Dynamic Controlled Atmosphere Research Articles

Aroma volatiles and sensory quality of organically-grown apple cultivars after dynamic controlled atmosphere (DCA) storage and comparison with CA-stored fruit with and without 1-methylcyclopropene (1-MCP)

Long-term storage of many apple cultivars can be especially challenging for organic production where use of 1-methylcyclopropene (1-MCP), a crop protectant that controls ripening is disallowed. For many cultivars, controlled atmosphere (CA) storage alone, is inadequate for managing disorders and ripening. Dynamic controlled atmosphere (DCA), by determining the pO2 just above the lower oxygen limit (LOL), permits the use of lower pO2 setpoints without any negative impacts of anaerobiosis. Consequently, DCA can replace 1-MCP for maintenance of fruit quality. The goal of this study was to determine where this held true for a selection of old and new release organically-grown cultivars in the context of sensory perception. Cultivars included ‘Enterprise’ and ‘GoldRush’ harvested in 2018 (year 1), and ‘Honeycrisp’, ‘Golden Delicious’, ‘Jonagold’, and ‘Fuji’ harvested in 2020 (year 2). The LOL was monitored for DCA using chlorophyll fluorescence (CF) and compared with conventional static CA with or without 1-MCP treatment at harvest. DCA storage suppressed ripening to a similar level as 1-MCP plus CA in both years as indicated by reduced ester biosynthesis and, for some cultivars, maintenance of flesh firmness. However, ripening suppression did not impact the overall sensory preference of ‘Enterprise’, ‘Honeycrisp’, or ‘Fuji’, as all cultivars retained firmness and tartness regardless of storage regime and even negatively impacted it for ‘Goldrush’, an especially tart and firm cultivar. Sensory liking of ‘Golden Delicious’ and ‘Jonagold’ which have more typical diminishing firmness and acid profiles were most benefited by either 1-MCP treatment or DCA storage. The results highlight that use of storage technologies that suppress ripening beyond conventional CA storage are best employed on cultivars with more conventional softening and acid metabolism profiles as opposed to new cultivars that were selected primarily against these ripening phenotypes. The results also demonstrate the value of sensory evaluation compared with instrumental measurements to reveal the influence of different storage regimes on human perception.

Repeated low oxygen stress on dynamic controlled atmosphere storage of ‘Elstar’ and ‘Nicoter’ apples

Repeated low oxygen stress on dynamic controlled atmosphere storage of ‘Elstar’ and ‘Nicoter’ apples

Impact of different storage conditions with combined use of ethylene blocker on ‘Shalimar’ apple variety

This research investigates the impact of storage conditions on the quality and preservation of 'Shalimar' apples, a relatively new cultivar known for its resistance to apple scab and powdery mildew. The study explores the efficacy of different storage techniques such as regular atmosphere (RA), controlled atmosphere (CA), and dynamic controlled atmosphere with CO2 Monitoring (DCA-CD), as well as the integration of 1-methylcyclopropene (1-MCP) at different storage temperatures (1 °C and 3 °C). Various fruit quality parameters were monitored under different storage conditions, including firmness, titratable acidity, total soluble solids, background color, respiration, ethylene production, and volatile compounds. The results indicate that the controlled atmosphere (CA) at 1 °C emerges as an efficient method for long-term storage. However, it is noted that CA storage may impact the apple aroma, emphasizing the need for a balance between preservation and consumer acceptability. On the other hand, DCA-CD at variable temperatures (approximately 2.5 °C) offers a promising approach for maintaining fruit quality and a higher concentration of volatile compounds. Integrating 1-MCP enhances firmness, but its impact varies across storage conditions. Principal component analysis (PCA) provides insights into the relationships between storage conditions, fruit quality, and volatile compounds. This study contributes valuable insights into optimizing storage strategies for ‘Shalimar’ apples, addressing sustainability and quality preservation in apple production.

Dynamic controlled atmosphere (DCA) – a chance for sustainable fruit storage

Dynamic controlled atmosphere (DCA) – a chance for sustainable fruit storage

Dynamic controlled atmosphere monitored by respiratory quotient as a new method to store pears: Effect on the volatile compounds profile and general quality

Pears (Pyrus communis) are climacteric fruit that require storage under appropriate conditions to extend availability and delay ripening. This study evaluated the production of volatile organic compounds (VOCs) and the physicochemical quality of ‘Santa Maria’ and ‘Rocha’ pears after storage in a controlled atmosphere (CA) or dynamic controlled atmosphere (DCA), monitored by respiratory quotient (RQ). The pears, harvested from an orchard in São Joaquim (Santa Catarina State), were stored at − 0.5 °C in CA (2.0 kPa O2) and DCA with RQ levels of 1.1, 1.2, 1.3, and 1.4, all under 1.0 kPa CO2. ‘Santa Maria’ pears were stored for four months, and ‘Rocha’ pears for six months, followed by seven days at 20 °C before quality analysis. Storage of ‘Santa Maria’ pears in CA resulted in fruit with a more yellow skin color, lower flesh firmness, and higher ethylene production, while ‘Rocha’ pears in CA retained higher flesh firmness and produced less ethylene at 4 and 7 days at 20 °C compared to DCA conditions. Storage conditions did not significantly affect soluble solids and acidity. In ‘Rocha’ pears, DCA, regardless of RQ, suppressed the production of butyl acetate, hexyl acetate, pentyl acetate, methyl acetate, and propyl acetate, while in ‘Santa Maria’ pears, esters such as butyl acetate and hexyl acetate were less affected. In conclusion, no significant differences were found between the DCA-RQ levels evaluated in this research in maintaining physicochemical quality and VOCs production. However, DCA suppressed VOCs production in both ‘Santa Maria’ and ‘Rocha’ pears compared with CA storage.

Monitoring low O2 stress in apples – What we can learn from chlorophyll fluorescence and respiratory characteristics

Dynamic controlled atmosphere (DCA) is becoming a storage method of choice for apple producers seeking to store long-term. There is limited prior work comparing DCA monitoring chlorophyll fluorescence yield (DCA-CF) and respiratory characteristics (DCA-RQ), particularly for the popular UK-grown apple cultivars ‘Gala’ and ‘Braeburn’. However, these techniques can give an insight into the physiological response of apples to low O2 storage, which could help to design more efficient and sustainable storage regimes. In this study the chlorophyll fluorescence (CF) and respiratory quotient (RQ) responses of ‘Gala’ and ‘Braeburn’ are compared in typical and exaggerated DCA conditions. Results show that not only do the two techniques differ in their detection of low O2 stress but the two cultivars studied also differ noticeably in their behaviour. CF increase was confirmed to be a reaction to a stress signal from inside the fruit. Respiration rate curves were found to reflect the internal structure of the fruit, with ‘Gala’’s more homogeneous tissues and greater gas permeability resulting in a strongly bimodal O2 consumption rate where the change in rate hypothetically corresponds with the majority of the fruit tissue switching to anaerobic respiration at the same time. CF and RQ showed noticeable differences between cultivars, agreeing with previous observations that ‘Braeburn’ is less tolerant of low O2 and elevated CO2 than ‘Gala’ (CF Lower O2 Limit (LOL) for Braeburn of approximately 0.75 kPa O2 relative to 0.5 kPa O2 for Gala). Additionally, the CF and RQ responses indicated different LOLs for ‘Gala’, at approximately 0.5 kPa O2 for CF and 0.25 kPa O2 for RQ. Elevated CO2 depressed both the CF and RQ response, with a strong depressive effect on the rate of CO2 evolution but little effect on the rate of O2 consumption.

Effects of Different Irrigation Regimes, Nitrogen Levels and Storage Conditions on Volatiles of 'Gala' Apple.

With a characteristic flavour and aroma, "Maçã de Alcobaça" are apples produced in the western region of the mainland of Portugal. Given the known influence of pre-harvest cultural techniques and post-harvest conservation methods on fruit quality, this work evaluated the effect of cultural factors and conservation methods on the volatile profile of 'Gala' apples. Tests were carried out during four seasons (2018 to 2021) in two 'Gala' apple orchards (F and S) maintained with different irrigation rates and nitrogen fertilisation [normal irrigation and normal nitrogen (Control, NINN), normal irrigation and excess nitrogen (NIEN), excess irrigation and normal nitrogen (EINN), excess irrigation and excess nitrogen (EIEN)], and under three storage conditions [Controlled Atmosphere + 1-methylcyclopropene (CA+1-MCP), Dynamic Controlled Atmosphere (DCA) and DCA+1-MCP]. The intact fruit volatiles were isolated by headspace solid-phase microextraction (HS-SPME) and analysed by Gas Chromatography with Flame Ionisation Detection and Gas Chromatography-Mass Spectrometry at harvest (T0) and after 8 months of storage (T8). HS-SPME volatiles from 'Gala' apples, obtained at T0 in control conditions, were characterised by trans,trans-α-farnesene dominance (36-69%), followed by hexyl acetate (5-23%) and hexyl hexanoate (3-9%). The four irrigation and nitrogen treatments did not evidence main changes in the apple volatile profile. Instead, storage conditions changed the ratio between compounds; previously undetected compounds attained high percentages and decreased the intensity of the dominant compounds in the control conditions. Although all storage conditions tested changed the volatile profile and emanation intensity, the effect was more accentuated in storage for 8 months with DCA+1-MCP.

Superficial scald development in ‘Granny Smith’ and ‘Nicoter’ apples: The role of key volatile compounds when fruit are stored under dynamic controlled atmosphere

A positive correlation of α-farnesene and its oxidation metabolites with superficial scald is commonly reported in apples stored in air or controlled atmosphere (CA) systems, where O2 levels are above the lower oxygen limit (LOL) tolerated by the fruit. Nevertheless, the LOL can be monitored by the dynamic controlled atmosphere (DCA) techniques and to provide different physiological responses. Therefore, this study aimed to evaluate key volatile metabolites from ‘Granny Smith’ and ‘Nicoter’ (‘Kanzi®’) apples stored under dynamic controlled atmosphere (DCA) monitored by respiratory quotient (RQ), i. e. at extremely low oxygen partial pressures (ELO) and correlate their emissions with the incidence of superficial scald (SS). The volatile compounds (VCs) were isolated by solid phase microextraction (HS-SPME) and analyzed by gas chromatography. For the first time, higher concentrations of α-farnesene and its oxidation metabolites (6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol) were negatively correlated with SS in DCA-RQ. This is likely due to the higher levels of ethanol in fruit stored under this condition having an inhibitory effect on SS incidence even when α-farnesene, 6-methyl-5-hepten-2-one, and 6-methyl-5-hepten-2-ol accumulate. Additionally, SS is more correlated to internal ethylene concentration (IEC) than α-farnesene accumulation and their metabolites, even when fruit were stored under ELO, where ethylene action is reduced.

Extremely low oxygen with different hysteresis and dynamic controlled atmosphere storage: Impact on overall quality and volatile profile of ‘Maxi Gala’ apple

This study aimed to evaluate the effect of the novel strategy of extreme low oxygen (ELO) associated to low O2 hysteresis (HY) and compare it with traditional controlled atmosphere (CA) and dynamic controlled atmosphere (DCA) methods during ‘Maxi Gala’ apple storage. The overall quality and volatile compounds were evaluated after 9 months of storage plus 7, 14, and 21 d of shelf life. Two experiments were performed in different years, evaluating ELO conditions, CA, CA + 1-methylcyclopropene (1-MCP), DCA monitored by chlorophyll fluorescence (DCA-CF), and monitored by respiratory quotient (DCA-RQ 1.3). ‘Maxi Gala’ apple stored under CA showed higher ethylene production, respiration rate, and physiological disorders incidence than fruit stored under CA + 1-MCP, ELO, and DCA. However, only storage in CA + 1-MCP and DCA-RQ 1.3 maintained higher flesh firmness. Fruit stored under 0.4 kPa O2 with 0.4 and 0.6 hysteresis had similar amount of healthy fruit to DCA-RQ 1.3 and higher than CA, CA + 1-MCP, and DCA-CF. Furthermore, CA + 1-MCP and DCA-CF suppressed the main esters of ‘Maxi Gala’ apple during all shelf life periods. On the other hand, storage in 0.4 kPa O2 + 0.6 HY resulted in fruit with higher alcohols and aldehydes concentration, in addition to have high amount of some important esters for ‘Maxi Gala’ aroma, such as 3-methylbutyl acetate. DCA-RQ and ELO storage, despite reduce main esters soon after storage, may result in aroma recovery after 21 d of shelf life. Thus, storage under ELO at 0.4 kPa O2, with 0.4 or 0.6 hysteresis, can be a promising alternative for ‘Maxi Gala’ apple storage, especially to CA and DCA-CF, without resulting in additional costs to the storage systems.

Transcriptome and metabolic survey disclose the mode of action of static and dynamic low oxygen postharvest storage strategies to prevent the onset of superficial scald disorder in fruit of ‘Granny Smith’ apple cultivar

To preserve quality features and ensuring availability of fresh fruit on the market, apples need to be stored after harvest. The low temperature applied during storage, beside avoiding important fruit loss, can also promote the development of serious chilling injury disorders, such as superficial scald. One of the strategies largely employed to prevent the development of this phenomenon is the control of the storage atmosphere by lowering down the oxygen concentration. In this work, a multifaceted survey was carried out to investigate transcriptome variation together with three categories of metabolites (phenolics, lipids and volatile organic compounds ) in fruit of ‘Granny Smith’ apple cultivar stored in both static and dynamic controlled hypoxia atmosphere for five and seven months, respectively. The global transcriptome survey identified a core set of differentially expressed genes in three main functional groups, revealing as the duration of storage had an important effect in the coordination of gene expression. The effect of the length of storage was furthermore highlighted by the DEG-network analysis that identified a distinct number and type of transcriptomic hubs. Samples characterized by the development of superficial scald were distinguished by a higher concentration of chlorogenic acid and a higher expression of phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) in a time-dependent fashion. The prevention of this disorder was instead related to distinctive re-programming events, involving the accumulation of specific antioxidant types of metabolites, very long chain fatty acids (VLCFAs) and the expression of genes coordinating a hypoxia acclimation process, such as RAP2-like and plant cysteine oxidase (PCO).

Recording of Low-Oxygen Stress Response Using Chlorophyll Fluorescence Kinetics in Apple Fruit

AbstractLong-term storage of apples (Malus x domestica, Borkh.) is increasingly taking place under Dynamic Controlled Atmosphere (DCA). The oxygen level is lowered to ≤ 1 kPa O2 and the apples are stored just above the Lower Oxygen Limit (LOL). Low oxygen stress during controlled atmosphere storage can lead to fermentation in apples if oxygen levels are too low. Chlorophyll fluorescence can be used to detect low-oxygen stress at an early stage during storage. The currently available non-imaging fluorescence systems often use the minimal fluorescence (Fo) parameter. In contrast, the use of chlorophyll fluorescence kinetics is insufficiently described. Therefore, this study aimed to gain more knowledge about the response of chlorophyll fluorescence kinetics to low oxygen stress in apples using a fluorescence imaging system. The results show that the kinetic fluorescence curves differ under aerobic and fermentation conditions. The fermentative conditions initiated a decrease in fluorescence intensity upon application of the saturation pulses during exposure to actinic light. This result was made at 18 °C and 2 °C ambient temperatures. Interestingly, the kinetic curve changed at 2 °C before fermentation products accumulated in the apples. Non-photochemical quenching (NPQ) decreased under fermentation conditions in the dark phase after relaxation. Upon entering the dark relaxation phase after Kautsky induction, ɸPSII began to increase. Under atmospheric oxygen conditions, ɸPSII reached values of 0.81 to 0.76, while under fermentation, ɸPSII values ranged from 0.57 to 0.44.

Interaction between dynamic controlled atmosphere (DCA-CD), 1-methylcyclopropene and elevated temperatures in the long-term storage of organic ‘Santana’ apples

This study investigated the effects of controlled atmosphere (CA - 1.0 kPa O2 and < 0.7 kPa CO2), dynamic controlled atmosphere based on carbon dioxide production (DCA-CD), 1-methylcyclopropene (1-MCP), and raised storage temperatures (1 °C to 3 °C), on fruit metabolism and quality, disorder incidences and the volatile profile of ‘Santana’ apples after 6 months storage and 7 d shelf life at 20 °C. The evaluation is based on a comparison to a control group of cold storage under regular atmosphere (RA). Low oxygen partial pressures (pO2) in CA and DCA-CD in combination with 1-MCP slowed down fruit respiration and ethylene production and thus compensated for the ripening-inducing effect of raised storage temperatures. ‘Santana’ apples stored under CA or DCA-CD with additional 1-MCP, had the highest flesh firmness, titratable acidity, and greener peel coloration after storage and shelf life. CA and DCA-CD reduced core browning and fungal decay in comparison to RA. Low pO2 and 1-MCP application lowered the abundance of straight-chain alcohols and esters in ‘Santana’ apples. DCA-CD storage enabled a safe induction of anaerobic metabolism in ‘Santana’ apples, which increased levels of ethanol and derived ethyl esters. 1-MCP enhanced anaerobic metabolism in DCA-CD. Raised storage temperatures were found to increase alcohol and ester accumulation in DCA-CD. This technology consequently enables the storage of ‘Santana’ apples at higher temperatures, which could contribute to limiting stress experienced by the fruit and enhancing the formation of key aroma compounds, while also reducing energy usage of the refrigeration system.

Minimum O2 levels during storage to inhibit aerobic respiration and prolong the postharvest life of 'Tommy Atkins' mangoes produced in different growing seasons

The definition of the minimum O2 levels required to maximally inhibit fruit aerobic respiration is essential to efficiently delay ripening and senescence during long-distance transportation. The aim of this study was to determine the minimum O2 levels required to maximally inhibit the aerobic respiration and prolong the postharvest life of 'Tommy Atkins' mangoes produced during the summer, winter and spring growing seasons in the São Francisco Valley (SFV), Brazil. For the identification of the minimum O2 levels, mangoes were stored for 42 days at 9 °C and 90–95% RH. The change from aerobic to anaerobic metabolism was weekly determined based on the levels of O2, CO2 and ethanol production inside hermetically closed containers containing fruit samples. The minimum O2 levels required to maintain aerobic respiration of mangoes produced in the summer, winter and spring changed from 0.25 to 13.75 kPa, 0.80 to 2.30 kPa and 1.42 to 17.40 kPa, respectively, as the storage duration increased. In order to validate the minimum O2 levels to maintain fruit aerobic respiration and quality, ‘Tommy Atkins’ mangoes produced in the SFV were harvested at the commercial maturity in the winter growing season in 2022 and were stored under dynamic controlled atmosphere (DCA) conditions with the minimum O2 levels determined with fruit produced in the same growing season in the previous year, 2021. Fruit stored under DCA were compared to fruit stored in refrigerated atmosphere (RA) for 60 days at 9 °C and 90–95% RH. The minimum O2 levels used in the DCA effectively inhibited fruit ripening, controlled black flesh and reduced rot incidence during 60 days of cold storage and 60 + 7 days of shelf life.

Impacts of dynamic controlled atmosphere and temperature on physiological disorder incidences, fruit quality and the volatile profile of 'Braeburn' apples

DCA-CD Plus is a novel dynamic storage technology that determines both the optimum oxygen partial pressures (pO2) and room temperatures for the storage of apples, based on monitoring the fruit CO2 production (CD). This study evaluated the effects of DCA-CD Plus on the physiological disorder incidences, fruit quality and the volatile profile of ‘Braeburn’ apples after eight months of storage and seven days shelf life. This was achieved by comparison to storage under regular atmosphere (RA), controlled atmosphere (CA, 1.3 kPa O2) and one-factor dynamic controlled atmosphere (DCA-CD, dynamic oxygen), while incorporating the influence of 1-methylcyclopropene (1-MCP). RA-stored fruit had the highest respiration rate and ethylene production and the lowest flesh firmness, while CA, DCA treatments and 1-MCP application slowed down fruit ripening. 1-MCP application increased browning and cavity symptoms in ‘Braeburn’ apples. Storage under DCA-CD and DCA-CD Plus resulted in lower browning incidences than RA or static CA treatments. Dynamic storage temperatures in DCA-CD Plus did not accelerate fruit ripening but showed no effect on the development of physiological disorders. Most volatile organic compounds showed a negative response to low pO2 and 1-MCP application, as the highest levels of key alcohols and esters were measured in RA. Storage under DCA conditions and RA correlated with increased levels of anaerobic metabolites. No correlation between internal browning symptoms and specific alterations in the volatile profile could be detected.

Effect of RQ-based dynamic controlled atmosphere on some quality attributes and volatile aroma metabolites (VAMs) of ‘Jonagold’ apple

Effect of RQ-based dynamic controlled atmosphere on some quality attributes and volatile aroma metabolites (VAMs) of ‘Jonagold’ apple

Ethanol fermentation- and ethylene physiology-related gene expression profiles in Red Delicious apples stored under variable hypoxic conditions and protocols

Dynamic Controlled Atmosphere (DCA) is beneficial in maintaining specific quality parameters but, due to the extreme oxygen levels applied, can cause adverse effects on the fruit by inducing excessive anaerobic metabolism and the production of off-flavors. The metabolic adaptation and responses of apples (Malus domestica Borkh.) cv. Red Delicious to static or dynamic oxygen concentrations (0.3 and 0.8%, with sequential shifts) during cold storage for 7 months were studied by monitoring quality parameters and the expression of genes involved in sugar, fermentative metabolism, and ethylene physiology. Ethanol content reached the highest levels (around 400 mg/kg FW) under 0.3% oxygen concentration and fruit firmness appeared to be reduced in samples accumulating the highest levels of ethanol. Oxygen switch was effective in reducing the ethanol concentrations with timing-dependent variable effects. The expression of fermentative (alcohol dehydrogenase, lactate dehydrogenase, pyruvate decarboxylase) and sugar metabolism (β-amylase; phosphofructokinase; sucrose synthase) genes resulted to be differently affected by the hypoxic conditions imposed, in particular during the early stages of storage. Sucrose synthase expression appeared to be highly sensitive to changes in low oxygen concentration. Ethylene biosynthesis (ACC synthase and oxidase) genes showed marked differences in their expression in relation to the static and dynamic protocols and the hypoxic conditions, as well as six Ethylene Responsive Factors (ERF) genes, some of them possibly involved in the oxygen sensing mechanism operating in fruit tissues.

The Effect of Aminoethoxyvinylglycine and Dynamic Controlled Atmosphere on the Storage of ‘Bartlett’ Pear

Storage trials of 4 and 8 months’ duration, using ‘Bartlett’ pear (Pyrus communis) fruit treated with and without aminoethoxyvinylglycine (AVG) and stored using ultra low oxygen (ULO) storage (1.5 kPa O2) versus dynamic controlled atmosphere (DCA) (≈ 0.6–0.7 kPa O2) based on chlorophyll fluorescence were conducted over 2 years. AVG applied preharvest and DCA storage produced pears with significantly lower respiration, ethylene, acetaldehyde, ethyl acetate and ethanol post-storage compared to the other treatment combinations. Lower volatiles reflected a higher level of fruit quality. AVG + DCA also exhibited greater green color and firmness retention than the other treatment combinations. There were few disorders in both years of study, with no correlation with field and storage treatments, with the exception of pear scuffing, which was only present in year 2. The incidence of scuffing was positively associated with both fruit softening and yellowing, with DCA + AVG showing the lowest incidence (10%) and ULO + control, the highest (65%). Softening occurred during the shelf life period, as required, and was not an issue for any treatment combination. However, uneven degreening was a concern for fruit treated with DCA + AVG (mainly when firmness at harvest was > 85 N). Future research on higher maturity levels at harvest or reduced AVG rates could address this concern.

A Review of Storage Temperature Recommendations for Apples and Pears.

An exploration of the range of expert opinions on the optimum storage temperature for apples and pears in RA (refrigerated air), CA (controlled atmosphere), and DCA (dynamic controlled atmosphere) is provided, based on the accumulated postharvest data from the last 20 years. Apple cultivars have been divided into two storage temperature groups (0 to 1 °C and >1 °C), based on chilling sensitivity. Increasingly, gradual cooling, rather than rapid cooling, is recommended for apple cultivars, especially for chilling-sensitive cultivars. European pear cultivars are held at storage temperatures close to or just below 0 °C since they are not chilling-sensitive, and most cultivars require a cold temperature to induce ethylene production and ripening, especially if picked early for long-term storage. Asian pears apparently have higher temperature requirements in CA, compared with European pears. The temperature recommendations for RA and CA storage differ in some apple and European pear cultivars. In such cases, the CA recommendation is, on average, approximately 0.9 °C higher for apple cultivars and approximately 0.5 °C higher for pear cultivars, compared with RA. Research evidence suggests that some apple and pear cultivars can be stored at higher temperatures in DCA than in CA, and if the ethylene inhibitor, 1-methylcyclopropene (1-MCP), is applied in CA and/or DCA, leading to possible energy savings and quality benefits. A cool growing season may increase postharvest disorders, depending on cultivar and region. The store or packinghouse manager may choose to mitigate potential postharvest problems by maintaining the storage temperature at or above the temperature listed here and/or using stepwise (gradual) cooling. The storage temperature can affect the humidity and vapour pressure deficit (driving force) in the storage room. Altering the vapour pressure deficit controls the water loss in stored fruit, which can affect various quality parameters and the occurrence of several storage disorders.

Controlled atmosphere and dynamic controlled atmosphere for Fuzzy logic-based banana storage

The insertion of New Information and Communication Technologies is increasingly present in the most diverse fields of knowledge, among them agriculture. This insertion results in what is called precision agriculture. Postharvest of bananas requires the application of new technologies to increase storage time and reduce losses. Bananas are highly perishable. Losses in postharvest may vary from 20% to 80% of the crop. Therefore, the purpose of this article is to present the impact of applying new information and communication technologies in the quality and time of conservation of bananas in control atmosphere. To meet the goals, five treatments in the cold storage process of bananas, refrigerated environment, static controlled atmosphere (2% of O2 and 7% of CO2), dynamic controlled atmosphere with static respiratory quotient, dynamic controlled atmosphere with dynamic respiratory quotient, and controlled atmosphere with intelligent control (2% of O2 and 7% of CO2) were applied. These five treatments were implemented based on a computing embedded system, sensors and actuators. The intelligent control system used was built with Fuzzy logic techniques. The system controls the respiration gases of bananas and a cold chamber controls the temperature. To validate the research, the storage of pome banana was evaluated in all the treatments to compare the fruit technical requisites and quality. As results we can see the expressive increase of storage time of bananas with the keep of fruit quality. The treatment system with dynamic and intelligent atmosphere control was also seen (2% of O2 and 7% of CO2) as the most efficient, reaching a storage for 45 days and thus proving that new technologies promotes precision agriculture.

Volatile compounds profile and quality of “Cripps pink” apple: Impact of dynamic controlled atmosphere combined to delayed storage and 1‐MCP treatment

This study evaluated the effects of delayed storage followed by storage under static controlled atmosphere (CA) and dynamic controlled atmosphere established by respiratory quotient (DCA-RQ) with and without 1-methylcyclopropene (1-MCP) application on quality and volatile profile of “Cripps Pink” apple. A fruit batch was immediately stored at 1.5 ± 0.1°C, and another remained for 7 days at 20°C (delay) until storage. The storage conditions were: (1) CA (1.0 kPa O2 + 1.0 kPa CO2); (2) DCA-RQ 1.3; (3) DCA-RQ 1.5. Additionally, for each storage condition and delay strategy, a batch of fruit was treated with 1-MCP, and another batch was left untreated. Practical applications DCA-RQ 1.3 maintened flesh firmness even without 1-MCP and with delayed storage. 1-MCP application reduced all esters. Delayed storage increased the esters concentration and when associated with DCA-RQ 1.3 and 1.5 should be recommended to reduce decay, increase the healthy fruit amount, and improve the aroma emission of “Cripps Pink” apple.