Changes in physicochemical characteristics and volatile constituents of strawberry (Cv. Cigaline) during maturation

Changes in the volatile composition of strawberries (cv. Cigaline) at six stages of maturity, from 28 to 44 days after anthesis, were investigated over two harvesting seasons. Volatiles were isolated by direct solvent extraction and analyzed by means of GC-FID and GC-MS, with special attention to the quantification of furanones. Firmness, skin color, soluble solids (SS), titratable acidity (TA), SS/TA ratio, organic acids, and sugars were also determined. With increasing maturity, soluble solids, SS/TA ratio, Minolta a value, and levels of sucrose, glucose, fructose, and malic acid increased, whereas Minolta L value, hue angle (), titratable acidity, and levels of citric acid decreased. Furanones and esters were generally not detected before half-red fruits, whereas C(6) compounds were the main compounds in immature fruits. During maturation, levels of these so-called green components decreased drastically, whereas levels of key flavor compounds increased significantly and were closely correlated with skin color development. Maximum volatile production was observed in fully red fruits.     

Factors affecting taste scores of early season seedless table grape cv. Mystery and Prime.

Table grapes of cv. Mystery and Prime were harvested from 10 farms in two growing areas of Israel over two seasons. The grapes were separated on the basis of sucrose solutions from 12 to 18%; soluble solids content (SSC), titratable acidity (TA), and pH were determined; and taste tests were conducted. SSC gave the best correlation with taste tests, and multiple regression of SSC, TA, and pH improved the correlation. There were both seasonal and regional differences in the measured maturity parameters. Lower TA and higher pH were found in grapes from the Jordan Valley. Volatiles were predominantly C(6) compounds hexanal and 2-hexanal, contributing a fresh aroma to the grapes. It is concluded that Mystery and Prime grapes have good organoleptic quality if harvested at SSC levels of >14%.     

Nondestructive measurement of fresh tomato lycopene content and other physicochemical characteristics using visible-NIR spectroscopy

Measurement of fresh tomato fruit overall quality, and particularly lycopene content, is challenging in the context of high-volume production. An experiment was conducted to simultaneously measure various quality parameters of tomato in a nondestructive manner using vis-NIR reflectance spectroscopy and chemometrics. The sampling set included different cultivars that are obtainable from both retailers' shelves and two greenhouse producers. Results indicate that lycopene content was accurately predicted [r(2) = 0.98; root mean square error of cross-validation (RMSECV) = 3.15 mg/kg], along with color variables such as Hunter a (r(2) = 0.98), L, and b (r(2) = 0.92). Tomato color index (TCI) was better predicted (r(2) = 0.96) than the a/ b ratio (r(2) = 0.89). Firmness prediction, with an r(2) of 0.75, is comparable to what is reported in the literature for other fruits and may have a practical interest. Prediction of internal quality such as pH, soluble solids, titratable acidity, and electrical conductivity was less accurate, partly due to a low variability of these parameters among samples. Predictions were robust with regard to cultivars, except for pink variety tomato. The 400-1000 nm range gave results almost as accurate as the 400-1500 nm range.     

Changes in physicochemical characteristics and volatile constituents of yellow- and white-fleshed nectarines during maturation and artificial ripening

Changes in the volatile composition during maturation and artificial ripening of yellow-fleshed nectarines were investigated by means of GC-FID and GC-MS over three years (1999-2001). Unripe and commercially ripe fruits were placed in ripening chambers until complete ripening and compared to tree-ripe nectarines. Firmness, weight, soluble solids (SS), titratable acidity (TA), SS/TA ratio, organic acids, and sugars were also determined. Furthermore, the tree-ripe and artificially ripened yellow-fleshed nectarines were subjected to sensory analysis by a taste panel. In 2001, a similar experiment on white-fleshed nectarines (cv. Vermeil) was performed to compare with the results obtained on yellow-fleshed nectarines. Levels of volatiles compounds, in particular, lactones and C(13) norisoprenoids, were found to be the same or higher in the artificially ripened nectarines compared with the tree-ripe nectarines. In addition, no significant difference was observed for sweetness, sourness, and the intensities of "peach odors" or "peach aroma" in the sensory analysis between the tree-ripe samples and the artificially ripened nectarines. However, in the latter the levels of SS and the SS/TA ratio were very close to those observed in the initial unripe samples and significantly lower than those observed in tree-ripe nectarines.     

Physico – biochemical properties of tomato (Solanum lycopersicum) grown in heavy – metal contaminated soil

The present study was undertaken to investigate the effect of soil contamination with heavy metals on physico-biochemical properties of tomato fruit. The deleterious effect of soil contamination on the quality and quantity of tomato plant yield was determined. Harvested tomato fruit characteristics including fruit length, diameter, volume and fresh and dry weights, total soluble solids, titratable acidity, lycopene and carbohydrates contents were measured in tomato fruits cultivated in soil contaminated with industrial effluents. In addition, some secondary metabolites (total phenols and flavonoids), micro- and macronutrients were also detected. Residual heavy metals (Cd, Co, Ni and Pb) were examined in the harvested fruits. The obtained results were compared with those of tomato fruits cultivated in non-contaminated soil. Results demonstrate that soil contamination with heavy metals have a negative effect on tomato fruits characteristics, titratable acidity, total soluble solids, lycopene, ascorbic acid, micro-elements and carbohydrates content. Moreover, fruits originated from plants grown in contaminated soil possess high phenols and flavonoids contents and higher heavy metals content compared to control fruits. It is recommended that fruits cultivated in that area not to be eaten by large quantities, to avoid excessive accumulation of heavy metals in the human body.

Abbreviations: (AsA): Ascorbic acid; (DTPA): diethylenetriamine penta acetic acid; (TA): Titratable acidity; (TSS): Total soluble solids     

Effect of Vermicompost in Media on Growth,Yield and Fruit Quality of Cherry Tomato (Lycopersicon esculentun Mill.) Under Net House Conditions

Effects of VC application on tomato production and media properties can last for the third successive season, which was verified in this study to evaluate effects of VC application on growth, productivity and fruit quality of cherry tomato for the third season. Six treatments were designed similarly in the first and second seasons (unchanged design compared to the previous season), including: VC with rice husk ash (RHS) and coconut fiber (CF) 0% VC+ 50% RHS +50% CF (T1- control), respectively. 20%VC + 40% RHS + 40% CF(T2), 40% VC+ 30% RHS + 30% CF(T3), 60% VC + 20% RHS + 20% CF(T4), 80% VC + 10% RHS + 10% CF(T5), and 100% VC(T6). The results showed that the pH, EC, N, P, K, Ca, and Mg available in media were increased with the addition of VC. This finding revealed that the addition of VC significantly improved the physic-chemical media properties, increasing the EC and also increasing the macronutrients in the media resulting in substantial increased the yield and quality of tomato fruits. It is concluded that EC of VC was the key factor for the positive increase of the productivity and quality of tomato and the salinity (EC at 3.52 dS/m) causing restriction of water to fruits that resulted in the increase of the total soluble solids in tomato fruit and without affecting yield reduction.     

Storage temperature effects on blood orange fruit quality.

Orange fruits of two blood varieties (Tarocco and Moro) were stored at 8 degrees C and 22 degrees C for 85 and 106 days, respectively, and analyzed periodically for standard quality parameters (total soluble solids, total acidity, ascorbic acid, juice yield, and rind color) and sensory influencing parameters (anthocyanins, and total and free hydroxycinnamic acids). A decrease in total acidity (TA) and juice yield during storage was observed for both cultivars; total soluble solids (TSS) increased only in the Tarocco oranges stored at 8 degrees C. The increase in TSS observed for Tarocco and the simultaneous decrease in TA in both varieties resulted in a higher maturity index (TSS/TA) for the two cultivars. No loss of vitamin C was noted in Tarocco orange at either temperature, whereas a sharp reduction in vitamin C occurred in the first 50 days of storage for Moro. A significant increase in anthocyanin content was observed in Tarocco and Moro stored at 8 degrees C. Overlong storage induces extensive hydrolysis of hydroxycinnamic derivatives to free acids in Moro orange and these, in turn, could develop the malodorous vinylphenols.     

岩棉短程栽培模式中营养液对番茄生长及果实品质的影响

为实现设施番茄短程栽培过程中营养液的高效供给及标准化管理,寻求短程栽培模式中最优的营养液供给方式,在兼光型植物工厂条件下,研究了营养液电导率值(electric conductivity,EC值)、灌溉频率对番茄植株形态和果实品质的影响.试验以岩棉为栽培基质,3水平EC值为2、4和6 dS/m,3水平灌溉频率为1、3和5次/d,采用全因子试验设计方法,进行9组处理.采用综合评价方法获取最佳的营养液EC值和灌溉频率,并对植株形态和果实品质指标进行数理统计分析.结果表明:营养液EC值和灌溉频率影响植株的株高、茎粗、叶数、叶面积、叶形指数和根面比,同时也影响果实的平均质量、可溶性固形物(soluble solids content)和果形指数.其中EC值对平均果实质量影响显著(P＜0.05),灌溉频率对叶面积和平均果实质量影响极显著(P＜0.01);试验因素的交互作用对茎粗和果形指数影响极显著(P＜0.01),对SSC影响显著(P＜0.05).EC值为4 dS/m,灌溉频率为5次/d的营养液灌溉方式能兼顾植株发育和果实品质良好,该灌溉方式下SSC与平均果实质量呈极显著负相关(P＜0.01).该研究可为设施短程栽培番茄优质高产提供指导依据.     

Irrigation with salt water affects growth,yield, fruit quality,storability and marker-gene expression in cherry tomato

The use of saline water for plant production will become increasingly necessary over future decades. In some cases, fruit quality such as in tomato, can be improved by irrigation with saline water. The influence of different salt concentrations on physiological responses and the expression of some selected genes of cherry tomato (Solanum lycopersicum L), cv. West Virginia 106, was examined. Tomato plants were grown in peatmoss substrate and irrigated with 0, 25, 50, 75, 100 or 150?mM sodium chloride (NaCl) in a glasshouse. The NaCl treatments of 75, 100 and 150?mM salt resulted in shorter plants, decreased stem width, a lower plant dry weight, fewer flowers, and smaller leaf area, while yield was reduced by treatment with concentrations of 50?mM NaCl and above. Average fruit weight and fruit number were also negatively affected by treatment with 50?mM salt and above. Salinity treatment led to increased fruit total soluble solids, titratable acidity and firmness and improved the taste index. Salt-responsive marker genes identified in Moneymaker were also induced in cherry tomato but not at the highest salt concentrations. Our results indicated that cherry tomato treated with 25?mM NaCl produced fruit with improved quality in comparison with non-salinized control plants without compromising yield, while at 50 and 75?mM the improved fruit quality was accompanied by a reduction in yield.     

Effects of substrate hydroponic systems and different N and K ratios on yield and quality of tomato fruit

The present study was carried out to determine the influence of wick and drip substrate hydroponic systems and different ratios of nitrogen (N) and potassium (K) in the nutrient solution on fruit yield and quality (titratable acidity, total soluble solids, ascorbic acid, total soluble sugars, firmness, lycopene, carotenoids) in tomato. Summer and winter tomato crop was raised under two substrate hydroponic systems. Four nutrient solutions (N:K ratios in four combinations) were tested in both the growing seasons at vegetative and reproductive stages of plant development. Among the different nutrient solutions, the solution containing N and K in the ratio of 1.4:3 at vegetative and 1.7:3.5 at reproductive stage increased the total fruit yield and quality of tomato irrespective of hydroponic system or season. Among the hydroponic systems, wick system produced higher fruit yield and better quality in terms of firmness, ascorbic acid, and total soluble sugars in winter crop.     

施钾时期对葡萄转色和品质及钾吸收基因表达的影响

  【目的】  钾肥可促进葡萄果实的提前着色,本研究比较了不同时间施用钾肥对葡萄转色和品质的影响,并从分子水平初步验证了钾肥施用时期对葡萄转色的效果。  【方法】  以江苏盱眙、浙江天台和浙江金华3个地区的5年生‘夏黑’葡萄为试材,分别在果实膨大后4 (T1)、8 (T2)、12 (T3)、16 (T4)天的上午10:00,沟施120 g/株 K₂SO₄水溶肥,以不施钾肥为对照。在每次处理前观察果实颜色,处理后每隔4天统计果实转色率,并采集30粒果实用于测定果实纵横径、果粒重、硬度、可溶性固形物(SS)、可滴定酸(TA)等生理指标。于施肥处理前1 h (上午9:00),采集葡萄第8～9节位成熟叶片4～5片,用于检测VvKUP1、VvKUP2荧光定量相对表达量。  【结果】  4个施肥时期沟施120 g/株钾肥后,3个地区施肥处理均促进了葡萄果实提前转色。与对照相比,在江苏盱眙和浙江金华均以T3处理促进着色效果最好,果实分别提前4和8天左右着色,转色率分别达到95.0%和80.6%;在浙江天台以T2处理促进果实着色效果最好,提前4天左右着色,转色率达到83.4%。沟施钾肥可以促进果粒重和纵横径的增加,在江苏盱眙和浙江金华均以T3处理最好,在浙江天台以T1处理最好。在江苏盱眙,4个沟施钾肥处理均提高了果实可溶性固形物含量,T2、T3、T4处理降低了果实硬度;在浙江金华地区,4个施钾处理均降低了果实可滴定酸含量和果实硬度,提高了可溶性固形物含量;在浙江天台,沟施钾肥降低了果实可滴定酸含量和果实硬度,T1、T2、T3处理提高了可溶性固形物含量。通过对不同时期‘夏黑’葡萄叶片中钾吸收基因的表达分析,发现当钾吸收基因VvKUP1表达趋势由下降转为上升,且VvKUP2表达趋势由上升转为下降时,与最适施肥时期相符合。  【结论】  沟施钾肥可以促进‘夏黑’果实提早着色和果实品质的提高。果实膨大后12天施钾肥在江苏盱眙和浙江金华地区促进‘夏黑’葡萄转色的效果较好,果实膨大后8天施钾肥促进浙江天台地区‘夏黑’葡萄的转色效果较好。葡萄膨大后叶片中两个钾吸收关键基因(VvKUP1和VvKUP2)表达量的变化证明了该时期施钾的必要性。     

番茄综合营养品质指标构建及其对水肥供应的响应

为构建番茄综合营养品质指标,分析其对水肥供应的响应,该文以灌水量和氮、磷、钾肥用量为试验因素,按照四元二次正交旋转组合设计,进行番茄盆栽试验,监测番茄可溶性固形物、可溶性糖、可滴定酸、糖酸比、番茄红素和维生素C 6项单一品质指标,根据主观层次分析法与客观熵权法和基于博弈论的组合赋权法,确定番茄单一营养品质评价指标权重,次序为:番茄红素糖酸比维生素C可溶性糖可溶性固形物可滴定酸;通过近似理想解法,构建番茄果实综合营养品质评价指标。在此基础上,通过回归分析建立番茄综合营养品质与水肥因子的数学模型,分析其对水肥因子的响应关系。结果表明,各水肥因子对番茄综合营养品质的主效应表现为:施磷量施氮量灌水量施钾量。当其他因素为中间水平时,番茄营养品质随灌水量或施氮量的增加呈开口向下的抛物线型变化,随磷肥用量的增加线性增加,随施钾量的增加呈开口向上的抛物线型变化。交互作用表现为,灌水量与施氮量、磷与钾肥用量之间存在显著交互作用。表明灌水量、氮肥用量过高不利于番茄综合营养品质的提高,合理增施磷肥和钾肥可有效提高番茄营养品质。     

Effects of nitrogen application on flavor compounds of cherry tomato fruits

A pot experiment was conducted to determine the effects of N application on volatile compounds, taste compounds, and firmness of fresh tomato fruits. Each pot was filled with 8 kg of clean sand. The experiment consisted of six nitrogen (N)‐application rates with 0, 2.25, 4.50, 9.00, 18.00, and 36.00 mmol N L^–1 in the nutrient solution. Volatile compounds, soluble sugars, soluble solids, titratable acidity, and firmness of fresh tomato fruits were measured. The results show that increasing N application increased the concentrations of 1‐penten‐3‐one, hexanal, cis‐3‐hexenal, 2‐methyl‐4‐pentenal, trans‐2‐hexenal, 6‐methyl‐5‐hepten‐2‐one, titratable acidity, soluble sugars, and soluble solids. By contrast, increasing N supply decreased the concentration of phenylacetaldehyde and first increased and then decreased the concentrations of 2E–4E‐hexadienal and the firmness of fresh tomato fruits. Close relationships between the concentration of various volatile compounds, titratable acidity, soluble sugars, and soluble solids were found. However, concentrations of these flavor compounds were very poorly correlated with fruit firmness. Based on contributions of these compounds to tomato flavor, we assume that moderate high N supply improves tomato flavor, whereas excessive N supply can deteriorate it.     

Juice components of a new pigmented citrus hybrid Citrus sinensis (L.) Osbeck x Citrus clementina Hort. ex Tan

Fruit juice of a new pigmented citrus hybrid named Omo-31 and those of its parents clementine cv. Oroval (Citrus clementina Hort. ex Tan.) and Moro orange [Citrus sinensis (L.) Osbeck] were analyzed during fruit maturation to determine juice yield, total soluble solids (TSS), total acidity (TA), TSS/TA ratio (classical parameters of quality), and potential health beneficial components, such as vitamin C, flavanones, anthocyanins, and phenolic acids. Results showed that juice yield, TA, TSS, and TSS/TA ratio values of Omo-31 were similar to those of the Moro orange. Vitamin C content of the new hybrid was slightly higher than that of clementine and lower than that of the Moro orange, but at maturity stage no differences were observed among the three genotypes. The phenolic compounds content of the new hybrid and those of the parents and their evolution during maturation were studied. At maturity stage the amount of anthocyanins, flavanones, and hydroxycinnamic acids in Omo-31 was found to be notably higher than those of the parents. The high level of antioxidant substances makes this new fruit important for its nutritional benefits.     

Effects of Potassium Application on Flavor Compounds of Cherry Tomato Fruits

ABSTRACT

A pot experiment was conducted to determine the effects of potassium (K) application on volatile compounds, taste compounds, and firmness of fresh tomato fruits. Each pot was filled with 8 kg of clean sand. The experiment consisted of six K application rates with 0, 1.25, 2.5, 5.0, 10.0, and 20.0 mmol K L^?1 in the nutrient solution. Volatile compounds, soluble sugars, soluble solids, titratable acidity, and firmness of fresh tomato fruits were measured. The results show that the concentrations of 3-methylbutanal, 1-penten-3-one, hexanal, cis-3-hexenal, 2-methyl-4-pentenal, trans-2-hexenal, 2E-4E-hexadienal, 6-methyl-5-hepten-2-one, phenylacetaldehyde, phenylethanol, soluble sugars, and soluble solids tended to increase at first and then decrease between 0 to 10.0 mmol K L^?1. K application rate obtaining the highest values of the concentrations ranged from 1.4 to 3.0 mmol K L^?1, with the exception of cis-3-hexenal (1.1 mmol K L^?1), phenylacetaldehyde (4.5 mmol K L^?1), and phenylethanol (4.8 mmol K L^?1). By contrast, increasing K supply increased the concentration of titratable acidity, decreased the ratios of soluble sugars to titratable acidity and soluble solids to titratable acidity. Close correlations were observed between the concentrations of various volatile compounds, soluble sugars, and soluble solids. Based on contributions of these compounds to tomato flavor, we assume that moderate K supply (1.4–3.0 mmol K L^?1) improves tomato flavor, whereas tomato fruits with either no K or high K fertilization have poor flavor due to having undesirable levels of flavor compounds.     

不同品种樱桃番茄氨基酸组成及风味分析

为评价不同品种樱桃番茄的风味及营养价值,比较分析了8个品种樱桃番茄的可溶性固形物含量、总糖含量、有机酸含量、糖酸比、Vc含量、氨基酸含量和氨基酸组成。结果表明,红果樱桃番茄品种的部分风味指标(可溶性固形物、总糖、有机酸、Vc)、氨基酸组成及营养价值(总氨基酸、必需氨基酸含量及氨基酸模式谱)优于黄果品种,尤其是红果品种浙樱粉1号和浙樱红1号,其中,浙樱粉1号樱桃番茄可溶性固形物含量、总糖含量、有机酸含量、Vc含量、呈味类氨基酸(鲜味、甜味、芳香类)含量及氨基酸营养价值均处于较高水平。红果樱桃番茄品种之间的总糖含量、Vc含量,以及黄果樱桃番茄品种之间的有机酸含量、总氨基酸含量、必需氨基酸含量和甜味类氨基酸含量等指标均呈现出较低的变异系数。氨基酸营养价值分析表明,缬氨酸和亮氨酸是樱桃番茄的2个主要限制氨基酸。本研究结果为高品质樱桃番茄的品种选育提供了理论指导。     

Optimization of irrigation and nutrient concentration based on economic returns,substrate salt accumulation and water use efficiency for tomato in greenhouse

To evaluate the effects of different irrigation and nutrient concentration strategy on growth, yield, water use efficiency (WUE), fruit quality and substrate salt accumulation, tomatoes were grown with five different levels of water (W: 50%, 75%, 100%, 125% and 150%) and nutrient concentrations (N: 0.5, 0.75, 1.0, 1.5 and 2.0 times of Hoagland strength(X)). Fruit quality index was determined by normalization of fruit quality parameters. Deficit irrigation at standard concentration of nutrients reduced yields by 17.43% and 15.52% for T₇ (W_75%-N_1.0x) and 49.54%–51.99% for T₈ (W_50%-N_1.0x) during spring-summer (SS) and fall-winter (FW) seasons, respectively. Contents of total soluble solids (TSS), titrable acidity (TA) and sugar acid ratio (SAR) were all increased in water-deficit treatments. T₈ was found to be highest in TSS, TA and SAR except SAR in FW. Over-irrigation with excessive and standard Hoagland nutrient concentration caused non-significant reduction in yield except T₆ (W_125%-N_1.0x) in SS. T₂ (W_100%-N_2.0x) and T₄ (W_100%-N_1.5x) caused more substrate salt accumulation which resulted in significant decrease in yield and WUE. Through economic analysis, over-watering along with excessive nutrients caused profit reductions. Considering water saving, yield and fruit quality through economic analysis, T₇ found to be optimal strategy.     

基于土壤电导率控制的养分供给对设施番茄生长、产量和品质的影响

我国设施蔬菜生产中缺乏有效决策指标来引导养分的科学投入,过量施肥已成为设施农业可持续发展的主要瓶颈。选用土壤电导率（EC）作为控制养分投入的决策指标,探索不同土壤EC对番茄生长、产量以及品质的影响,为未来智能化设施生产提供科学依据。通过在设施番茄体系实地试验,运用可视化电导率传感器对土壤进行实时监测,并结合水肥一体化设备进行养分投入,通过测定不同土壤EC对应的番茄生长、产量以及品质指标来分析最适合番茄生长的土壤EC。结果表明,番茄的株高、茎粗、叶片SPAD值等指标与土壤EC呈二次曲线关系,通过营养生长末期建立的二次曲线拟合得出株高在EC为4.03 mS/cm时达到最大值,茎粗和叶片SPAD值分别在EC为2.93和2.54 mS/cm时达到最大值;干物质累积量和产量也与土壤EC呈二次曲线关系,通过模型拟合得出番茄干物质累积量在EC为2.97 mS/cm时达到最大值,单果重在EC为3.19 mS/cm时达到最大值;外形品质和营养品质多个指标也与土壤EC呈二次曲线关系,模拟结果显示番茄商品果率在EC为2.77 mS/cm时达到最大值,番茄可溶性糖、有机酸、维生素C分别在EC为2.94、3.1...     

Ripening attributes of new passion fruit line featuring seasonal non-climacteric behavior

The passion fruit hybrid cultivar 'Passion Dream' (PD) produces two cycles of fruiting per year, in the summer and winter. Self-hybridization of PD created various lines, including 'Ripens during Summer' (RS), which lacks the ability to abscise during winter, suggesting a seasonal nonclimacteric behavior. The two lines were characterized by several quality traits: PD produced high ethylene levels in both seasons; RS produced significantly less ethylene during summer and almost none during winter. The ratio of total soluble solids to titratable acidity (TSS/TA), and aroma volatiles production, as determined by solid-phase microextraction/gas chromatograph-mass spectrometer (SPME/GC-MS) techniques, and taste indices were highest in PD summer fruits and lowest in RS winter fruits. Peel color in PD was affected by environmental and storage temperatures, whereas RS fruits always showed a strong purple color. The present findings suggest that ethylene production levels in passion fruit greatly influence various ripening processes, including acid degradation, increased TSS/TA ratio, accumulation of aroma volatiles, and tastiness.