番茄（Solanum lycopersicum）果皮和果肉挥发物及香气比较

为探究番茄果皮和果肉挥发物以及香气的差异，以挥发物浓度高的自交系CI1005（红色樱桃番茄）和浓度低的自交系TI4001（绿色普通大果番茄）为材料，采用顶空固相微萃取-气相色谱-质谱-嗅闻法分析番茄绿熟期、转色期、橙熟期和红熟期果皮和果肉挥发物组分及其浓度，描述气味特征及其强度。结果表明，果实成熟过程中，同一自交系果皮和果肉挥发物组分差异较小。每个成熟阶段，CI1005果皮挥发物浓度均显著高于果肉，尤其是醛类、醇类、酮类、酯类和酸类挥发物；TI4001果肉挥发物浓度均显著高于果皮，特别是醛类、酯类和酸类挥发物。CI1005果皮香气强度显著高于果肉，尤其是清香、脂香和麦芽香；果肉仅甜感强于果皮。果皮清香最浓，果肉果香最浓。果实成熟过程中，果皮香气比果肉增加得多，红熟期差异最大。TI4001果肉香气强度显著高于果皮，特别是脂香、蘑菇香和清香。果肉脂香最浓，果皮花香最浓。转色期果皮和果肉香气均最浓，二者香气差异最大。CI1005挥发物组分和浓度及其香气强度均显著高于TI4001。总之，果皮和果肉中挥发物和香气差异显著。     

采收成熟度对红色甜椒贮藏品质的影响

为研究不同采收成熟度对红色甜椒贮藏品质的影响,以"红苏珊"品种为实验材料,分别采收绿熟期、微熟期、半熟期和全熟期的果实,10℃下贮藏。结果表明,贮藏35 d时全熟期采收的甜椒色泽最好,维生素C、类胡萝卜素、花青素含量最高,但失重率较大。半熟期果实的失重率最小,转色较好,可溶性固形物含量和糖酸比水平最高,蛋白质、维生素C、类胡萝卜素含量以及感官评价指数较高。微熟期果实的感官品质最好,蛋白质含量较高,但其他营养成分含量较低,失重率最大,转色欠佳。绿熟期果实的各种营养物质含量最低,转色差。综合考虑红色甜椒的外观品质、营养品质和目标贮藏期,当贮藏期小于21 d时,可以选用全熟期的果实;当贮藏期为21~28 d时,应该选用半熟期的甜椒;当贮藏期在28~35 d时,应该选用半熟期或微熟期的果实进行贮藏。     

电子束辐照对不同成熟度番茄后熟及乙烯生成的影响

为明确电子束辐照对跃变型果蔬采后后熟和保鲜的影响,以不同成熟度番茄为试材,10Me V、10 kW电子直线加速器为射线源,采用不同剂量(0、0.4、1.0 kGy)电子束辐照新鲜采收的番茄果实,测定货架(20±1℃,50%RH,14 d)期间的果皮红色指数、乙烯释放量、ACC合成酶(ACS2)基因和ACC氧化酶(ACO1)基因的表达量及保鲜效果。结果表明,电子束辐照可抑制番茄果实货架期后的变红后熟,剂量越高,抑制程度越大,果皮红色指数越低。电子束辐照对14 d货架期间番茄果实的失重、皱缩、霉变无显著影响。电子束辐照对番茄果实乙烯释放量、ACC合成酶基因和ACC氧化酶基因表达量的影响因番茄果实成熟度不同而异。对成熟度低的绿熟期果实,电子束辐照可抑制其乙烯释放和ACC合成酶基因、ACC氧化酶基因的表达。对成熟度高的红熟期果实,电子束辐照可促进其乙烯释放,但乙烯合成关键酶基因表达量高低因电子束辐照剂量而异,1.0 kGy处理可抑制ACC合成酶基因、ACC氧化酶基因的表达。     

颜色好看的蔬菜一定营养好吗?

颜色好看的蔬菜一定营养好吗？彭惠仙蔬菜的颜色来自不同的色素，但颜色好看营养成分未必高。成熟的番茄由于番茄红素含量增多而呈现红色。鲜红的番茄，吃口较好，但维生素Ｃ的含量，却是转色期（由青变红）的果实最高。辣椒的红色来源于胡萝卜素，在红熟以前，叶绿素含量...     

一氧化氮对绿熟和粉红期番茄采后抗氧化相关酶的影响

以"申冠油"番茄果实为试材,采用不同浓度一氧化氮(20、40、60μL·L-1 NO)在空气条件下处理绿熟期和粉红期的番茄果实3h,在16℃和相对湿度为85%的条件下贮藏20d。分析NO处理对番茄果实中过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)等抗氧化相关酶活性及丙二醛(MDA)和可溶性糖含量变化的影响。实验结果表明:NO处理能促进绿熟期和粉红期番茄中CAT、POD、SOD活性的增加和绿熟期番茄中APX酶活性的增加,降低了绿熟期番茄中MDA含量,延缓果实中可溶性糖的流失,且60μL·L-1 NO处理效果较好。但NO处理对粉红期番茄中APX活性和MDA含量无显著影响,这可能与NO对绿熟期和粉红期这两种不同成熟度番茄中作用方式不一样有关。     

外源茉莉酸甲酯处理对采后绿熟番茄果实根霉果腐病抗病性的影响

以"中蔬4号"绿熟期番茄果实为材料,通过真空渗透的方法,筛选能够有效控制采后绿熟期番茄果实抵抗根霉果腐病的茉莉酸甲酯处理浓度,研究外源茉莉酸甲酯处理后的接种果实抗性相关酶活性的变化.结果表明,10 mmol/L茉莉酸甲酯处理有效地减弱采后绿熟期番茄果实病害症状的发展,抑制果实发病率,控制病斑的扩增,同时也提高接种番茄果实中苯丙氨酸解胺酶、几丁质酶、β-1,3葡聚糖酶的活性.     

骤冷处理对番茄的贮藏保鲜研究

把刚采收的绿熟强丰番茄果实置于一１０℃～－５℃的冷空气中分别处理３０、４０、６０和１２Ｏｍｉｎ,然后分别装入聚乙烯薄膜袋,放在温度２０℃～２２℃和相对湿度８０～８５％的条件下贮藏。结果表明：经骤冷处理未发生冷害,后熟正常;绿熟果实转红时间比对照延迟４～１０天,达到食用成熟度的时间比对照延长８～２２天,且成熟后果实鲜红,色泽均匀,风味同对照一样。     

‘桂蕉1号’香蕉成熟过程中挥发性成分和香气特征分析

采用固相微萃取结合气相色谱串联质谱技术对‘桂蕉1号’香蕉果实的不同后熟时期进行挥发性物质的分析,并使用气味“ABC”法对果实的香韵进行了分析。结果表明,‘桂蕉1号’香蕉的绿熟、黄熟和过熟期共检测出24种相对含量大于1%的挥发性物质,包括醛类、酯类和其他烷烃挥发性物质。其中绿熟期以反式-2-壬醛和反式-2-, 顺-6-壬二烯醛为主的挥发性物质,黄熟期以反式-2-己烯醛、异丁酸异戊酯和己醛为主的挥发性物质,在过熟期相对含量最高的是乙酸异戊酯。香韵分析结果表明绿熟期涵盖15种香型,其中脂肪香味香型载荷较大,黄熟期和过熟期分别包含13种和14种香型,其中黄熟期以青香载荷最大,过熟期以果香载荷最大。‘桂蕉1号’果实在不同的成熟阶段,其香气成分的种类和相对含量有较大的变化,并随着果实成熟度的增加,其香韵的种类也有明显的变化,绿熟期和过熟期的香型种类最多,是食品香精开发的最佳时期。     

骤冷处理结合木霉制剂对番茄的双重保鲜研究

把刚采收的绿熟番茄果实经木霉制剂处理后,再置于－ １０ ～－ ５ ℃的冷空气中分别骤冷处理３０ 、４０ 、６０ 和１２０ｍｉｎ ,然后分别装入聚乙烯薄膜袋,放在温度２０ ～２２ ℃、相对湿度８０ ％ ～８５ ％ 的条件下贮藏。贮藏结果表明：经木霉制剂协同骤冷处理的果实未发生冷害,腐烂率比对照低４ ％ ～１０ ％ ,后熟正常,绿熟果实转红时间比对照延迟４～１０ｄ ,达到食用成熟度的时间比对照推迟８ ～２２ｄ ,且成熟后果实鲜红,色泽均匀,风味同对照一样良好。     

酵母甘露聚糖处理对番茄果实贮藏效果的影响

为了研究酵母甘露聚糖对番茄果实贮藏效果的影响,利用不同质量浓度（0、1.0、10.0 g/L）酵母甘露聚糖溶液对番茄果实进行负压渗透处理,测定贮藏过程中果实硬度、可溶性固形物含量、色差、转色指数、乙烯释放速率、呼吸强度、β-半乳糖苷酶活性及损伤接种链格孢菌等指标。结果表明：酵母甘露聚糖能够延缓番茄果实硬度的下降,减缓可溶性固形物含量的变化,降低乙烯释放速率和呼吸强度,推迟果实转色,从而有效地延缓了番茄果实后熟进程,提高了贮藏效果。其中,1.0 g/L酵母甘露聚糖作用效果最为显著。进一步测定表明,酵母甘露聚糖处理可抑制番茄果实β-半乳糖苷酶活性变化。损伤接种链格孢菌实验表明,酵母甘露聚糖还能有效地抑制由链格孢菌引起的番茄果实黑霉病,减小病斑面积,降低病害发病率。     

Effect of 1-methylcyclopropene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature

BACKGROUND: In Florida, tomatoes are harvested green (GR), which includes mature green (MG) and immature green (IG) fruits, and stored at low temperature (13 °C), resulting in poor flavour. Flavour improvement might be achieved if fruits were harvested with some colour (to eliminate IG fruits) and/or stored at higher temperature with the ripening inhibitor 1‐methylcyclopropene (1‐MCP). RESULTS: ‘Florida 47’ tomatoes were harvested at GR (MG + IG), breaker (BR), turning (TR) and pink (PK) stages, treated (+) or not (?) with 1‐MCP and stored at 13 and/or 18 °C. 1‐MCP treatment resulted in a gain of up to 6 days of shelf life depending on harvest maturity and storage temperature. Storage at 18 °C rather than 13 °C resulted in an increase in internal red colour, soluble solids (SS)/titratable acidity (TA) ratio and levels of many volatiles studied. The shelf life of BR (+) MCP fruits stored at 13 °C was similar to that of MG fruits. IG fruits exhibited lowest levels of SS, TA and ten volatiles compared with BR fruits. CONCLUSION: Harvesting tomatoes with colour (BR), thereby eliminating IG fruits, and treating with 1‐MCP resulted in better quality with adequate shelf life. Published 2011 by John Wiley & Sons, Ltd.     

红色和粉色樱桃番茄与大果番茄果实品质特性分析

利用不同测定方法对8 份红色和粉色樱桃番茄与大果番茄的抗坏血酸含量、可溶性固形物含量、番茄红素含量和β-胡萝卜素含量进行测定。利用气相色谱-质谱联用仪分别对8 份番茄材料果实挥发性物质和糖酸成分进行测定。结果表明：红色和粉色番茄中主要的糖是果糖、葡萄糖和蔗糖,主要的有机酸是苹果酸、丁二酸和柠檬酸。在8 份番茄材料中都能检测到的挥发性物质有25 种,主要是醇类、醛类、酮类和酯类物质。对8 份番茄材料聚类结果表明,红色樱桃番茄、粉色樱桃番茄、红色大果番茄以及粉色大果番茄分别聚在一起,且4 份樱桃番茄之间的聚类距离更近;对主要营养指标和25 种挥发性物质的主成分分析结果表明,前3 个主成分的累积方差贡献率达到82.293%。     

The effects of 1-methylcyclopropene treatment on the shelf life and quality of cherry tomato (Lycopersicon esculentum var. cerasiforme) fruit

The use of 1‐methylcyclopropene (1‐MCP) to extend the shelf life of cherry tomato (Lycopersicon esculentum var. cerasiforme) was investigated. Higher concentrations of 1‐MCP delayed the ethylene induced climacteric peaks in mature green (MG) and breaker (BR) fruits. Thirteen days after treatment, control fruits were 55% as firm as fruit treated with 0.11 μL L^?1 1‐MCP. The initiation of fruit softening, chlorophyll degradation and accumulation of lycopene and carotenoids was delayed in treated fruits. Higher 1‐MCP concentrations inhibited the accumulation of lycopene and carotene such that the colour of the fruit did not reach that of control fruit. Treatment of MG cherry tomatoes with 1‐MCP enhanced shelf life optimally, while treatment of BR fruits was beneficial where full colour and high content of lycopene and carotenoids is important. Differentiation of the different stages of ripening before application of 1‐MCP is needed in order to succeed in accomplishing different postharvest objectives.     

Evaluation of tomato textural mechanical properties

The texture of fresh tomatoes (Lycopersicum esculentum Mill., ‘Momotaro’) at three different stage of ripeness (mature green, pink, and red) was intensively evaluated. The double-cycle load plate compression test showed that initial firmness, average firmness, energy absorption, deformation ratio, and relaxation ratio were sensitive textural parameters for identifying the maturity stages. From a puncture test, initial firmness, average firmness, apparent modulus of elasticity, rupture force, toughness, and deformation at the rupture point were sensitive to the maturity stages. The mature unripe tomato deformed linearly as a function of force; hence, the firmness was constant. However, the fully ripe tomato firmness increased as a function of applied force. The fruit strain increased during ripening, and it was independent of fruit size. The unripe tomato was more elastic than the ripe one. The peel at the mature green stage contributed approximately 70% of the firmness of the fruit and approximately 90% at the pink stage and red stage. The rupture force by the puncture test (traditionally, peak force) was correlated well with other textural parameters, which indicated that it could be used as a firmness representative parameter, as has been used by many researchers. The degree of elasticity was a better indicator for elasticity than the relaxation ratio.     

Recent Advance in Aromatic Volatile Research in Tomato Fruit: The Metabolisms and Regulations

Aroma, an essential characteristic of tomato fruit, plays an important role in determining the perception and acceptability of tomato products by consumers. During tomato fruit ripening, associated with color changes from green to red involving the conversion of chloroplasts to chromoplasts are changes of aromatic volatile profiles. Although the biosynthetic pathways for some aromatic volatiles have been established in tomato fruit recently, our knowledge of regulatory mechanisms is still rudimentary. On the other hand, many internal and external factors modify volatile metabolism in tomato fruit. This review first summarizes the current knowledge of expression patterns and biosynthetic pathways of aromatic volatiles in tomato fruit along with the role of ethylene in their biosynthesis. The impact of internal and pre- and postharvest external factors on volatile composition is then discussed. This review will provide critical information for research on tomato aromatic volatiles and their manipulation.     

Antioxidant Bioactive Compounds in Selected Industrial Processing and Fresh Consumption Tomato Cultivars

Four selected fresh consumption tomato varieties, harvested at different ripening stages (green, breaker, pink, red) and five industrial processing tomato varieties, harvested at red ripe stage, were analysed for lycopene and its isomers, β-carotene, total and individual phenolics, vitamin C and hydrophilic antioxidant activity. Tomato variety and ripening stage significantly affected carotenoids, total phenolic compounds and hydrophilic antioxidant activity when fresh consumption tomatoes were compared. The average of total lycopene content at the different ripening stages was 0.63, 12.20, 26.76 and 116.66 mg/kg of fresh weight (FW). Vitamin C ranged from 2.79 (breaker Cherry Pera) to 297.62 (red Cherry Pera) mg/kg FW. In green and breaker tomatoes, a positive correlation of hydrophilic antioxidant activity with vitamin C and chlorogenic acid was observed. However, in industrial tomato varieties (red ripe stage) and fresh consumption varieties harvested at pink and red stages, hydrophilic antioxidant activity was correlated with total phenolics and rutin. Tomato varieties for industrial processing did not show significant differences in total phenolic compounds and lycopene content. Lycopene ranged from 83.17 to 97.60 mg/kg FW, while total phenolic compounds varied between 257.91 and 284.13 mg/kg FW. Chlorogenic acid and rutin were the most abundant individual phenolics found in all the samples studied. Moreover, the content of total phenolics was always significantly correlated with the content of rutin. The amounts of all individual phenolics were affected by variety, with the exception of ferulic acid. Generally, these individual phenolics were more abundant in green and intermediate ripening stages, decreasing in full red tomatoes.     

Influence of different concentrations of 1-methylcyclopropene on the quality of tomato harvested at different maturity stages

BACKGROUND: A wide range of 1‐methylcyclopropene (1‐MCP) concentrations as well as various treatment durations have been studied in tomatoes by different researchers. However, little is known about interaction of 1‐MCP doses and maturity stages of tomatoes. Therefore the effects of different concentrations of 1‐MCP on storage and postharvest quality of ‘Zorro’ tomatoes harvested at mature green or pink maturity stages were investigated in a 2‐year trial study. RESULTS: Higher concentrations of 1‐MCP delayed and/or inhibited all parameters related to fruit ripening, such as lycopene, chlorophyll, surface color, polygalacturonase (PG) activity and soluble solids content/titratable acidity (SSC/TA), and these effects were greater in tomatoes harvested at the mature green stages. Lower concentrations of 1‐MCP slightly reduced the loss in general quality features compared with untreated tomatoes. CONCLUSION: The results suggest that 1‐MCP, especially at higher doses, is effective for delaying ripening of mature green tomatoes. Mature green fruits treated with 1000 nL L^?1 1‐MCP were stored for 35 days without significant decreases in quality characteristics such as elasticity, surface color and SSC/TA with certain physiological processes (ethylene production, PG activity, lycopene synthesis). Copyright © 2011 Society of Chemical Industry     

Rapid Tomato Volatile Profiling by Using Proton‐Transfer Reaction Mass Spectrometry (PTR‐MS)

Abstract: The availability of rapid and accurate methods to assess fruit flavor is of utmost importance to support quality control especially in the breeding phase. Breeders need more information and analytical tools to facilitate selection for complex multigenic traits such as flavor quality. In this study, it is shown that proton‐transfer reaction mass spectrometry (PTR‐MS) is a suitable method to monitor at high sensitivity the emission of volatiles determining the tomato aromatic profile such as hexanal, hexenals, methanol, ethanol, and acetaldehyde. The volatiles emitted by 14 tomato varieties (at red stage) were analyzed by 2 solvent‐free headspace methods: solid‐phase microextraction/gas chromatography MS and PTR‐MS. Multivariate statistics (principal component analysis and cluster analysis) of the PTR‐MS results allow an unambiguous separation between varieties, especially with a clear fingerprinting separation between the different tomato types: round truss, cocktail, and cherry tomatoes. PTR‐MS was also successfully used to monitor the changes in volatile profiles during postharvest ripening and storage. Practical Application: These results show that proton‐transfer reaction mass spectrometry (PTR‐MS) is suited to monitor at high sensitivity the emission of a large number of volatiles that describe the tomato aroma profile. This technology can easily monitor and quantify compounds related to ripening and/or senescence so that it can be used to improve the breeding of new fruit and vegetable cultivars based on volatiles. Moreover, PTR‐MS can be used to monitor changes in volatile profile during ripening and storage.     

Fresh tomato specific fluctuations in the composition of lipoxygenase-generated C6 aldehydes

Linoleoyl and α-linolenoyl fatty acyl groups are converted to hexanal and hexenal ((Z)-3-hexenal and (E)-2-hexenal), respectively, on the maceration of tomato fruits. These C6 aldehydes greatly contribute to the mix of volatile compounds which determines the flavour of the tomato. Cherry and standard fresh tomatoes were used to study the relationship between fatty acid composition of the intact fruit and the C6 aldehydes produced on maceration. The cherry tomato (var. Cherry Belle) had approximately twice as much α-linolenic acid as the standard tomato (var. Solairo). The enrichment of α-linolenic acid in the cherry tomato compared to the standard tomato was not evenly distributed between the major lipid classes (neutral lipids, glycolipids and phospholipids) but was prominent in the neutral fraction. The linoleic/α-linolenic acid ratio in the cherry and standard tomatoes was 1.75 and 4.1, respectively; this was reflected but not matched by the hexanal/hexenal ratio on macerating these tomatoes (0.1 and 0.27, respectively). Analysis of volatile compounds on macerating tomato fruits was extended to 14 other commercially available varieties which were nominally split into ‘cherry’ (50 g average fruit weight and below) and ‘standard’ (average fruit weight above 50 g) tomatoes. Hexanal/hexenal ratios were remarkably different between ‘cherry’ (0.05–0.1) and ‘standard’ (0.14–0.27) tomatoes. The concept of increasing α-linolenic acid levels in tomatoes to increase desirable flavour is discussed.