Storage Life Research Articles

Postharvest physiology and biochemistry of Valencia orange after coatings with chitosan nanoparticles as edible for green mold protection under room storage conditions.

Because of their unique features, nanomaterials have been proposed and have gained acceptance in postharvest applications in fruit. Increasing the storage life and improving the quality of Valencia oranges was investigated using nano-chitosan. A chitosan nanoparticle was prepared by using high-energy ball milling. Chitosan nanoparticles were characterized by Dynamic light scattering, FTIR spectroscopy and Surface morphology by transmission electron microscopy. Fully mature Valencia oranges were harvested and then coated with one of these concentrations (0.2, 0.4, and 0.8% nano-chitosan) and control. The fruits were stored under room storage conditions for 75 days. The quality parameters (fruit weight losses, fruit decay percentage, fruit firmness, total acidity, total soluble solids percentage and T.S.S./acid ratio, ascorbic acid content) were taken in biweekly intervals after 0, 15, 30, 45, 60, and 75 days. Beside the in vitro testing of antifungal activity of chitosan nanoparticles. According to the findings of the two succeeding seasons, the nano-chitosan 0.8% treatment showed the best effects and had the lowest rate of fruit weight loss, fruit deterioration, and T.S.S./acid ratio in comparison to the other treatments in both seasons. Furthermore, the 0.8% nano-chitosan reveled the highest levels of fruit hardness and fruit pulp firmness. Fruit weight loss, fruit deterioration, TSS, and TSS/acid ratio, as well as other metrics, were steadily elevated prior to the storage time. The best results were obtained when Valencia oranges fruits were treated with 0.8% nano-chitosan for 75 days at room temperature.

Comprehensive responses of aroma production in 'Benihoppe' strawberry to low oxygen associated with the changes of key gene expressions and energy levels.

The influence of low oxygen on the biosynthesis of aroma-related esters and alcohols in strawberries has been well revealed. However, how low-oxygen conditions affect other volatile compounds, such as terpenes and furans, is still to be elucidated. The effects of 2 kPa O2 low oxygen on the biosynthesis of aroma in 'Benihoppe' strawberries were comprehensively investigated in this study. The results showed that, like esters, the accumulations of key terpene alcohols and furans in strawberries were also inhibited by 2 kPa O2 low oxygen during storage and subsequent shelf life, which was associated with the down-regulation of expression of FaNES1 (nerolidol synthase) and FaOMT (O-methyltransferase). However, no anaerobic fermentation occurred in 'Benihoppe' strawberries since no ethanol and acetaldehyde were produced under the 2 kPa O2 condition. As expected, the 2 kPa O2 condition suppressed the respiratory intensity and lowered the energy charge to maintain the quality of strawberries. The negative effects of low-oxygen storage on aroma accumulations and the energy charge of strawberries were more pronounced when transferred to the period of shelf life. The 2 kPa O2 condition caused a full-scale loss of aroma in 'Benihoppe' strawberries, including esters and alcohols as well as terpenes and furans, which was mainly reflected in the reduction of aroma emissions rather than the production of off-flavor, probably due to the reduced expressions of related genes and energy charge. © 2022 Society of Chemical Industry.

The carbon footprint of stone fruit production: Comparing process-based life cycle assessment and environmentally extended input-output analysis

The development of sustainable products and practices must be supported by methodologies capable of evaluating their environmental performance in an objective and systematic manner. The most popular tool for carbon footprint (CF) assessment is arguably process-based life cycle assessment (pLCA). However, interest in tools such as environmentally extended input-output analysis (EEIOA) is growing rapidly due to the convenience of using economic-based inventories rather than material/energy-based ones. The objective of this investigation is to evaluate divergences between conventional pLCA and EEIOA in the analysis of CF using the production of stone fruits as a case study. The study uses a cradle to grave approach and it is based on a detailed economic, material and energy life cycle inventory of nectarines produced in Southeast Spain. The analyses yielded 1.07 kg CO2 eq./kg for the EEIOA and 0.899 kg CO2 eq./kg for the pLCA. This difference, which might sound acceptable, is due to the compensation of larger opposing discrepancies in the various stages and processes that make up the product life cycle. Thus, pLCA yielded significantly higher total CF emissions than EEIOA (0.23 EEIOA/pLCA ratio) in the upstream stage (agricultural and packaging processes). The opposite is observed in the core stage, where EEIOA carbon emissions were significantly higher than those calculated by pLCA (4.38 EEIOA/pLCA ratio). Differences in the downstream stage (mainly distribution and storage, and EoL phase) were less notable (1.40 EEIOA/pLCA ratio). Economic-based inputs, used in EEIOA (such as labour and service costs) and unaccounted for in pLCA, may be partly responsible for such divergences, while others should be linked to differences in the impact assessment procedures followed by each of these methodologies. These results raise some doubts about the potential of EEIOA and calls for further research on the validity, complementarity and the application domains of these methodologies. In any case, both modelling approaches agree in identifying the distribution and storage life cycle stages as main contributors to carbon emissions, calling for the implementation of measures to promote the consumption of seasonal and local fruit.

Application of a Posttreatment to Improve the Viability and Antifungal Activity of Trichoderma asperellum Biomass Obtained in a Bioreactor during Submerged Cultivation.

T. asperellum MSCL 309 was used in the study. T. asperellum was grown in the stirred bioreactor under submerged cultivation. The resulting biomass was filtered to obtain a thick biomass. The viability and antifungal activity of T. asperellum biomass samples were determined simultaneously by studying the colonization of the malt extract agar medium surface and its competitiveness with the plant pathogenic fungus Fusarium graminearum using in vitro dual culture experiments. Treatment with starch, alone or in combination with copper (II) sulphate and/or hydrochloric acid did not significantly affect fungal viability compared to control. An important factor in maintaining viability was the addition of hydrochloric acid, which significantly increased the storage life of biomass. In all post-treatments, F. graminearum was overgrown with T. asperellum in seven days, and accordingly, the larger the area occupied by T. asperellum, the smaller the area of F. graminearum colonization. Viability and antifungal activity of T. asperellum persisted throughout the experiment, at least for eight weeks. All the post-treatment methods we studied improved the viability and antifungal activity of Trichoderma, at least in terms of the area of the colonized surface. For the development of long-term viable and active T. asperellum preparations, we recommend the use of acidification of T. asperellum biomass obtained by submerged fermentation.

A method for isolation of DNA from Polyphagous Insects by cetyltrimethylammonium bromide (CTAB-PVPP method)

Insects are diverse in their distribution amongst kingdom Animalia. Order Lepidotera (butterflies & moths) stands second after coloeoptera in diversity. Noctuidae is one amongst the important families of order Lepidoptera with 36 families and 4200 genera in it. As moths exhibit great diversity besides the presence of many sub-species and cryptic species it has turned out to be tough conducting the taxonomical studies on them. The DNA isolation of polyphagous insects by SDS based methods and commercially available kits tend to produce low DNA yields with short storage life from tissues rich in phenolics. We evaluated the efficacy of the traditionally used CTAB-PVPP method for isolation of DNA from the Polyphagous insect Spodoptera frugipedra.

Cinnamon essential oil liposomes modified by sodium alginate‐chitosan: application in chilled pork preservation

SummaryIn this study, cinnamon essential oil liposomes (CEO‐Lip), chitosan (CH) modified CEO‐Lip (CH‐CEO‐Lip) and sodium alginate (SA) and CH modified CEO‐Lip (SA‐CH‐CEO‐Lip) were prepared based on layer‐by‐layer electrostatic self‐assembly deposition technique and their preservative effects on fresh pork were investigated. The average particle size of SA‐CH‐CEO‐Lip was 178.73 nm with polymer dispersity index (PDI) of 0.380, zeta potential of −23.83 mV. Results showed that the formation of SA‐CH‐CEO‐Lip was efficient (encapsulation efficiency 89.5%). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) confirmed that SA‐CH‐CEO‐Lip was prepared successfully. The in vitro cumulative release study during 72 h revealed that SA‐CH‐CEO‐Lip (71.42%) showed better sustained release capability than CEO‐Lip (81.24%). The pork assessment test showed that SA‐CH‐CEO‐Lip could effectively inhibit the increase in pH, total volatile basic nitrogen (TVB‐N) and thiobarbituric acid reactants (TBARS) of pork compared with CEO‐Lip group (P < 0.05). The total number of colonies (TBC) showed that the storage life of SA‐CH‐CEO‐Lip group could be extended to 12 days, which was significantly different from that of control group (6 days) (P < 0.05). In addition, SA‐CH‐CEO‐Lip also effectively maintained the good sensory quality of pork. In conclusion, SA‐CH‐CEO‐Lip showed good antiseptic effects on chilled pork preservation.

Retardation of quality loss and extension of shelf life of prepackaged hard clam heating by a novel microwave-assisted induction heating (MAIH) during refrigerated storage

Microwave-assisted induction heating (MAIH) is an emerging thermal processing technology that combines microwave and induction heating to provide rapid and even heating of food. A research found that the optimum MAIH cooking temperature for hard clams was 130 °C for 110 s or 90 °C for 130 s. The purpose of this work was to investigate whether MAIH could delay or not the loss of quality and prolong the shelf life of clams. Fresh clams were heated via MAIH to 130 °C for 110 s and to 90 °C for 130 s, respectively, and compared to the traditional boiling method of 90 °C for 150 s. Cooked clams were stored at 4 °C for 30 days to determine changes in microbiological quality and physicochemical properties. The results showed the undetectable aerobic plate count (APC) and psychrotrophic bacteria count (PBC) in the samples when heated via MAIH for the first 20 days of storage; thereafter, the counts increased gradually. By the end of the storage period, the final counts were approximately 4.0 log CFU/g. The initial APC and PBC in the sample heated with boiled water were at approximately 3.20 log CFU/g, which then increased over time to reach 7.66 log CFU/g and 8.06 log CFU/g, respectively, by the end of the storage period. After 30 days of storage, the total volatile basic nitrogen (TVBN) in the MAIH-treated samples was significantly lower than that in the water-boiled samples, by less than 36 mg/100 g. In terms of color, the lightness (L*) and whiteness (W) of all samples decreased gradually, while the redness (a*) and yellowness (b*) increased. In terms of texture, the MAIH-treated samples retained greater hardness, cohesiveness, and chewiness than the water-boiled samples (p < 0.05). Based on the above findings, compared to the traditional heating method of water boiling, the treatment of clam samples with MAIH retarded the degradation of texture, and inhibited the increase of TVBN and the growth of microorganisms during refrigerated storage. Thus, MAIH processing can prolong the storage life of the heat-treated clams from 10 days (when treated with boiling water) to 30 days at 4 °C.

Outcomes of 1‐MCP combined with aerosolization of ε‐polylysine antimicrobials on storage quality of flat peach

AbstractFruit decay and deterioration in overall quality are the main problems of preserving peaches after they are harvested. In this article, the outcomes of 1‐MCP combined with polylysine atomization on Xinjiang flat peaches were evaluated. Distilled water atomization treatment, 1,000 mg/L polylysine atomization treatment for 10 min and 1,000 mg/L polylysine atomization treatment for 20 min were employed. Results showed that the combined treatment using 1‐MCP and polylysine helped to delay the fruit decay rate, respiration, ethylene production, respiration intensity, organic acids, soluble solids, hardness, and microorganisms. Furthermore, reactive oxygen metabolism of O2− and OH− was inhibited. A combined treatment can effectively improve the antioxidant capacity during almond storage, and thus improve shelf life. Therefore, 1‐MCP combined with polylysine atomization treatment is necessary to control fruit rotting and to extent the storage life.

Cell wall composition and enzyme-related activities in eggplant as affected by hot water, 1-MCP and calcium chloride treatments.

The effects of postharvest applications of hot water (HWT) (45, 50, and 55 °C), 1-MCP (1, 5, and 10 μL/L), and CaCl2 (1, 2, and 3%) on polygalacturonase (PG), pectin methylesterase (PME), α-galactosidase (α-Gal), β-galactosidase (β-Gal) and β-1,4-glucanase (β-1,4-Glu) activities, and the fruit firmness and cell wall composition of eggplant fruit were investigated. The results showed that the decrease in the eggplants firmness was delayed by HWT, 1-MCP, and CaCl2 treatments during storage compared with the control. However, HWTs were less effective than the 1-MCP and CaCl2 treatments. The results show that 1-MCP and CaCl2 treatments inhibited the depolymerization of water (WSP), CDTA (CSP), and sodium carbonate (SSP) soluble polyuronides. The results suggest that 1-MCP (5 and 10 μL/L) and CaCl2 (1, 2, and 3%) could prevent eggplant softening by inhibiting hydrolase enzymes and reducing the disintegration of the polysaccharides. In addition, 1-MCP and CaCl2 were more effective than hot water treatment in extending postharvest storage life. There is a significantly high correlation between firmness, polyuronide content and cell wall enzyme activity.

Pomegranate Husk Scald Browning during Storage: A Review on Factors Involved, Their Modes of Action, and Its Association to Postharvest Treatments.

The pomegranate (Punica granatum L.), which contains high levels of health-promoting compounds, has received much attention in recent decades. Fruit storage potential ranges from 3 to 4 months in air and from 4 to 6 months in Controlled Atmospheres (CA) with 3-5% oxygen and 10-15% carbon dioxide. Storage life is limited by decay, chilling injury, weight loss (WL), and husk scald. In particular, husk scald (HS) limits pomegranate long-term storage at favorable temperatures. HS appears as skin browning which expands from stem end towards the blossom end during handling or long-term storage (10-12 weeks) at 6-10 °C. Even though HS symptoms are limited to external appearance, it may still significantly reduce pomegranate fruit marketability. A number of postharvest treatments have been proposed to prevent husk scald, including atmospheric modifications, intermittent warming, coatings, and exposure to 1-MCP. Long-term storage may induce phenolic compounds accumulation, affect organelles membranes, and activate browning enzymes such as polyphenol oxidases (PPO) and peroxidases (POD). Due to oxidation of tannins and phenolics, scalding becomes visible. There is no complete understanding of the etiology and biochemistry of HS. This review discusses the hypothesized mechanism of HS based on recent research, its association to postharvest treatments, and their possible targets.

Impacts of carboxymethyl cellulose-based coatings with calcium oxide and GABA on storage life and quality maintenance of fresh pistachio fruit

ABSTRACT The fresh in-hull pistachio fruit was sprayed with 1% calcium oxide (CaO), 10 mM w/v γ-aminobutyric acid (GABA), 1% carboxymethyl cellulose (CMC), and their combination (CMC+GABA+CaO) for 30 sec at room temperature. Spraying with distilled water was considered as a control. Following drying of fruits at room temperature, they were packed in perforated polyethylene terephthalate containers and kept under cold storage (at 2 ± 1 °C with 85 ± 2% RH) for 75d. Pistachios treated showed the lower weight loss, and the highest hull safety, taste, aroma, and overall acceptance than control. Total chlorophyll and anthocyanin of fresh pistachio kernel were preserved by combined treatment. Combined treatment reduced the PPO, POD, PAL activity and MDA content of the hull and maintained kernel phenolic compounds compared to other treatments. Besides these, the best effects were obtained with combined treatment, which maintained the physical, biochemical and visual characteristics of the fresh fruit for 50 days.

Energy efficient drying technologies for sweet potatoes: Operating and drying mechanism, quality-related attributes.

Sweet potatoes (SPs) are a versatile tuberous crop used as subsistence and cash crop in raw and processed forms. The major issue with SPs is post-harvest losses, which result in noticeable quality decline because of inappropriate handling, storage, delayed transit, and sales, as well as microbiological and enzymatic activity. Drying is an excellent strategy for managing short postharvest storage life, preserving nutrients, and maximizing long-term benefits. However, several parameters must be considered before drying SPs, such as relative humidity, temperature, drying duration, size, and shape. The current review looks at the factors influencing SPs' moisture loss, drying kinetics, diverse drying methods, pretreatments, operating conditions, and their efficacy in improving the drying process, functional, and nutritional qualities. An optimal drying process is required to preserve SPs to obtain concentrated nutrients and improve energy efficiency to be ecofriendly. Drying sweet potatoes using traditional methods such as sun or open-air drying was found to be a slow process that could result in a lower quality. Various advanced drying techniques, like vacuum, infrared, freeze drying, and pretreatments such as ultrasound and osmotic dehydration, have been developed and are successfully used globally. The best-fit thin-layer models (Hii, Page, two-term, logarithmic) utilized for drying SPs and appropriate modeling methods for optimizing drying procedures are also discussed.

Effect of evaporative cooling on peel browning and quality of litchi (Litchi chinensis)

The present study was carried out during 2016-18 at Punjab Agricultural University Ludhiana to examine the effect of evaporative cooling (EC) on peel browning and postharvest quality of litchi fruit during cold storage. The litchi fruits cv. Dehradun were harvested at the physiological maturity and subjected to EC treatments for 2 h, 4 h and 6 h. The fruits without EC were kept as a control. Thereafter, fruits were packed in corrugated fiberboard boxes and stored in a walk-in-cold room maintained at 2-3°C temperature and 90-95% relative humidity. The fruit samples were analyzed at weekly interval till four weeks for various physiological attributes, biochemical traits and enzymatic activities. The application of evaporative cooling for 6 h maintained lower physiological weight loss (6.38%), retained higher firmness (106.1g force),TSS (16.96°B), acidity (0.26%), anthocyanins (0.19 ΔA/g FW) and total phenols (218.43 mg/100g) during storage. The browning index of fruits was observed to be 3 (1/4-1/2 surface area brown up to 14 days of storage) with 4 and 6 h exposure to EC. The fruits subjected to EC for 6 h also maintained the lower activities of polyphenol oxidase (PPO) and peroxidase (POD) activity as compared to control. The study exhibited the expediency of EC treatment (6 h) to maintain the acceptable peel colour and prolong the storage life of fruits for 14 days as compared to 7 days in case of control.

Hydrocolloid edible coatings extend shelf life, reduce postharvest decay, and maintain keeping quality of mango fruits (Mangifera indica L.) under ambient storage.

Mango fruit exhibit high postharvest losses due to physiological, biochemical, and pathological deterioration during storage. Edible coatings such as hydrocolloids (HC) bear promising potential for fruit quality preservation at ambient storage due to its triple action (physiological, biochemical and pathological) on fruit and thus widely researched in recent years. This study demonstrates the influence of health and eco-safe hydrocolloid edible coatings such as "Carboxymethyl cellulose" (CMC) (1%), "Guar gum" (1.5%), "Gum Arabica" (10%), and "Xanthan gum" (0.3%) as dip treatment to enhance the postharvest quality and storage life of mangoes at ambient storage (25 ± 4°C and 65 ± 5% RH). "Xanthan gum" (0.3%) treatment exhibited the highest efficacy in reducing the decay loss by more than threefold and physiological loss by twofold over control fruit. It lowered the physiological and fruit softening enzyme activities (PG, PME, and LOX), while maintaining the biochemicals. Moreover, it maintained both internal as well as external (consumer preference) quality of fruit and extended 6 days shelf life on the physiological loss standard basis (≤10%) than that of the control. The results recommend the application of "Xanthan gum" (0.3%) as an efficacious ecological, sustainable, and health-friendly surface edible coating for quality preservation and storage period extension of mango fruit under ambient storage. PRACTICAL APPLICATIONS: The selected hydrocolloid edible coatings dip treatment showed promising potential in controlling the physiological, biochemical, and pathological deterioration of mango fruit stored under ambient condition. The selected treatments extended the shelf life without diminishing fruit quality. However, among the attempted HC treatments, the "Xanthan gum" (0.3%) (XG) coating displayed the excellent results. It added the storage life of mango fruit by 6 days over the control. XG treated fruit displayed the excellent results in terms of storage period extension, quality retention, consumer preference, and control over the fruit decay and softening enzymes activities. Postharvest preservation of mango fruit using HC is nonchemical, cost-effective approach which is GRAS (generally recognized as safe), health, and eco safe.

A high-purity AgO cathode active material for high-performance aqueous AgO–Al batteries

The aqueous divalent silver oxide (AgO)-aluminum (Al) batteries have garnered international attention due to the advantages of high safety, high specific energy, and environmental friendliness. However, the low purity of the AgO used as the cathode material shortens the battery's storage life and causes two voltage plateaus during discharge. Herein, we employ a quick and efficient approach to make AgO for aqueous AgO–Al batteries' cathode active material. The outcomes exhibit the successful production of high purity AgO with good thermal stability. The prepared AgO cathode additionally displays an excellent specific capacity of 394.7 mAh g−1, and the plateau of the discharge profile is closed to 1.7 V at the current density of 500 mA cm−2, taking advantage of the good electronic conductivity and charge transfer kinetics. A maximum output power density of 1260.54 mW cm−2 at 900 mA cm−2 is also possible. Furthermore, the electrochemical mechanism of the AgO electrode is further uncovered by Ex-situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) studies. Thus, this research presents a viable possibility for the fabrication of aqueous AgO–Al batteries by demonstrating the use of high purity AgO as a cathode active material.

Extension of CO2 storage life in the Sleipner CCS project by reservoir pressure management

In this study, we performed reservoir simulations to investigate CO2 storage in the saline aquifer in Sleipner by reservoir pressure management. Results show that by producing water at the lowest aquifer structure far away from the CO2-water contact in the vertical direction, an additional 73% (24 Mt) CO2 can be stored compared to the case without water production. This extra CO2 stored can generate a revenue of $800 millions at the prevailing carbon tax of $69 per ton in Norway. There is 5.31 Mtpa of natural CO2 production from 124 gas and oil fields in Norway in 2020. Of these, the Marulk, Dvalin, Skarv, Morvin, Åsgard, Kristin, Tyrihans and Mikkel fields in the Norwegian Sea, and the Kvitebjørn, Valemon, Visund, Gudrun fields in the North Sea produce a total of 4.55 Mtpa CO2 potentially supplying CO2 to Sleipner for project life extension.

Integrated transcriptomics, proteomics, and metabolomics analysis reveals the mechanism of litchi pulp deterioration during long-term cold storage

Litchi (Litchi chinensis Sonn.) fruit is delicious and nutritious but has a short storage life. Cold storage is widely used in the litchi industry as the most efficient preservation method for litchi fruit. In this study, comparative analyses of the transcriptomics, proteomics, and metabolomics of 0-d and 28-d litchi pulp were revealed the mechanism underlying litchi pulp deterioration during long-term cold storage. The results indicated that long-term cold storage might maintain the appearance of litchi fruit, but it cannot ensure the quality of the pulp. The differential genes, proteins, and metabolites were primarily involved in the metabolism of amino acids, nucleic acids, lipids, and secondary metabolites, which are regulated by transcription and translation. However, the changes in the gene, protein, and metabolite levels were inconsistent. The metabolic pathways of 28-d pulp were imbalanced because of the degradation of sugars, organic acids, amino acids, and nucleotides, as well as the synthesis of lipids and secondary metabolites. The 28-d pulp was primarily stressed by cold and disease; it resisted these stresses by accumulating resistance proteins, strengthening and maintaining the cell wall and cell membrane structure, and synthesizing secondary metabolites. The deficiencies in energy metabolism substrates and synthesized ATP of 28-d pulp hindered its ability to support life activities and stress resistance. Therefore, the litchi pulp could not maintain regular metabolism, stress resistance, energy supply, and exhibited deteriorated pulp quality during long-term cold storage. This study provides new insights into the effect of cold storage in preserving litchi fruit.

Color and physiochemical attributes of pointed gourd (Trichosanthes dioica Roxb.) influenced by modified atmosphere packaging and postharvest treatment during storage.

The efficiency of modified atmosphere packaging (MAP) in combination with postharvest treatment on the shelf-life, physiochemical attributes, color, and nutrition of pointed gourd was studied after storing in refrigerated (low temperature, LT) and ambient (room temperature, RT) conditions. Fresh pointed gourd fruits were dipped in NaOCl solution (0.01% w/v) and potassium metabisulphite (KMS) (0.05% w/v), blanched (100°C for 4 min), and then packed in perforated and non-perforated polythene and polypropylene packets of each type and brown paper bags as MAP before storing at LT and RT. Physiochemical attributes, color, and nutrition were measured until the marketable level of acceptance (up to shelf-life) after storage and compared with the untreated and unpacked samples (control). The results showed profound differences among the treatment variables in all the studied dependent parameters regarding the LT and RT storage conditions. Among the treatments, perforated and non-perforated polyethylene (NPE) and polypropylene (NPP) packaging performed well to retain a considerable amount of ascorbic acid, β-carotene, and greenish color (lower L*, high h*) in pointed gourd treated with NaOCl (0.01%) and KMS (0.05%) after storing at LT and RT. Furthermore, the principal component analysis suggested that five major quality attributes (L*, C*, h*, shelf-life, and ascorbic acid) were influenced remarkably in terms of non-perforated polyethylene packaging in combination with KMS treatment both in LT and RT storage conditions. However, perforated polythene and polypropylene in combination with NaOCl responded well in RT but only for the shortest storage life. Thus, a non-perforated polythene package with KMS treatment would be the best solution for retaining market quality acceptance with green color up to the extended shelf-life of 23 and 10 days, respectively, in the refrigerator (LT) and in ambient (RT) storage conditions.

Nitric oxide promotes energy metabolism and protects mitochondrial DNA in peaches during cold storage.

The mitochondria are important organelles related to energy metabolism and are susceptible to oxidative damage. In this experiment, peaches (Prunus persica) were treated with distilled water (as the control), 15 μmol L−1 of nitric oxide (NO), and 20 μmol L−1 of carboxy-PTIO (NO scavenger). The changes in mitochondrial physiological indicators, energy metabolism process, and mitochondrial DNA (mtDNA) damage and repair were quantified. Compared with the control, NO treatment reduced mitochondrial oxygen consumption and the reactive oxygen species content, increased mitochondrial respiration control rate, and promoted energy metabolism by influencing the activities of citrate synthase, aconitase, isocitrate dehydrogenase, and α‐ketoglutarate dehydrogenase in the tricarboxylic acid cycle and ATPase activity in peach mitochondria. NO treatment also maintained the relative copy number of mtDNA and the relative amplification of long PCR in peaches, decreased the level of 8-hydroxy-2 deoxyguanosine, and upregulated the expression of PpOGG1, PpAPE1, and PpLIG1. These results indicated that exogenous NO treatment (15 μmol L−1) could reduce mtDNA oxidative damage, maintain mtDNA molecular integrity, and inhibit mtDNA copy number reduction by reducing the reactive oxygen species content, thereby promoting mitochondrial energy metabolism and prolonging the storage life of peaches at low temperatures.

Thermal Decomposition of GAP Studied by Dynamic Pressure-measuring Thermal Analysis

The thermal decomposition process of GAP in a vacuum confined space was measured by Dynamic Pressure-measuring Thermal Analysis(DPTA). In order to avoid the test error, the test process was improved: the method of liquid nitrogen condensation was used to prevent GAP volatilization in the process of vacuum pumping in the reaction test tube, and the vapor pressure at different temperatures was measured by thermogravimetric analysis. The results show that at 80°C to 120°C, the mechanism function of GAP non-isothermal decomposition reaction is Jander equation, the apparent activation energy is 159.8kJ·mol-1, and the pre-exponential factor lnA is 25.8. At the GAP isothermal reaction stage, the mechanism function changes with the temperature. When the temperature increases, the thermal decomposition reaction changes from diffusion reaction to activation reaction. The decomposition rate constant K increases exponentially with increasing temperature. When T=80°C, K=1.27×10-6; when T=120°C, K=36.93×10-6. According to the data of the decomposition time of 0.1% in the temperature range of 80~120 °C, the Semenov equation is lntT = 19039.90/T- 43.012. The storage life is 35.96 years at 25°C.