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Use of basil in its fresh form is increasingly popular due to its unique aromatic and sensory properties. However, fresh basil has a short shelf life and high chilling sensitivity resulting in leaf browning and loss of characteristic aroma. Moderate CO 2 atmospheres have shown potential in alleviating symptoms of chilling injury in basil during short-term storage but its effect on the flavor volatiles is unclear. Moreover, studies on basil volatile profile as impacted by chilling temperatures are limited. We investigated the response of two basil genotypes to low temperatures and atmosphere modification, with emphasis on the volatile organic compounds responsible for basil aroma and flavor. Leaves were stored for 6 days at 5, 10, or 15°C combined with three different CO 2 atmospheres (0.04%, 5% or 10%). Basil volatile profile was assessed using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Leaves suffered severe chilling injury and greater loss of aroma volatiles at 5°C compared to 10°C and 15°C. More than 70 volatiles were identified for each genotype, while supervised multivariate analysis revealed 26 and 10 differentially-accumulated volatiles for ‘Genovese’ and ‘Lemon’ basil, respectively, stored at different temperatures. Storage in 5% CO 2 ameliorated the symptoms of chilling injury for up to 3 days in ‘Genovese’, but not in ‘Lemon’ basil. Both chilling temperatures and controlled atmospheres altered key volatile compounds implicated in basil aroma and flavor, but temperature had a bigger influence on the observed changes in volatile profile.

There is a need for alternative treatments for postharvest pests on stored products. In this study, 45-d long-term controlled atmosphere (CA) treatments with 3, 5, 6.5, and 8% O2 were studied to determine effects on survival and development of rice weevil (Sitophilus oryzae) and confused flour beetle (Tribolium confusum) eggs and susceptibility of different life stages to a 14-d 5% O2 treatment. Low oxygen treatments were effective against S. oryzae and T. confusum. The 45-d CA treatments with 6.5, 5, and 3% O2 resulted in 0.26, 0.004, and 0% survival rates from egg to adult respectively for S. oryzae and 6.51, 0.14, and 0% survival rates from egg to later stages respectively for T. confusum. For both species, eggs were more susceptible to low oxygen treatment than larvae or pupae. A 14-d CA treatment with 5% O2 resulted in 4.9 and 3.3% survival of eggs of S. oryzae and T. confusum, respectively, as compared with over 50% survival of larvae and pupae for both species. S. oryzae adults, however, were very susceptible to low oxygen treatment and 14-d exposure to 5% O2 atmosphere resulted in zero survival. In contrast, the 14-d exposure to 5% O2 atmosphere resulted in over 94% survival for T. confusum adults. This study suggested there were considerable differences between stored product insects in susceptibility to low oxygen treatment and that long-term CA storage treatments with a low oxygen level of ≤6.5 and ≤5% have potential in controlling S. oryzae and T. confusum, respectively.

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.

Long-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 O 2 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.

Storage insects are aerobic organisms requiring oxygen for their survival. Therefore, they respond to altered atmospheric gas compositions containing low O2 or high CO2. The lower the grain moisture content (m.c.) and the corresponding intergranular humidity, the higher the mortality—due to the desiccation effect on insects caused by low O2 or elevated CO2 concentrations. To achieve insect control, the temperature of the grain should be above 21 °C. Hermetic storage is based on the principle of generation of an oxygen-depleted, carbon dioxide-enriched interstitial atmosphere caused by the respiration of the living organisms in the ecological system of a sealed storage. A sufficiently low oxygen and elevated CO2 atmosphere is created through a natural metabolic process based on insect respiration and, in cases where the commodity has sufficiently high moisture, the respiration of the microorganisms within a sealed storage system. An O2 ingress rate of 0.05 %/day is sufficient to arrest the theoretical weight loss at a level of 0.018 % over 1-year storage period. At this ingress rate, the possibility of a residual surviving insect population is eliminated. This low O2 ingress level could serve as a guideline for the sealing specifications of structures appropriate to the hermetic storage method. The applications for which hermetic technology has been most widely accepted are (a) for long-term storage of cereal grains, primarily rice, corn, barley, and wheat; (b) for long-term storage of a variety of seeds to preserve germination potential and vigor, and (c) for quality preservation of high-value commodities, such as dried fruits.

The zucchini market is growing worldwide due to its health and nutritional properties and culinary versatility. However, fruits harvested in the early stages of development are very perishable, which requires efforts to extend their shelf life. The aim of this study was to determine the effect of an innovative method involving a dynamically controlled atmosphere (DCA) and controlled atmosphere (CA) on the quality of zucchini stored at two temperatures (5 and 8 °C). After 20 d of cold storage, the fruit was further monitored under retail conditions (air, 15 °C). CA and DCA applied in a cold store at 8 °C improved the storage ability of the zucchini and allowed it to remain marketable for another 8 days at 15 °C. However, there were no significant effects of the storage method at 5 °C on the shelf life of zucchini at 15 °C. In addition, after storage at 8 °C under CA and DCA conditions, zucchini contained more total soluble solids (4.0%), glucose (8.0 g kg−1), fructose (11.0 g kg−1), and polyphenols (436 mg kg−1) than those stored under normal atmosphere (3.6%, 6.2 g kg−1, 9.9 g kg−1, 377.8 mg kg−1 respectively). The use of CA and DCA extends the shelf life and supports sustainable production and consumption of zucchini fruit.

The purpose of this study was to quantify the effectiveness of ultrasound treatment combined with controlled atmosphere storage (UCA) in preserving quality of cucumbers ( Cucumis sativus L.) compared with the controlled atmosphere storage (CA) alone. The combination of ultrasound (especially at 200 W for 10 min) with CA (5% O 2  + 2% CO 2  + 93% N 2 ) storage was most effective in preserving the fresh-like quality of cucumbers. The treatment reduced the loss in mass, firmness, soluble solids content and color, maintained cell wall integrity, and limited the redistribution of water in cucumbers. UCA significantly better preserved the flavor volatiles and retained the taste characteristics. This method also better preserved the intermolecular hydrogen and carbonyl bonding in aldehyde and ketone compounds of cucumbers which helped them to preserved longer. These results suggested that UCA can be a much effective preservation method than CA alone for fruits and vegetables.

Combined effects of controlled atmosphere and different postharvest treatment (salicylic acid, oxalic acid and putrescine) on bioactive compounds and quality of pomegranate cv. Hicaznar were investigated. Pomegranates were harvested at commercial harvest stage and transported immediately to postharvest physiology laboratory. Fruit were divided into four groups. 1 Control: Dipped into distilled water + 0.01% Tween-20 solution for 10 min. 2 Oxalic acid (OA): Dipped into 6 mM OA + Tween-20 solution for 10 min. 3 Salicylic acid (SA): Dipped into 2 mM SA + Tween-20 solution for 10 min. 4 Putrescine (PUT): Dipped into 2 mM PUT + Tween-20 solution for 10 min. After treatments, pomegranates were stored at 6 °C and 90 ± 5% relative humidity for 6 months in controlled atmosphere (5% O2 + 15% CO2). Weight loss, color, total soluble solids content, titretable acidity (TA), total phenolic content, vitamin C, antioxidant activity and sugar content (glucose and fructose) were determined at 0th, 2th, 4th and 6th month of cold storage. Generally, weight losses were minimized by treatments, especially PUT, compared to control. The level of ascorbic acid significantly tended to decrease throughout the storage in all treatments. Treated pomegranate exhibited higher titratable acidity, total phenolic contents and antioxidant activity compared to control samples. However, PUT was the best among all treatments. The results suggest that SA, OA and PUT have the potential to extend the storage life of pomegranate by delaying quality loss and maintaining some bioactive compound and antioxidant activity.

Sweet cherry is a highly appreciated seasonal fruit with a high content of bioactive compounds; however, this highly perishable fruit has a relatively short shelf-life period. Here, we evaluated the evolution of the physicochemical and sensory qualities of sweet cherries (Prunus avium (L.) cv. Satin) under different storage conditions, namely at a Farmers’ Organization (FO) and in a Research Centre (RC) under normal and four different conditions of controlled atmosphere for 49 days. Additional parameters were monitored, such as rotten fruit incidence and stem appearance. Temperature was the factor that most influenced the fruit quality changes over the study time. In fact, fruits stored at higher mean temperatures showed higher weight loss, higher variation in CIE-Lab colour parameters, higher firmness loss, and browner and more dehydrated stems and were less appealing to the consumer. Controlled atmosphere conditions showed a smaller decrease in CIE-Lab colour parameters and lower weight loss. The incidence of rotting was very low and was always equal or lower than 2% for all conditions. Thus, RC chamber conditions were able to sustain fruit quality parameters over 28 days under normal atmosphere conditions and 49 days under controlled atmosphere conditions.

Onion is one of the oldest and most consumed crops in the world. Its quality deteriorates gradually during prolonged storage. In the present study, white onions of the variety “Sierra Blanca” were stored in a controlled atmosphere (CA) for 7 months. The color, total pungency, microbiological load and total carbohydrates were evaluated. Three treatments were applied: control treatment (CT), regular atmosphere at 2.5 °C without controlled relative humidity (RH); (T1)1% O2 + 1% CO2 at 2.5 °C and 60–75% RH and (T2)3% O2 + 5% CO2 at 2.5 °C and 60–75% RH. The statistical analysis showed a significant effect of the treatments and storage time in most of the variables analyzed. The CA managed to preserve the quality of the onion during the storage period while the control bulbs exhibited greater deterioration. These increased 2.9 times their level of pungency, had a higher microbial load and showed a very noticeable color change at the end of storage with respect to freshly harvested onions and those stored in a CA. They had a more yellow-green coloration. Both CA treatments were effective in preserving onion quality, but a more positive effect for T1 than T2 was observed on most of the parameters evaluated.