热水结合果蜡处理抑制振动引起哈密瓜衰老的机理

远距离运销是哈密瓜流通过程中的重要过程,其中运输过程中的振动是影响哈密瓜衰老的重要逆境。为了减少运输振动导致的哈密瓜的成熟衰老。该文以哈密瓜为原料,利用模拟振动台对哈密瓜进行振动处理,并利用热水结合果蜡对哈密瓜进行保鲜。随后在模拟销售条件的室温条件下（23℃）对哈密瓜的细胞膜完整性及相关的指标进行了检验,同时还利用透射电镜对新鲜和贮藏结束后哈密瓜组织细胞微观结构变化进行了检测。结果表明,运输振动胁迫加速了哈密瓜细胞的微观变化及细胞膜完整性丧失,在经过28 d的模拟销售条件的室温条件下,对照组（未经处理）的相对电导率分别是振动处理组的95%和热水果蜡处理组的1.15倍,且三者间区别显著（P<0.05）。这主要是由于运输振动增加了哈密瓜果实的呼吸作用,伴随较高的丙二醛产生,较低的超氧化物歧化酶,过氧化氢酶和过氧化物酶等抗氧化酶活性。而热水结合果蜡处理抑制了运输振动引起的哈密瓜细胞膜脂质的氧化及与相关的变化,延缓了哈密瓜的衰老,保持了贮藏过程中哈密瓜的品质。研究结果可以为提高采后哈密瓜的运销品质和保鲜效果提供一定的参考。     

热处理降低哈密瓜果实活性氧代谢减轻冷害

为探讨热处理能否激发哈密瓜果实抗冷性,减轻冷害。该文以"西州密25号"哈密瓜为原料,在已有研究的基础上,将哈密瓜在55℃热水中浸泡3 min,以室温(22±2)℃清水浸泡3 min为对照,待其表面水分完全晾干以后,放置于3~5℃机械冷库中贮藏,测定贮藏期间哈密瓜品质及生理指标。结果表明,与对照相比,热处理诱导哈密瓜果肉过氧化氢H_2O_2和超氧阴离子O_2~-含量短暂增加,但明显减少贮藏中后期(14~35 d)H_2O_2,O_2~-的积累(P0.05),提高活性氧清除酶过氧化物酶和超氧化物歧化酶的活性(P0.05),抑制细胞膜相对渗透率和丙二醛含量上升,降低贮藏后期的冷害发生率(P0.05),缓解果实可溶性固形物和抗坏血酸含量下降(P0.05),保持果实较好的品质。热处理主要通过诱导活性氧信号分子,提高活性氧清除酶活性、减少膜脂过氧化作用,从而减轻果实的冷害。研究结果为哈密瓜采后贮藏技术提供理论参考。     

模拟运输振动对新疆杏呼吸途径和品质的影响

通过建立与实际冷藏运输相近的三轴向模拟运输振动条件和温度条件,比较振动果实与静置果实不同途径呼吸速率及品质因子的差异和关联,探知运输振动诱导鲜杏品质劣变的可能途径。以七成熟的小白杏为材料,3℃环境使用振动平台模拟与冷藏车实际运输过程三轴向振动强度重叠率57.60%~67.75%的模拟条件处理果实。观测3 d模拟运输和冷藏货架期间,果实不同途径呼吸速率、硬度、可溶性固形物含量、表面色值与等温条件静置下果实的差异。与静置鲜杏相比,模拟运输鲜杏总呼吸峰提前8 d、峰值提高3.26倍,三羧酸循环途径(tricarboxylic acid cycle)呼吸峰提前3 d、峰值提高1.22倍,糖酵解途径(Embden-Meyerhof-Parnas)和细胞色素途径(cytochrome pathway)的呼吸速率提高4.62倍和9.64倍,磷酸戊糖途径(phosphopentose pathway)呼吸峰提前9d。振动果实硬度偏低13.18%~19.34%,可溶性固形物含量偏高12.26%~27.15%,色彩饱和度相对增加7.09倍~11.49倍,果色转黄3.82。模拟运输振动果实的呼吸主路径由三羧酸循环途径转换为糖酵解途径,电子传递主链由交替途径(alternative pathway)转换为细胞色素途径(cytochrome pathway),加快了冷藏鲜杏的后熟劣变。研究结果为鲜杏冷链物流品质调控技术的研发提供参考。     

温度对黑莓采后贮藏品质及生理代谢的影响

以"赫尔"黑莓为材料,研究了不同温度贮藏条件对黑莓果实采后品质及活性氧代谢相关酶活性的影响。果实经预冷处理后,分别置于0、5、10和20℃下贮藏,分析了果实贮藏期间的可溶性固形物(TSS)、可滴定酸(TA)、硬度和腐烂率以及多酚氧化酶(PPO)、过氧化物酶(POD)、脂氧合酶(LOX)和过氧化氢酶(CAT)等活性的变化。结果表明,与20、10和0℃相比,5℃贮藏不仅降低了黑莓果实的腐烂率,延缓了TSS和TA含量的下降,而且抑制了果实LOX活性的上升,同时POD、CAT活性维持在较高水平,这有利于果实保持较低的自由基水平,在一定程度上延缓果实衰老进程和延长贮藏期。     

1-MCP和Co-γ辐照处理对自发气调包装大五星枇杷贮藏品质的影响

为研究1-甲基环丙烯(1-MCP)熏蒸和60Co-γ辐照处理对枇杷贮藏品质的影响,本研究以大五星枇杷为试验材料,对采后自发气调包装枇杷的腐烂指数、木质素、硬度、呼吸强度、乙烯生成速率、相对电导率、可滴定酸(TA)、可溶性固形物(TSS)以及苯丙氨酸解氨酶(PAL)、脂氧合酶(LOX)、多酚氧化酶(PPO)、过氧化物酶(...     

模拟运输振动胁迫对樱桃番茄生理品质和电学特性的影响

为研究振动胁迫对樱桃番茄采后品质的影响,本研究选取无损伤、成熟度相同、大小一致的樱桃番茄,分别采用2 Hz(CL1)和3 Hz(CL2)两种振动频率处理模拟不同运输路况,以未处理为对照组（CK）,10 h后,将樱桃番茄置于8℃贮藏,每隔3 d对3组樱桃番茄的生理指标和电学特性进行测定。结果表明,振动胁迫对樱桃番茄采后品质具有明显影响。随着贮藏天数的增加,在生理品质方面,与CK组相比,经过振动处理后的相对电导率、可溶性固形物、丙二醛、抗坏血酸、过氧化氢含量在CL1组差异显著（P<0.05）、CL2组差异极显著（P<0.01）;电学特性方面,与CK组相比,振动处理组CL1和CL2的并联等效电容（Cp）上升趋势明显,并联等效电阻（Rp）、复阻抗（Z）下降趋势明显。生理品质和电学特性的变化幅度均表现为CL2>CL1>CK。振动频率越大,樱桃番茄的生理品质和电学特性受到的破坏程度越明显。对生理品质和电学特性的相关性分析发现,可滴定酸含量和相对电导率与电学特性相关性最高,说明电学特性可以用于生理品质的检测。本研究结果可为减轻物流运输过程中樱桃番茄生理品质损伤和电学特性的品质...     

高能电子束辐照对鲜切哈密瓜生理生化品质的影响

通过0．5、1．0、1．5和2．0kGy剂量的电子柬辐照处理鲜切哈密瓜,采用聚丙烯（PP）材质托盘和聚乙烯（PE）保鲜膜包装,置于5℃,相对湿度85％-95％的冷库中贮藏,研究高能电子束辐照对鲜切哈密瓜生理生化品质的影响。结果表明,电子束辐照能显著降低呼吸速率,显著抑制Vc、可溶性固形物的含量的下降,减少丙二醛积累,降低多酚氧化酶和过氧化物酶活性,并提高苯丙氨酸解氨酶活性。1．5kGv辐照处理的鲜切哈密瓜在贮藏至第13天时,感官品质保持良好。综合电子束辐照对鲜切哈密瓜的保鲜效果,确定最佳处理剂量为1．5kGy。     

基于酶动力学方程的双孢蘑菇气调贮藏呼吸速率模型

为了给气调贮藏设计提供理论设计依据,采用酶动力学方程,建立了双孢蘑菇呼吸速率随贮藏时间变化的理论模型;研究了在贮藏温度为5℃、气体体积分数为20%O_2、80%N2的贮藏条件下,贮藏时间对双孢蘑菇采后呼吸速率的影响,并建立了双孢蘑菇呼吸速率随贮藏时间变化的数学模型,模型决定系数R~2为0.9766、0.9331。模型与实测值进行配对T检验差异不显著(P0.05),呼吸速率值的绝对误差小于5 m L/(kg·h),相对误差变化范围为0.06%~24.95%。在已建模型基础上,研究不同贮藏温度(5、10、15、20℃)对已建模型参数的影响,利用Arrhenius方程来描述贮藏温度对果蔬呼吸速率的影响,建立了包含温度和贮藏时间因子的呼吸速率模型,模型决定系数R~2为0.9073、0.9350。验证试验结果表明,模型与实测值进行配对T检验差异不显著(P0.05),呼吸速率值的绝对误差小于17 m L/(kg·h),相对误差变化范围为1.00%~25.25%。该模型可为双孢蘑菇气调贮藏期间呼吸速率的预测及贮藏品质研究提供参考。     

1- MCP和60Co-γ辐照处理对自发气调包装大五星枇杷贮藏品质的影响

为研究1-甲基环丙烯(1-MCP)熏蒸和⁶⁰Co-γ辐照处理对枇杷贮藏品质的影响,本研究以大五星枇杷为试验材料,对采后自发气调包装枇杷的腐烂指数、木质素、硬度、呼吸强度、乙烯生成速率、相对电导率、可滴定酸(TA)、可溶性固形物(TSS)以及苯丙氨酸解氨酶(PAL)、脂氧合酶(LOX)、多酚氧化酶(PPO)、过氧化物酶(POD)活性进行测定,研究6±0.5℃条件下1 μL·L^-1 1-MCP、1.5 kGy⁶⁰Co-γ、1 μL·L^-1 1-MCP+1.5 kGy ⁶⁰Co-γ不同处理对枇杷贮藏品质的影响。结果表明, 1-MCP和⁶⁰Co-γ复合处理效果最好,可延缓腐烂指数和木质素含量上升,维持果实硬度,降低果实呼吸强度、乙烯生成速率和相对电导率,保持果实TA和TSS含量,抑制PAL、LOX、PPO和POD活性的上升。在贮藏40 d时,1-MCP和⁶⁰Co-γ复合处理枇杷的腐烂指数仅为17.95%,而1-MCP组、⁶⁰Co-γ组、CK组分别为22.86%、25.72%和36.24%。因此,1-MCP和⁶⁰Co-γ复合处理对枇杷果实的贮藏效果最好。本研究结果为枇杷的贮藏保鲜提供了理论依据。     

壳聚糖-改性纳米SiO_2复合涂膜对沪产哈密瓜生理生化品质影响的研究

为研究壳聚糖涂膜(CTS)和壳聚糖-改性纳米SiO2复合涂膜(CTSS)对哈密瓜采后贮藏过程中生理生化品质的影响。对东方密一号哈密瓜分别进行涂膜处理,,并置于室温下贮藏。结果表明,CTSS处理哈密瓜贮藏期间呼吸作用的峰值比对照和CTS处理降低21.7%和9.7%,贮藏15d,CTSS处理哈密瓜的维生素C(Vc)和可滴定酸(TA)含量分别比CTS处理高17%和37.1%。CTSS处理提高了过氧化氢酶(CAT)和过氧化物酶(POD)的活性,加强对H2O2和O2-的清除,延缓果实衰老。该研究为维持哈密瓜采后品质,延长保鲜期提供理论依据。     

基于深度学习与图像处理的哈密瓜表面缺陷检测

针对传统人工检测哈密瓜表面缺陷效率低等问题,提出利用卷积神经网络(Convolutional Neural Networks,CNN)对哈密瓜表面缺陷进行快速检测.对原始图像进行主成分分析(Principal Components Analysis,PCA)、奇异值分解(Singular Value Decomposi...     

基于三维重构的哈蜜瓜均瓣雕花算法

为解决哈密瓜雕刻速度慢、花瓣大小不一致等问题，该研究提出了一种基于三维重构的哈蜜瓜均瓣雕花算法。对多角度拍摄得到的哈蜜瓜照片进行滤波处理，提取其图像特征并进行稀疏重建，通过点云坐标得出哈蜜瓜的特征参数；接着在稀疏点的基础上利用CMVS/PMVS算法进行稠密重建；最后调节八叉树算法与泊松表面重建，得到哈密瓜精确三维空间坐标。根据哈密瓜体型特征及设定花瓣数量，将点云三角网格化在深度优先算法的基础上结合粒子群算法，规划雕刻起点、终点及雕刻深度，使每个花瓣体积相同。采用48个哈密瓜，雕刻花瓣数取15~30，雕刻深度为1.5、2.0、2.5 cm。其中切割花瓣数为28这一组精度最低，测得最大与最小花瓣体积分别为3.40与3.25 cm3，最大体积差为0.15 cm3，误差小于5.00%。结果表明，该研究提出的基于三维重构的哈蜜瓜均瓣雕花算法精度高，研究结果可为机器人雕刻哈密瓜提供技术支持。     

哈密瓜常温保鲜贮运技术研究

该研究旨在解决新疆哈密瓜采后低温贮运费用高,常温贮运腐烂率高,损失严重的问题。针对哈密瓜采后腐烂的主要病原菌匍枝根霉(R.stolonifer)、链格孢霉(A.Alternata)、半裸镰刀菌(F.semitectum)、脂状青霉(P.digitatum),筛选出对症的抑菌剂,并研究其最适使用浓度;以常温贮藏哈密的瓜失重率、呼吸强度、过氧化氢酶(CAT)、纤维素酶、果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)活性等为指标,研究云南虫胶作为被膜对哈密瓜采后生理的影响及其最适使用浓度。含有0.60g/L扑海因、0.8g/L氯硝胺、0.6g/L特克多、0.8g/L施宝功和1∶24(V.V-1)虫胶的混合溶液浸泡哈密瓜10s,于28℃,85%RH,贮藏30d,腐烂率1.87%,同期对照腐烂率49.54%。处理后的哈密瓜在室外温度28～34℃、棚车内温度30～38℃的条件下,经过12～15d由新疆哈密运抵苏州、上海、广州的腐烂率分别为3.37%、4.12%和4.86%。哈密瓜表皮以内0.8cm几乎无抑菌剂残留。用上述配方的虫胶与抑菌剂的混合溶液浸泡哈密瓜,可有效降低哈密瓜采后常温贮运中的腐烂率,保持良好风味和商品质量,大量节省运输费用     

Carotene and novel apocarotenoid concentrations in orange-fleshed Cucumis melo melons: determinations of β-carotene bioaccessibility and bioavailability

Muskmelons, both cantaloupe (Cucumis melo Reticulatus Group) and orange-fleshed honeydew (C. melo Inodorus Group), a cross between orange-fleshed cantaloupe and green-fleshed honeydew, are excellent sources of β-carotene. Although β-carotene from melon is an important dietary antioxidant and precursor of vitamin A, its bioaccessibility/bioavailability is unknown. We compared β-carotene concentrations from previously frozen orange-fleshed honeydew and cantaloupe melons grown under the same glasshouse conditions, and from freshly harvested field-grown, orange-fleshed honeydew melon to determine β-carotene bioaccessibility/bioavailability, concentrations of novel β-apocarotenals, and chromoplast structure of orange-fleshed honeydew melon. β-Carotene and β-apocarotenal concentrations were determined by HPLC and/or HPLC-MS, β-carotene bioaccessibility/bioavailability was determined by in vitro digestion and Caco-2 cell uptake, and chromoplast structure was determined by electron microscopy. The average β-carotene concentrations (μg/g dry weight) for the orange-fleshed honeydew and cantaloupe were 242.8 and 176.3 respectively. The average dry weights per gram of wet weight of orange-fleshed honeydew and cantaloupe were 0.094 g and 0.071 g, respectively. The bioaccessibility of field-grown orange-fleshed honeydew melons was determined to be 3.2 ± 0.3%, bioavailability in Caco-2 cells was about 11%, and chromoplast structure from orange-fleshed honeydew melons was globular (as opposed to crystalline) in nature. We detected β-apo-8'-, β-apo-10', β-apo-12'-, and β-apo-14'-carotenals and β-apo-13-carotenone in orange-fleshed melons (at a level of 1-2% of total β-carotene). Orange-fleshed honeydew melon fruit had higher amounts of β-carotene than cantaloupe. The bioaccessibility/bioavailability of β-carotene from orange-fleshed melons was comparable to that from carrot (Daucus carota).     

Genetic diversity of melon landraces (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.) in the Xinjiang Uygur Autonomous Region on the basis of simple sequence repeat markers

We investigated the genetic variation and relationships among 35 melon landraces collected from the Xinjiang Uygur Autonomous Region in northwestern China by using 19 polymorphic simple sequence repeat markers (SSRs). A total of 55 polymorphic alleles were amplified. The number of alleles per SSR locus ranged from 2 to 5 with an average of 2.89 alleles per locus. The average gene diversity (GD) was 0.42 with a range of 0.06–0.71, and the average observed heterozygosity was 0.22 with a range of 0.06–0.97, indicating that the genetic diversity among the Xinjiang melon landraces was abundant. Genetic variation was also detected between the landrace populations in different regions in Xinjiang. The most abundant genetic diversity was observed among the landraces in Eastern Xinjiang, with the highest GD of 0.45 and PIC of 0.39. Eleven alleles (20 %) were found exclusively in the landraces from Eastern Xinjiang, and two alleles (3.6 %) were unique to the landraces from Southern and Northern Xinjiang. The genetic similarity matrix was defined on the basis of Jaccard coefficient to determine the genetic relationships among Xinjiang landraces. Cluster analysis was performed using the unweighted pair group method with arithmetic means, showing that the ‘wild Hami’ (XJ-34) landrace was distinct from the 34 other landraces that were divided into three clusters. Therefore, the genetic background of XJ-34 differed from that of the other landraces. The landraces were not precisely separated on the basis of their geographic origins, although most of these landraces were likely grouped near one another, as visualized through principal coordinate analysis. Thus, western China is one of the primary or secondary centers of melon diversity because of the relatively higher genetic variation detected among Xinjiang landraces. Except the ‘wild Hami’ landrace, Xinjiang melon landraces could be classified into two botanical varieties, namely, var. inodorus and var. cantalupensis. However, the distinction between these two genotypes was not significantly different.     

Wild melon diversity in India (Punjab State)

We present here the first comprehensive genetic characterization of wild melon accessions from northern India. The genetic diversity among 43 wild melon accessions collected from the six agro-ecological regions of the Punjab State of India was assessed by measuring variation at 16 Simple Sequence Repeat (SSR) loci, morphological traits of plant habit and fruit morphological traits, two yield-associated traits, root nematode resistance and biochemical composition (ascorbic acid, carotenoids, titrable acidity). Variation among accessions was observed in plant habit and fruit traits and wild melon germplasm with high acidity and elevated carotenoid content and possessing resistance to Meloidogyne incognita was identified in the collection. A high level of genetic variability in wild melon germplasm was suggested by SSR analysis. Comparative analysis using SSRs of the genetic variability between wild melons from the north and other melons from the south and east regions of India and also reference accessions of cultivated melon from Spain, Japan, Korea, Maldives, Iraq and Israel, showed regional differentiation among Indian melon accessions and that Indian germplasm was not closely related to melon accessions from other parts of the world. A highly drought tolerant accession belonging to var. agrestis Naud. was also identified.     

Near-infrared imaging spectroscopy based on sugar absorption band for melons.

A method for visualizing the sugar content in the flesh of melons was developed. This method was based on the sugar absorption band in the near-infrared (NIR) region to avoid bias caused by the color information of a sample. NIR spectroscopic analysis revealed that each of the two second-derivative absorbances at 874 and 902 nm had a high correlation with the sugar content of melons. A high-resolution cooled charged couple device camera with band-pass filters, which included the above two wavelengths, was used to capture the spectral absorption image of a half-cut melon. A color distribution map of the sugar content on the surface of the melon was constructed by applying the NIR spectroscopy theory to each pixel of the acquired images.     

Diversity among melon (Cucumis melo L.) landraces from the Indo-Gangetic plains of India and their genetic relationship with USA melon cultivars

We report here the first broad genetic characterization of farmer-developed landraces of melon (Cucumis melo L.) from the Indo-Gangetic plains of India, an area overlooked in previous melon genetic diversity analyses of Indian melon germplasm. Eighty-eight landraces from three melon Groups in two subspecies (C. melo subsp. agrestis Momordica Group, and C. melo subsp. melo Cantalupensis Group and Reticulatus Group) were collected from the four agro-ecological regions (six sub-regions) of two northern states of the Indo-Gangetic plains of India, Uttar Pradesh and Uttarakhand. Significant differences were found among the landraces and eight USA Reticulatus Group reference cultivars for 18 plant and fruit traits: no. of primary branches per plant, days to marketable maturity, sex expression, fruit shape, flesh colour, netting, no. of fruit per plant, fruit weight, shelf life, total soluble solids (°Bx), ascorbic acid (mg/100 g), titratable acidity (%), fruit length and diameter, seed cavity length and diameter, flesh thickness, and resistance to Cucumber mosaic virus. The three melon groups differed significantly for 10 of the plant and fruit traits. Cantalupensis Group and Reticulatus Group accessions were andromonoecious, and the Momordica Group was monoecious. Neighbour-joining (NJ) tree and factorial correspondence analysis (FCA) of simple sequence repeat loci also revealed a high level of genetic variability in this germplasm. The 96 melon genotypes clustered into five groups in the NJ tree analysis: the 16 Indian Reticulatus Group accessions and eight USA reference cultivars formed a distinct group; and the 60 Cantalupensis Group accessions clustered in four other groups with the 12 Momordica Group accessions in a distinct subgroup of one of the Cantalupensis groups. The FCA plot largely confirmed the NJ tree with three distinct groups, one for each melon group. The close affinity of the Indian and USA Reticulatus melons was not unexpected, but it is not clear whether it was inherent in the group and maintained as Reticulatus melons moved from India through Central Asia and Europe to North America, or the result of recent intercrossing of Indian landraces with the USA-derived cultivars and selection for a broad range of Reticulatus type melons.     

吐鲁番哈密瓜土壤养分及酶活性对连作年限的响应

哈密瓜(Cucumis melo var.saccharinus)连作障碍已经成为制约其产业发展的重要因素,为探明哈密瓜连作年限对土壤养分及酶活性的影响,以吐鲁番鄯善县不同连作年限哈密瓜田为研究对象,分析了不同连作年限哈密瓜农田根际土壤及非根际土壤的养分含量及酶活性特征.结果表明:1)随连作年限的递增,哈密瓜根际土壤和...