Climacteric and non-climacteric behavior in melon fruit: 2. Linking climacteric pattern and main postharvest disorders and decay in a set of near-isogenic lines

A set of near-isogenic lines (NILs) of melon (Cucumis melo L.) was used to test the relationship between the climacteric pattern and postharvest disorders at harvest and after 30 days at 8 °C. The NILs contained different chromosome introgressions in the linkage group III from the non-climacteric exotic Korean accession PI 161375 transferred into the genetic background of the non-climacteric Spanish cultivar ‘Piel de Sapo’ (PS). A quantitative trait locus (QTL) in this linkage group induced climacteric behavior in eight NILs accompanied by a peak of ethylene production and fruit dehiscence to different degrees. The cultivar ‘Nicolás’ and one NIL showed a non-climacteric pattern of respiration rate and ethylene production. The climacteric NILs were used to test the relationship between this pattern and postharvest disorders. The reference climacteric lines ‘Fado’ and ‘Védrantais’ were more sensitive to CI and associated Cladosporium rot than the NILs or PS. In general, a more intense climacteric behavior was accompanied by fruit dehiscence, and higher total losses and greater skin scald after storage, than in PS. A higher incidence of chilling injury (CI) in the climacteric NILs was found compared with the non-climacteric ones, although with exceptions (one NIL for CI in the form of scald; the same NIL and one more for pitting). The climacteric onset and netting scald were not related, and CI in the form of skin spots was only found in climacteric NILs and was positively correlated with the maximum peak of ethylene production. Some climacteric NILs did not follow the rule of a higher susceptibility to other disorders and decay after storage compared with PS, such as for example in fruit over-ripening (detected externally or internally), Cladosporium rot at the peduncle and Alternaria rot. Mealiness was independent of climacteric behavior. Three climacteric NILs obtained better flavor scores after storage than PS, although the maximum peak of ethylene production was positively correlated with off-flavor. Genotypic correlation between disorder data and the physiological data of climacteric fruit revealed positive (flavor index) or negative postharvest consequences (skin injuries, rots or off-flavors). At least one QTL can be assigned to most of the quality traits analyzed.     

不同品种甜瓜果实成熟过程中香气物质动态分析

研究不同甜瓜品种果实成熟过程中香气物质成分。采用顶空固相微萃取技术(HS-SPME)提取不同品种甜瓜果实成熟过程中的香气成分,用气相色谱质谱联用仪(GC-MS)进行测定分析。4个甜瓜品种在花后25 d(未成熟时期)的芳香物质以醛类和醇类物质为主。花后30 d的果实是一个醛类和醇类物质向酯类物质转化的时期。花后35d是甜瓜果实的成熟期,香气成分以酯类物质为主,仅有少量的醛类和醇类物质。4个甜瓜品种在果实成熟期共有的芳香物质有6种,均为酯类物质,分别是乙酸己酯、乙酸苯甲酯、乙酸异丁酯、乙酸丁酯、乙酸-2-甲基丁酯、2,3-丁二醇双乙酸酯和十四酸异丙酯;它们特有的香气物质以及特征性酯类种类和含量均不同,这些差异是不同甜瓜品种的香气类型不同的原因,从而构成了各品种甜瓜特有的典型性香气。     

甜瓜不同品种类型芳香物质和营养品质的比较分析

试验采用固相微萃取(SPME)和气相色谱-质谱联用技术(GC-MS)等方法测定了10个不同品种类型的甜瓜芳香物质,结果表明薄皮甜瓜芳香物质的种类比厚皮甜瓜多：在薄皮甜瓜中分离出的芳香物质以乙酸乙酯、乙酸-2-甲基丙酯和乙酸正己酯等乙酸酯类为主;在厚皮甜瓜中,哈密瓜的芳香物质主要以正辛醇、2-辛醇和辛醛等醇醛类物质为主;网纹甜瓜和薄皮型厚皮甜瓜中甜1号以(Z,Z)-3,6-壬二烯醛、(Z)-6-壬烯醛和正壬醇等饱和与不饱和的九碳脂肪醛和脂肪醇为主;光皮型厚皮甜瓜中白兰瓜和伊丽莎白甜瓜主要以乙酸甲酯、乙酸乙酯和乙酸-2-甲基丙基酯等低分子的酯类物质为主,这与薄皮甜瓜的芳香物质相似,但在白兰瓜和伊丽莎白中没有分离出醛类物质,光皮型厚皮甜瓜心里美2号、元首和天蜜以(Z,Z)-3,6-壬二烯醛、壬醛和正壬醇等饱和与不饱和的九碳脂肪醛和脂肪醇为主。对十个品种的营养品质分析表明,薄皮甜瓜之间的营养品质含量都有显著性差异;在厚皮甜瓜中,光皮型厚皮的营养品质优于其它厚皮甜瓜;薄皮甜瓜的糖酸比显著低于厚皮甜瓜。     

Effects of exogenous putrescine on improving shelf life of four plum cultivars

Four plum cultivars (‘Golden Japan’, ‘Black Diamond’, ‘Black Star’ and ‘Santa Rosa’) were treated with 1 mM putrescine, and then stored at 20 °C. Storage duration was different for each cultivar, but the effect of putrescine in terms of increased shelf life, delayed ripening process, and higher quality attributes when compared with controls was significant for all cultivars. In addition, putrescine-treated plums showed delay and/or reduction on ethylene production, the intensity of reduction being dependent on the maximum of ethylene production at the climacteric peak. Also, higher fruit and flesh firmness, lower soluble solids concentration and titratable acidity evolution, reduced weight loss and delayed colour changes were found after putrescine treatment during storage. Moreover, higher putrescine and spermidine levels (free forms) were observed in putrescine-treated plums. The results revealed that plum storability could be extended by putrescine treatment due to its effect on delaying the ripening processes.     

Sodium bicarbonate reduces postharvest decay development on melons

Sodium bicarbonate (SBC) inhibited in vitro mycelial growth of A. alternata, Fusarium spp. and R. stolonifer. SBC action was fungistatic rather than fungicidal. Coating commercially harvested ‘Galia’ and ‘Ein-Dor’ melons with wax containing 2% SBC reduced decay incidence after storage and shelf life simulation by four to seven-fold, to a commercially acceptable level of 6–7%, compared to untreated or waxed-treated controls. This treatment also maintained the fresh and blemish-free appearance of the fruit at harvest. Higher concentrations of SBC (3%) were phytotoxic and significantly reduced general fruit appearance. A trial shipment by sea transport to Europe demonstrated that 2% SBC incorporated into a wax coating maintained the marketability of ‘Galia’ melon fruits compared to that of untreated fruit. SBC can be an alternative biocide to the fungicide imazalil, thus eliminating unwanted residues on melon fruits.     

不同风味类型甜瓜果实发育过程中风味品质比较

采用风味类型不同的4个甜瓜品种为试材,测定果实发育过程中的可溶性糖、可滴定酸、Vc、可溶性固形物和芳香物质等风味品质。结果表明:日本甜宝(TB)在果实发育过程中的可溶性糖含量最高,其次是雪奶香(XNX),泽甜十里香(ZT)第三,风味4号(FW)最低;但FW中有机酸含量显著高于其他品种,成熟期XNX的Vc含量最为丰富;在花后25/35 d时FW的芳香物质以6和9碳醛类为主,其他3个品种则以醇类为主,尤其是9碳醇,随着果实的成熟,芳香物质总量均有较大提高,特别是乙酸酯类,FW的酸类和含苯化合物增加显著。在36/46 d时芳香物质的总含量为XNX最高,其次为ZT,TB第三,FW最低,品种间差异极显著(P<0.01)。不同品种的糖酸比、芳香物质的组分与含量,及其特有芳香物质的差异共同导致了品种间风味品质的差异。     

西洋梨品种间糖酸及风味物质含量差异性比较

以4个西洋梨品种为材料,通过测定果实糖酸含量和芳香成分,并计算其风味指数,研究、比较了西洋梨品种间糖酸含量、风味指数及香味成分差异。结果表明：各个西洋梨品种间糖、酸组分及含量差异较大;在其他因素一致的条件下,风味指数考虑了各个糖组分对果实风味的贡献,更能体现各个品种间果实风味的差异。4个品种中均检测到乙酸乙酯、乙酸丁酯、乙酸己酯、乙酸辛酯、丙酸乙酯、丁酸乙酯及(2E,4Z)-癸二烯酸乙酯等7种特征香味成分,但各个品种间芳香成分含量存在较大差异,而酯类芳香成分相对含量较其他特性芳香成分的相对含量较高。本研究中,从风味指数（味感物质）角度考虑,‘早红考密斯’风味最佳,‘巴梨’和‘康佛伦斯’次之,‘三季梨’风味较淡。从香味成分（嗅感物质）角度考虑,‘康佛伦斯’香味最浓,而‘早红考密斯’香味较淡。     

2个野生型苹果果实香气成分分析

为给苹果野生资源的开发利用提供参考指导,以2个野生型苹果（小金海棠和新疆野苹果）为试验材料,采用顶空固相微萃取-气质联用技术分析了果实香气成分。结果表明：小金海棠香气成分总含量高于新疆野苹果;小金海棠和新疆野苹果分别检测出90和97种香气成分,其中共有的香气成分有88种,2-己烯醛在二者中含量均最高;小金海棠主要香气物质为醛类和酯类,新疆野苹果则为酯类、醛类以及醇类。2个野生型苹果共有成分相对含量的差异和特有香气成分的存在可能是造成两者香味差异较大的重要原因。     

烤烟‘渝金香1号’致香物质含量分析

对烤烟新品种‘渝金香1号’的致香物质含量进行分析,为该品种的栽培技术改进以及卷烟配方应用提供依据。取重庆市巫山县烟区的‘渝金香1号’以及主栽烤烟品种‘云烟87’、‘K326’（对照）中部C3F等级烟叶,经蒸馏萃取后,采用气相色谱质谱联用法测定其致香成分及含量。试验检测出70种致香物质或潜香物质成分;‘渝金香1号’萜烯类、醛、酮类物质的含量稍低于对照品种‘云烟87’和‘K326’;氮杂环类和酚类物质含量稍高于‘云烟87’和‘K326’;醇类、酯类和酸类物质低于‘云烟87’,高于‘K326’;致香物质占测出致香或潜香物质总量的比例为23.48%,高于‘云烟87’(22.74%)和‘K326’(17.98%),有利于在陈化过程中快速降解生成致香成分;新植二烯与致香物质总量的比例低于‘云烟87’和‘K326’,对于降低烟气的刺激性、协调吃味有利;植物呋喃类含量与新植二烯含量的比例高于‘云烟87’和‘K326’,类胡萝卜素重要致香降解产物总量比‘云烟87’和‘K326’分别高5.92%和5.22%,叶面分泌物降解产物或衍生物总量(34.310 µg/g)高于对照品种‘云烟87’(32.996 µg/g)和‘K326’(32.490 µg/g),有利于彰显‘渝金香1号’烤后烟叶的香气特征。‘渝金香1号’致香物质含量较高,比例较协调,香气质量较好。     

Colour at harvest and post-harvest behaviour influence paprika and chilli spice quality.

Capsicum annuum L. paprika and cayenne chilli pepper fruit were grown for red spice production and harvested at various colour stages on the same day. Fruit of each stage were allowed to change colour at room temperature with or without the addition of 100 μl l⁻¹ ethylene. Fruit appearance and colour development, and respiration and ethylene production were measured during the colouring period. Ethylene treatment had no effect on colour development or pungency for both cultivars, even though it easily crossed the cuticle, epidermis and flesh tissues into the fruit cavity. Green or deep green harvested fruit failed to fully colour red, while fruit that were harvested at or after the colour break stage visually completed their red colour development within 7–9 days. However, the colour intensity of spice powder was low for all fruit that had not developed a deep red colour prior to harvest. For paprika no difference between deep red fruit that were succulent or that had partially dried on the plant was found, but chilli fruit that had partially dried before harvest produced the most intense colour. American Spice Trade Association (ASTA) extractable red colour was the best measure of spice colour quality, compared to reflected lightness (L*), chroma (C*) and hue angle (h°) colour measurements. Pungency did not change between ripeness stages for chilli and was absent in paprika. Paprika and chilli fruit showed climacteric behaviour as long as they were attached to the plant, but when detached were non-climacteric.     

存放时间对光皮木瓜芳香物质的影响

以成熟光皮木瓜为试材,在采后2d和采后1月两次采用顶空固相微萃取与气质联用方法分析检测木瓜果实中的芳香成分,共鉴定出64种芳香物质,主要为醛类、醇类、酮类、呋喃类、萜类、烯烃类和酯类化合物。含量较高的芳香成分有2-己烯醛、反式-2-甲基-环戊醇、4-(2,6,6-三甲基-环己--1-烯基)-2-丁醇、正已醛、(E,E)-2,4-己二烯醛、(E)-3-己烯-1-醇等。存放1月后检测,光皮木瓜的芳香物质含量不但没有降低,而且有很大的提高。其中醛类、醇类、酮类、酸类和酯类化合物的含量有不同程度的增加,而呋喃类和烯烃类化合物含量有所降低。试验中看出C6化合物是构成光皮木瓜果实清香味的主要成分     

内蒙古河套地区小麦粉风味物质GC-IMS分析

为了研究河套小麦麦香味的本质,以期找出河套春小麦和冬小麦之间的风味及风味物质差异,采用气相离子迁移谱(GC-IMS)对河套产‘永良4号’小麦风味物质进行测定,同时选取冬小麦品种‘新麦26’和‘百农4199’作为对照品种。在3个小麦粉样品中共检测到风味物质73种,其中醛类26种,醇类15类,酮类12种,酯6种,酸3种,酚2种,呋喃类和烯类各1种。‘永良4号’检测出的风味物质中,醛类物质含量最高,占30.55%,其次是酮类占30.28%,醇类占27.80%,其余组分占比较小,分别为酚类占3.19%,酸类占1.70%,酯类占1.62%,2-戊基呋喃和α-蒎烯共占0.87%。河套地区产‘永良4号’麦芽酚、丁醛等风味物质含量高,与‘百农4199’、‘新麦26’在不同风味物质含量上具有较大差异。这些具有特殊香气的风味物质含量高,可能是导致河套小麦麦香味浓郁的物质基础。     

两种砧木对布鲁克斯大樱桃果实芳香成分的影响

【研究目的】为研究考特和吉塞拉作为砧木对甜樱桃果实香气成分的影响。【方法】采用顶空微萃取技术提取成熟期果实的香气成分,经气相色谱质谱联用仪进行测定分析。【结果】不鲁克斯甜樱桃的香气成分共检测到61种,主要成分为醛类、醇类和酯类。从布鲁克斯（吉塞拉）中检测出38种香气成分占总峰面积的59.66 %,相对百分含量较高的是乙醇、乙酸己酯、1-乙基－3－甲基苯、苯乙烯、1,2,3－三甲基苯。从布鲁克斯（考特）中检测出30种香气成分占总峰面积的64.74 %,相对百分含量较高的是乙醇、（E)2－己烯－1－醇、3-异丁基-6-烯-1-辛醇、乙酸己酯。【结论】吉塞拉和考特作为砧木对布鲁克斯甜樱桃果实中香气成分的影响较明显,在香气种类上吉塞拉砧木具有明显优势。（E)2－己烯－1－醇、己醛、乙酸己酯、(E)-丁酸－2－己烯酯、3-异丁基-6-烯-1-辛醇是不鲁克斯甜樱桃成熟果实的特征香气成分。     

气质联用分析云南老树茶香气成分

老树茶是一种有别于其他茶类的茶,具有特殊的香气和品质,为了更好的认识和研发老树茶,解决老树茶在市场上信息混乱的问题,应用同时蒸馏萃取法（SDE）提取和气质联用色谱（GC/MS）分析9个具有代表的老树茶样品的香气成分。试验共鉴定出63种香气化合物,其中醇类15种、碳氢化合物13种、醛类14种、酮类9种、酸类8种、酯类4种;主要香气成分有芳樟醇及其氧化产物、α-松油醇、香叶醇、水杨酸甲酯、糠醇、β-紫罗兰酮、苯甲醛、苯乙醛、(E,E)-2,4-庚二烯醛等。研究初步探明老树茶的香气组成与特点,为老树茶的科学开发、消费提供科学依据。     

不同干燥工艺对枣粉挥发性香气成分的影响

以新疆哈密红枣为原料,通过喷雾干燥和冷冻干燥工艺方法制取枣粉,采用色差仪和固相微萃取-气相色谱质谱联用技术,对两种红枣粉的色泽进行评定,并对其香气成分进行检测分析,研究不同干燥工艺对枣粉香气成分的影响。结果表明:冷冻干燥的枣粉色泽呈淡绿色,喷雾干燥的枣粉色泽呈淡黄色;从冷冻干燥枣粉、喷雾干燥枣粉和原枣浆中分别检测出挥发性化合物42、52和43种,均含有醛类、酮类、酸类、酯类、醇类、烷烃类、烯烃类、芳香烃类及少量未知物,其有效组分分别占总挥发物质的52.37%、72.07%和56.44%,且喷雾干燥枣粉的酯类和酸类化合物显著多于原枣浆,冷冻干燥枣粉组分无明显减少,其醇类物质所占总有效组分比例显著增加,且枣的特征香气成分相对较稳定。     

Expression of expansin genes during postharvest lignification and softening of ‘Luoyangqing’ and ‘Baisha’ loquat fruit under different storage conditions

Four expansin cDNA fragments, EjEXPA1, EjEXPA2, EjEXPA3 and EjEXPA4, were isolated and characterized from loquat (Eriobotrya japonica Lindl.) fruit. EjEXPA1 mRNA accumulated consistently with the increase in fruit firmness in 0 °C storage of ‘Luoyangqing’ (LYQ) fruit, where chilling injury with increased fruit firmness due to lignification was observed. EjEXPA1 mRNA levels were lower in fruit that underwent low temperature conditioning (LTC, 6 d at 5 °C then 4 d at 0 °C), and in 1-methylcyclopropene (1-MCP) treated fruit, in both cases where chilling injury was alleviated. Fruit of the ‘Baisha’ (BS) cultivar soften after harvest rather than increase in firmness, and high expression levels of EjEXPA1 and EjEXPA4 accompanied the softening of BS fruit stored at 20 °C; such mRNA accumulation was much lower when fruit were stored at 0 °C, where softening was significantly inhibited by the low temperature. Very low expression of EjEXPA2 and EjEXPA3 was observed during storage of both LYQ and BS fruit under the different storage conditions. Our results showed that of the four genes characterized, EjEXPA1 might be associated with chilling-induced lignification while both EjEXPA1 and EjEXPA4 were closely related to softening of loquat fruit during the postharvest period.     

不同生态环境木薯高产高效栽培分析

为研究在不同生态环境地区不同木薯间差异和发掘高产高效木薯品种,对6个试验点的4份木薯品种进行鲜薯产量和经济效益的研究。结果表明,在不同生态环境下不同品种的木薯鲜薯产量不同,不同品种的经济效益不同。其中栽培在新马街试验点的木薯品种‘SC124’的鲜薯产量是供试样品中最高的,达到66816.67 kg/hm²,该品种的经济效益也是供试品种中最高的,可达40090.00元/hm²。试验结果为进一步推广高产高效木薯品种提供了有利材料,并为木薯资源开发提供了方法和手段。     

4个矮化自根砧短枝富士品种套袋与不套袋果实品质比较分析

为研究双矮栽培模式下套袋、不套袋管理对短枝富士苹果品质的影响,以嫁接在M9T337矮化自根砧上的4个短枝富士品种为试材,检测不同栽培条件下的果实品质和香气物质成分。结果表明,套袋果实的可溶性固形物含量和总糖含量均低于不套袋果实;苹果酸和琥珀酸是苹果中的主要酸组分,不同的短枝富士品种表现出不同的差异;4个短枝型富士品种的主要香气成分均为酯类,占总香气成分的77.71%~96.49%,是典型的酯香型苹果品种;‘烟富6’、‘沂源红’、‘宫崎短枝’3个品种,套袋和不套袋管理情况下主要香气成分均是乙酸己酯;‘龙富短枝’品种套袋果实的主要香气成分为乙酸己酯,而不套袋果实的主要香气成分为2-甲基丁酸己酯。