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     

Impact of exogenous salicylic acid treatment on the cell wall metabolism and ripening process in postharvest tomato fruit stored at ambient temperature

Tomato is a climacteric fruit susceptible to rapid softening and ripening after harvest. In this study, the changes of physicochemical characters, cell wall-degrading enzymes, cell wall compositions and ethylene production of ‘Hisar Arun’ and ‘BSS-488’ tomato fruits were investigated under the influence of salicylic acid treatment. Salicylic acid treatment effectively delayed firmness decline and increase in PLW, TSS and lycopene content. The treated fruits maintained the integrity of cell wall composition by delay in increase in activities of cell wall-degrading enzymes (pectin methylesterase, polygalacturonase and cellulose) and cell wall components (cellulose, hemicellulose, lignin and pectin) decline. Moreover, salicylic acid treatments significantly suppress expression level of ethylene-producing genes (ACO1 and ACS2) and inhibited ethylene production during storage. Overall, the salicylic acid-induced delay in the ripening process occurs via the strong inhibition of ethylene biosynthesis, lowered cell wall-degrading enzyme activities and slowed cell wall degradation.     

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.     

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.     

Changes in ethylene and CO2 during the ripening of apples

The internal concentrations and production of both ethylene and CO₂ were measured during the maturation and ripening of Cox's Orange Pippin apples. Within 12 hours of the onset of the respiration climacteric there was no measurable increase in the production of ethylene and the data indicate that the increase in ethylene production is synchronous with the increased CO₂ production that marks the start of ripening. It therefore appears that a factor other than a change in the rate of ethylene production determines the time at which apples commence ripening.     

Some inhibitory effects of radiation stress on tomato fruit ripening

Detached tomato (Lycopersicon esculentum Mill. cv. Vendor) fruit exposed to 650 W m^?2 radiation from incandescent lamps for 1.5 or 4 h developed visible injury during subsequent storage. In tissues directly exposed to the radiation, ascorbic acid content was decreased and lycopene accumulation and protopectin solubilisation were blocked. For intact fruit, the respiratory climacteric was depressed, but ethylene production was enhanced following the radiation stress. Radiation injury blocks both the initiation and the progress of ripening.     

Changes in cell-wall-degrading enzyme activities in stored olives in relation to respiration and ethylene production Influence of exogenous ethylene

 The activity of various enzymes (α-D-galactosidase; β-D-galactosidase; α-L-arabinofuranosidase; α-D-mannosidase, β-D-N-acetylglucosaminidase, cellulase and polygalacturonase) associated with the cell wall during olive storage was assayed in order to establish the behaviour of the enzymes as a function of the ripening stage and in relation to the production of ethylene. The effect of exogenous ethylene (100 mg/l for 24 h) was also evaluated. In addition, gaseous emissions of CO₂ and ethylene during olive storage were monitored. The results obtained indicate that the high initial CO₂ level in the green olive coincides almost exactly in time with the climacteric maxima when the fruit is on the tree. After the rapid decrease in the respiration rate of green olives during storage, the CO₂ production rate increases as the stage of maturity advances. The results also indicate that ethylene is not capable of stimulating the activity or synthesis of enzymes in green olives, but can produce such a stimulation in black olives. Furthermore, during the first day of storage there were very marked decreases in enzyme activities. Small variations in the conditions of aerobiosis in post-harvest ripening were shown to have notable effects on the normal metabolism of the fruits. Received: 29 January 1996 / Revised version: 1 July 1996     

The Effects of Ultrasound Treatment and Nano-zinc Oxide Coating on the Physiological Activities of Fresh-Cut Kiwifruit

This study evaluated the efficacy of ultrasound treatment and nano-zinc oxide (ZnO) coating individually and in combination in preserving the quality of fresh-cut kiwifruit. The nano-ZnO coating solution was prepared by mixing the ZnO nanoparticles in premixed chitosan–acetic acid solution. The fresh-cut kiwifruit were dipped in NaClO solution (50 μL?L^?1 sodium, control), subjected to ultrasound treatment (40 KHz, 350 W, 10 min), or coated with nano-ZnO solution. The fresh-cut kiwifruit samples were also subjected to combined ultrasound treatment and nano-ZnO coating. All of these test samples were stored at 4 °C for 10 days. The effects of these treatments on the quality parameters such as the production of carbon dioxide and ethylene, mass loss, and flesh firmness were investigated. At the end of storage, the combination treatments with ultrasound treatment at 40 KHz with 1.2 g?L^?1 nano-ZnO coating showed lower production of ethylene (1.86 μL?kg^?1?h^?1) and carbon dioxide (10.01 mg?kg^?1?h^?1), water loss (0.46 %), and texture (7.87 N). Hence, it was concluded that the combination of ultrasound treatment with nano-ZnO coating is a promising approach to extend the shelf-life of fresh-cut kiwifruit.     

1-MCP对采后果实贮藏品质影响的研究进展

1-甲基环丙烯(1-MCP)为一种新型乙烯受体抑制剂,具有延缓果实衰老作用。它通过与乙烯受体蛋白的不可逆的竞争结合,干扰乙烯与其受体上的金属离子正常结合而在激素水平上影响果实对乙烯的响应。本文就1-MCP处理分别对呼吸跃变型和非呼吸跃变型果实采后生理及品质的效应以及对贮藏病害的影响进行了综述,旨为1-MCP绿色安全果实保鲜剂的应用推广提供技术思路。1-MCP对果实保鲜具有双向调节作用,1-MCP对采后果实的贮藏品质影响与其使用浓度、处理时间、处理方法及不同种类果实、呼吸漂移类型、采收期、贮藏温度等多种因素密切相关。     

鸭梨采后种子呼吸乙烯与果心褐变关系的研究

研究急速和缓慢两种降温方法对早、中、晚三种采收成熟度鸭梨采后种子呼吸、乙烯的影响及其与果心褐变的关系.结果表明:鸭梨采后种子属于呼吸高峰型,成熟度越高,呼吸和乙烯高峰出现的时间越早;采后同期,种子呼吸强度、乙烯释放量和果心褐变指数的变化规律是晚采>早采>中采;缓慢降温较好地抑制了种子的呼吸和乙烯代谢,从而减少鸭梨果心褐变,且时中采果效果更为明显.贮藏后期,种子的呼吸强度和乙烯释放量大幅度提高,变化趋势与果心指数变化规律相似,二者都与果心褐变存在着显著的正相关关系.     

Extending shelf-life of persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> L.) fruit by hot air treatment

‘Qiandaowuhe’ persimmon fruits (Diospyros kaki L.) were stored at 20 °C after exposed to 20 °C (control), 44 °C (T ₄₄), 48 °C (T ₄₈) or 52 °C (T ₅₂) hot air for 3 h, respectively. Firmness, weight loss, peel color, total carotenoids content, soluble solids content (SSC), titratable acidity (TA), respiration, and ethylene production and cell wall hydrolysis enzymes activities were monitored to determine the efficacy of hot air treatment in delaying persimmon fruit ripening. Results showed that ‘Qiandaowuhe’ persimmon fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak of CO₂ and ethylene production was observed after 4 days. Fruit softening was accompanied by a progressive increase in weight loss, total carotenoids content and decrease in h°. The activities of pectinmethylesterase (PME) and polygalacturonase (PG) sharply increased and reached maximal values after 4 and 6 days, respectively. Hot air treatment significantly delayed the onset of climacteric ethylene production, respiration, PME and PG activities in persimmon fruit. Moreover, it also significantly retarded the increase in carotenoids content and SSC, while decreased the firmness, h°, and TA. The hot air treatment promoted fruit weight loss. The shelf-life of persimmon ripening increased 4 days by T ₄₄, and 6 days by T ₄₈ or T ₅₂. Results suggest that hot air treatments can greatly extend the postharvest life of ‘Qiandaowuhe’ persimmon fruit.     

Delayed harvest and cold storage period influence ethylene production,fruit firmness and quality of ‘Cripps Pink’ apple

The effects of harvest date and cold storage period on ethylene production, fruit firmness and quality of ‘Cripps Pink’ apple were investigated. Fruit were harvested from Perth Hills and Donnybrook (Western Australia) at commercial maturity (CM), 2, 4 and 6 weeks after CM prior to 0, 45, 90 and 135 days cold storage in 2003 and 2004. Delayed harvest significantly increased ethylene production, CIE values a* and C* at both locations in 2 years. Delayed harvest and extended cold storage period increased the internal ethylene production and reduced fruit firmness, soluble solids concentration: titratable acidity (SSC:TA) ratio and reduced CIE values L*, b*, h° during both years and locations. Fruit harvested 2 weeks after CM can be cold‐stored for 90 days with acceptable fruit quality. If the fruit is intended to be sold fresh immediately in local markets, the harvest can be delayed up to 6 weeks after CM to harness substantially improved fruit colour with acceptable fruit quality.     

Chinese gooseberry: Seasonal patterns in fruit growth and maturation,ripening, respiration and the role of ethylene

Fruits of Chinese gooseberry (Actinidia chinensis Planchon, cv. Bruno) were harvested and respiration rates and other attributes were measured at regular intervals throughout the season. The fruit matured at about 23 weeks after anthesis as shown by patterns of respiration, response to ethylene treatment and changes in texture and content of soluble solids. Fruit growth followed a unique triple sigmoid curve. Natural ripening showed the fruits to be of climacteric type but, although associated with a peak of ethylene production, the respiratory pattern was somewhat atypical and initiation of ripening within any lot of uniform fruits was very variable. Ethylene treatment stimulated ripening in fruits of all ages, but a large induced respiratory peak was seen only in immature fruits. The physiological observations confirmed present horticultural practices and provide a basis for development of objective enforceable quality grades.     

1‐METHYLCYCLOPROPENE DELAYS POSTHARVEST RIPENING AND REDUCES DECAY IN HAMI MELON

ABSTRACT

The effects of 1‐methylcyclopropene (1‐MCP) on postharvest ripening and fruit decay in Hami melon were investigated. Melons were treated with 0, 0.1, 1, or 5 µL/L 1‐MCP at 25C for 24 h and then stored at 25C for 16 days. 1‐MCP treatment significantly inhibited respiration rate and ethylene production and delayed their climacteric rise. The treatment also significantly inhibited the decrease of firmness and the increase of electrolyte leakage. Moreover, treatment with 1 or 5 µL/L 1‐MCP maintained significantly higher total soluble solids, vitamin C and chlorophyll contents. In addition, 1‐MCP treatment significantly delayed the incidence of fruit decay and inhibited the increase of decay index. The efficacy of 1‐MCP on delaying postharvest ripening and controlling fruit decay increased with increasing concentration. These results indicate 1‐MCP treatment has great potential to extend shelf‐life and maintain quality in Hami melon during distribution at ambient temperature.

PRACTICAL APPLICATIONS

1‐Methylcyclopropene (1‐MCP) has been commercially used to delay postharvest ripening and extend the storage life on some climacteric fruits. Hami melon has a very short shelf‐life mainly due to fruit ripening and decay, which causes significant economic losses. In this study, a postharvest application of 1‐MCP significantly delayed ripening and reduced fruit decay while maintaining overall quality during storage at 25C. The results will allow long‐distance transportation and marketing of Hami melon and benefit growers, shippers and distributors of this melon fruit.     

不同减振衬垫对模拟运输猕猴桃生理和品质影响

合理包装对于减轻果实采后损伤和保持其新鲜品质具有重要作用。本研究采用模拟公路运输振动方法,研究聚苯乙烯泡沫衬垫、聚氯乙烯塑料衬垫以及自主研制的珍珠棉衬垫对猕猴桃果实生理和品质的作用效果。结果表明,三种减振衬垫均能不同程度降低猕猴桃模拟运输后的果实失重率、呼吸强度、乙烯释放量,延缓果肉软化。其中,珍珠棉衬垫能保持猕猴桃较高的硬度和可溶性固形物含量,降低失重率、呼吸强度以及乙烯释放量。综合各指标,珍珠棉衬垫效果最优,可以有效延缓猕猴桃模拟运输后的品质劣变,更利于运输后的贮藏和品质保持。     

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。     

The effects of fruit maturation,delayed storage and ethylene treatment on the incidence of low‐temperature breakdown of ‘Hayward’ kiwifruit

BACKGROUND: Low‐temperature breakdown (LTB), a disorder inducing quality loss, during and after cold storage of ‘Hayward’ kiwifruit was investigated. Harvested kiwifruits during fruit maturation or after delayed storage (DS) at 20 °C for 0, 1, 2, 3 and 4 weeks and 1 µL L^?1 ethylene treatment for 24 h were stored at ? 0.5 °C for 24 weeks and additional ripening at 20 °C for 5 days. Fruit quality indices and LTB incidence and severity were determined before and after treatments. RESULTS: Harvested fruits ripened during maturation, DS and after ethylene treatment. After storage and shelf life, fruits of all treatments were at complete ripening stage. LTB incidence of early harvested fruits was high, while that of fruits of the mid (third) and late harvests was low. Fruits of the third harvest date showed progressively increased LTB incidence with increasing duration of DS to as high as 95–100% after 4 weeks. Ethylene‐treated fruits showed a comparable increase in LTB to that corresponding to 2–3 weeks of DS. CONCLUSION: In contrast to fruit maturation, postharvest (after harvest and before storage) DS at non‐chilling temperature and ethylene treatment advanced the ripening of ‘Hayward’ kiwifruit and resulted in increased LTB incidence. Copyright © 2012 Society of Chemical Industry     

Effect of nanocomposite-based packaging on postharvest quality of ethylene-treated kiwifruit (Actinidia deliciosa) during cold storage

A novel nanocomposite-based packaging (NCP) was prepared by blending polyethylene (PE) with nano-Ag, nano-TiO₂ and montmorillonite. The effects of NCP on the quality parameters of ethylene-treated mature kiwifruit were investigated during the 42 d of storage at 4 °C. The results showed that adding nanoparticles to the PE significantly decreased the oxygen, water vapor permeability and longitudinal strength, and inhibited spore germination. The weight loss, softening, color variation and soluble solid content of kiwifruit were significantly inhibited by 22.67%, 124.84%, 23.46% and 14.42% respectively, which indicated that NCP could delay the ripening of kiwifruit. However, ascorbic acid and total phenols contents in NCP-treated fruit were increased compared with the controls. Additionally, kiwifruit in NCP exhibited 57.44% lower headspace ethylene concentration, 29.44% for malondialdehyde (MDA), lower polyphenol oxidase (PPO) activity and higher peroxidase (POD) activity than the controls. These results suggest that NCP may be a useful technique to reduce fruit decay and maintain quality in kiwifruits during postharvest storage.     

Effect of 1-methylcyclopropene and/or chitosan coating treatments on storage life and quality maintenance of Indian jujube fruit

Indian jujube (Ziziphphus mauritina, cv. ‘Cuimi’) fruits were harvested at stage of mature-green and then treated with 1-methylcyclopropene (1-MCP) at two doses (0 and 600 nl l⁻¹) for 12 h at room temperature. Half of the fruits were coated with 1.5 g/100 ml of chitosan (CTS) solution after 1-MCP treatment and subsequently stored at room temperature and 80-90% relative humidity (RH). Results indicated that 600 nl l⁻¹ of 1-MCP, 1.5 g/100 ml of CTS or their combination were effective in terms of senescence inhibition during storage and compared to control, the storage life was extended by 7, 5 and 8 d, respectively. Fruits treated with the combination of 1-MCP and CTS coating showed better retention of chlorophyll content, total soluble solids, ascorbic acid and fruit firmness, delayed climacteric ethylene evolution and respiration rate, reduced stem-end rots incidence, decreased PG and LOX activities than those with other treatments. Coating alone reduced weight loss and stem-end rots incidence. It delayed the declining firmness and the onset of climacteric ethylene production and respiration rate, but did not influence the peak levels of ethylene and respiration rates. The treatment with only 1-MCP delayed the degreening process and suppressed PG and LOX activities through 10 d at room temperature. The results showed that the treatment with the combination of 1-MCP and CTS coating improved greatly the storage life extension and quality maintenance of Indian jujube fruit at room temperature storage.     

SEQUENTIAL TREATMENTS OF HOT WATER AND MODIFIED ATMOSPHERE PACKAGING IN CHERRY TOMATOES

ABSTRACT

The effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on the storage and fruit quality of cherry tomatoes (Lycopersicon esculentum Mill. cvs. “Alona” and “Naomi”) were investigated. For this purpose, light‐red cherry tomato fruits were dipped in hot water (54C for 5 min) and subsequently stored in plastic film materials with various O₂ and CO₂ permeabilities. The cultivars used in the study were stored in a cold room at 5–7C and 90 ± 5% relative humidity (RH). The changing gas composition within the films and quality changes of the fruits were evaluated during the storage period. At the end of the study, HWT combined with MAP produced better results than MAP alone in both cultivars. Therefore, the HWT + MAP treatment proved effective with regard to fruit quality and delaying the maturity of cherry tomatoes during storage. HWT + 50 micropolyethylene (μPE) treatment produced the best result in the two cultivars at the end of the 28‐day storage with respect to the parameters evaluated in the study.

PRACTICAL APPLICATIONS

Tomato is considered a climacteric fruit, in which ripening is accompanied by a peak in respiration and a concomitant sharp increase in ethylene production, which accelerates quality loss through the physicochemical changes related to this process, such as softening and color evolution. Postharvest heating is a noncontaminating physical treatment that delays the ripening process, reduces chilling injury and controls the activity of pathogens. Because of these beneficial effects, heat treatments are currently used commercially for quality control of fresh products. Modified atmosphere packaging is another technique that has been used to prevent or retard postharvest fruit ripening and its associated biochemical and physiological changes by favorably altering the O₂ and CO₂ levels around the products. In recent years, the use of combined techniques in the postharvest handling of fresh products is increasing, and numerous authors have obtained good results using a combined treatment. Diseases have the potential to destroy the market value and utility of large amounts of fresh tomato annually. The present work evaluated a prestorage conditioning treatment to protect against these losses. The results will allow the long storage of cherry tomato, benefiting the growers, exporters, shippers and distributors of this horticultural product.