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1.
Storage performance of Fortune mandarins following hot water dips   总被引：2，自引：0，他引：2  
Commercially ripe ‘Fortune’ mandarins were dipped in water at 50 °C (Dip50), 52 °C (Dip52), 54 °C (Dip54), 56 °C (Dip56), or 58 °C (Dip58) for 3 min before storage at 6 °C for 30 days and 3 additional days at 20 °C (simulated shelf-life). Untreated fruits were used as control. Scanning electron microscopy of untreated fruit revealed rough and granular wax surface structures with a number of deep surface cracks. In contrast, fruits dipped at 50–54 °C did not exhibit similar fractures and the fruit surface appeared relatively homogeneous. Dip56 resulted in parts of the surface with no apparent epicuticular wax and zones with an accumulation of waxy deposits. With Dip58, the fruit surface appeared as if the treatment had melted and completely removed epicuticular waxes. Dip50–54 reduced chilling injury and levels of decay, both during cold storage and simulated shelf-life. Dip56–58 showed no advantages compared with untreated fruit. Neither Dip50 nor Dip52 caused adverse effects to rind surface, either during or after simulated shelf-life. Conversely, higher dip temperatures induced heat damage in the form of rind browning, the extent and number of fruits affected increasing as bath temperature increased. Water loss was consistently lower in untreated fruit. Peel water loss was consistently higher in Dip56 and Dip58 fruit. Differences in external appearance, physiological behaviour and internal quality attributes between untreated and Dip50–54 fruit were minimal. Dip56 and especially Dip58 had negative effects on the external appearance of fruits. The off-flavour found in Dip58 was probably due to increased levels of ethanol in the juice.  相似文献   

2.
A near-isogenic line (NIL) SC3-5 and a further nine NILs of melon contained introgressions of an exotic non-climacteric accession of Cucumis melo ‘Shongwan Charmi’ [SC (PI 161375), Conomon Group)] into the non-climacteric Spanish Inodorus type of melon cultivar ‘Piel de Sapo’ (PS). The NILs exhibited different climacteric behavior and aroma. Fruit from SC3-5 and seven NILs showed a climacteric pattern, while fruit from one NIL, both parentals and the cultivar ‘Nicolás’, were non-climacteric. The NILs were compared with the reference aromatic cultivars ‘Fado’ and ‘Védrantais’, which show climacteric behavior with high levels of respiration and ethylene production. The twenty-eight aromatic compounds common to the cultivars and NILs studied defined the aroma profile, which was composed of fifteen esters, six aldehydes, two alcohols, three derived sulfur compounds (methyldisulfanylmethane; methanethiolate; methyl 2-sulfanylacetate) and other three compounds (1,7,7-trimethylnorbornan-2-one; acetone; 2-ethylfuran). On the basis of the total ion count peak area, three compounds (isobutyl acetate; benzyl acetate; pentanal) allowed the climacteric to be distinguished from the non-climacteric NILs according to univariate analysis. Multivariate analysis of the aroma data on the basis of total ion count peak area separated the aromatic attributes of the climacteric ‘Védrantais’ and ‘Fado’ melons from the NILs that were closer to their inbred parentals when analyzed by partial least squares regression plus discriminant analysis. In the climacteric reference cultivars or NILs, esters were the predominant volatiles while aldehydes predominated in non-climacteric ones. These results support the hypothesis that at least one QTL in linkage group III boosts a series of maturation signals that are characteristic of climacteric fruit, including a different aroma profile.  相似文献   

3.
The role of phospholipase A2 (PLA2) activity in development of postharvest peel pitting in mature ‘Fallglo’ tangerines [Bower citrus hybrid (Citrus reticulata Blanco × C. reticulata Blanco × C. paradisi Macf.) × Temple (C. reticulata Blanco × Citrus sinensis L.)] and ‘Navel’ oranges (Citrus sinensis L. Osbeck) was investigated. Changes in RH from 30% to 90% followed by fruit waxing increased electrolyte leakage and PLA2 activity in flavedo, and induced pitting. Treatment with an aqueous dip of aristolochic acid (AT), a specific inhibitor of secretory phospholipase A2 (sPLA2) activity, immediately before transfer from 30% to 90% RH storage, markedly reduced peel pitting symptoms. Five genes encoding various phospholipase As isolated from citrus (three patatin-like and two sPLA2-like sequences) differentially accumulated in healthy areas, areas with developing lesions and necrotic lesions of disordered fruit. Other PLA2, phospholipase C, and phospholipase D inhibitors also reduced peel pitting; however, PLA2 inhibitors were the most effective in preventing the disorder. In addition, phospholipase inhibitors promoted fruit decay, suggesting that innate resistance is impacted by phospholipase action. Together, the results provide evidence for involvement of phospholipase activity in development of postharvest peel pitting symptoms in citrus fruit.  相似文献   

4.
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.  相似文献   

5.
Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of ‘Oroblanco’ fruit (Citrus grandis L.×C. paradisi Macf.). The following heat treatments were used: curing at 36°C for 72 h, hot water dip at 52°C for 2 min or ‘hot drench brushing’ at 52, 56 or 60°C for 10 s. The standard packinghouse treatment included waxing with addition of thiabendazole (TBZ) and 2,4- isopropyl ester. The fruit was stored for 2 weeks at 1°C (simulated low-temperature quarantine treatment), followed by 12–13 weeks at 11°C (simulated sea transportation to Japan) and 1 additional week at 20°C (simulated retail shelf-life period). The lowest weight loss and the highest firmness were observed with individually sealed fruit. Polyethylene liners were usually more efficient for weight loss control than waxing. However, the liner packaging enhanced the risk of postharvest disease development, if not accompanied by appropriate decay-controlling measures. Applying TBZ, hot water dip or curing controlled the development of postharvest pathogens, especially that of Penicillium molds. In another trial, both hot drench brushing at 56 or 60°C and hot water dip reduced decay incidence. Hot drench brushing at 60°C and hot water dip slowed fruit softening and reduced buttons abscission. In addition, the hot drench brushing at 60°C significantly delayed the loss of ‘Oroblanco’ green rind color, especially at the stylar and stem ends of the fruit. The hot dip at 52°C inhibited yellowing only when combined with individual seal-packaging.  相似文献   

6.
'Laiyang Chili’ and ‘Ya Li’ (Pyrus bertschneideri Reld) pears were treated with 3, 6, and 9% emulsions of commercial or refined (reduced -tocopherol levels) plant (soybean, corn, peanut, linseed, and cottonseed) oils at harvest an stored at 0°C for 6 months. Effects of oil treatments on ethylene production, respiration, fruit firmness, fruit color, soluble solid content (SSC), titratable acids (TA), internal browning (IB), and internal CO2, O2, and ethanol were studied. At the same concentration, oil treatments induced similar responses regardless of their sources or their -tocopherol concentrations. In both cultivars, ethylene production and respiration in fruit treated with 9% oils were lower in early storage and higher in late storage than that in the controls. Oils at 6% reduced IB, at 9% inhibited IB completely, and at 3% was not effective after 6 months at 0°C and 7 days at 20°C. Plant oil treatment maintained fruit color, firmness, SSC, and TA in a concentration-dependent manner during storage. In the first 4 months storage, 9% corn oil-treated fruit contained similar partial pressure of CO2 and O2 as the controls. After 5 months storage, oil-treated fruit contained higher partial pressure of CO2 and lower levels of O2 than the controls. When held at 20°C for 7 days, changes of internal CO2 and O2 were slower but partial pressure of CO2 were higher, and O2 were lower, in 9% corn oil-treated fruit than in the controls. Internal ethanol was not affected by oil treatment compared with control, either during storage or 7 days at 20°C. No off-flavor was detected in either oil-treated and control fruit by sensory evaluation.  相似文献   

7.
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8.
The effect of delays of 1, 5, 10 or 15 d after harvest in establishing a static controlled atmosphere (SCA) or dynamic controlled atmosphere (DCA) on the quality of ‘Hass’ avocados (Persea americana Mill.) was investigated. Fruit were stored at 5 °C in SCA (5% O2/5% CO2) or DCA (<3% O2/0.5% CO2) for 6 weeks and compared with fruit stored in air. In addition, to determine whether increasing the CO2 in the DCA would affect the fruit quality, DCA-stored fruit were compared with fruit held in a DCA with 5% CO2 (DCA + CO2) established 1 d after harvest. The quality of fruit was assessed at the end of storage and after ripening at 20 °C. DCA-stored fruit ripened in 4.6 d compared with 7.2 d for SCA-stored fruit, or 4.8 d for air-stored fruit. In addition, the incidences of stem end rot (SER), body rot (BR) and vascular browning (VB) were lower in DCA-stored fruit (35%, 29% and 29%, respectively) than in SCA-stored fruit (57%, 52% and 49%, respectively), or air-stored fruit (76%, 88% and 95%, respectively). Delaying the establishment of both SCA and DCA for 15 d resulted in significantly more advanced skin colour at the end of storage (average rating score 11.9) compared with other delay periods (4.6–5.1). There was no significant effect of delay on the time to ripen, skin colour when ripe or any ripe fruit disorder incidence. The incidence of diffuse flesh discolouration (DFD) was not only <1% when averaged over all delays but only occurred at >0.5% incidence in the 15 d delay treatment in DCA (4.8%) and not in SCA. The incidence of diffuse flesh discolouration was 62% in air-stored fruit. Inclusion of 5% CO2 in DCA retarded fruit ripening from 4.7 to 6.9 d and increased the incidence of rots at the end of storage from 5% to 14%, and increased the incidence in ripe fruit of SER from 30% to 56% and of BR from 27% to 55%. It is concluded that fruit quality was better after CA storage than after air storage, and that DCA storage was better than SCA. The effect of DCA is to independently reduce the time to ripen after storage and the incidence of rots when ripe. Delaying the application of SCA or DCA did not affect the expression of rots, but may increase the incidence of DFD. Inclusion of CO2 at 5% in CA retarded fruit ripening but stimulated rot expression and should not be used for CA storage of New Zealand grown ‘Hass’ avocados.  相似文献   

9.
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10.
Storage of ‘Fuji’ apple fruit in a high CO2 (3 kPa) and low O2 (1.5 kPa) controlled atmosphere (CA) reduced firmness and titratable acidity (TA) loss during long term storage. This CA environment also induced development of internal CO2-injury (brown-heart) and slowed the disappearance of watercore. The symptoms of internal CO2-injury were first detected 15 days after CA establishment and the severity increased during the first 4 months of CA-storage. Delaying establishment of CA conditions for 2–12 weeks significantly reduced the severity of CO2-injury. Delaying CO2 accumulation to 3 kPa for 1–4 months during CA (1.5 kPa O2+0.05 kPa CO2) storage also reduced development of CO2-injury symptoms. Delaying CA or CO2 accumulation resulted in lower firmness and TA compared to establishment of CA within 72 h of harvest. However, the delay treatments did result in firmness and TA that were significantly higher compared to values for fruit stored in air. The incidence and severity of senescent injuries (flesh browning and core flush) detected during the late period of storage were greater in air- than CA-stored fruit. The results indicate the susceptibility of ‘Fuji’ apples to CO2-injury is highest during the first weeks of storage after harvest. Delaying establishment of CA or exposure to elevated CO2 after harvest may be a practical strategy to reduce CO2-injury while maintaining other important quality attributes at acceptable levels.  相似文献   

11.
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.  相似文献   

12.
为明确苹果果实品质与海拔的相关性关系,以河北省44个果园的‘富士’苹果为试材,采用成熟期采样、测定和相关性分析的方式,研究果实外观品质、内在品质、质构特性与海拔高度的相关性。果园平均海拔247.77 m,在果实外观品质方面,果实单果重与海拔呈显著负相关(r=-0.33,P<0.05),着色指数与海拔呈极显著正相关(r=0.43,P<0.01),裂果指数与海拔呈极显著负相关(r=-0.64,P<0.01);在果实内在品质方面,果实可溶性固形物含量与海拔呈显著正相关(r=0.37,P<0.05),硬度、可滴定酸、固酸比均与海拔无显著相关性;在果实质构特性方面,果实粘附性与海拔呈显著负相关(r=-0.30,P<0.05),内聚性与海拔呈显著正相关(r=0.34,P<0.05),脆裂性与海拔呈显著正相关(r=0.30,P<0.05),胶粘性与海拔呈显著正相关(r=0.30,P<0.05),咀嚼性与海拔呈显著正相关(r=0.32,P<0.05),弹性与海拔无显著相关性。海拔高度在700 m以下时,较高的海拔能够显著提高果实的外观品质和可溶性固形物含量,海拔高度与果实质构特性显著相关。  相似文献   

13.
1-MCP对贮藏酥梨品质的影响   总被引：1，自引：0，他引：1  
为了延长贮藏酥梨货架期品质,以酥梨果实为试材,研究了0.5 μL/L和1.0 μL/L 1-MCP 2种浓度对通风库贮藏酥梨货架期品质的影响。处理果实与对照相比,能较好维持原有外观品质;处理果实呼吸强度和乙烯释放量比对照都有所降低。0.5 μL/L处理效果较明显,果实呼吸强度最低比对照降低24%;1 μL/L处理乙烯释放量最低比对照降低53%,0.5 μL/L处理比对照最低下降了31%。1-MCP处理能延缓果实硬度和可溶性固形物的下降,0.5 μL/L处理果实硬度平均比对照高4.6%,1.0 μL/L处理果实硬度平均比处理高8.6%;0.5 μL/L处理果实可溶性固形物含量与对照有明显差异,最低可下降13%。综合来看,0.5 μL/L对延长地下通风库酥梨货架期有较好的效果。  相似文献   

14.
1-MCP处理对鲜切哈密瓜贮藏品质的影响   总被引：2，自引：0，他引：2  
"早佳"哈密瓜采后经4℃温度下预冷48 h,同时采用1μL.L-1浓度的1-MCP进行处理,研究其对哈密瓜鲜切加工产品在4℃下贮藏8 d品质变化的影响。结果表明,哈密瓜采后用1-MCP处理,能够减缓其生理代谢速率和后熟衰老进程,有利于保持鲜切产品的品质,推迟鲜切哈密瓜的呼吸跃变高峰的出现时间,延缓硬度下降速率,减少可溶性固形物的消耗,保持较好的色泽、口感和风味,延长货架期1~2 d。  相似文献   

15.
为评估橘小实蝇对桃果的危害风险,以'大久保'、'川中岛'、'中蟠11'、'岱妃'、'中华寿桃'等品种及'莱山蜜'未成熟、近成熟、成熟的果实为材料,探究橘小实蝇在不同品种及3个成熟度果实上的产卵量,测定不同桃果果实生理指标,分析果实品质与橘小实蝇产卵量的相关性;并选取在生产中较为常用的果袋,测定其对橘小实蝇产卵的阻隔效果...  相似文献   

16.
为比较分析广东省主要鲜食橄榄果实质构特性的差异,探讨鲜食橄榄果实质地评价的量化参数,验证感官评价质地的有效性。采用质构刺穿试验法对7个优质鲜食橄榄品种果肉质构参数和2种水肥管理方式不同成熟期的‘香甜榄’果实品质进行测定和比较分析。结果表明,不同品种之间果肉的各质构参数变异系数为12.57%~23.95%,差异性显著,与感官评价一致;果皮强度与果皮脆性和果皮韧性均呈显著正相关,果皮破裂深度与果肉硬度呈显著负相关。采用本次试验栽培管理方式可以提高橄榄完熟果实可溶性固形物6%、可滴定酸3.5%、单宁54.9%、果皮强度12.7%、果皮脆性23.5%,降低粗纤维10%、果皮韧性13.7%。果实质地品质参数主成分分析表明,果皮强度、果实硬度和纤维指数可作为质地参数量化区分不同品种间的差别,并明确果皮强度、果实硬度分别小于2300、1600 g和纤维指数大于10,为鲜食橄榄果肉质地品质较好的数值范围。研究初步建立了利用质构刺穿试验法量化评价鲜食橄榄果实质地品质的方法。  相似文献   

17.
The effect of ethylene (2 μL L−1) on total and soft epicuticular wax content and wax morphology has been investigated in mature ‘Navelate’ (Citrus sinensis, L. Osbeck) oranges held under non-stressful environmental conditions (22 °C and constant high relative humidity (90–95% RH)). In addition, the objective of the study was to understand whether the ethylene-induced changes in epicuticular wax might participate in the beneficial effect of ethylene reducing non-chilling peel pitting, by modifying peel water, osmotic or turgor potential, or disease incidence caused by Penicillium digitatum (Pers.:Fr.) Sacc. Ethylene increased total and soft epicuticular wax content in ‘Navelate’ fruit and induced structural changes in surface wax that might be related to the formation of new waxes. Changes in epicuticular wax morphology, but not in its content, might be involved in the protective role of ethylene reducing non-chilling peel pitting, although the beneficial effect of the hormone is not related to water stress. Cell water and turgor potentials in freshly harvested fruit and fruit stored in air under non-stressful conditions suggest that water stress is not a limiting factor leading to the development of this physiological disorder. In addition, the results indicated that formation of new waxes in fruit treated with ethylene may partially cover stomata, cracks or areas lacking wax occurring in stored fruit and is likely to improve physical barriers to P. digitatum penetration.  相似文献   

18.
The growth and production of sweet sorghum [Sorghum bicolor (L.) Moench] crops under semi-arid conditions in the Mediterranean environment of southern Italy are constrained by water stress. The effects of temporary water stress on growth and productivity of sweet sorghum were studied during three seasons at Rutigliano (Bari, Italy). The aim of this research was to evaluate the sensitivity of phenological stages subjected to the same water deficit. In a preliminary study it was observed that stomata closed when pre-dawn leaf water potential (Ψb) became lower than −0.4 MPa. This criterion was used in monitoring plant water status in three different plots: one never stressed and two stressed at different phenological stages (‘leaf’ and ‘stem’) when mainly leaves or stems were growing, respectively. An evaluation of the sensitivity of phenological stages subjected to identical water stress was obtained by comparing the above-ground biomass and WUE of drought crops with those of the well-irrigated crop (up to 32.5 t ha−1 of dry matter and 5.7 g kg−1). The sensitivity was greatest at the early stage (‘leaf’), when a temporary soil water stress reduced the biomass production by up to 30% with respect to the control and WUE was 4.8 g kg−1 (average of three seasons). These results help quantify the effects of water constraints on sweet sorghum productivity. An irrigation strategy based on phenological stage sensitivity is suggested.  相似文献   

19.
研究旨在阐明‘文紫椒1号’果实在不同发育阶段的色素比例和组织定位,为丘北辣椒在观赏园艺中的应用和观赏型新奇果色新品种的选育提供参考。以种植于云南文山州砚山县的‘文紫椒1号’果实为试材,将果实分为5个发育阶段,用分光光度法检测了果实的叶绿素含量([Chl])、类胡萝卜素含量([Car])、总黄酮类含量(TFC)、总花色苷含量(TAC)和辣椒红素含量([Cap]),并分析其配比和相关性,同时用徒手切片法检测了色素的组织定位。结果表明,在发育过程中,‘文紫椒1号’果实[Chla]/[Chlb]的最大值出现在发育阶段3,[Chl(a+b)]/[Car]、[Chl(a+b)]/TFC和[Chl(a+b)]/TAC的最大值均出现在阶段2,而[Chl(a+b)]/[Cap]、TFC/TAC、TFC/[Cap]和TAC/[Cap]的最大值均出现在阶段1。[Chla]、[Chlb]、[Chl(a+b)]、[Car]、TFC、TAC和[Cap]之间的相关性不尽一致,其中,TAC与[Chl(a+b)]、TFC之间均呈不显著正相关,而与[Car]之间呈不显著负相关,[Cap]则与[Chl(a+b)]、[Car]、TFC和TAC之间分别呈显著负相关、极显著正相关、不显著正相关和不显著负相关。果实色素主要定位在中果皮细胞中,细胞的色相和色度变化趋势与果色的高度一致。所以,‘文紫椒1号’的果色源于各发育阶段果皮细胞中叶绿素、类胡萝卜素（含辣椒红素）和黄酮类（含花色苷）色素的比例差异。  相似文献   

20.
Potassium sorbate (PS) is a well-known and widely used food preservative. Among other applications, it is used as a GRAS fungistatic postharvest treatment for citrus, although its use is not free of significant adverse effects. In this paper, we study in detail the efficacy of wax containing increasing concentrations of PS to control Penicillium digitatum decay in citrus fruit, and its effect on fruit weight loss. Decay control and weight loss increased with the concentration of PS in the wax. Wax with typical amounts of 2–5% PS showed poor decay reduction indices (DRI), between 26% and 32%, whereas fruit weight loss increased compared with non-waxed controls. Waxing of fruit reduced weight loss by up to 40%, depending on wax formulation, but the addition of just 2% PS to the wax caused an increase in fruit weight loss of up to 65% compared with the waxed fruit. Similar results were observed for all the types of wax formulations tested. The hygroscopic effects of PS are even more damaging for citrus fruit with leaves. The leaves lose weight very rapidly when PS is added to the wax and they become desiccated in 24 h.We also present the results of a similar study where PS was applied to citrus as an aqueous treatment. When applied in water, PS was far more effective for decay control than when applied in wax, but there was also a considerable increase in fruit weight loss. A treatment combining aqueous PS with Fortisol® Ca Plus biostimulant completely solved the problem of weight loss, these mixtures being commercially feasible treatments.  相似文献   

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