在授粉后第30-34天。气相色谱表明,"风味2号"果实中主要可溶性糖为果糖、葡萄糖和蔗糖,有机酸为苹果酸和柠檬酸,其中柠檬酸是主要有机酸。气相色谱-质谱联用分析显示:果实有35种挥发性物质,其中酯类占35.24%,酸类占19.21%,醇类为14.28%,醛类为11.71%。     

Proteomic analysis of up-accumulated proteins associated with fruit quality during autumn olive (Elaeagnus umbellata) fruit ripening

Fruit ripening is a complex phenomenon that makes berries attractive and also determines their nutritional value. Autumn olive ( Elaeagnus umbellata Thunb.) fruit is a rich source of many human health-related nutrients. The changes in pericarp color are initiated at early developmental stages, coinciding with the fast increase in fruit size. Fruit quality traits with special emphasis on soluble sugars, organic acids, lycopene, and total protein contents were assayed during the fruit ripening. In the fully ripe fruit, glucose and fructose were the principal sugars, malic acid was the most abundant organic acid, and lycopene concentration was extremely high. A proteomic analysis was used to identify up-accumulated proteins induced by the ripening. Among 63 up-accumulated protein spots, 43 were successfully identified by MALDI-TOF/TOF-MS. All 43 proteins were novel for autumn olive, and 8 were first reported in the fruit. Twenty-one proteins of known function were involved in sugar metabolism, citric acid cycle, isoprenoid metabolism, fatty acid synthesis, and protein hydrolysis. The possible roles of these 21 accumulated proteins in autumn olive fruit quality are discussed.     

施有机肥及套袋对鸭梨果实风味品质的影响

为探讨施有机肥和套袋对鸭梨果实风味品质的影响,采用气相色谱-质谱联用技术（GC-MS）及高效液相色谱技术（HPLC）,研究了生长期施有机肥和套袋对鸭梨果实挥发性成分、 糖类和有机酸组分等风味物质的组成和含量的影响。结果表明, 供试鸭梨共检测到挥发性物质3类30种,其中酯类26种、 烯类3种、 醇类1种。施有机肥和套袋改变了鸭梨果实的特征香气成分的种类和含量。施用有机肥使套袋和不套袋鸭梨香气物质种类分别增加8种和6种,香气物质总量分别增加182.89%和127.16%。套袋使施有机肥和复合肥鸭梨的香气物质种类分别减少了8种和10种,香气物质总量分别减少66.32%和72.98%。不同处理鸭梨共检测到4种糖、 7种有机酸组分,其中糖组分主要为果糖,其次为蔗糖、 山梨醇、 葡萄糖; 有机酸组分主要为苹果酸,其次为乙酸、 柠檬酸、 莽草酸、 奎宁酸、 酒石酸、 琥珀酸。施用有机肥使鸭梨糖总量和酸总量升高,套袋使鸭梨糖总量和有机酸总量降低。施有机肥使鸭梨果实香气物质种类和含量增加,糖类和有机酸含量升高,而套袋使鸭梨果实香气物质种类和含量减少,糖类和有机酸含量降低。     

设施油桃果实发育过程中有机酸代谢的研究

以设施栽培"超红珠"油桃为试材,测定了果实发育过程有机酸含量及相关代谢酶——柠檬酸合酶(CS)、苹果酸酶(ME)、苹果酸脱氢酶(MDH)的活性,并对果实中有机酸积累及酶活性的关系进行了分析。研究结果表明:随油桃果实发育,其有机酸含量呈先升高后降低趋势,于盛花后49d达到最高值;苹果酸含量与总有机酸含量变化趋势相似;柠檬酸含量呈逐渐升高趋势,至果实成熟有所降低;果实成熟期苹果酸与柠檬酸含量相近。有机酸相关代谢酶CS活性变化与柠檬酸含量相关性不大;果实发育后期ME活性逐渐升高,促进了苹果酸的降解和转化;MDH活性变化与苹果酸含量显著相关。因此抑制果实发育前期MDH的活性、促进果实发育后期ME的活性可以降低果实酸含量,提高糖酸比。     

不同变种甜瓜糖分积累及蔗糖代谢酶活性动态变化

为了解不同类型甜瓜糖分积累及糖代谢特点,选用厚皮甜瓜品种X228、普通甜瓜品种B154及越瓜品种H227为材料,定期取样测定果实成熟过程中的葡萄糖、果糖、蔗糖含量和蔗糖代谢相关酶活性,研究不同变种甜瓜果实发育过程中糖分积累及相关酶动态变化差异。结果表明,授粉15 d至果实成熟期间,3个甜瓜品种的果实葡萄糖与果糖含量的变化均较小,品种间差异不显著。3个甜瓜品种果实蔗糖含量存在显著性差异,其中H227果实几乎无蔗糖积累,葡萄糖和果糖是果实的主要糖组分;B154和X228果实蔗糖含量随着果实发育而快速增加,蔗糖积累存在明显的转折点,蔗糖是B154和X228这2个品种成熟果实中最主要的糖组分,且果实蔗糖含量提高的同时蔗糖磷酸合成酶(SPS)活性上升、酸性转化酶(AI)活性降低,蔗糖合成酶(SS)合成方向的活性与蔗糖含量关系不显著。根据蔗糖含量的差异,可将甜瓜分为蔗糖积累型和低蔗糖积累型两类,前者果实蔗糖含量的上升被认为是SPS活性上升与转化酶(特别是AI)活性下降共同作用的结果,后者果实内极低的蔗糖含量被认为是SPS活性较低导致的。本研究结果为甜瓜种质资源创新利用和甜瓜果实糖分积累调控研究奠定了理论基础。     

五九香梨贮藏期间挥发性化合物和理化性状的变化(英)

利用高效液相色谱法测定贮藏期间五九香梨的糖和有机酸的组成及变化,采用固相微萃取方式（SPME）进行萃取,并结合气相色谱和质谱（GC/MS）分析检测梨果实中的挥发性香气成分。得出以下主要结论：果糖是五九香梨的主要糖类,其次是葡萄糖和蔗糖。随着贮藏期的延长,果糖先有增加的趋势,在贮藏的第三个月内,果糖含量处于最高,而蔗糖和葡萄糖减少趋势不明显。五九香梨果实中的主要有机酸是苹果酸和柠檬酸,整个贮藏期间,柠檬酸和酒石酸含量处于上升趋势,苹果酸和奎宁酸含量在第一、二月贮藏期间增加,而后开始下降;莽草酸含量在贮藏期第一到第三阶段上升,而后略下降;琥珀酸含量在第一到第二阶段变化不明显,接着有上升的趋势,在第三阶段含量达到最高,第四和第五阶段略低于第三阶段;乙酸含量变化不明显。梨果实的硬度略有下降,贮藏的前3个月,可溶性固形物含量有上升的趋势,随后开始缓慢下降。五九香梨的主要香气成分化合物有乙酸己酯 (49.35%),乙酸丁酯 (19.56%),己酸乙酯 (5.16%),丁酸乙酯 (4.92%),乙酸乙酯 (1.08%),(E,Z)-2,4-癸二烯酸乙酯 (0.84%)等。在整个贮藏期间,部分香气成分随着贮藏期的延长而略有增加,尤其是酯类化合物。结果显示：果实硬度、可溶性固形物、糖、有机酸和香气的组成与变化对五九香梨果实的品质都有一定的影响。     

土壤有机营养对“红富士”苹果果实产量和品质的影响

通过野外调查与室内分析相结合,运用相关分析和通径分析等统计方法,研究苹果园土壤有机酸、 单糖、 B族维生素的含量与苹果果实品质和产量的关系。结果表明,土壤阿拉伯糖、 烟酰胺、 柠檬酸与果实有机酸含量呈极显著正相关,相关系数分别为0.621、 0.648、 0.587; 阿拉伯糖、 柠檬酸和维生素B2与果实可溶性糖含量通径系数大,为1.123、 0.668、 0.757,是影响可溶性糖含量的主要正因子,土壤草酸含量与其通径系数为负值（－0.558）; 核糖和鼠李糖与果实花色苷的通径系数最大,为0.706、 0.644,而乙酸和草酸对花色苷形成有负影响,通径系数为－0.765、 －0.664; 三类土壤有机营养与果实维生素C含量的正相关性都极为显著;果实可溶性固形物与酒石酸、 维生素B6含量呈极显著正相关,相关系数为0.682、 0.613;土壤糖类与果实硬度大小呈负相关,与果实的大小呈显著正相关; 阿拉伯糖、 核糖、 维生素B2和乳酸与果树产量的通径系数及相关系数明显,是影响果树产量的主要因素。     

Effect of sample preparation on the measurement of sugars, organic acids, and polyphenols in apple fruit by mid-infrared spectroscopy

The objectives of this study were (i) to test different conditions of freezing, thawing, and grinding during sample preparation and (ii) to evaluate the possibility of using mid-infrared spectroscopy for analyzing the composition of sugars, organic acids, and polyphenols in apples. Seven commercial apple cultivars were chosen for their large variability in composition (total polyphenols from 406 to 1033 mg kg(-1) fresh weight). The different conditions of sample preparation affected only the phenolic compounds and not sugars or organic acids. The regression models of the mid-infrared spectra showed a good ability to estimate sugar and organic acid contents (R(2) ≥ 0.96), except for citric acid. Good predictions were obtained for total phenolic, flavan-3-ols, and procyanidins (R(2) ≥ 0.94) provided oxidation was avoided during sample preparation. A rapid and simple procedure was then proposed for phenolic compounds using sodium fluoride during sample homogenization at ambient temperature and freeze-drying before spectra acquisition.     

Effects of genotype, latitude, and weather conditions on the composition of sugars, sugar alcohols, fruit acids, and ascorbic acid in sea buckthorn (Hippophaë rhamnoides ssp. mongolica) berry juice

Sea buckthorn berries (Hippopha? rhamnoides ssp. mongolica) of nine varieties were collected from three growth locations in five inconsecutive years (n = 152) to study the compositional differences of sugars, sugar alcohols, fruit acids, and ascorbic acid in berries of different genotypes. Fructose and glucose (major sugars) were highest in Chuiskaya and Vitaminaya among the varieties studied, respectively. Malic acid and quinic acid (major acids) were highest in Pertsik and Vitaminaya, respectively. Ascorbic acid was highest in Oranzhevaya and lowest in Vitaminaya. Berry samples of nine varieties collected from two growth locations in five years (n = 124) were combined to study the effects of latitude and weather conditions on the composition of H. rhamnoides ssp. mongolica. Sea buckthorn berries grown at lower latitude had higher levels of total sugar and sugar/acid ratio and a lower level of total acid and were supposed to have better sensory properties than those grown at higher latitude. Glucose, quinic acid, and ascorbic acid were hardly influenced by weather conditions. The other components showed various correlations with temperature, radiation, precipitation, and humidity variables. In addition, fructose, sucrose, and myo-inositol correlated positively with each other and showed negative correlation with malic acid on the basis of all the samples studied (n = 152).     

红壤施用包膜有机酸对解除小麦铝毒的作用研究

通过盆栽试验研究红壤施用柠檬酸、草酸和苹果酸三种不同包膜有机酸对不同小麦品种解铝毒的作用。结果表明,红壤上施用包膜有机酸对小麦具有较好的解铝毒效果,增加了小麦产量。三种包膜有机酸中柠檬酸的效果最佳。有机酸解铝毒的效果因小麦品种而异,其中敏感小麦优于抗性小麦。     

Detection of exogenous citric acid in fruit juices by stable isotope ratio analysis

A new method has been developed for measuring the D/H ratio of the nonexchangeable sites of citric acid by isotope ratio mass spectrometry (IRMS). Pure citric acid is transformed into its calcium salt and subsequently analyzed by pyrolysis-IRMS. The citric acid isolated from authentic fruit juices (citrus, pineapple, and red fruits) systematically shows higher D/H values than its nonfruit counterpart produced by fermentation of various sugar sources. The discrimination obtained with this simplified method is similar to that obtained previously by applying site specific isotopic fractionation-nuclear magnetic resonance (SNIF-NMR) to an ester derivative of citric acid. The combination of carbon 13 and deuterium measurements of extracted citric acid is proposed as a routine method for an optimum detection of exogenous citric acid in all kinds of fruit juices.     

Influence of mitochondria origin on fruit quality in a citrus cybrid

Sugar, organic acid, and carotenoid are the most important indicators of fruit taste and nutritional and organoleptic quality. These components were studied on fruit pulp of the cybrid between Willow leaf mandarin ( Citrus deliciosa Ten.) and Eureka lemon [ Citrus limon (L.) Burm.] and the two parents. The cybrid possessed nuclear and chloroplast genomes of Eureka lemon plus mitochondria from Willow leaf mandarin. The impact of new mitochondria on fruit quality was studied during the mature period. Levels of organic acids were slightly higher in the cybrid fruit pulp than in Eureka lemon. No significant difference in sugar and carotenoid content was observed between the cybrid and the lemon. Results confirm that the main genetic information for the biosynthesis of sugars, organic acids, and carotenoids is contained in the nucleus. In Citrus, cybridization can be used as a strategy to breed specific traits associated with mitochondrial genomes, such as male sterility, without affecting the main organoleptic and nutritional qualities.     

Content and bioavailability of organic forms of nitrogen in the O horizon of a podzol

It is often thought that the most important source of nitrogen for plants and microorganisms comes from amino acids and amino sugars when they are hydrolysed in acid conditions. We did a microcosm experiment to test the hypothesis. In the experiment spruce seedlings (Picea abies L. Karst) were grown for 145 days in soil taken from a podzol Oa horizon under a long-term nitrogen fertilization experiment (control and N-treated soil). Net changes in different pools of organic N were determined using standard fractionation (acid hydrolysis and pyrophosphate extraction). During the experiment the amino acid and amino sugar pools decreased significantly (14% and 15% for the control and 10% and 17% for the N treatment), whereas no significant change was observed in the non-amino acid plus non-amino sugar fraction. On a per organic C basis there was even a significant increase in the non-amino acid plus non-amino sugar fraction of 11% for the control and 8% for the N treatment. Pyrophosphate extractions suggest that amino acids or amino sugars associated with the humin fraction were more accessible to microbes and plants than those associated with the humic acid, fulvic acid and hydrophilic substances. The long-term N fertilization (about 73 kg N ha⁻¹ was added annually as NH₄NO₃ during a 24-year period) resulted in an enrichment of all major fractions of organic N, i.e. amino acids, amino sugars and non-amino acids plus non-amino sugars. This enrichment was largely the result of small increases in all of the amino acids rather than large increases in just a few.     

INFLUENCE OF NITROGEN FERTILIZATION ON NICKEL ACCUMULATION AND CHEMICAL COMPOSITION OF COFFEE PLANTS DURING FRUIT DEVELOPMENT

Nutritional and physiological significance of micronutrients in coffee plants, especially with regard to nickel (Ni) is still unknown. The dynamics of nitrogen (N), phosphorus (P), potassium (K) and Ni accumulation in coffee fruits, as well as their relationships with total soluble protein, amino acids, reducing sugars, and starch content during coffee fruit development (green, ripe, and dry fruits), were investigated. Coffee trees received three N fertilizer rates (0, 150, and 300 kg of N ha^?1) as ammonium sulfate split into three applications per year. Nitrogen fertilization increased reducing sugars and starch concentrations in ripe fruits. In contrast, green fruits showed the highest amino acid and Ni concentrations. Fruit Ni concentration decreased in both green and ripe fruits as N rates increased; thus, indicating the possibility of either a N-associated dilution effect on Ni concentration or that Ni uptake by roots and/or transport to developing fruit was limiting. Plant nutritional status and fruit development stage influenced the coffee grain chemical composition. Furthermore, the variation in reducing sugars and starch content was more closely linked to the stage of fruit development than to N supply. A supposed relationship among the decreased of caffeine, starch, amino acids, and proteins with Ni content during green fruit development suggests a fundamental role for Ni in coffee fruit ripening. The interaction between N and Ni metabolism during fruit ripening might influence the chemical parameters involved in the coffee grain quality. This is the first report documenting changes in Ni concentrations of coffee fruit as a function of N fertilization rates and the development stage, but further research is needed to better understand the significance of N-Ni interaction in developing coffee fruit.     

Effect of Recent Genetic Improvement on Some Analytical Parameters of Tomato Fruit Quality

Abstract

Poor flavor in tomato fruit is a serious consumer concern. It could be said that tomato flavor has declined as variety selection and tomato production has placed emphasis on yield, fruit size, firmness, disease resistance, and processing performance and not on aspects of organoleptic fruit quality. Consumers frequently associate recent varieties with a lack of flavor, although such an association has not been proven. We have reviewed the scarce available literature on the influence of recent genetic improvement on quality attributes of tomato. As a case study, we have analyzed several parameters related to fruit quality in some traditional Spanish cultivars and commercial F1 hybrids of tomato. Organic acids and sugars were determined by high performance liquid chromatography (HPLC). Sodium (Na), potassium (P), and phosphorus (K) were analyzed by atomic absorption spectroscopy. Levels of respiration and ethylene production were measured, and fruit firmness was determined using a texture analyzer. All determinations were performed at two maturity stages, representing two frequent consumption stages. Differences between traditional cultivars and hybrids were found for respiration rates, ethylene production, P and K fruit contents. We also found important differences between “old” and “modern” cultivars for their organic acids profile. All cultivars showed similar levels of malic and succinic acids, but the modern hybrids showed a ～75% higher content of citric acid. This could be due to the F1 hybrids carrying chromosomal segments recently introgressed from wild Lycopersicon species. The influence of recent genetic improvement on quality attributes of tomato fruit is discussed.     

沙地桃品种果实物候期和果实品质比较研究

提高桃果实品质一直是学者们研究的热点,为全面了解不同桃品种在光热资源充足的沙漠边缘地区的栽培表现,为同类区域桃树栽培提供科学依据,基于利用光热资源增加桃果实糖分积累的理论,以6个桃品种为试材,通过田间调查和品质指标测定,比较这6个桃品种在武威沙地栽培条件下的物候期和果实品质表现。结果表明,6个桃品种在武威沙地栽培,果实发育期92～174 d。不同桃品种单果重97.35～269.68 g,由大到小依次为中华寿桃、雨花露、夏甜、中桃5号、红油桃4号、瑞光27号。果实着色由深到浅依次为瑞光27号、中桃5号、红油桃4号、夏甜、雨花露、中华寿桃。不同桃品种可溶性固形物含量为112.8～150.0 g/kg,蔗糖、果糖和葡萄糖含量为80.48～127.34 mg/g,甜度值由高到低依次为雨花露、夏甜、红油桃4号、中桃5号、中华寿桃、瑞光27号。不同桃品种苹果酸含量为0.85～3.22 mg/g,柠檬酸含量为0.27～2.77 mg/g,总酸含量由高到低依次为红油桃4号、中桃5号、瑞光27号、雨花露、中华寿桃、夏甜。可见,雨花露、夏甜、红油桃4号、中桃5号、瑞光27号这5个桃品种在武威沙地栽培时均能正常成熟,且果实品质表现良好。     

Changes in sugars,acids, and volatiles during ripening of koubo [Cereus peruvianus (L.) Miller] fruits

The columnar cactus Cereus peruvianus (L.) Miller, Cactaceae (koubo), is grown commercially in Israel. The unripe fruits are green, and the color changes to violet and then to red when the fruit is fully ripe. The content of soluble sugars was found to increase 5-fold during ripening. Glucose and fructose were the main sugars accumulated in the fruit pulp, and each increased from 0.5 to 5.5 g/100 g fresh weight during ripening. The polysaccharides content decreased during ripening from 1.4 to 0.4 g/100 g fresh weight. The titratable acidity decreased and the pH increased during ripening. The major organic acid found in the fruit was malic acid, which decreased from 0.75 g/100 g fresh weight at the mature green stage to 0.355 g/100 g fresh weight in ripe fruits. Citric, succinic, and oxalic acids were found in concentrations lower than 0.07 g/100 g fresh weight. Prominent accumulation of aroma volatiles occurred toward the end of the ripening process. The main volatile found in the ripe fruit was linalool, reaching concentrations of 1.5-3.5 microg/g fresh weight.     

磷、钾营养对柑桔果实产量、品质和贮藏性的影响

采用田间试验以柑为材料研究了连续4年施用磷、钾肥后对柑桔果实的产量、品质和贮藏性的影响。结果表明,施用磷、钾肥,尤其磷、钾肥配施可显著提高柑桔果实的单果重和产量,以及采收时果实的可溶性固形物含量、可溶性糖含量、还原糖含量、糖/酸比和维生素C(Vc)含量,降低可滴定酸含量;并且可以有效地降低柑桔果实在贮藏过程中的失重率和烂果率,减缓糖分、酸度和Vc含量的下降。磷钾营养对于提高柑桔果实的耐贮性和维持贮藏过程中果实的风味和营养品质有一定的作用。