温度和乙烯对京白梨后熟进程及其品质的影响

研究温度、乙烯对京白梨果实后熟进程及品质的影响。测定果实乙烯释放量、呼吸强度、果实硬度、可溶性固形物含量、pH值、果皮颜色ΔE 值和h 值、失重率、病果率等指标,并进行感官评价。结果表明：温度和乙烯直接影响果实的后熟进程和后熟品质;后熟过程中果实硬度与后熟时间呈极显著线性负相关(P＜ 0.01),温度过高或过低均导致果皮转色和果实硬度后熟不一致,适度的低温(14℃)延迟了果实乙烯峰值的启动时间,高温(28℃)抑制乙烯的生成和果实的软化,温度越高,失重率和烂果率越高;外源乙烯有助于果实乙烯的生成和呼吸强度的增加,乙烯加快了果实的后熟进程,并且后熟更均匀一致,且品质最佳。研究表明：京白梨后熟的适宜温度范围17～23℃,最佳温度20℃,最佳乙烯催熟用量为100μL/L。     

采后乙烯利处理对软儿梨果实后熟期生理及品质的影响

以软儿梨为试材,研究了1 mL/L乙烯利处理对(20±3)℃、相对湿度85%~90%条件下贮藏的采后软儿梨果实后熟期生理和品质指标的影响。结果表明:采后乙烯利处理软儿梨果实能够提高果实乙烯释放量并使其呼吸高峰提前2 d出现,加速了果实的后熟;在后熟第16天时,乙烯利处理组果实的质量损失率(5.4%)显著低于对照组果实(6.1%)(P0.05),提升了果实的色泽,但就整个后熟过程而言,对果实的硬度、还原糖、可滴定酸和石细胞含量无显著性影响(P0.05)。     

Browning Potential,PPO, Catalase and Acid Phosphatase Activities during Ripening of Non-chilled and Chilled Avocado

During storage at 17°C, an increase in respiration and ethylene production and a decrease in firmness occurred sooner in avocados chilled previously than in non-chilled ones. The browning potential of avocado mesocarp changes markedly during ripening of both non-chilled and chilled fruits, reaching the same maximal level in both groups. However, non-chilled ripened avocados are characterised by a much lower browning potential than ripened chilled fruits. The changes in browning potential during ripening are associated with larger changes in polyphenol oxidase (PPO) and catalase than in acid phosphatase activities. The levels of PPO and of catalase detected during ripening are about the same in non-chilled and chilled avocado, yet the former produced much more ethylene than the latter, implying that the level of these enzymes per se does not determine the level of ethylene produced by the fruit.     

The tamarillo: Fruit growth and maturation,ripening, respiration,and the role of ethylene

The tamarillo (tree tomato, Cyphomandra betacea Sendt.) flowers and sets fruit over an extended period. Many blossoms and young fruits abscise; survival of tagged fruitlets ranged from 0 to 32%. Tagged fruits were harvested at known ages for measurement of size and shape, respiration rate, ethylene production, and response to ethylene treatment. Fruit growth followed a single sigmoid pattern, and fruits were commercially mature at 21–24 weeks after anthesis. The amount of red skin pigment increased with age from 15 weeks, but harvesting of immature fruits appeared to stop red pigment development. Fruits harvested at 12–19 weeks or younger shrivelled in storage. Respiration studies showed tamarillo fruits to be non-climacteric, and only traces of ethylene were produced until final senescence. Ethylene treatment increased the respiration rate and hastened senescence of harvested fruits of all ages. The yellow strain behaved similarly to the red and had a somewhat longer storage life.     

Respiration rate,ethylene production and biochemical changes during fruit development and maturation of jujube (Ziziphus mauritiana Lamk)

Jujube fruits (Ziziphus mauritiana Lamk) of cv Zaytoni were harvested from fruit set until maturity to study some physiological and biochemical changes. Jujube fruit cv Zaytoni displayed a double‐sigmoid growth curve with a very short second stage (2 weeks). Changes in respiration rate and ethylene production during fruit development were typical of climacteric fruits, the peak of ethylene production coinciding with the climacteric rise in respiration. As for chemical constituents, reducing sugars were dominant and sucrose was absent in ripe fruit. Total soluble solid content was low during the early stages of growth, then increased to a peak in ripe fruit. Titratable acidity was low initially, but increased to a peak in physiologically mature fruit and declined rapidly in ripe fruit. The pattern of changes in protein content was typical of that characterising climacteric fruits. © 2002 Society of Chemical Industry     

施加外源乙烯时机对自发气调贮藏桃果实生理效应的影响

在自发气调(MA)贮藏期间,不同时间(0、15、30d)加入外源乙烯处理(50～80μl/L),研究大久保桃果实的呼吸、乙烯和色素的变化。结果表明,MA贮藏过程中,桃果实的呼吸和乙烯释放很低,而且变化值未表现出高峰,外源乙烯处理诱导了贮藏期和货架期桃果实内源乙烯的释放,增强了果实的呼吸强度;外源乙烯处理时间越早,桃果实的呼吸强度、乙烯释放量高峰出现越早或者峰值越高;外源乙烯处理促进了桃果实果皮叶绿素的降解,抑制了类胡萝卜素的快速下降,使桃果实正常着色。以上结果说明外源乙烯处理对于减轻桃果实低温贮藏冷害具有明显的作用。考虑到外源乙烯减轻低温冷害和促进果实衰老的双重作用,在时间上以贮藏30d时进行外源乙烯处理效果最好。     

Determination of optimum harvest maturity and physico-chemical quality of Rastali banana (Musa AAB Rastali) during fruit ripening

BACKGROUND: A series of physico‐chemical quality (peel and pulp colours, pulp firmness, fruit pH, sugars and acids content, respiration rate and ethylene production) were conducted to study the optimum harvest periods (either week 11 or week 12 after emergence of the first hand) of Rastali banana (Musa AAB Rastali) based on the fruit quality during ripening. RESULT: Rastali banana fruit exhibited a climacteric rise with the peaks of both CO₂ and ethylene production occurring simultaneously at day 3 after ripening was initiated and declined at day 5 when fruits entered the senescence stage. De‐greening was observed in both of the harvesting weeks with peel turned from green to yellow, tissue softening, and fruits became more acidic and sweeter as ripening progressed. Sucrose, fructose and glucose were the main sugars found while malic, citric and succinic acids were the main organic acids found in the fruit. CONCLUSION: Rastali banana harvested at weeks 11 and 12 can be considered as commercial harvest period when the fruits have developed good organoleptic and quality attributes during ripening. However, Rastali banana fruit at more mature stage of harvest maturity taste slightly sweeter and softer with higher ethylene production which also means the fruits may undergo senescence faster than fruit harvested at week 11. Copyright © 2011 Society of Chemical Industry     

间歇升温对香蕉李贮藏中生理生化变化的影响

以香蕉李为试材,研究了不同的间歇升温对低温下贮藏的李果实生理生化的影响。结果显示:对照果在冷藏20d时,呼吸强度和乙烯释放量逐渐增加,相对电导率明显上升;说明冷害已经开始启动,而且随着贮藏时间的延长,冷害指数显著增大,冷害程度明显加剧,果实正常后熟过程受阻。经过间歇升温的果实,果皮逐渐由绿变黄,再由黄转红而逐渐完成后熟过程。间歇升温到10℃虽然对冷害症状有所缓解,但李果实更易成熟老化,可溶性固形物含量快速下降,呼吸强度明显高于冷害果,膜透性增加最快,贮藏后期老化的果实更易发生冷害。而间歇升温到18℃的李果实呼吸强度、膜透性、贮藏初期的乙烯释放量明显受到抑制,可溶性固形物含量较高,冷害指数显著下降,说明间歇升温到18℃能有效地抑制李果实冷害的发生,延缓了李果实的衰老进程,保持了李果实良好的贮藏品质。     

贮前热处理对番茄采后生理的影响

绿熟番茄采后用38℃热水处理60min,晾干,1±1℃,RH80%～95%冷藏37d后,转入20℃后熟,以20℃室温水处理为对照。结果显示,热处理果实的后熟率比对照提高了1.8倍。贮前热水处理对冷藏中果实的硬度和多聚半乳糖醛酸酶(PG)活性无显著影响,但促进该酶在后熟期间的增加,却减缓果实的软化;热处理刺激果实的呼吸、1-氨基环丙烷-1-羧酸(ACC)含量的增加,和ACC合酶(ACS)活性、乙烯含量的减少,但长期冷藏后作用消失,且显著增加后熟期间ACS的活性、ACC含量、乙烯生成以及呼吸强度。热处理可能通过调节乙烯的代谢来促进果实的后熟,降低果实的冷害。     

Respiratory rate of olive drupes during their ripening cycle and quality of oil extracted

During the ripening cycle of Frantoio and Leccino olive varieties, the respiration rate of drupes was measured, giving the respiratory curve of fruits. This curve, for both varieties, dropped to a minimum point towards the end of November (a few days earlier for the Leccino variety) followed by a rise up to a maximum. This phase of the ripening process of olives corresponds to the climacteric crisis of the fruits. In this period the oil extracted from drupes gave the best analytical characteristics and was rich in tocopherols, phenols and aromatic volatile substances, components closely related to the shelf-life and the organoleptic quality of the product. The climacteric phase of drupes therefore corresponds to the optimal ripening stage of fruits and the harvesting of olives should be carried out during this period, in order to obtain oils of elevated quality. The respiration rate of drupes is therefore proposed as a new ripening index for drupes. © 1998 SCI.     

ACC oxidase activation by cold storage on ‘Passe-Crassane’ pears: effect of calcium treatment

Ethylene biosynthesis and respiration in untreated and in calcium-treated Passe-Crassane pear fruits during cold storage and during ripening at 20°C after removal from storage at 2°C was studied. Results suggest that the increase in ACC oxidase activity along with free-ACC availability for enzyme action is the most important limiting factor in the capacity of these fruits to produce ethylene and to ripen. A chilling period of at least 30 days was shown to be required for inducing the climacteric increase in ethylene biosynthesis. Calcium treatment partially prevented ethylene production and retarded the onset of the climacteric process in Passe-Crassane fruits. The role that calcium plays in preventing cellular wall and membrane degradation is probably responsible for this delaying effect on the ripening process of this pear cultivar. © 1998 SCI.     

EFFECT OF GAMMA IRRADIATION ON SOFTENING CHANGES AND ENZYME ACTIVITIES DURING RIPENING OF PAPAYA FRUIT

The aim of this work was to study the role of cell wall and ethylene related enzymes to papaya fruit firmness. Irradiation treatment was used as an imposed stress to cause changes in firmness. Physiologically mature papaya fruits were irradiated (500 Gy) and allowed to ripen at 22C and 90% RH. Polygalacturo‐nase (PG), pectinmethylesterase (PME), βgalactosidase, cellulose and 1‐aminocyclopropane‐1‐carboxylate oxidase (ACC‐oxidase) activities were followed during ripening and correlated to changes in firmness, skin and pulp color, respiration and ethylene production. The firmness of irradiated fruits was retained at least 2 days longer than in normal fruits and also had a slower rate of softening. Total soluble solids (d?Brix), cellulase activity and ethylene production were not altered by irradiation treatment. The activity patterns of PG, PME and β‐galactosidase were related to pulp softening and affected by irradiation. ACC‐oxidase activity was influenced by irradiation treatment, but its changes were not temporally related to those in firmness. It was concluded that irradiation had no direct effect on firmness but it acted by altering the ripening induced synthesis of cell wall enzymes, mainly PME.     

The Role of Ethylene in the Regulation of Fruit Ripening in the Hillawi Date Palm ( Phoenix dactyliferaL)

The role of ethylene in the regulation of fruit ripening in the date palm ( Phoenix dactylifera L) was investigated. It was found that the rate of CO₂ output was high initially, but the rate declined steadily as the fruit advanced in maturity, reaching its lowest level as the fruit entered the stage of physiological maturity, but then the rate of respiration increased as the fruit entered the ripening phase, reached a peak value and then declined. Ethylene emission was not detected until the 91st day from pollination when ethylene production began with a rapid increase in emission, reaching a peak value within 15 days and then declining rapidly. The peak of ethylene production preceded the climacteric peak by 7 days.     

Residual effect of atomised water vapour treatment on carbohydrate metabolism during ripening of cv “Fino de Jete” cherimoya fruit

Atomised hot water vapour at between 46 and 54 °C for 60 min was tested as a method of delaying ripening and extending shelf life in cv “Fino de Jete” cherimoya fruit (Annona cherimola Mill.). Heat treatment at 46 °C stimulated the respiration rate and starch degradation, induced ethylene production, increased the accumulation of soluble sugars and α-amylase activity, and moved the onset of ethylene production (OEP) forward. Treatment at 50 °C, and especially at 52 °C, delayed the climacteric peak and the OEP, decreased sugar and organic acid accumulation, and reduced α-amylase and invertase activity. The results obtained indicate that temperatures higher than 48 °C slowed physiological processes and carbohydrate metabolism and extend the shelf life of the cherimoya fruits, while temperatures higher than 52 °C blocked ripening irreversibly.     

苹果果实超弱发光、乙烯释放和呼吸跃变对1-MCP的响应

以耐贮藏的“红富士”(MalusdomesticaBorkhvar.RedFuji)苹果果实为试材,研究了果实采后衰老过程中超弱发光(Ultra-weakLuminescence,UWL)、乙烯释放和呼吸跃变对1-甲基环丙烯(1-methycyclopropene,1-MCP)的响应。结果显示,自然状态贮藏的果实UWL的变化与呼吸速率、乙烯释放速率的变化趋势相似,均有明显的高峰出现,且出峰时间一致。1-MCP处理后,果实的超弱发光峰明显拖后,但峰值不低于对照。高峰之后UWL值明显高于对照。与此同时,果实软化明显延缓,呼吸与乙烯释放速率下降,乙烯、呼吸跃变高峰也推迟。果实超弱发光能够反映富士苹果采后衰老过程中代谢的变化。     

1-MCP及其结构相似物处理对番茄采后贮藏效果的影响

为了研究环丙烯类乙烯抑制剂的作用效果,以绿熟期番茄为试材,用1-甲基环丙烯(1-MCP)、1-戊基环丙烯(1-PentCP)、1-辛基环丙烯(1-OCP)处理后,常温(18℃±2℃)贮藏,每隔3 d测定1次理化指标,研究三者对番茄果实后熟衰老和贮藏效果的影响。结果表明:1-MCP及其结构相似物处理番茄不同程度地降低了呼吸强度和乙烯释放量的峰值,抑制了番茄果实硬度的下降,延缓了可溶性固形物含量的上升,同时也有效抑制了后熟期番茄果实过氧化氢酶(CAT)活性、过氧化物酶(POD)活性,延缓了果实的后熟衰老。3种试验的抑制剂中,1-MCP、1-PentCP和1-OCP处理随支链长度的增加,抑制后熟衰老的效果依次降低。     

Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas

The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.     

硫化氢对采后粉蕉果实贮藏品质的影响

为研究不同浓度硫化氢(Hydrogen sulfide,H₂S)处理对采后粉蕉果实品质的影响,将粉蕉果实分别用0.3、0.6和0.9 mmol/L NaHS溶液释放的H₂S处理,并定期观察和测定了贮藏期间果实的硬度、色泽、失重率、褐变指数、可溶性固形物(TSS)、可滴定酸(TA)、呼吸速率和乙烯生成速率。结果表明：H₂S处理明显延缓了粉蕉果实表皮黄化和果肉褐变指数的增加,减缓了果实的软化和失重率的上升,果实TSS含量以及TA含量上升幅度受到一定程度抑制。并且,除了TSS 3个不同浓度处理组间差别不显著外(P>0.05),其余都表现出0.6 mmol/L NaHS处理组效果更明显;与此同时,经NaHS处理还显著地抑制了果实的呼吸作用和乙烯生成速率的上升(P<0.05),推迟了呼吸和乙烯达到峰值的时间4 d。但不同浓度NaHS处理组间对乙烯影响不显著(P>0.05)。综合来看,不同浓度NaHS处理均可以延缓采后粉蕉果实的成熟衰老,其中以0.6 mmol/L NaHS处理的保鲜效果最明显。     

1-MCP和预贮对深州蜜桃采后生理和品质的影响

为保持深州蜜桃冷藏期间良好的品质, 延长贮藏时间, 采用1 . 0 μ L / L 1 - 甲基环丙烯
（1-methylcyclopropene,1-MCP）熏蒸和预贮（8 ℃、5 d转入0 ℃）的方法对采后深州蜜桃进行处理,测定0 ℃冷
藏期间果实呼吸速率、乙烯释放速率和品质的变化。结果表明,1-MCP处理能够明显抑制桃果实冷藏期间的呼吸速
率和乙烯释放速率,推迟呼吸高峰期的出现;同时延缓了果实软化,抑制可溶性固形物含量上升,降低了果实的褐
变指数和腐烂指数;预贮促进了果实后熟,但预贮和1-MCP处理均明显降低了贮藏期果实褐变度和酚类物质含量,
二者结合处理对抑制果实褐变效果最佳。