1-MCP处理对不同采收期圆黄梨冷藏保鲜效果的影响

以圆黄梨果实为试材,研究了1-MCP处理对不同采收期果实冷藏期间主要生理指标和感官指标变化规律的影响。结果表明,不同采收期圆黄梨经1-MCP处理后均推迟了果实乙烯和呼吸高峰出现的时间;抑制了果实丙二醛和果皮相对膜透性的升高,延缓其衰老速度;明显地延缓了果实硬度的下降,抑制了果实可溶性固形物含量的升高,但对果实可滴定酸含量无明显影响。     

采收期对京白梨果实货架期品质的影响

以京白梨为试材,分3个采收期（盛花后130、137和144d,采期Ⅰ、Ⅱ、Ⅲ）,对果实货架期生理生化指标进行了研究。结果表明：京白梨属于呼吸跃变型果实,不同采收期之间,果实单果重、乙烯释放量、果肉硬度、可溶性固形物（SSC）、pH值、种子颜色指数、果皮颜色差异明显,可作为京白梨适宜采收成熟度的参考指标。同时发现,随着采期的延后,果实乙烯峰值启动时间缩短,硬度和pH值下降加快。果实采收越晚,货架期果实SSC越高,L值越高。     

不同采收期对阿克苏富士苹果贮藏品质的影响

以阿克苏红富士苹果为试材,研究了不同采收期对采后果实品质的影响,为苹果选择合理的采收期和保持果实良好的贮藏品质提供依据。结果表明:采收期对苹果呼吸高峰的出现时间影响较小,但对呼吸高峰的峰值影响明显;早期采收的果实硬度较大,但失重率也明显高于其他晚采果实;适宜采收期采收的果实在贮藏期间,其VC、可滴定酸、可溶性固形物含量变化幅度小。用于鲜食的果实可在10月22左右采收,此时果肉硬度为10.01 kg/cm2,固酸比为29.16,口感酸甜。用于长期贮藏的阿克苏红富士苹果的最佳采收期为11月1日左右,低温贮藏150 d后果实硬度≥8.79 kg/cm2,可溶性固形物含量≥14.67%。     

1-甲基环丙烯对红星苹果常温贮藏期间生理、品质和电子鼻特性的影响

为了探讨1-甲基环丙烯(1-MCP)对红星苹果贮藏品质、生理以及电子鼻特性的影响，以红星苹果为研究对象，测定1-MCP处理后常温贮藏(20±1)℃过程中果实呼吸速率、乙烯释放速率、内在品质及外观色泽和电子鼻响应情况。结果表明：随着贮藏时间延长，红星苹果采后呼吸速率、乙烯释放速率升高，分别于10,15 d达峰值后降低。同时，果实硬度下降、可滴定酸含量降低，SSC先升高后降低；果皮a^*值、b^*值、C^*值和ΔE^*值升高。1-MCP处理抑制红星苹果贮藏期呼吸速率和乙烯释放速率，延缓果实硬度、SSC和TA含量下降，同时抑制果皮a^*值、b^*值、C^*值和ΔE^*值升高。电子鼻检测表明，1-MCP处理明显减少了硫化物和萜烯类化合物(W1W)、氮氧化合物(W5S)、有机硫化物和芳香族化合物(W2W)、甲基类芳香物(W1S)以及醇类和醛酮芳香化合物(W2S)的生成。判别分析(LDA)能区分不同贮藏时期对照和1-MCP果实的电子鼻感应值...     

采收期对澳洲青苹苹果采后品质及虎皮病的影响

研究了在常温（20±1）℃和冷藏（0±0.5）℃条件下澳洲青苹苹果不同采收期对果实采后品质、生理和虎皮病发病率的影响。结果表明,晚采果实的品质和风味相对较好。常温贮藏条件下,晚采果实的乙烯跃变出现时间较早,但采收期对乙烯峰值的大小影响不大,直至果实严重腐烂也未发生虎皮病;冷藏条件下,延迟采收期能明显抑制和延缓澳洲青苹苹果虎皮病的发生,保持果实较高的可溶性固形物含量;贮藏后期早采果实的腐烂率急剧升高是由极其严重的虎皮病造成的。但果实采收越晚,耐贮性越差,腐烂率高而且腐烂出现的时间早,不宜长期贮藏。因此,综合上述因素,建议辽西地区澳洲青苹苹果贮藏果实应于生长发育后期（163～170 d）的10月中下旬采收,常温20℃条件下贮藏30～40 d,冷藏0℃条件下贮藏180 d内,虎皮病发病率低,可保持良好的品质与风味。     

采收期结合精准控温对维纳斯黄金苹果贮藏品质和防褐保鲜的效应

为明确用于贮藏的维纳斯黄金苹果果实最佳采收期和最适贮藏温度。研究了3次采收期结合(-1.5±0.5),(0±0.5),(3±0.5)℃3个精准贮藏温度对维纳斯黄金苹果冷藏后20℃货架期果实品质和防褐变保鲜的效应。结果表明,采收期Ⅰ(相对早采)结合-1.5℃(相对低温)贮藏能保持果实较高的硬度,但果实可溶性固形物含量(SSC)低、口感和风味较差,货架期间出现了不同程度的果皮、果心和果肉褐变;采收期Ⅲ(相对晚采)结合3℃(相对高温)贮藏至1月20日,果实SSC高、口感和风味好,但贮藏至3月20日+20℃平衡24 h和货架放置7 d,果肉发绵并严重褐变。结果还表明,与-1.5,3.0℃相比,0℃维持了贮藏后期果实较高的硬度、SSC、可滴定酸(TA)和抗坏血酸含量,并更好地保持了果实叶绿素荧光活力,延缓了果实衰老。对于同一贮藏温度来说,采收期Ⅱ果实的TA和抗坏血酸含量高于采收期Ⅰ、Ⅲ。采收期Ⅱ、Ⅲ结合0,3℃能保持中短期贮藏的维纳斯黄金苹果较好的商品性和内在品质。对于中长期贮藏的维纳斯黄金苹果来说,采收期Ⅱ结合0℃精准温度贮藏,既能有效抑制果实褐变、减缓果实软化衰老,又能维持货架期果实较好的风...     

套袋苹果果皮色素含量的变化

红星及长富２号苹果套袋的试验结果表明：（１）果实套袋期间果皮叶绿素ａ＋ｂ含量低于对照,果皮中花青苷含量在脱袋前亦代于对照。但在脱袋后急剧增加,显著高于对照。（２）１３－Ａ纸袋处理的红星及长富２采收期的花青苷含量分别增加６４、７９％和３１．５６％,但叶绿素含量则分别降低了４８．６３％和３６．０９％。（３）不同类型纸袋处理均降低了果皮叶绿素ｂ含量。红星及长富２叶绿素ｂ／ａ值分别比对照降低了３６．４６％     

鲜食橄榄果实的适宜采收期及其品质评价参数的研究

以"檀香"橄榄果实为试材,研究7个采收期(从9月7日到12月7日按节气采果,分别为采收期Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅶ)对鲜食橄榄果实品质的影响及其品质评价参数。结果表明:随着采收期的延迟和果实成熟度的提高,采收期Ⅰ~采收期Ⅵ的橄榄果实表面色调角h°、果皮叶绿素含量、果肉可滴定酸和单宁含量下降,果皮类胡萝卜素含量、果肉可溶性固形物含量、固酸比值、可溶性总糖含量、还原糖含量和糖酸比值增加,果实食用品质提高;但采收期Ⅶ(过熟)的橄榄果实果肉可溶性固形物、可溶性总糖、还原糖含量和果实食用品质下降;因此认为,采收期显著影响鲜食橄榄果实品质,且以采收期Ⅵ(完熟,小雪节气采收)的橄榄果实鲜食品质最佳。同时发现,橄榄果实表面色调角h°,果皮叶绿素、类胡萝卜素含量,果肉可溶性固形物、可滴定酸、固酸比值、可溶性总糖、还原性糖、糖酸比值、单宁含量等品质指标可作为确定鲜食橄榄果实食用品质及采收期Ⅰ~采收期Ⅵ成熟度的参数,为量化衡量橄榄果实食用品质和成熟度提供方法。     

红富士苹果气调贮藏参数的研究

气调对比试验结果表明，气调贮藏可明显抑制富士苹果果肉硬度下降，减少内源乙烯含量，贮期达8个月仍能保持良好的品质；富士苹果贮藏期间的果肉褐变主要同CO2浓度有关，降O2会增加果实对CO2的敏感性；果实衰老也可导致富士苹果的果实褐变；2％CO2＋5％O2是富士苹果长期贮藏的理想气体指标。     

南瓜籽油溶剂法提取工艺及脂肪酸成分的研究

以鸭梨为试材,经1-MCP处理后冷藏,研究不同采收期鸭梨在冷藏期间的生理与贮藏品质的变化.试验结果表明,1-MCP对果实的呼吸强度和乙烯释放量具有显著的抑制作用,对早采果实抑制呼吸作用效果最为显著;在冷藏期间具有乙烯释放高峰,不同采收期的果实均于贮藏180天时达到峰值.1-MCP对减缓果实可溶性固形物含量的消耗,以及对早采和稍晚采果实抑制硬度效果明显,也对适时采收和稍晚采收果实果皮相对电导率变化的作用效果较好.     

Postharvest physiology of ‘Aroma’ apples in relation to position on the tree

The effects of fruit position within the canopy on the onset of the respiratory climacteric and the rise in ethylene production as well as changes in peel colour and chemical composition were studied in apples (Malus x domestica Borkh. cv. Aroma) during ripening in normal air at 20 °C for 6–8 weeks over two crop seasons. The commencement of the rise in both CO₂ and ethylene production was equal independent of fruit position but the peak of ethylene was behind that of CO₂ with a lag of several days. While the climacteric ethylene peak was considerably higher in shaded inside apples, the internal ethylene concentration was at the same level independent of canopy position. During maturation on the tree outside fruit developed a red peel colour while inside fruit remained green. Outside fruit had a higher content of dry matter, soluble solids and soluble sugars but a somewhat lower amount of titratable acidity than inside fruit. High summer temperatures in the second year resulted in a significantly higher content of soluble solids and organic acids independent of fruit position but diminished the soluble solids difference between outside and inside fruit and increased the difference in malic and citric acid concentrations. High summer temperatures also increased the difference in peel colour between outside and inside fruit. Independent of canopy position, the soluble solids concentrations remained unchanged during ripening while the amounts of sucrose as well as malic acid and the titratable acidity decreased with a concomitant rise in the cell sap pH. The higher content of soluble sugars and a somewhat lower amount of titratable acidity in outside red-coloured apples probably contribute to improved fruit quality but the difference seems to be strongly dependent on the growing conditions, especially the sum of heat units.     

Relationships between mineral content, lipoxygenase activity, levels of 1-aminocyclopropane-1-carboxylic acid and ethylene emission in apple fruit flesh disks (cv. Jonagold) during storage

Lipoxygenase activity (LOX), levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and of 1-malonyl-aminocyclopropane-1-carboxylic acid (MACC) and the capacity of isolated fruit disks to evolve ethylene were examined during storage of apples having different fruit mineral content. The internal ethylene concentration (IEC) of the whole fruit was also measured before removing discs of tissue. The results show that all these activities depend on the fruit mineral content and confirm general knowledge on the relations between minerals and fruit storage. For instance, fruits rich in calcium and/or phosphorus presented a lower LOX activity, a lower ACC content and a lower ethylene emission while fruits rich in potassium and/or with a relatively high K/Ca presented a higher LOX activity, a higher ACC level and a higher ethylene emission. Results are discussed in an attempt to explain the effects of minerals on storage quality.     

Towards flexible management of postharvest variation in fruit firmness of three apple cultivars

Stochastic modeling provides a useful tool in managing biological variation in the postharvest chain. In the current study, the fruit-to-fruit variability in the postharvest firmness of apples was modeled. Apples from three cultivars (‘Jonagold’, ‘Braeburn’, and ‘Kanzi’) were harvested at different levels of maturity, and stored at different temperatures and controlled atmosphere (CA) conditions. By using a kinetic model describing firmness breakdown as a function of time, temperature, controlled atmosphere conditions and endogenous ethylene concentration, the main stochastic variables were identified as the initial firmness and the rate constants for firmness breakdown and ethylene production. Treating these variables as random model parameters, the Monte Carlo method was used to simulate the propagation of the fruit-to-fruit variability in flesh firmness within a batch of apples during storage under different CA conditions and subsequent shelf-life exposure. The model was validated using independent data sets from apples picked in a different season. The model developed in this study can be used to predict the probability of having apples of certain firmness after long term storage for different scenarios of temperatures and CA conditions.     

Managing biological variation in skin background colour along the postharvest chain of ‘Jonagold’ apples

Skin background colour is an important quality aspect in the grading of ‘Jonagold’ apples, with consumers usually preferring fruit with a green background colour. However, apple handlers are usually faced with large fruit-to-fruit variability of background colour within a population of fruit. In this study, a stochastic modelling approach was used to describe how the initial fruit-to-fruit variability in the background colour of ‘Jonagold’ apples present at harvest, propagates throughout the postharvest chain. Two hundred and twenty ‘Jonagold’ apple fruit were harvested and stored at 1 °C or 4 °C, under different controlled atmosphere (CA) conditions for 6 months, followed by 2 weeks exposure to shelf-life conditions, during which the background colour and ethylene production of the individual fruit were measured. A kinetic model was developed to describe the postharvest loss of skin greenness, by assuming that the loss was principally due to chlorophyll breakdown, the rate of which was dependent on the endogenous ethylene concentration. Stochastic model parameters were identified, and by treating these parameters as fruit-specific, the model could account for more than 95% of the variability of the data. By treating the stochastic model parameters as random factors, the Monte Carlo method was used to model and describe the propagation of the fruit-to-fruit variability of the background colour within a population of fruit. The model developed in this study might allow better management of variability in quality along the postharvest chain, by predicting how the initial fruit-to-fruit variability within a batch of apples will propagate throughout the postharvest chain, as a function of storage and shelf-life conditions.     

Biological variance in the colour of Granny Smith apples: Modelling the effect of senescence and chilling injury

The colour of ‘Granny Smith’ apples, harvested from three orchards at two stages of maturity, was measured individually using the CIE L*a*b* system during storage in regular atmosphere at three temperatures: 1, 4 and 10 °C. A model was developed based on a simplified mechanism to describe the development of the apple colour during storage as affected by senescence (aging) and chilling injury. Monitoring of individual apples made it possible to include and to describe the biological variance of colour in batches of apples and to correct the colour of each apple individually for its own biological shift factor (biological age; random effect). The biological shift factor is related to the initial condition and range of colour change. The rate of the colour development was estimated in common (fixed effects) for all batches using non-linear mixed effects regression analysis. The variance accounted for by the developed model, including effects of temperature, harvest maturity and orchard location, was more than 95% on 3211 observations. The overall reaction rate constant of decolouration, combining the effects of senescence and chilling injury, was found to depend on temperature. The temperature that showed the lowest overall reaction rate of decolouration is 8 °C, which is in contrast with the currently recommended storage temperature for ‘Granny Smith’ apples.     

苹果双相变动气调贮藏研究

双相变动气调是一项崭新的苹果气调贮藏技术与理论.本文介绍了双相变动气调与传统气调的主要区别,以及在严格对比条件下的试验结果.双相变动气调贮藏红星苹果150天,果实品质与果肉硬度好于冷库,与气调库基本相同,并能明显抑制原果胶水解,乙烯生物合成和MACC累积.     

Relationship of IAD index to internal quality attributes of apples treated with 1-methylcyclopropene and stored in air or controlled atmospheres

The research was conducted to evaluate the relationship between I_AD index (index of absorption difference between 670 and 720 nm) values and internal quality attributes of apples treated with 1-methylcyclopropene (1-MCP) and stored in air and controlled atmospheres (CA). Apples of ‘8S6923’ (Aurora Golden Gala™), ‘Fuji’ and ‘Royal Gala’ were tested. The results with Aurora Golden Gala™ show that I_AD index values were maintained at higher levels if the fruit were stored in CA and that 1-MCP had no significant effect on retaining at-harvest values. The I_AD values correlated with chlorophyll a content in the peel (R² = 0.95, P < 0.0001), but not with chlorophyll b content, internal ethylene levels, firmness or titratable acidity. ‘Royal Gala’ apples showed a similar response to Aurora Golden Gala™ apples, showing no correlation between I_AD index values and internal quality attributes of those apples when treated with 1-MCP and/or CA. In contrast, ‘Fuji’ apples showed a relationship between I_AD index value changes and internal ethylene concentrations (R² = 0.67, P < 0.05) and titratable acidity changes (R² = 0.89, P < 0.01), but not firmness. These results suggest that when 1-MCP and/or CA are applied to apples after harvest, that I_AD index values do not consistently correlate to any internal quality attributes other than peel chlorophyll a content.     

Correlation and path-coefficient analyses of ripening attributes and storage disorders in ‘Ambrosia’ and ‘Empire’ apples

The objectives of this study were: (1) to determine correlation effects among the ripening attributes of ‘Empire’ and ‘Ambrosia’ apples during storage, and (2) to determine the direct and indirect contributions of these ripening attributes on the incidence of physiological disorders and storage rots using path-coefficient analysis. The analysis was applied to data obtained from a variety of harvest dates and storage regimes from apples. Pearson correlation analysis of the data indicated a strong positive correlation between internal ethylene concentration (IEC) and peel greasiness, a negative correlation between IEC and soluble solids concentration, and a negative correlation between firmness and peel greasiness in both cultivars, as well as a negative correlation between IEC and firmness in ‘Empire’. Results indicated that increased IEC in ‘Ambrosia’ apples during storage was related to higher incidences of core browning and lenticel damage and lower incidence of internal browning. Higher IEC in ‘Empire’ apples during storage was associated with less internal browning. Several significant correlations, representing different relationships among the ripening attributes and storage disorders were obtained.     

Involvement of ethylene in browning development of controlled atmosphere-stored ‘Empire’ apple fruit

‘Empire’ apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] are susceptible to development of chilling injury, expressed as firm flesh browning, during controlled atmosphere (CA) storage. Because of this susceptibility, fruit are typically stored at 2–4 °C, but the incidence of flesh browning can be increased by 1-methylcyclopropene (1-MCP) treatment at these temperatures. In this study, flesh browning development has been investigated in relationship to ethylene production, internal ethylene concentration (IEC), flesh firmness, total phenolic concentrations, and the activities of polyphenol oxidase (PPO) and peroxidase (POX) in the flesh tissues. Fruit were harvested from two orchards, either untreated or 1-MCP treated, and then stored under CA conditions at either 0.5 or 4 °C. Fruit were removed from storage at 1.5-month intervals for 10.5 months. 1-MCP treated apples were firmer than those of untreated apples, and had lower IECs, at all removals. Flesh browning incidence and severity developed earlier in 1-MCP-treated apples than untreated apples stored at either temperature. Total phenolic concentrations differed by orchard, but no major differences in concentrations were detected between untreated and 1-MCP treated apples. However, PPO activities were higher in the flesh of 1-MCP treated apples than untreated apples from both orchards and at both storage temperatures. POX activity was not consistently affected by 1-MCP treatment or storage temperature. Overall, our results suggest that inhibited ethylene production, either as a result of storage at 0.5 °C, or by treatment with 1-MCP at either temperature, may cause stress and damage to cells and result in higher PPO activity that leads to progressive flesh browning development during CA storage.