Regular Atmosphere Research Articles

Evaluating low pressure storage for prolonging the postharvest life of blueberries

Low pressure storage (LPS) is a postharvest technology that has shown the potential to extend the storage life of various horticultural commodities. LPS addresses core postharvest challenges, such as desiccation, decay and senescence by creating an environment that maintains fully saturated air (i.e., high relative humidity) and ultra-low oxygen (ULO) conditions that can reduce respiration rates and suppress fungal growth. In this study, LPS chambers were evaluated for their ability to extend the storage life of blueberries (Vaccinium corymbosum L., cv. ‘Draper’), compared to regular atmosphere (RA), across four different storage locations in the Pacific Northwest, USA. In three of the four locations, blueberries were field picked and loaded by hand, while at one location, fruit was loaded through mechanical harvesters. Following two weeks of storage, LPS chambers reduced blueberry respiration rates by 47 % from initial to lowest point, on average. Vacuum chambers filled with machine harvested fruit exhibited respiration rates 28 % higher than chambers with hand harvested fruit, although still sustained rates lower than at the initial loading (i.e., harvest). After five to eight weeks of storage, LPS chambers sustained nearly no weight loss, while fruit stored under RA conditions demonstrated weight loss between 2 and 7 % in the same period. LPS fruit was firmer, exhibited less incidence of superficial mold and fungal decay and better maintained titratable acidity than RA fruit. LPS chambers, when field loaded by hand, demonstrate significant potential in maintaining the at-harvest quality and condition of blueberries for up to eight weeks postharvest. Under these conditions, LPS can extend the storability of blueberries for eight weeks or more. Further investigation is required to determine the compatibility of extended LPS on machine harvested blueberries and with other commercially relevant cultivars.

Dynamics of quality and metabolic activity of stored ‘Galaxy’ apples affected by maturity and 1-methylcyclopropene

ABSTRACT To preserve the quality traits of late-harvested ‘Galaxy’ apples during extended storage, the effects of 1-methylcyclopropene (1-MCP) treatment and storage conditions on postharvest quality were analysed. Alongside quality measures, indicators like ethylene production, respiration rate, aminocyclopropane-1-carboxylic acid oxidase (ACO) activity, and membrane permeability were assessed. Apples were harvested at an optimal harvest date or later and stored for 7 months at 1°C under regular atmosphere or controlled atmosphere. Treatments with 1–MCP at 300, 600 or 900 nL L−1 were applied pre- or post-storage. After 7 days shelf-life, apples subjected to 1-MCP and controlled atmosphere exhibited reduced ethylene production, respiration rate, and ACO activity compared to untreated or regular atmosphere counterparts. While the time of 1-MCP application and its concentration did not impact the respiration rate during shelf-life, controlled atmosphere effectively decreased it. The combination of controlled atmosphere and 1–MCP pre-storage was most effective in lowering ACO activity. Irrespective of conditions, 1-MCP curtailed ethylene production, respiration rate, and ACO activity during shelf-life, alleviating firmness and acidity loss. Only controlled atmosphere preserved quality and minimised disorders for optimally harvested apples, not late-harvested ones. None of the treatments maintained late-harvested apples’ quality after long-term storage plus shelf-life.

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.

Effect of doping the PM6:Y7 active layer with MoS2 nanospheres in organic solar cells

Herein, MoS2 nanostructures were synthetized and characterized, as well as PM6:Y7 based organic solar cells (OSCs) were fabricated, tested, and modelled through SCAPS-1D software. Devices were assembled and tested under regular atmosphere conditions including the top electrode Field's Metal (FM), which is a eutectic alloy of Bi, In and Sn easily deposited by melting it at ∼ 95 °C. The modelled binary OSCs through SCAPS-1D achieved a PCE of 14.2%. The active layer was doped with MoS2 nanoparticles at two different concentrations, 1 and 2% v/v, the reached experimental average PCE values were 9.1%, 10.2% and 9.3% for control devices, and for the two doping concentrations, respectively; it means a PCE percentage enhancement of 11.2% when doping at 1% of MoS2. The enhanced experimental PCE value could be partially explained because of the light absorption into the active layer through the localized surface plasmonic resonance (LSPR) phenomenon induced by the nanostructures, among other optical phenomena such as light reflection and interference effects.

Short-Term Storage in a Modified Atmosphere Affects the Chemical Profile of Blueberry (Vaccinium corymbosum L.) Fruit

Short-term modified-atmosphere storage with an adjusted CO2 and/or O2 concentration could recover blueberry fruit infested with the larvae of quarantine pests. However, this could significantly affect the fruit quality. In our experiment we investigated the performance of highbush blueberry ‘Bluecrop’ fruit (firmness, peel color, individual phenolics, sugars, and organic acids) under four short-term storage regimes: (1) a regular atmosphere with 0.03% CO2, 21% O2, and 78% N2 at 22 °C, i.e., the control; (2) a regular atmosphere with 0.03% CO2, 21% O2, and 78% N2 at 2 °C; (3) a modified atmosphere with 10% CO2, 5% O2, and 85% N2 at 2 °C; and (4) a modified atmosphere with 100% CO2 at 2 °C. Fruit sampling took place after 24 h, 48 h, and 72 h. Fruit firmness was not significantly altered by storage regime or duration, while some significant, but minor, changes were detected in the color parameters. Regarding the primary metabolites, the sugar/organic acid ratio stagnated in the first 48 h in all storage regimes. The content of the majority of the individual phenolics was significantly higher in the fruit stored under control conditions. From our results, we can conclude that the short-term storage of highbush blueberry ‘Bluecrop’ fruit for 24 h in a cold atmosphere does not affect the phenolic content, and storage for 48 h does not affect the total sugar/organic acid ratio, regardless of the atmosphere composition.

Images du Soleil et de la Lune, depuis le sol ou la Station spatiale internationale

Study of the image formation near the optical horizon for a regular atmosphere. One investigates in detail the case of the Sun and Moon at rise and set and provides the relationship between the image flattening and the local physical conditions for a standard atmosphere. The second case deals with a more complex situation of a documented observation of the moonset observed on board of the space station (ISS) by astronauts, displaying large distortions in the image. An analytical and numerical approach allows us to account for the details of this observation. We show that the vertical scale of this famous image is likely wrong.

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.

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.

Fruit maturity and antioxidant activity affecting superficial scald development in ‘Abate Fétel’ pears

Superficial scald (SS) is one of the main physiological disorders affecting postharvest of pears. Its onset is linked to oxidative processes. Antioxidant compounds such as ascorbic acid and phenolics could play a key role in preventing SS. Growing environment and fruit quality also have an influence on SS symptoms occurrence. The aim of this project is to understand the relationship between antioxidant activity, phenolic content, and development of SS in ‘Abate Fétel’ pear. Moreover, the effect on SS of fruit maturity at harvest was assessed using multivariate statistical approach. Data were collected in thirty orchards in the Emilia-Romagna region (Italy) in three seasons (2018, 2019 and 2020), and the fruit were stored in a regular atmosphere for 120 days. Antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazy (DPPH) method and total phenol content by Folin-Ciocalteau colorimetric protocol. The results showed that 340 mg of ascorbate/100 g of FW and 300 mg of gallic ac./100 g of FW at least provide good protection against SS. Multivariate analysis indicated that pulp firmness and index of absorbance difference ( lAD ) seem to keep low the SS occurence, when at harvest are higher than 6.3 kg and 1.9, respesctively. In conclusion, it would be possible to build a forecasting model to control SS that considers pre-harvest data and content of antioxidants in different orchards, to improve the postharvest management of ‘Abate Fétel’.

Crop Load and Thinning Methods Impact Yield, Nutrient Content, Fruit Quality, and Physiological Disorders in ‘Scilate’ Apples

Most apple cultivars produce too many flowers to enable consistent yields of high-quality fruit, thus, crop load management (thinning) is an integral part of orchard management in modern apple cultivation. Crop load is managed by thinning excess flowers and/or fruit from a tree, however ideal targets vary between cultivars. In this two-year study, the effect of thinning methods at different levels of crop load on fruit quality and production, post-harvest storability and physiological disorders, and fruit and leaf nutrient content in ‘Scilate’ apples were investigated in southern Tasmania, Australia. Two thinning methods, artificial bud extinction (ABE) and hand thinning (HT), were compared at three levels of crop load: 3, 6, or 12 fruit cm−2 limb cross-sectional area (LCSA), described as low, medium, and high, respectively. During the second season, all the ABE and HT treatments received additional chemical thinning (CT). The results demonstrated that ABE consistently outperformed HT in terms of improved fruit set, return bloom, and fruit weight. The fruit quality parameters, such as flesh firmness, total soluble solids, dry matter content, malic acid content, and fruit shape, were also improved under the ABE regime, with these positive effects being the clearest in the second season. In general, high-quality fruits were obtained from the low and medium crop loads, while the fruit quality was poor for the high crop load trees, but the low crop load fruit had a slightly higher incidence of internal flesh browning (predominantly radial) and fruit softening after regular atmosphere storage. The crop load also impacted on the fruit and leaf mineral nutrient content, where fruit N, Ca, Mn, and Zn, and leaf N, Fe, Zn, and Cu content increased while fruit and leaf K declined with a higher crop load. High crop load, irrespective of the thinning regime, and HT with a medium crop load, induced severe biennial bearing, whereas, the fruit yield was relatively consistent with ABE, even with a medium crop load. We conclude that ABE with a medium crop load (around six fruit cm−2 LCSA) is an effective method of managing crop load and optimizing the fruit quality in ‘Scilate’ apples.

Keeping ability of apple fruits of new cultivars under different storage technologies

The fruits of new apple cultivars bred by the FSBSI “Federal Scientific Center named after IV Michurin”, adapted to the stressful weather conditions of the Central Black Earth Region of Russia, were used. During storage of control and 1-MCP-treated fruits of 5 studied apple cultivars in air (regular atmosphere: CO2 = 0.03%, O2 = 21%), modified atmosphere (O2 = 16-19%, CO2 = 1.5-5.0%) and controlled atmosphere with ultra-low oxygen content (O2 = 1.2-1.5%, CO2 = 1.2-1.5%), the following main diseases were identified: for cv. Uspenskoye – scald, bitter pit, breakdown; for cv. Fregat - bitter pit, breakdown, CO2-skin injury. Development of several diseases at the same time is also possible (CO2-skin injury + bitter pit, bitter pit + breakdown); for cv. Flagman - scald, bitter pit, breakdown, scald + bitter pit; for cv. Bylina - CO2-skin injury, bitter pit, breakdown, soft scald; for cv. Vympel - CO2-skin injury. Maximum storage efficiency was shown by fruits cv. Vympel stored under CA + 1-MCP technology. Data on the keeping ability of apple fruits of the studied cultivars allow developing high-precision varietal storage technologies.

Comprehensive Analysis of 13C6 Glucose Fate in the Hypoxia-Tolerant Blind Mole Rat Skin Fibroblasts.

The bioenergetics of the vast majority of terrestrial mammals evolved to consuming glucose (Glc) for energy production under regular atmosphere (about 21% oxygen). However, some vertebrate species, such as aquatic turtles, seals, naked mole rat, and blind mole rat, Spalax, have adjusted their homeostasis to continuous function under severe hypoxic environment. The exploration of hypoxia-tolerant species metabolic strategies provides a better understanding of the adaptation to hypoxia. In this study, we compared Glc homeostasis in primary Spalax and rat skin cells under normoxic and hypoxic conditions. We used the targeted-metabolomics approach, utilizing liquid chromatography and mass spectrometry (LC-MS) to track the fate of heavy Glc carbons (13C6 Glc), as well as other methodologies to assist the interpretation of the metabolic landscape, such as bioenergetics profiling, Western blotting, and gene expression analysis. The metabolic profile was recorded under steady-state (after 24 h) of the experiment. Glc-originated carbons were unequally distributed between the cytosolic and mitochondrial domains in Spalax cells compared to the rat. The cytosolic domain is dominant apparently due to the hypoxia-inducible factor-1 alpha (HIF-1α) mastering, since its level is higher under normoxia and hypoxia in Spalax cells. Consumed Glc in Spalax cells is utilized for the pentose phosphate pathway maintaining the NADPH pool, and is finally harbored as glutathione (GSH) and UDP-GlcNAc. The cytosolic domain in Spalax cells works in the semi-uncoupled mode that limits the consumed Glc-derived carbons flux to the tricarboxylic acid (TCA) cycle and reduces pyruvate delivery; however, it maintains the NAD+ pool via lactate dehydrogenase upregulation. Both normoxic and hypoxic mitochondrial homeostasis of Glc-originated carbons in Spalax are characterized by their massive cataplerotic flux along with the axis αKG→Glu→Pro→hydroxyproline (HPro). The product of collagen degradation, HPro, as well as free Pro are apparently involved in the bioenergetics of Spalax under both normoxia and hypoxia. The upregulation of 2-hydroxyglutarate production detected in Spalax cells may be involved in modulating the levels of HIF-1α. Collectively, these data suggest that Spalax cells utilize similar metabolic frame for both normoxia and hypoxia, where glucose metabolism is switched from oxidative pathways (conversion of pyruvate to Acetyl-CoA and further TCA cycle processes) to (i) pentose phosphate pathway, (ii) lactate production, and (iii) cataplerotic pathways leading to hexosamine, GSH, and HPro production.

Preharvest Factors Affecting Quality on “Abate Fetel” Pears: Study of Superficial Scald with Multivariate Statistical Approach

Although superficial scald (SS) is well characterized on apples, there are only a few insights concerning the influence that agronomic and management variability may have on the occurrence of this physiological disorder on pears. In this study, we aimed to improve our understanding of the effect of different preharvest factors on SS development using a multivariate statistical approach. Pears (Pyrus communis L.) cv “Abate Fetel” were picked during two consecutive seasons (2018-2019 and 2019-2020) from twenty-three commercial orchards from three growing areas (Modena, Ferrara, and Ravenna provinces) in the Emilia-Romagna region of Italy. Bioclimatic indices such as weather and soil, agronomic management such fertilization and irrigation, orchard features such as rootstock and training systems, and SS incidence were carried out at harvest and periodically postharvest in all producers. Two different storage scenarios (regular atmosphere and use of 1-MCP) were also evaluated. Our data in both seasons showed high heterogeneity between farms for SS symptoms after cold storage either in the regular atmosphere or with 1-MCP treatment. Nevertheless, in 2018, all the producers showed SS at the end of the storage season, but in 2019 some of them did not exhibit SS for up to 5 months. In fact, some preharvest factors changed considerably between the two seasons such as yield and weather conditions. Indeed, some factors seem to affect SS in both growing seasons. Some can increase its occurrences such as physiological and agronomical factors: high yields, late date of blooming, heavy downpours, improper irrigation management (low watering frequency and high volumes), nitrogen (included that deriving from organic matter), soil texture (presence of clay), orchard age, and canopy volume in relation to training system and rootstock. Others can decrease SS such as climatic and management factors: late harvest dates, rain, gibberellins, calcium, manure, absence of antihail nets or use of photoselective nets, and site (probably related to better soils toward the Adriatic coast). Initial preharvest variability is an important factor that modulates physiological plant stress and, subsequently, the SS after cold storage in “Abate Fetel” pears. Multivariate techniques could represent useful tools to identify reliable multiyear preharvest variables for SS control in pear fruit different batches.

Application of Dynamic Controlled Atmosphere Technologies to Reduce Incidence of Physiological Disorders and Maintain Quality of ‘Granny Smith’ Apples

The efficacy of dynamic controlled atmosphere technologies; repeated low oxygen stress (RLOS) and dynamic controlled atmosphere-chlorophyll fluorescence (DCA-CF) to control superficial scald development on ‘Granny Smith’ apples during long-term storage was studied. Fruit were stored for 2, 4, 6, 8, and 10 months at 0 °C in DCA-CF (0.6% O2 and 0.8% CO2), regular atmosphere (RA)(≈21% O2 and 90–95% RH), and RLOS treatments: (1) 0.5% O2 for 10 d followed by ultra-low oxygen (ULO) (0.9% O2 and 0.8% CO2) for 21 d and 0.5% O2 for 7 d or (2) 0.5% O2 for 10 d followed by controlled atmosphere (CA) (1.5% O2 and 1% CO2) for 21 d and 0.5% O2 for 7 d. Development of superficial scald was inhibited for up to 10 months and 7 d shelf life (20 °C) under RLOS + ULO and DCA-CF treatments. Apples stored in RLOS + ULO, RLOS + CA, and DCA-CF had significantly (p &lt; 0.05) higher flesh firmness and total soluble solids. The RLOS phases applied with CA or ULO and DCA-CF storage reduced the development of superficial scald by possibly suppressing the oxidation of volatiles implicated in superficial scald development.

Impact factory assessment on the air on the Pekhorka river basin

The background ecological situation on Pekhorka river of the Balashikha district is determined by its location in the eastern part of the Moscow agglomeration. Most of the neighboring industrial centers are located to the west of it, from the side of the prevailing winds. Enterprises harm the air state during construction works. The vast majority of the enterprises are concentrated on the territory of Balashikha. The article discusses an example of calculating air pollution from the enterprise influencing the environmental pollution on the river Pekhorka basin. Air samples were taken and data on emissions of substances into the atmosphere were obtained. The calculation of the impact of the enterprise on atmosphere pollution was carried out with a specialized program. As a result, calculation of the dispersion of pollutants concentrations were carried out, the schematic map of the concentrations of substances nitrogen dioxide and sulfur dioxide was created and measurs for the state of atmospheric air were suggested. Studies had shown that substances’ emissions slightly exceed the MPC and or did not exceed the MPC at all. However, it was necessary to carry out the regular atmosphere state monitoring to prevent damage to the environment.

Fifty Ohm radio frequency heating treatment under controlled atmosphere for inactivating Escherichia coli ATCC 25922 inoculated on almond kernels

The purpose of the study was to validate effects of radio frequency (RF) heating under controlled atmosphere (CA) on thermal inactivation of E. coli ATCC 25922 in almond kernels. A 2.4 kW, 27.12 MHz, 50 Ω RF heating system was used to treat 1.5 kg size almond kernel samples with the adjusted moisture content of 8.0% wet basis under regular atmosphere (RA, 21% O2, 79% N2) and CA (2% O2, 20% CO2, 78% N2) conditions. The power level of 900 W under an electrode gap of 11.5 cm was used at the ramping stage for quick heating, and a maximum temperature difference of 3 °C in the inoculation area was achieved by continuing the RF heating at reduced power level during the 40 min holding stage. A 4-log reduction time under CA treatment was achieved with 21 ± 1 min holding at 75 ± 3 °C, reducing treatment time by 38% as compared with RA environment. The various quality attributes of treated samples remained within acceptable range based on nut industry standards. The RF heating under CA conditions may hold potential as an effective treatment method to control E. coli ATCC 25922 in raw almond kernels and be possibly extended for pasteurization applications.

Fruit Quality and Storability of Some Asian Pear Cultivars Collected in the Gene Bank of the Research Institute of Horticulture, Central Poland

Abstract The aim of this study was to evaluate the fruit quality of 13 Asian pear cultivars grown in climatic conditions of central Poland. The following cultivars were tested: ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Nijisseiki’, ‘Dżin Li’, ‘Er Shi Shinge’, ‘Er Jang Li’, ‘Golden 20th’, ‘Min Czi Li’, ‘San Li’, and ‘Shinseiki’. Pears were harvested in Experimental Orchard of Research Institute of Horticulture in Dąbrowice (near Skierniewice). Fruits were stored for 10 weeks at 0 °C in regular atmospheric conditions. Flesh firmness (FF), total soluble solids (TSS), and titratable acidity (TA) were measured at harvest and after the storage followed with 1 and 7 days of shelf life (SL) at 18 °C. After the storage, the sensory evaluation was also performed. Among the tested cultivars, ‘Min Czi Li’ and ‘San Li’ were the most firm (above 45 N) and ‘Kosui’ was the least firm (below 28 N) at harvest time. High amount of TSS (above 11% in both seasons and harvest dates) was observed in ‘Chojuro’, ‘Hayatama’, ‘Kosui’, ‘Yuan Huang’, and ‘Er Jang Li’ pears. Low TSS (not more than 10.6% at harvest) was observed in ‘Nijisseiki’, ‘Dżin Li’, and ‘Er Shi Shinge’ cultivars. The large differences among cultivars were observed in TA. High TA was observed in ‘Nijisseiki’ (above 0.32% in all terms of analyses) and low TA in ‘Hayatama’ and ‘Kosui’ (below 0.14%). All of the evaluated cultivars can be stored for 10 weeks at 0 °C in regular atmosphere without major negative impact on their quality characteristics. Fruits showed a slight (sometimes significant) decrease in FF after storage and a slight or no changes in TSS and TA. In sensory evaluations, ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Er Jang Li’, ‘Er Shi Shinge’, and ‘Shinseiki’ (mostly cultivars characterized by high TSS) obtained highest scores for the overall quality (above 5.0 points in 10 points scale).

Functionalized and reduced graphene oxide as hole transport layer and for use in ternary organic solar cell

Here is reported the performance of organic solar cells (OSCs) by using a new graphene oxide derivative as hole transport layer (HTL). OSCs are based on the PTB7:PC71BM blend as active layer and the alternative top electrode Field's metal (Bi/In/Sn: 32.5%, 51%, 16.5%), which can be easily deposited through a vacuum-free process at regular atmosphere and low temperature (90 °C). Graphene oxide (GO) was chemically functionalized and reduced with pentafluorophenylhydrazine, this fluorinated reduced graphene oxide (F5-rGO) was suspended in dimethylformamide for easy deposit by wet techniques such as spin-cast. F5-rGO has a work-function of 5.1 eV due to the high electronegativity of fluorine atoms incorporated into the GO sheets. The best achieved PCE of the OSCs fabricated for a single layer of F5-rGO was 5.82%. An enhanced PCE of 7.67% when F5-GO was used as interlayer between ITO and PEDOT:PSS was reached (PCE of PEDOT:PSS-based was 7.29%). Additionally, functionalized and reduced (chemically) graphene oxide (H5-rGO) was also obtained from GO treated with phenylhydrazine, and ternary OSCs were also prepared by adding H5-rGO to the PTB7:PC71BM blend at different weight ratios: 0, 3, and 6%. The best results were achieved with 3% of H5-rGO: OSCs presented a PCE of 7.56%.

ХРАНЕНИЕ ПЛОДОВ СМОРОДИНЫ ЧЕРНОЙ В РЕГУЛИРУЕМОЙ АТМОСФЕРЕ

The research was conducted in 2017-2018 in I.V. Michurin Federal Research Centre (Tambov region, Russia) with our own breeding black current varieties ‘Tamerlan’ and ‘Shalunya’. In the Central-Chernozem region of Russia there are zoned 29 varieties. However they do not fully meet the requirements of consumers (because of quality problems and short terms of fresh sales). The study goal is to develop an innovative technology for extending storage time of fresh fruits of modern commercial black currant varieties. Fruits of black currant were harvested in experimental plot planted in 2012, planting scheme 4,0x0,75 m. Black currant fruits were stored at 0…+1° in regular (RA), modified (MA) and controlled (CA) atmosphere. There were determined the losses from gray rot (Botritis cineria), sensory (color, taste, consistence) and biochemical and other characteristics of fruit quality (vitamin C, dry soluble substances, titric acid content, total content of phenolic compounds, berry firmness, weight loss). Storage factors and their combinations inhibit the ripening and development of gray rot of black currant fruits in different degrees, provide different time of effective storage of production: in regular atmosphere it is limited to 5-7 days, in modified atmosphere — to 10- 15, in controlled atmosphere — to 45 days and even more. The variety ‘Tamerlan’ provides a higher level of keeping quality of fruits with all storage technologies. CA conditions keep slowing ripening, inhibiting of fungal rot, extending storage time with high quality (color, taste, fruit structure) during storage and bringing to consumers. CA technology (O 2 — 14.0-16.0 %, CO 2 — 13.5-15.5 %, humidity 95 %) provides preserving or insignificant changes of biochemical and other indicators of fruit quality (vitamin C, dry soluble substances, titric acid content, total content of phenolic compounds, berry firmness) after 30 days of storage. The developed technology is environmentally safe and could be used in organic production of black currant.

New technology of protecting apple fruits from bitter pit and other physiological diseases during storage

The work was performed in the I. V. Michurin Federal Scientifi c Center (Tambov region, Russia) in 2015-2018. The fruits of Sinap Orlovsky variety with high susceptibility to bitter pit, medium – to superfi cial scald and CO2 -skin injuries were used. The main post-harvest strategy of protecting fruits from bitter pit (BP) is storage in a controlled atmosphere (CA), short-term low oxygen storage (10 days, O2&lt;1 %) reduces losses from scald and BP, but does not provide protection from diseases of varieties with high susceptibility; post-harvest treatment with ethylene biosynthesis inhibitor (1-MCP) provides protection from scald, but has an ambiguous effect on the development of BP, and may increase the degree of disease appearance. The purpose of the research is the development of innovative technology of managing of bitter pit and other post-harvest pathological diseases. In the experiment, the control and 1-MCP-treated fruits were stored at 0 + 1 °C under regular (RA) and controlled atmosphere (CA) conditions: CA-1 (CO2 – 1.2-1.5 %, O2 – 1.2-1.5 %), CA-2 (СО2&lt;0.1 %, О2 – 1.2-1.5 %), under conditions of short (10 days) post-harvest impact of controlled factors: temperature 18-20 °С, О2 – 1.2-1.5 %, CO2&lt;0.1 % and further storage in regular atmosphere (LO2 ). Ethylene, α-farnesen and its oxidation products (CТ281), phenolic compounds were determined in fruits, losses from bitter pit, scald, CO2 -skin injuries, quality (fi rmness) were estimated. 1-MCP-treatment ensured a low level of ethylene and CT281 accumulation in fruits, protection from scald, preservation of fi rmness in all variants of fruit storage, with maximum effi ciency of variants CA-2, CA-1 and LO2 . Fruit protection from bitter pit was provided by CA-2 technology, a signifi cant reduction of losses – LO2 . When using the technology of CA-2, losses from CO2 -skin injuries, noted in the conditions of CA-1, were excluded. The maximum efficiency of protection of fruits from BP, scald, CO2 -injuries is provided by the developed technology CA-2 (CO2&lt;0.1 %, O2 — 1.2-1.5 %).