Active Modified Atmosphere Packaging Research Articles

Efficacy of active modified atmosphere packaging containing thymol on fortification of antioxidant capacity and reducing the microbial contamination of pomegranate arils

Pomegranate arils pose a significant challenge when it comes to preserving their nutritional value and preventing microbial contamination. This study aimed to explore the impact of thymol fumigation and active modified atmosphere packaging (MAP) on enzymatic activity and microbial contamination prevention in pomegranate arils. The results indicated that arils stored in a high O2 atmosphere (HO2A) with thymol had notably different catalase (CAT) and peroxidase (POD) activity levels compared to other treatments. These arils exhibited the highest CAT activity and the lowest POD activity. The highest phenylalanine ammonia-lyase (PAL) activity was observed in arils stored in HO2A with thymol, although it was not significantly different from those stored in a high CO2 atmosphere (HCO2A) with thymol (P<0.05). Arils stored in a low oxygen atmosphere (LO2A) and HCO2A with thymol showed the highest polyphenol oxidase (PPO) activity levels, while arils in HO2A with thymol had the lowest. The HO2A with thymol treatment resulted in the lowest presence of psychrophilic bacteria, although it was not significantly different from arils stored in LO2A with thymol (P<0.01). Based on cluster analysis results, HO2A with thymol, LO2A with thymol, and HCO2A with thymol could be considered the most effective treatments for extending the storage life of packaged pomegranate arils.

Active Modified Atmosphere Packaging Helps Preserve Quality of Edible Flowers

Edible flowers are becoming increasingly popular as food products, since they give aroma, color, and visual appeal and are also health-promoting compounds. However, they are a highly perishable product, thus post-harvest technologies are needed to extend their marketability. In this study, active (N2: 100%) and passive modified atmosphere packaging (MAP) technologies were applied to three edible flower species, namely Begonia grandiflora ‘Viking’, Tropaeolum majus, and Viola cornuta, stored at 4 °C. Even if the flowers’ quality decay occurred differently according to the species, active MAP better maintained petal colors and slowed down the edible flowers’ decay than passive MAP by decreasing flower respiration in all three species and sugars consumption in begonia; there was weight loss in nasturtium, and better preserved total phenolic content in begonia and viola. Coupling cold storage with active MAP can be an effective method to extend edible flowers’ post-harvest life.

Exploring the feasibility of biodegradable films for antimicrobial absorbent sachets and CO2 emitters as sustainable active packaging

The use of biodegradable polymer films for packaging materials as eco-friendly alternatives to traditional plastics is limited by their water sensitivity and poor gas barrier properties. This study developed a multifunctional supplemental packaging system using poly(butylene adipate-co-terephthalate) (PBAT) and thermoplastic starch (TPS) blend film incorporated with 3% and 5% zinc oxide (ZnO) nanoparticles. The system targets the triple-active packaging displayed antimicrobial activity with water absorption and CO2 emission properties. ZnO incorporation effectively reduced water solubility of the PBAT/TPS film (from 16% to 7%), and exhibited excellent antimicrobial activity against Gram-positive and Gram-negative bacteria (>99% reduction). Well-dispersed ZnO, verified by scanning electron microscopy, decreased water vapor and CO2 gas permeation. A PBAT/TPS-ZnO sachet was fabricated, comprising carboxymethyl cellulose as the absorbent function and CO2 precursors (sodium bicarbonate and citric acid). The 3% ZnO loading achieved optimal performance, balancing water absorption (2.48 g weight gain after 144 h) and CO2 emission (35% in headspace at equilibrium). Kinetic studies suggested diffusion as the dominant mechanism for CO2 release, driven by concentration differences between the sachet and headspace. This system showed potential as active modified atmosphere packaging to extend product shelf life.

Untargeted volatolomic approach for the identification of sensory quality markers of fresh-cut iceberg lettuce stored in modified atmosphere packaging

Fresh-cut iceberg lettuce is appreciated by consumers for its nutritive properties, convenience, and ease of use. Producers are then pushed to preserve the quality of these products by using modified atmosphere packaging (MAP). In this study, the influence of passive MAP (air) or active MAP (1–5 % O2), on several quality attributes of fresh-cut iceberg lettuce samples was evaluated during storage time (from 3 to 14 d) at 4 °C. The respiration rate and the electrolyte leakage values of samples packaged in active MAP were higher than those of fresh-cut iceberg lettuce stored in the air, indicating stressful storage conditions. Inverse trends were observed for O-quinones content and browning index until the end of the storage period. Sensory analysis highlighted that active MAP has preserved the visual quality, limiting the browning of the cut surfaces. On the other hand, active MAP modified the sensory profile after 3 d at 4 °C, and samples scored below the marketability limit for both odor and off-odor. Finally, a volatile organic compound characterization by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC–MS) allowed the identification of target molecules that could signal a decrease in food quality under different conditions. A total of 118 compounds were identified and, among them, ethyl alcohol and acetaldehyde were identified as the best quality markers for passive MAP and active MAP samples, respectively, while ethyl acetate could represent a good compromise to assess the quality of fresh-cut iceberg lettuce, regardless of MAP conditions.

Ready-to-use broccoli raab (Brassica rapa L. subsp. sylvestris) quality and volatilome as affected by packaging

Broccoli raab (Brassica rapa L.) is a cruciferous vegetable primarily grown in the southern regions of Italy. Distinguished from the more common broccoli head (B. oleracea), its edible parts consist of sprouts, buds, younger stems, and leaves. Considering the high perishability of broccoli raab, it is necessary to apply postharvest technologies to make it a ready-to-use product. In this paper, active modified atmosphere packaging (aMAP, closed at 3% O2 and 97% N2) was applied, in combination with two types of packaging materials (polypropylene/polyamide microperforated, PP/PA MF, and polypropylene, PP). Shrink-wrap packaging and air-storage were included as control measures. The purpose was to assess the effects of different packaging conditions on enhancing knowledge about volatile compound development and quality aspects of the produce. Both packaging materials resulted in a 10% accumulation of CO2, combined with 1% O2 for PP bags and 10% for PP/PA. Different gas mixtures led to varied sensory and volatile development in minimally processed broccoli raab during storage. PP exhibited the lowest odor score (1.2, well below the marketability limit) and the highest concentrations of off-odor-related volatile compounds (ethanol, acetaldehyde, dimethyldisulfide, dimethyltrisulfide, and methanethiol) while samples packed in PP/PA MF reached an intermediate odor score with superior visual quality evaluation up to 12 days of storage. Both packaging materials reduced weight loss compared to control samples, up to less than 2% and 6%, respectively. In conclusion, active MAP using PP/PA MF bags demonstrated the best suitability in maintaining broccoli raab quality, with a final gaseous composition of 10% O2 and 12% CO2 deemed optimal for storage.

Evaluation of modified atmosphere packaging system developed through breathable technology to extend postharvest life of fresh muscadine berries.

Muscadine grapes (Vitis rotundifolia Michx.) are delicate in nature with short shelf life. Postharvest technologies like modified atmosphere packaging (MAP) with reduced oxygen (O2) and elevated carbon dioxide (CO2) could increase the postharvest storage life with better quality. In the current experiment, physical and biochemical quality attributes of black and bronze cultivars of muscadine grapes ('Supreme' and 'Granny Val', respectively) were evaluated in active MAP. Fruit were packed in plastic trays, sealed with impermeable film, and CO2 was introduced into the package. The MAP was created by a rigid microperforated plastic patch coated with a proprietary semipermeable resin, which was applied over a hole in the tray; packages with the same size hole without a patch were the control. Fruit were stored at 4°C for 42 days (6 weeks). MAP resulted in significantly lower decay incidence and better retention of fruit firmness for up to 28 days of storage in both cultivars as well as reducing color changes in 'Supreme' fruit. Although MAP did not affect the biochemical quality of muscadine grapes, total antioxidants increased initially and then decreased during storage, irrespective of packaging treatments. A significant linear increase in total phenolic content was also found during storage, regardless of treatments applied. Overall, the results of the current study demonstrate that MAP can be an affective technology to increase storage duration of muscadines with better retention of physical quality, without affecting the biochemical attributes.

Effects of Storage in an Active and Spontaneous Controlled O2/CO2 Atmosphere on Volatile Flavor Components and the Microbiome of Truffles.

This study explored the potential to improve the storage quality and prolong the shelf life of truffles by storing them in a modified atmosphere fresh-keeping box with sealed gas components of Active Modified Atmosphere Packaging (AMAP, 40% O2 + 60% CO2) at 4 °C. During the storage period, a total of 63 volatile components in 10 categories were detected, with aldehydes being the most abundant and the relative content of ethers being the highest. The relative odor activity value and principal component analysis revealed that isovaleraldehyde, 1-octen-3-ol, 1-octen-3-one, and dimethyl sulfide were the characteristic flavor components of fresh truffles. However, 3-methylthiopropionaldehyde and (E, E)-2,4-nonadienal were the components that caused the deterioration of truffle flavor and could potentially serve as markers of truffle decay characteristics. 16S rDNA high-throughput sequencing showed that Leuconostoc and Lactococcus were dominant in the truffle samples stored for 14 days, but the abundance of putrefactive pathogenic bacteria showed an increasing trend in the truffle samples stored for 28 days. During the whole storage period, the common fungi detected in the different treatment groups were Candida and Aspergillus. The relative abundance of the former decreased, while the relative abundance of the latter decreased initially and then increased. The correlation between volatile components and the microbial flora was further analyzed, which indicated that Lactococcus and Lactobacillus had the same contributions to the same flavor, while Pseudomonas and Glutamicibacter had the opposite contributions to the same flavor. The results provide a reference for the storage and preservation of truffles.

Preserving freshness and nutrients: the impact of passive and active modified atmosphere packaging on ready-to-eat orange (var. Navel) segments

Preserving freshness and nutrients: the impact of passive and active modified atmosphere packaging on ready-to-eat orange (var. Navel) segments

Preserving freshness and nutrients: the impact of passive and active modified atmosphere packaging on ready-to-eat orange (var. Navel) segments

Preserving freshness and nutrients: the impact of passive and active modified atmosphere packaging on ready-to-eat orange (var. Navel) segments

Hurdle approach for enhancing storage life of minimally processed apple slices using active modified atmosphere packaging

Hurdle approach for enhancing storage life of minimally processed apple slices using active modified atmosphere packaging

A new strategy to design novel modified atmosphere packaging formulation maintains the qualities of postharvest strawberries (Fragaria ananassa) during low‐temperature storage

AbstractFor fresh foods, the purpose and benefits of modified atmosphere packaging (MAP) generally include the preservation of antioxidants, the extension of shelf life, deferral of microbial spoilage, and retention of product color. Commercial MAP products frequently involve a mixture of nitrogen, oxygen, and carbon dioxide, affecting consumer acceptability, cost‐effectiveness, and hygienic food safety issues. This study investigated a novel active MAP formulation for strawberries in retail packaging which ensures changes in quality‐related physicochemical characteristics [including hardness, moisture, vitamin C, total soluble solids (TSS), titratable acid, and appearance] during low‐temperature storage, whereas samples of different storage times were assessed for shelf life by sensory evaluation. The innovative active MAP formulation of 0.8 g of sodium ascorbate, 2.6 g of sodium carbonate, and 1.6 g of ferrous sulfate achieved atmosphere equilibrium in packaged strawberries in <48 h, compared to 5–6 days in the control group. Strawberries treated with active MAP maintained their moisture, firmness, vitamin C, TSS, and titratable acid contents better than the control group (p < 0.05). The strawberries showed softening and waterlogging of tissue and 50% moldiness by the 14th day, while the control group lost commercial value by the 8th. New applications of similar commodities in food are unavailable based on current knowledge. Therefore, the scope of fresh food applications covered in this study and the refinement of other functions will be helpful directions for future research.

Combined effects of ethylene scavenging‐active packaging system and modified atmosphere to reduce postharvest losses of ethylene sensitive produce: Banana and kiwifruit

AbstractEthylene scavenging‐active packaging is getting more interest to reduce postharvest losses of ethylene‐sensitive produce to overcome the limitations of traditional postharvest technologies. The aim of this study is to monitor behaviour of ethylene‐sensitive products to different ethylene scavenging systems combined with modified atmosphere packaging (MAP). Banana (Musa paradisicum L. var. Anamur) and kiwi (Actinidia deliciosa L. var. Hayward) were packaged with low‐density polyethylene (LDPE) bags containing ethylene scavenging sachet and ethylene scavenging‐active LDPE bags. Only passive MAP was used for bananas stored at 13°C for 12 d. Both passive and active MAP (5% O2, 5% CO2) were used for kiwi stored at 4°C for 30 d. LDPE bags with no ethylene absorber and unpackaged produces were the control groups. O2, CO2 and ethylene concentrations, mass loss, texture, colour, TSS %, titratable acidity and sensory analysis were performed during storage. O2% in the control LDPE bags decreased below 2% on 6th d, while LDPE bags containing sachet and active LDPE bags remained above critical O2 level for bananas during the entire storage. The lowest ethylene concentration was 0.45 μl L−1 in both active systems on 12th d. Equilibrium atmosphere was maintained in active and passive MAP after 5th d for kiwifruit. The lowest ethylene concentrations were determined as 0.47 μl L−1 and 0.50 μl L−1 in the sachet included LDPE and active LDPE, respectively under passive MAP at the end of the storage. In conclusion, bananas packaged with both active systems were acceptable for 9 d considering physicochemical and sensory properties. The kiwifruit was acceptable for 30 d using both ethylene absorbing systems under passive MAP.

Mathematical modeling of modified atmosphere package/LDPE film combination and its application to design breathing cylinders for extending the shelf life of green asparagus

BackgroundThe O2 levels in food packaging systems play an essential role in the deterioration of food quality and shelf life. Modified atmosphere packaging (MAP) supports the storage of fresh and processed foods by inhibiting chemical and physical changes while reducing the deterioration caused by microorganisms.Materials and methodsThis study established and validated the equations for the relationship between MAP formulation reagents, asparagus respiration, permeability of packaging film, and rates of O2 and CO2 mass transfer in which different interactions occur and affect each other.ResultsThe resulting atmosphere of packaging was determined to be the key to achieving the MAP benefits. The active MAP formulations developed in this study were combined with very-low-density polyethylene films to store green asparagus spears. During storage, the combined films effectively maintained the firmness of green asparagus spears, fiber, and vitamin C content, and outperformed the passive MAP and control groups. The above results confirm all the equations in the passive and active MAP systems established in this study.ConclusionsHence, maintaining the asparagus quality with an active MAP treatment will reduce economic loss and possibly provide new insights into applying active MAP retail packages to preserve fruits and vegetables in post-harvest shelf life.Graphical

Combination of 3’,4’,5,7-tetrahydroxy isoflavone and active modified atmosphere packaging inhibits yellowing, maintains quality, and prolongs shelf life of fresh peeled water chestnuts (Eleocharis dulcis)

Yellowing and quality loss shorten the shelf life of fresh peeled water chestnuts (FPWCs). The purpose of this study was to elucidate the mechanism by which the combination of 3’,4’,5,7-tetrahydroxy isoflavone (3’,4’,5,7-THIF) and active modified atmosphere packaging (AMAP) prolonged the shelf life of FPWCs. FPWCs were treated with 1.0% 3’,4’,5,7-THIF, AMAP (18.3% O2, 81.7% N2), and a combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2). The yellowing extent, mass loss rate, enzymatic activities, yellowing substance concentrations, quality, and microorganisms of FPWCs were analyzed. The results showed that the three treatments all inhibited the increase in the mass loss rate and activity of peroxidase and lowered the eriodictyol concentration. AMAP (18.3% O2, 81.7% N2) and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) inhibited the respiration of FPWCs and increased the total soluble solids, titratable acidity, and ascorbic acid concentrations. The three treatments had no significant effects on the activities of polyphenol oxidase and phenylalanine lyase and naringenin concentration. 3’,4’,5,7-THIF (1.0%), AMAP (18.3% O2, 81.7% N2), and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) prolonged the shelf life of FPWCs by 6, 6, and 12 d, respectively. The combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) was optimal among the three treatment methods. These results suggested that the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) might be used to extend the shelf life of FPWCs in practice.

Preparation and characterization of CO2/O2 selective facilitated transport films by coating polyvinyl alcohol/polyethylene glycol/aminated sodium lignosulfonate on TiO2/ZnO‐modified LDPE

AbstractA novel facilitated transport film was prepared by coating polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/aminated sodium lignosulfonate on TiO2/ZnO‐modified low‐density polyethylene (LDPE). Monoethanolamine (MEA), diethanolamine (DEA), ethylenediamine (EDA), diethylenetriamine (DETA), tetramethylpiperidine amine (TEMP), and acrylamide (AM) were selected to modify sodium lignosulfonate (Ls) for enhancing the selectivity and permeability of CO2/O2. The fabricated Ls were characterized by fourier transform infrared (FTIR), thermogravimetric test (TG), and scanning electron microscopy (SEM). The CO2 permeability and CO2/O2 selectivity were improved with the increase in the amount of amine groups. Compared with the addition of Ls modified by alcohol amine, the composite film has higher selectivity to CO2 after the addition of DETA‐Ls or TEMP‐Ls. The selectivity of the 1:3:3EDA/MEA‐Ls‐g‐AM composite film reached 13.7, and CO2 permeability increased by 5.54 times. The storage test also demonstrated that the composite films have better freshness retention ability. As a result, modified LDPE coated by PVA/PEG/aminated Ls has the potential as an active modified atmosphere packaging material.

Modified atmosphere packaging with chitosan coating to prevent deterioration of fresh in-hull Badami’s pistachio fruit

BackgroundFresh in-hull pistachio fruits are very perishable and hence have a limited storage life, with marketers and customers wishing for a longer shelf life. The present research was performed to explore the combined effects of different packaging conditions (ambient atmospheric condition, and passive- and active-modified atmosphere packaging) as well as chitosan coating (0, 1, and 1.5%w/v) on postharvest quality of fresh in-hull pistachios stored at 5 °C and 85–90% relative humidity for 45 days. The efficacy of treatments in prolongation of pistachio fruit shelf life was evaluated by determining weight loss, kernel firmness, acid (AV) and peroxide values (PV), mold and yeast count, aflatoxin content, and hull color parameters (L*, a*, b*, C*, h°, and BI) at 0, 15, 30 and 45 days of storage. In addition, O2 and CO2 concentrations in MAP headspace were monitored.ResultsBy applying high molecular weight chitosan coatings and MAP conditions, PV and AV values, microbial growth, aflatoxin B1 production, and weight loss values were inhibited, as well as kernel firmness reduction and hull color deterioration during storage were controlled. Active-MAP treatments in most cases performed better than passive-MAP treatments in this regard (P < 0.05). Combining chitosan coating with MAP demonstrated additive synergistic effects. At the end of storage, 1.5% chitosan-coated treatment under active-MAP maintained firmness (87% of the control treatment), hull lightness (76% of the control treatment), and microbial count (similar to the control treatment). It also maintained minimum weight loss (6.39%), acid (0.91 meq O2 kg−1 oil) and peroxide (0.49 goleic acid/100 goil) values compared to other treatments, proving that chitosan coating combined with MAP was more effective in preserving pistachio quality parameters. The equilibrium O2 and CO2 levels of passive-MAP treatments were maintained at higher values than those of active-MAP treatments which indicated that passive-MAP treatments had higher respiration rates than those of active-MAP treatments during storage.ConclusionsThe results revealed that applying the combination technique of MAP and chitosan coating effectively preserved the quality attributes and lengthened the shelf life of fresh in-hull pistachios. Therefore, it could potentially be commercialized as a new approach for future industry application.Graphical

Viability of sublethally injured indicator and pathogenic coliform bacteria on fresh-cut cabbage during storage in an active MAP of 10% CO2.

Shredded cabbage treated with either tap water or electrolyzed water was stored in an active modified atmosphere packaging (MAP) of 10% CO2 for 5 d at 10℃, 7 d at 5℃, and 8 d at 1℃ to evaluate the occurrence and viability of sublethally injured coliform bacteria. The CO2 and O2 concentrations in the packages approached an equilibrium of 10% CO2 and 10% O2 during storage at all temperatures tested. Coliforms in shredded cabbage increased during storage at all three temperatures, with the increase being greater at 10℃. Sublethal injury at 65% to 69% for the coliforms was detected only on cabbage samples treated with electrolyzed water and stored at 5℃ for 4 and 7 d. Enterobacter cloacae was one of the injured species of coliform bacteria in shredded cabbage. Shredded cabbage was inoculated with chlorine-injured Escherichia coli O157:H7 and stored at 5℃ for 6 d in an active MAP of 10% CO2. Counts of E. coli O157:H7 remained almost constant during storage, and injured E. coli O157:H7 ranging from 50% to 70% were found on shredded cabbage throughout the storage period. These results indicate that sublethally injured indicator and pathogenic bacteria would be found on fresh-cut cabbage in the realistic MAP storage at 5℃.

Active and Intelligent Packaging for Enhancing Modified Atmospheres and Monitoring Quality and Shelf Life of Packed Gilthead Seabream Fillets at Isothermal and Variable Temperature Conditions.

The study investigated the effect of active modified atmosphere packaging (20% CO2–60% N2–20% O2) with CO2 emitters (MAP-PAD) and conventional MAP (MAP) on the quality and shelf-life of gilthead seabream fillets during chill storage, while the most appropriate enzymatic Time Temperature Integrators (TTI) were selected for monitoring their shelf-life at isothermal and variable temperature storage conditions (Teff = 4.8 °C). The concentration of CO2 and O2 in the headspace of the package, volatile compounds and of the microbial population were monitored during storage. The kinetic parameters for bacterial growth were estimated at 0–10 °C using the Baranyi growth model. The MAP-PAD samples presented significantly lower microbial growth rates and longer lag phases compared to the MAP samples, leading to significant shelf-life extension: 2 days of extension at 2.5 °C and 5 °C, while 50% extension at variable conditions (Teff = 4.8 °C). CO2 emitters in the package improved the chemical freshness (K-values) and volatile compounds (characterizing freshness). The responses of different enzymatic TTI were modeled as the function of enzyme concentration, temperature and storage time. The activation energy (Ea) ranged from 97 to 148 kJ mol−1, allowing the selection of appropriate TTIs for the shelf-life monitoring of each fish product: LP-150U for the MAP and M-25U for the MAP-PAD samples. The validation experiment at Teff = 4.8 °C confirmed the applicability of Arrhenius-type models, as well as the use of TTIs as effective chill chain management tools during distribution and storage.

Microbiology and Quality Attributes of ‘Pione’ Grapes Stored in Passive and Active MAP

The quality of ‘Pione’ grapes was evaluated during passive and active modified atmosphere packaging (MAP) storage. In the passive MAP study, ‘Pione’ grapes were packaged in two types of films with an oxygen transmission rate (OTR) of either 440 mL/m2/d/atm (low OTR) or 1250 mL/m2/d/atm (high OTR) and stored at 25 °C or 10 °C. When the CO2 concentration in low and high-OTR films stored at 25 °C reached 10% and 3%, respectively, on day 2, grape berries showed lower bacterial counts in the low-OTR films than in the high-OTR films. At 10 °C, the packages approached an equilibrium of 12% CO2 in low-OTR films and 7% CO2 in high-OTR films during 8 days of storage, and no difference was observed in the bacterial counts between the two films. In an active MAP study, ‘Pione’ grapes were stored in low-OTR (440 mL/m2/d/atm) and high-OTR (1170 mL/m2/d/atm) films flushed with air or high CO2 (10%, 20%, and 30%) at 10 °C for 8 days. The CO2 concentration in active MAP with low-OTR films reached approximately 20% by the end of storage, while that with high-OTR films approached an equilibrium of 10% CO2 after 4 days of storage. The bacterial counts remained below the limit of detection until 4 days of storage in active MAP with high-OTR films. Although the fungal counts of berries were non-detectable or below the limit of detection in all active MAPs, Alternaria and Candida fungi and Chryseobacterium and Cutibacterium bacteria were found in the berries stored in active MAP. The firmness, soluble solid content, and surface color of the berries were not affected, regardless of the film type, in both passive and active MAP, and rachis browning due to high-CO2 injury was not observed in any samples in active MAP. These results indicate that passive MAP with low-OTR films or active MAP of 10–20% CO2 with high-OTR films at 10 °C were the optimum packing systems for ‘Pione’ grapes to control the physical and microbiological quality without high-CO2 injury, such as rachis browning.

Production and Postharvest Assessment of Tropical Pumpkin Flowers Harvested for Consumption

Consumption of staminate (male) flowers of squash and pumpkin (Cucurbita sp.) has generally been limited to summer squash (Cucurbita pepo), a species of temperate regions or highland tropical environments. In the lowland tropics of the Caribbean Basin, tropical pumpkin (Cucurbita moschata) is better adapted and more widely grown. We evaluated flower production in Lajas, Puerto Rico, and postharvest attributes (shelf life, chemical and nutritional properties, sensory quality) of flowers of four tropical pumpkin and two summer squash cultivars. Tested cultivars varied slightly among experiments. Passive and active modified atmosphere packaging (MAP) were compared. For passive MAP, packages were sealed without further intervention. Under active MAP, packages were adjusted to 6% to 7% oxygen (O2) and 12% to 13% carbon dioxide (CO2) during sealing. Sensory quality of fresh and canned tropical pumpkin flowers was evaluated by panelists. Production ranged from 1.8 to 4.0 flowers/plant per day. Flower weight and length were up to 50% greater in tropical pumpkin compared with summer squash. Packaged flowers turned more orange but with less color saturation as they aged. In active MAP packages, decreases in O2, and increases in CO2 observed after 5 days were small or not significant compared with initially established atmospheres at day 0. Storage temperature generally had no effect on changes in O2 and CO2. Packaged flowers lost about 27% of their initial weight after 5 days. Type of MAP had no consistent effect on the appearance of packaged flowers. Storing flowers at 5 °C often improved appearance compared with storage at 10 °C. The rate of deterioration was slower in packaged flowers of tropical pumpkin compared with summer squash, but by day 6 the poor appearance of flowers of all cultivars made them unmarketable. Compared with fresh flowers, packaged flowers stored for 5 days exhibited a decrease in soluble solids, total acidity, ascorbic acid, antioxidant capacity, and total phenolics, and generally an increase in pH. Beta-carotene often increased in stored flowers although this varied by cultivar. Storage temperature and type of MAP had inconsistent effects on chemical attributes of stored flowers. Panelists rated fresh flowers as “like moderately” to “like very much” for texture, taste, and overall acceptability, whereas canned flowers were rated as “like moderately” for overall acceptability. Male flowers of tropical pumpkin are suitable for human consumption but deterioration after 5 days of storage limits their market potential unless better packaging methods are developed. Canned tropical pumpkin flowers may be an alternative to packaged flowers.