Optimal Controlled Atmosphere Conditions for Storage of Broccoli Florets

Minimally processing broccoli heads into florets increased the rate of respiration throughout storage at 4°C in air, in response to wounding stress. Ethylene production was also stimulated after 10 days. At-mospheres for optimal preservation of the florets were evaluated using continuous streams of the following defined atmospheres (%CO₂/%O₂): O/20 (air control), 6/1, 6/2, 6/3, and 3/2, 6/2, 9/2. The atmosphere consisting of 6% CO₂+ 2% O₂ resulted in extended storage of broc-coli florets from 5 wk in air to 7 wk. This was demonstrated by delayed yellowing, prolonged chlorophyll retention, reduced development of mold and offensive odors (by sensory observation), and better water retention. These beneficial effects were especially noticeable when the florets were returned from CA at 4°C to air at 20°C.     

Assessment of Relationships between Sensory and Instrumental Quality of Controlled-atmosphere-stored 'Fuji' Apples by Multivariate Analysis

ABSTRACT: Physicochemical parameters, sensory attributes, and total aroma emission of ‘Fuji’ apples (Malus×domestica Borkh.) were studied in relation to storage conditions, storage duration, and shelf life period. Commercially ripe fruit were analyzed after 3, 5, and 7 mo of cold storage in normal atmosphere (AIR) (210 L/m³ O₂+ 0.3 L/m³ CO₂) or under 3 different controlled atmosphere (CA) treatments (10 L/m³ O₂+ 10 L/m³ CO₂, 20 L/m³ O₂+ 20 L/m³ CO₂, or 10 L/m³ O₂+ 30 L/m³ CO₂), after which apples were kept at 20 °C for 1, 5, and 10 d. Data were subjected to partial least square regression (PLSR) analysis. Physicochemical parameters were well preserved throughout storage, especially in CA‐stored apples; however, these apples showed lower total aroma emission. Sensory acceptability was also higher for CA‐stored fruit after 7 mo of storage, whereas no significant differences were found for shorter storage periods. Accordingly, greater scores in sensory firmness, sensory flavor, sensory acidity, and appearance were observed for fruit stored in 10 L/m³ O₂+ 10 L/m³ CO₂ after long storage. Two PLSR models were established, 1 for relating physicochemical parameters to overall acceptability, and another for assessing the correlation between sensory acidity and instrumentally measured titratable acidity. The 1st PLSR model indicated that soluble solids concentration, titratable acidity, flesh firmness, and background color of the shaded side have a positive influence on acceptability. The 2nd model indicated that sensory acidity also showed an excellent correlation to instrumentally measured titratable acidity.     

SENSORY, NUTRIENT AND CHLOROPHYLL CHANGES IN BROCCOLI FLORETS DURING CONTROLLED ATMOSPHERE STORAGE

Sensory (color, turgor, decay) and nutritional (vitamin C, β-carotene) quality of broccoli florets were evaluated during storage at 4C in air or under a controlled atmosphere containing 2% O₂+ 6% CO₂ (CA). Shelf-life, green color and chlorophyll retention were greater under CA than in air, although loss of stem turgor was accelerated. All samples stored in air had decayed sufficiently by the fourth week to be unfit for consumption, while samples stored under CA showed a few spots of decay after five weeks. However, CA was associated with browning at the cut surface of the stem. Retention of vitamin C was slightly greater in CA than in air, while β-carotene content increased at the end of CA storage. Returning the samples to ambient conditions for 24 h after storage under either conditions resulted in chlorophyll and vitamin C losses, whereas β-carotene content remained stable.     

Quality and biochemical changes of longan (Dimocarpus longan Lour cv. Daw) fruit under different controlled atmosphere conditions

Sulphur dioxide has been used to control pericarp browning in longan fruit. However, due to health and regulatory concerns, alternative treatments should be tested. The objective of this study was to find the tolerance levels of longan fruit to low O₂ (2%, 5%, 10% and 15%) and elevated CO₂ (5%, 10%, 15% and 20%) at 2 °C. According to the tolerance study, controlled atmospheres (CA) of 5% O₂ + 5% CO₂, 5% O₂ + 10% CO₂ and 5% O₂ + 15% CO₂ were compared with normal air (control) at 2 °C. Pericarp browning and decay incidence of longan were significantly (P ≤ 0.05) higher in control than all the CA treatments. CA storage reduced polyphenol oxidase (PPO) activity, maintained L* value and slowed down a decrease in total phenolic contents (TPC). Pericarp browning was highly correlated with PPO, L* and TPC.     

Quality of broccoli as influenced by film wrapping during shipment

'Shogun' broccoli florets were film-wrapped and stored for 7 days at 1 °C to simulate a maximum period of commercial shipment. After cold storage, florets were kept for 2.5 days at 20 °C to simulate a retail sale period. For wrapping, polyvinyl chloride (PVC) 9 µm thickness and low-density polyethylene (LDPE) 11, 15, and 20 µm thickness were used. Soluble solids content, pH, titratable acidity, weight loss, physiological disorders, visual quality, and gas composition within packages were monitored. Gas composition (about 18% O₂ and 1% CO₂ during cold storage and about 16% O₂ and 2-3% CO₂ during shelf life), overall quality, and yellowing and browning of the florets were at similar levels among the films studied. However, weight loss was about sixty times lower for all LDPE films than for PVC film. After shelf life the best results were obtained by using 15 µm LDPE. This polymeric film could be a good alternative to PVC for wrapping broccoli for commercial shipment purposes, particularly to those countries where use of PVC has been forbidden.     

EFFECT OF ATMOSPHERE ON BROCCOLI SENSORY ATTRIBUTES IN COMMERCIAL MAP AND MICROPERFORATED PACKAGES1

Broccoli was packaged using 2 microperforated (cross-micro, SM60®) and 3 modified atmosphere packages (MAP) (polyethylene MAP, broccoli MAP, lettuce MAP). Packaged broccoli was stored 9 days at 2C and an additional 1, 3, 4 and 6 days at 13C, for a total storage 10, 12, 13 and 15 days, respectively. Concentrations of CO₂ and O₂ were determined after 12 days. Sensory analyses were conducted after 10, 12, 13, and 15 days. Broccoli quality was evaluated for ten sensory attributes by eight trained judges. Analysis of variance and principal component analysis were used to determine the effect of packaging and storage time. Broccoli packaged in lettuce MAP was most anaerobic (3.9% CO₂, 1.2% O₂) and developed sauerkraut-like odors/flavors after 10 days of storage. The microperforated wraps did not alter the gas composition of the packages (16.3% O₂, 0.2% CO₂) and broccoli became yellow and limp after 15 days. In contrast, broccoli packaged in the polyethylene and broccoli MAP packages modified the CO₂ and O₂ concentrations and maintained the broccoli quality for the duration of the experiment (15 days).     

Mechanical parameters to assess quality changes in cherimoya fruit

 Several mechanical parameters obtained by means of compression and penetration tests, and changes in cherimoya (Annona cherimola Mill.) fruit quality during storage in air and two controlled atmospheres (CA), (3% O₂+0% CO₂ and 3% O₂+3% CO₂) were analysed. A gradient of softening was found among the equatorial and the apical areas of the flesh during CA storage, as assessed by localized penetration tests. The combination of low O₂/elevated CO₂ (3% O₂+3% CO₂) increased this gradient and had a greater inhibiting effect on skin softening than low O₂. It appeared that the prevention of softening by CA was stronger in the less mature tissues (equatorial and outer areas) than in the more mature tissues (apical and inner areas around the longitudinal axis). CA delayed or inhibited changes in fruit quality observed during air storage: increases in total soluble solids (TSS), titratable acidity (TA), and yellowness of the flesh (b), and diminution in flesh lightness of colour (L). A good relationship between an objective quality index (QI, where QI=TSS+TA+L/b) and the compression slope (CS) was found during storage under all the conditions tested. It is suggested that the relationship, QI=29.25+0.04×CS–0.0023×CS² could be useful when assessing stages of cherimoya fruit quality during storage under different conditions by performing a nondestructive, compression test.     

MICROFLORA CHANGES IN MODIFIED-ATMOSPHERE-PACKAGED BROCCOLI FLORETS STORED AT REFRIGERATED TEMPERATURE

Changes in the microflora of packaged (Resinite VF-71 film) and nonpackaged broccoli florets held at 8C for 7 days were analyzed. Oxygen and carbon dioxide concentrations, aerobic plate, coliform yeast/mold counts, and overall quality were determined. Level of O₂ decreased from 15.58 to 5.15%, while CO₂ increased from 2.88 to 8.22% after 94 h of storage. Within each microorganism group, similar growth trends were observed between the packaged and nonpackaged samples; however, the packaged samples consistently exhibited a statistically significant (p ≤ 0.05) lower microbial count compared with nonpackaged samples throughout the storage period. Packaged and nonpackaged florets retained their green color and no off-odor was detected; however, the nonpackaged florets were found to be less crispy than the packaged samples.     

Mechanical parameters to assess quality changes in cherimoya fruit

 Several mechanical parameters obtained by means of compression and penetration tests, and changes in cherimoya (Annona cherimola Mill.) fruit quality during storage in air and two controlled atmospheres (CA), (3% O₂+0% CO₂ and 3% O₂+3% CO₂) were analysed. A gradient of softening was found among the equatorial and the apical areas of the flesh during CA storage, as assessed by localized penetration tests. The combination of low O₂/elevated CO₂ (3% O₂+3% CO₂) increased this gradient and had a greater inhibiting effect on skin softening than low O₂. It appeared that the prevention of softening by CA was stronger in the less mature tissues (equatorial and outer areas) than in the more mature tissues (apical and inner areas around the longitudinal axis). CA delayed or inhibited changes in fruit quality observed during air storage: increases in total soluble solids (TSS), titratable acidity (TA), and yellowness of the flesh (b), and diminution in flesh lightness of colour (L). A good relationship between an objective quality index (QI, where QI=TSS+TA+L/b) and the compression slope (CS) was found during storage under all the conditions tested. It is suggested that the relationship, QI=29.25+0.04×CS–0.0023×CS² could be useful when assessing stages of cherimoya fruit quality during storage under different conditions by performing a nondestructive, compression test. Received: 23 April 1998     

Combined Post-harvest Treatments for Improving Quality and Extending Shelf-Life of Minimally Processed Broccoli Florets (<Emphasis Type="Italic">Brassica oleracea var. italica</Emphasis>)

Broccoli is an important source of many nutritional and bioactive compounds. However, its shelf-life is very short due to physicochemical losses and microbiological degradation. This study was undertaken to implement treatments that could improve the quality of ready-to-eat (RTE) broccoli during storage by evaluating the effect of pre-treatment with calcium chloride (CaCl₂) and alginate coating on the physicochemical and microbial properties of RTE broccoli. Broccoli florets were pre-treated with three different concentrations of CaCl₂ (1, 2.5, and 4 g L^?1), then coated with an alginate formulation (13 g L^?1) and stored at 4 °C for 24 days. Texture, color, weight loss, respiration rate, and total mesophilic flora (TMF) counts were evaluated at days 0, 3, 7, 14, and 24 of storage. The obtained results in this study showed that combining pre-treatment with calcium and alginate coating led to reducing the weight loss and respiration rate of broccoli, maintaining its color and texture as well as extending its shelf-life by 6 days. These results not only allowed reducing post-harvest losses resulting in the loss of the product but also have a major impact on the environment and resources involved in the production process.     

Effect of Controlled Atmosphere Storage and Chitosan Coating on Quality of Fresh-Cut Jackfruit Bulbs

Fresh-cut jackfruit bulbs were evaluated for quality changes as effect of an additive pretreatment with CaCl₂, ascorbic acid, citric acid, and sodium benzoate followed by chitosan coating. Different types of samples such as pretreated and coated, only pretreated, only coated, and untreated were subjected to controlled atmosphere (CA) storage (3 kPa O₂?+?6 or 3 kPa CO₂; N2 balance) or normal air at 6 °C. CA conditions, pretreatment, as well as chitosan coating in synergy with each other, could significantly minimize the loss in total phenolics and ascorbic acid content of the samples to the levels of around 5% and 17%, respectively, during extended storage up to 50 days. Chitosan coating could also restrict the changes in microbial load. The CA condition of 3 kPa O₂?+?6 kPa CO₂ was found to render higher efficacy in retaining quality attributes of the samples.     

Control of internal browning and quality improvement of ‘Fuji’ apples by stepwise increase of CO2 level during controlled atmosphere storage

To control internal browning injury and to reduce quality loss in ‘Fuji’ apples during storage, a stepwise controlled atmosphere (CA) method was applied in this study. Both non‐bagged and bagged apples during maturation were stored at 0 °C under 1% O₂ + 1% CO₂, 1% O₂ + 3% CO₂ or air for 10 months, and 1% O₂ + 1% CO₂ for 2 months followed by 1% O₂ + 3% CO₂ for 8 months (stepwise CA). The concentrations of internal ethylene and carbon dioxide in apples kept for 24 h at 20 °C after storage under CA conditions were maintained at low level, but there was no effect of stepwise CO₂ increase on internal gas concentrations. The non‐bagged and bagged apples stored under stepwise CA were not significantly different from those stored under 1% O₂ + 3% CO₂ continuously for 10 months in term of flesh firmness, titratable acidity and yellowing index. However, the apples stored under stepwise CA were firmer, more acid and greener than those stored under 1% O₂ + 1% CO₂ continuously for 10 months. Internal browning injury occurred in apples stored under 1% O₂ + 3% CO₂ continuously for 10 months, but it was suppressed completely by stepwise CA storage. The stepwise CA, increasing of CO₂ level after holding at 1% CO₂ for the first 2 months of storage, was effective in maintaining the quality and controlling the internal browning injury in non‐bagged and bagged ‘Fuji’ apples. Copyright © 2005 Society of Chemical Industry     

Enriched ozone atmosphere enhances bioactive phenolics in seedless table grapes after prolonged shelf life

‘Autumn Seedless’ table grapes (Vitis vinifera L.) were stored for up to 60 days at 0 °C under ten different gas treatments. An additional simulated retail display period of 7 days in air at 15 °C was also applied in all cases. These postharvest treatments were tested as an alternative to the usual industrial SO₂ application and included modified atmosphere packaging (MAP), with and without natural fungicides (hexanal and hexenal), controlled atmosphere (CA) and intermittent and continuous applications of ozone (O₃). The sensory quality was preserved with MAP of 13–16 kPa O₂ + 8–11 kPa CO₂, CA of 5 kPa O₂ + 15 kPa CO₂ and both O₃ treatments. Although O₃ did not completely inhibit fungal development, its application increased the total flavan‐3‐ol content at any sampling time. Continuous 0.1 µL L^?1 O₃ application also preserved the total amount of hydroxycinnamates, while all treatments assayed maintained the flavonol content sampled at harvest. Total phenolics increased after the retail period in O₃‐treated berries. MAP preserved the total polyphenol content, while a slight decrease was observed under the CA conditions used. Therefore the improved techniques tested for retaining the quality of ‘Autumn Seedless’ table grapes during long‐term storage seem to maintain or even enhance the antioxidant compound content. Copyright © 2007 Society of Chemical Industry     

Effect of atmosphere composition on the quality of ready‐to‐use broccoli raab (Brassica rapa L.)

BACKGROUND: Many leafy brassicas are widely used for ready‐to‐use salads. Broccoli raab (Brassica rapa L.), also called turnip top, or rapini, is extensively cultivated in southern Italy. The edible portion is made up of the green, immature inflorescences and the stem with its most tender leaves. Recently, interest in this crop has increased among European consumers; moreover, a substantial increase in consumption could come from the ready‐to‐use product. RESULTS: The effects of four different atmosphere compositions (air, 3% O₂ in nitrogen, 3% O₂ + 10% CO₂ in air, and 10% CO₂ in air) on quality attributes of ready‐to‐use broccoli raab were studied. Controlled atmosphere affected appearance, composition, respiration rate, weight loss, and presence of off‐odours. Storage of broccoli raab florets under low oxygen conditions delayed post‐cutting deterioration during storage at 5 °C and preserved appearance and typical odour, up to 17 days. Moreover, respiration rate as well as loss of green colour, chlorophyll and vitamin C were also slowed down in this condition. Finally, in this study no effect of controlled atmosphere storage was found on total phenols content and antioxidant activity. CONCLUSION: Results showed that cold storage in 3% O₂ can be beneficial in order to maintain quality of ready‐to‐use, broccoli raab for up to 17 days. Copyright © 2010 Society of Chemical Industry     

Effects of different storage techniques on rupture properties of kiwifruits

Storage of harvested agricultural products under optimum storage conditions is very important for selling them as an intended price in the market and for the maintenance of their quality longer. On the other hand, different storage techniques effects the resistance properties of products. In this research, some rupture properties like, maximum force and bioyield force, stress, maximum energy in maximum force, maximum energy in bioyield point, modulus of elasticity, bioyield deformation, maximum breaking dilatation and minimum damage height, of ‘Hayward’ kiwifruits stored under four different storage conditions (Normal Atmosphere; 21 % O₂ + 0 % CO₂ (NA as Control), NA storage after 1-Methylcyclopropene treatment (1-MCP + NA), NA storage with ethylene control (NA + EC), Controlled Atmosphere storage (2 % O₂ + 5 % CO₂) with ethylene control (CA + EC) and under two different load conditions were evaluated. Both under two load conditions rupture properties of kiwifruits stored under CA + EC conditions were measured higher than other storage conditions. In particular, maximum force and modulus of elasticity values of CA-stored kiwis were found to be statistically important.     

Modeling the Inactivation of <Emphasis Type="Italic">Listeria innocua</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> in Fresh-Cut Tomato Treated with Pulsed Light

The effectiveness of pulsed light (PL) treatments to inhibit microorganisms on fresh-cut tomatoes (Lycopersicon esculentum Mill., cv. Daniela) was investigated. Tomato slices inoculated with Escherichia coli or Listeria innocua were exposed to PL treatments (4, 6, or 8 J cm^?2 fluence) and kept cold at 4 °C for 20 days. L. innocua and E. coli counts, gases in the headspace of the containers (O₂ and CO₂), pH, titratable acidity, and soluble solid content were monitored throughout the cold storage. The PL treatments reduced significantly (p < 0.05) initial loads of both microbes. The effect of the PL fluence on the survival number of microoganisms was described by a log-linear model (R ² = 0.849–0.999). At any fixed time within the cold storing, the microbial counts for untreated samples were always higher than those cut tomatoes that had been previously PL-treated. The behavior of L. innocua and E. coli during the storage were well adjusted (R ² > 0.930) by Gompertzian models; the studied microorganisms exhibited different patterns during the storage period. On the other hand, O₂ and CO₂ partial pressures in containers with fresh-cut tomatoes were also significantly affected by PL treatments (p < 0.05). The highest PL fluence caused the greatest changes of O₂ and CO₂ contents. In addition, the application of PL triggered an acceleration of the O₂ consumption during the cold stage. PL treatments might be used to effectively extend the safety of fresh-cut tomatoes over 12 days of storage against E. coli and L. innocua growth.     

Effects of high oxygen concentration on pro- and anti-oxidant enzymes in peach fruits during postharvest periods

Peach fruits (Amygdalus persica cv. Okubao) were stored in air, controlled atmospheres (CA) of 5% O₂ plus 5% CO₂, or CA with high O₂ concentration (70% O₂ plus 0% CO₂ for 15 days, then in CA with 5% O₂ plus 5% CO₂) at 0 °C, to determine the effects of different O₂ and CO₂ atmospheres on the activities of lipoxygenase (LOX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), as well as malondialdehyde (MDA) content and membrane integrity during storage periods with or without 3 days of post-storage ripening at 20 °C. SOD, CAT and POD activities of the fruits stored in air markedly decreased during the first 30 days of storage, while LOX activity increased after 15 days. CA (5% O₂ plus 5% CO₂) reduced chilling injury, and delayed the reduction of SOD, CAT and POD activities compared to the control. CA with high O₂ treatment induced SOD and CAT activities and maintained membrane integrity, but no significant effect on alleviating chilling injury was found compared to CA storage. The results indicated that the decrease of SOD and CAT might contribute to the development of chilling injury in peach fruits.     

Controlled and modified atmospheres influence chilling injury,fruit quality and antioxidative system of Japanese plums (Prunus salicina Lindell)

Our objective was to compare the effects of controlled atmosphere (CA) and modified atmosphere packaging (MAP) on fruit quality, chilling injury (CI) and pro‐ and antioxidative systems in ‘Blackamber’ Japanese plums. Matured fruit were stored for 5 and 8 weeks at 0–1 °C in normal air, CA‐1 (1% O₂ + 3% CO₂), CA‐2 (2.5% O₂ + 3% CO₂) and MAP (~10% O₂ and 3.8% CO₂). CA was more effective than MAP in retention of flesh firmness and titratable acidity during cold storage. Fruit stored in CA‐1 showed reduced CI and membrane lipid peroxidation after 5 and 8 weeks of cold storage. Low O₂ atmospheres appeared to limit the generation of reactive oxygen species (ROS) and their efficient scavenging through the concerted action of superoxide dismutase and peroxidase. The role of ascorbate–glutathione (AsA–GSH) cycle in the regulation of oxidative stress was also studied during and after storage in different atmospheres. In conclusion, optimum CA conditions delayed fruit ripening and CI through augmentation of antioxidative metabolism and suppression of oxidative processes.     

Effect of hot air treatments on senescence and quality parameters of harvested broccoli (Brassica oleracea L var Italica) heads

Treatments with hot air were applied to broccoli (Brassica oleracea L) florets to investigate the effect on several quality and senescence parameters. To select the optimum treatment, florets were treated with different combinations of time/temperature ranging from 1 to 3 h and 37 to 50 °C and then placed in darkness at 20 °C. Most treatments delayed yellowing and loss of chlorophylls, except those performed at 37 °C, which accelerated senescence. Treatment at 48 °C for 3 h caused the highest delay in chlorophyll loss and was chosen to analyse its effect on quality and senescence. Non‐treated florets showed yellowing and reduced their chlorophyll content during storage. Heat treatment delayed the onset of chlorophyll catabolism by 1 day and slowed down the rate of degradation. Treated florets also showed lower losses of total sugars and proteins and an inhibition of protein solubilisation. Control heads showed an increment in CO₂ production, which was not detected in heat‐treated florets. Total antioxidants decreased and thiobarbituric acid‐reactive substances (TBARS) increased during storage. The treatment delayed the decrease in antioxidant content and inhibited the increment in TBARS. In conclusion, treatment at 48 °C for 3 h delayed broccoli senescence at 20 °C and contributed to maintaining an overall better quality of the product. Copyright © 2005 Society of Chemical Industry     

Impact of controlled atmosphere storage on physiological quality of soybean seed

Soybean seed tends to lose its quality property if kept in inappropriate storage conditions. The aim of this work was to evaluate the effect of different oxygen (O₂) and carbon dioxide (CO₂) partial pressures, combined with different temperatures on the soybean seed physiological potential maintenance. In 2017, seed of the cultivars 8473 RSF and TECIRGA 6070RR were stored for 7 months under: [1] ambient air; controlled atmosphere (CA) with [2] 1 kPa O₂ + 0.04 kPa CO₂; [3] 2 kPa O₂ + 0.04 kPa CO₂; [4] 2 kPa O₂ + 30 kPa CO₂; and [5] 2 kPa O₂ + 80 kPa CO₂. In 2018, seed of NA 5909 RG and FEPAGRO 37RR were stored for 7 months under the following conditions: [1] ambient air; and CA with [2] 1 kPa O₂ + 0.04 kPa CO₂; [3] 1 kPa O₂ + 15 kPa CO₂; [4] 1 kPa O₂ + 30 kPa CO₂; [5] 2 kPa O₂ + 0.04 kPa CO_2. In both years the storage conditions were conducted at three temperatures (20, 25 and 30 °C). The seed were stored with moisture content between 11 and 11.5. The reduction of the O₂ until 1.0 kPa maintained higher germination, however, storage above 25 °C is not recommended. High CO₂ partial pressure did not have additional effects on physiological quality conservation compared to solely low O₂. Seed of 8473 RSF stored at 25 and 30 °C resulted in low germination, regardless of the CA condition. NA 5909 RG reached 80% of germination, when CA was used, regardless of temperature. The ambient air did not maintain the seed physiological quality when stored at 25 and 30 °C and CA may efficiently maintain the physiological quality of soybean seed after 7 months, even in the higher temperature for NA5909 RG, but not for the other cultivars.