Passive Modified Atmosphere Packaging Research Articles

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.

Efficacy of active and passive modified atmosphere packaging on quality preservation and storage life of pomegranate fruit and arils: A review

Pomegranate has nutritional value and health benefits due to its bioactive compounds and antioxidant properties. Fruit consumption is strongly recommended due to its high content of vitamins, fiber, minerals, and polyphenols. Supplying ready-to-eat pomegranate can be a beneficial technique to increase consumption with regard to its nutritional properties. However, maintaining nutritional quality and preventing microbial spoilage is a major challenge. Fruit quality is lost with visible symptoms such as weight loss, shriveling, husk scald, chilling injury, fungal rot, aril color degradation, and off-flavor during long-term storage. Therefore, it is very important to use appropriate strategies to maintain pomegranate whole fruit and aril quality. Gases around the product create a suitable environment for oxidative reactions and aerobic microorganism growth. Therefore, changing the atmosphere around the product can help maintain its quality. One of the effective methods to increase the postharvest life of products is to use modified atmosphere packaging (MAP), which reduces microbial spoilage and chilling injury, preserves the quality, and extends the shelf life by reducing the respiration rate. Modified atmosphere packaging, which uses natural atmospheric components (O2, CO2 and N2), has been widely accepted due to the lack of toxic residues on the product. This review discusses on recent research in terms of MAP application on quality properties and postharvest life of pomegranate fruit and arils during storage.

Effect of modified atmosphere package on attributes of sweet bamboo shoots after harvest.

Tender bamboo shoots undergo rapid senescence that influences their quality and commercial value after harvest. In this study, the tender sweet bamboo shoots ('Wensun') were packed by a passive modified atmosphere packaging (PMAP) to inhibit the senescence process, taking polyethylene package as control. The increase in CO2 and the decrease in O2 gas concentrations in the headspace atmosphere of the packages were remarkably modified by PMAP treatments. The modified gas atmosphere packaging inhibited the changes in firmness, as well as the content of cellulose, total pectin, and lignin in the cell walls of bamboo shoots. The enzymatic activities of cellulase, pectinase, and polygalacturonase that act on cell wall polysaccharides, and phenylalanine ammonia lyase, cinnamyl alcohol dehydrogenase, peroxidase, and laccase regulating the lignin biosynthesis were modified by PMAP treatment different from control during storage. The expression levels of the lignin biosynthesis genes PePAL3/4, PeCAD, Pe4CL5, PeC4H, PeCCOAOMT, PeCOMT, cellulose synthase PeCESA1, and related transcription factors PeSND2, PeKNAT7, PeMYB20, PeMYB63, and PeMYB85 were clearly regulated. These results suggest that PMAP efficiently retards the changes in lignin and cell wall polysaccharides, thus delaying the senescence of tender sweet bamboo shoots during storage.

Effect of modified atmosphere packaging on quality of minimally processed fenugreek (Trigonella foenum-graecum L.) microgreens

Fenugreek (Trigonella foenum-graecum L.) microgreens is an underutilized vegetable with limited shelf life having good source of antioxidants, carotenoid as well as vitamins. The study deals with nutritional quality and optimization of a suitable passive modified atmosphere packaging (MAP) for improving the shelf life of fenugreek microgreens in its minimally processed form (MPFM) at 8oC Semipermeable plastic films viz., low density polyethylene, polypropylene, Cryovac PD 961® and stretchable PVC cling film with varying thickness were evaluated as packaging materials to obtain different MAP composition inside MPFM packages. Packaging of MPFM in 40 μm thick polypropylene film resulted in development of in-pack equilibrium MA with 10-14% oxygen and 5-8% carbon dioxide during storage. This in-pack MA maintained ‘fresh-like’ sensory properties, biochemical and nutritional quality in MPFM till 15 days of storage. Significant loss of B vitamins was recorded in all packages during low temperature storage. Packaging in 40 μm thick polypropylene film retained B vitamins significantly better than other semipermeable films. Low temperature storage in modified atmosphere conditions enhanced vitamin E content in MPFM. The outcome of the study will benefit the entrepreneurs and retailers for distant transport and storage of fenugreek microgreens in commercial open chillers maintained in supermarkets in their ready-to-cook form.

Coupling dynamics of respiration, gas exchange, and Pseudomonas fluorescens growth on fresh-cut cucumber (Cucumis sativus L.) in passive modified atmosphere packing

This study established microbial growth models for fresh-cut cucumber packaged with different O2 transmission rate (OTR) films. Biaxially oriented polyamide/low-density polyethylene (BOPA/LDPE) film (Ⅰ: OTR5, Ⅳ: OTR48) and polyethylene (PE) film (Ⅱ: OTR2058, Ⅲ: OTR3875) were used to construct a passive modified atmosphere packaging (MAP). Mathematic models have been established to account for dynamic variations in the O2/CO2 concentration and their impacts on Pseudomonas fluorescens growth. The coupling models included: 1) respiration models of cucumber and P. fluorescens based on Michaëlis-Menten equation, 2) coupling gas exchange models based on Fick’s law that contained models of P. fluorescens growth and respiration, 3) coupling microbial growth models contained respiration and gas exchange models. Coupling model with Baranyi function successfully fitted variations of O2/CO2 concentration and P. fluorescens growth in the two packaging. In addition, quality properties of packed fresh-cut cucumber were determined. The film Ⅳ (OTR48) as a high barrier film showed the highest inhibition of P. fluorescens growth, adequately retained its colour, firmness and total soluble solid (TSS) concentration in contrast to the PE films packaging. The constructed coupling models can be utilized for assessing the shelf life and microbial growth of fresh-cut vegetables with spoilage dominated by pseudomonads.

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.

Effects of Ultrasonication and Modified Atmosphere Packaging on the Physicochemical Characteristics and Quality of Ready-to-Eat Pomegranate Arils

The demand for ready-to-eat pomegranate arils has increased due to the high nutritional value and quality of this valuable fruit. However, the shelf life of arils is short. Therefore, we examined the effect of ultrasonication treatment (35 kHz power) for varying times (5, 10, and 15 min) at 25 °C, and their combination with different packaging types, i.e., vacuum and passive modified atmosphere packaging (passive MAP), on the physical, chemical, and sensory properties of pomegranate arils. The results showed that the combined treatment of ultrasonic and vacuum packaging leads to improving pomegranate arils’ quality and shelf life. The treatments significantly reduced weight loss (30%) and decay (16%) compared to the control. At the end of the storage time, the lowest bacterial count (0.25 log CFU/g) and the lowest yeast and mold count (0.37 log CFU/g) were obtained in ultrasound-treated arils for 15 min that were vacuum packed. In addition, they preserved the total soluble solids, titratable acidity, antioxidant capacity, phenolic compounds, and anthocyanin, leading to improving the organoleptic properties of arils. However, in terms of taste and overall quality, greater scores were recorded by panelists in vacuum-packed arils than in passive MAP. Overall, arils that were treated with ultrasound for 10 min and then vacuum packed had the best results compared to the control and other combination treatments.

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

Improvement of shelf-life of cherry (Prunus avium L.) by combined application of modified-atmosphere packaging and antagonistic yeast for long-distance export.

The last decade has seen a growing interest in reducing the use of chemical fungicides for postharvest decay control. In the research for new, safe alternatives, the combined application of biocontrol agents and passive modified-atmosphere packaging (MAP) has been shown to be a promising strategy to extend fruit quality. Therefore, the aim of this work was to evaluate the effect of the combined application of MAP and two antagonistic yeasts, Metschnikowia pulcherrima L672 and Pichia kudriavzevii PK18, on sweet cherry shelf life. Microbiological, physico-chemical, and quality fruit analysis from batches treated with antagonistic yeast were compared with a control batch without yeast application and a batch to which fludioxonil (Scholar®) was applied. The composition of the atmosphere and physico-chemical traits showed similar values among the different batches during cold storage. However, interestingly, the combination of MAP with the antagonistic yeasts M.pulcherrima L672 and P.kudriavzevii PK18 increases the control of microbiological spoilage with results comparable to the application of fludioxonil. In addition, these batches experienced a slight decrease in volatile compounds associated with fresh fruit aroma, whereas in the control batch an increase of altered fruit aromas was observed. The same effect of control of spoilage was observed during the shelf life period. These results showed the positive effect of the combination of antagonistic yeasts and MAP, obtaining similar results in terms of control of microbiological spoilage and physico-chemical quality compared with the application of fludioxonil. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Fabrication and design of poly(l‐lactic acid) membrane for passive MAP packaging of Brassica chinensis L

PLDx L copolymers were synthesized from physically stable rigid poly(l-lactic acid) (PLLA) and a few different molecular weights of polydimethylsiloxane (PDMS) to increase the O2 and CO2 permeabilities of PLLA films and make them acceptable for packaging highly respirable products. The effect of PDMS on the morphology, mechanical properties, and gas permeability of PLDx L was investigated. Copolymers showed approximately 10 times the fracture strain and 1.7 times the CO2 and O2 permeabilities of neat PLLA. Additionally, PLDx L maintained an increased CO2 /O2 perm-selectivity consistent between 5 and 40°C. Passive modified atmosphere packaging of Brassica chinensis L was developed to assess the membrane's impact on headspace gas inside the package. The results showed that poly(amide)/poly(ethylene) packaging with 48cm2 PLD1.8 L membrane as a breathing window can provide 50g B. chinensis L. with a healthy atmosphere of 3%-8% O2 and 5%-8% CO2 between 6 and 22 days. Vegetables packaged in PLD1.8 L had the lower respiration rate, lower nitrite contents, and less proliferation of microorganisms. Moreover, a suitable atmosphere kept vegetables with higher ascorbic acid and a good appearance after more than 2 weeks of storage at 5°C. PRACTICAL APPLICATION: The permeability of the PLLA-based membrane can be adjusted for the breathable window membrane of sealed fresh products. In the future, several types of film could be developed to match the respiratory and metabolic characteristics of different kinds of products. Such PLLA-based specialized membranes can refine the fresh-keeping function and be more attractive to the customer.

An innovative approach for maintaining the quality of pink tomatoes stored at optimum and above-optimum temperatures using a microporous membrane patch

This study evaluated the effect of passive modified atmosphere packaging (MAP) using BreatheWay® technology on the postharvest quality of pink tomatoes (Solanum lycopersicum L. cv. ‘BHN 589’) when stored at optimum and above-optimum temperatures. Pink tomatoes were packaged in MAP or perforated trays and stored at the optimum temperature of 12.5 °C or at 21 °C, for 35 or 21 days, respectively. MAP significantly delayed ripening and maintained quality at both temperatures. The tomatoes in MAP demonstrated decreased electrolyte leakage, firmer fruit as well as slower color development and lycopene accumulation. Fruit in MAP had more β-carotene but there was no effect on ascorbic acid. However, the control tomatoes stored at 21 °C demonstrated higher antioxidant capacity and total phenols. Overall, tomatoes in MAP maintained higher overall quality compared to the air control and demonstrated a shelf life extension of approximately 5 days at 12.5 °C and 3 days at 21 °C.

Combined effect of UV–C and passive modified atmosphere packaging to preserve the physicochemical and bioactive quality of fresh figs during storage

Figs are an important constituent of the Mediterranean diet, widely consumed fresh. Due to their very short shelf life, postharvest techniques to preserve quality and safety should be implemented. The current work aimed to study the combined effect of a postharvest UV–C treatment (5 or 10 kJ m−2) followed by packaging under passive modified atmosphere (MAP) on physicochemical and bioactive quality of fresh figs (cv. ‘Colar’) stored up to 12 d at 0 ºC (90–95% RH). As controls, UV–C untreated and air-stored (AIR) samples were used. The flesh firmness, skin colour, soluble solids content (SSC), titratable acidity (TA), pH, total phenolic content and total antioxidant activity were monitored. The steady-state modified atmosphere reached since day 8 was 17 kPa CO2 and 4 kPa O2. UV-C treated samples did not show visual decay incidence, while mycelial growth was observed in untreated figs on day 12. Figs treated with 10 kJ m-2 UV–C and stored under MAP conditions showed the highest flesh firmness with values of 0.6 N, which is 50% higher than in AIR. Skin darkening observed among samples was higher in 10 kJ m-2 with Chroma decreases of 2.6 units on day 12 under MAP, although panellists preferred this treatment according to its visual appearance. Higher SSC and TA differences were found in UVC-treated samples during storage. Moreover, 10 kJ m-2 UV–C and MAP induced the highest total phenolic content accumulation, with 260% and 540% higher values from day 4 to day 12 for skin and flesh, respectively. In conclusion, a 10 kJ m−2 UV–C treatment after harvesting followed by packaging under MAP conditions may be considered a good tool to preserve the physicochemical and bioactive quality of fresh figs during 12 d at 0 ºC.

New passive modified atmosphere packaging to extend peaches shelf life at ambient temperature to reduce economic losses

PurposeHoney peaches are rich in a variety of vitamins and are well known in China as the queen of fruit. However, as highly climacteric fruit, peach is too easy to affect its economic value. In this paper, a new passive modified atmosphere packaging system was proposed to solve the lack of water vapour removal capacity – which is still the technical bottleneck of passive modified atmosphere packaging. This paper aims to address this issue.Design/methodology/approachUnder the conditions of relative humidity 85−90% and temperature 28°C−38°C, the influence of new passive modified atmosphere packaging on the shelf life and quality of 70% ripe peaches was studied in the paper. The effect of the new passive modified atmosphere packaging (PMAP) on fruit appearance, colour, taste, flavour, soluble solids, Vitamin C and titratable acid was investigated.FindingsRegardless of whether 1-Methylcyclopropene is added or not, the research results show that the new PMAP has a significant effect on extending the shelf life and maintaining the quality of peaches. Compared with the control group, the shelf life of peaches treated with modified atmosphere packaging and 1-Methylcyclopropene was prolonged by 7 and 11 days, increasing the retailer's revenue by 44 and 75%.Originality/valueA new integrated structure, which is composed of two types of films with high oxygen and high water vapour permeability was designed for the retail of peaches at room temperature. The former was mainly responsible for regulating the concentration of O2 and CO2, while the latter was for removing water vapour and regulating the relative humidity in PMAP.

Effects of Passive Modified Atmosphere Packaging on Physico-Chemical Traits and Antioxidant Systems of ‘Dottato’ Fresh Fig

Fig is a very perishable fruit with short postharvest life. Low-cost postharvest techniques should be employed to reduce fresh fig postharvest losses. The purpose of this study was to design a passive modified atmosphere packaging (PMAP) to extend the shelf-life of fresh ‘Dottato’ figs stored at 4 °C for 21 days. Physico-chemical traits and enzymatic and non-enzymatic antioxidant systems were evaluated. Storage in PMAP reduced the losses of fruit weight as well as maintained physico-chemical traits and nutraceutical traits such as polyphenol and flavonoid contents and the antioxidant activity in fresh figs. PMAP reduced oxidative stress, inducing the activities of antioxidant enzymes such as ascorbate peroxidase and catalase, involved in reactive oxygen species scavenging. A reduction in browning process due to polyphenol oxidase and guaiacol peroxidase activities was observed in PMAP samples. Multivariate analysis indicated that storage conditions and storage time affected the responses of qualitative and enzymatic traits. Fig fruit storage in PMAP was suitable to delay its postharvest decay and to preserve nutraceutical traits and antioxidative enzymes during 21 days of cold 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.

Effect of Cold Shock Pretreatment Combined with Perforation-Mediated Passive Modified Atmosphere Packaging on Storage Quality of Cucumbers.

This study evaluated the application of cold shock combined with perforation-mediated passive modified atmosphere packaging technology (CS-PMAP) for cucumber preservation through physicochemical, sensory, and nutritional qualities. The effectiveness of CS-PMAP in maintaining the quality of fresh cucumbers was studied; cucumbers were pretreated with cold shock and then packed into perforated polyethylene bags (bag size of 20 × 30 cm; film thickness of 0.07 mm; and two holes in each bag with a diameter of 6 mm), while the cucumbers without cold shock were considered as the control. Storage of the samples was performed at (13 ± 2) °C for 20 days to determine the quality changes in terms of gas composition, weight loss, skin color, texture, total soluble solids (TSS), ascorbic acid, malondialdehyde (MDA), and volatile organic compounds (VOCs). The CS-PMAP showed a significant improvement in maintaining firmness, TSS, ascorbic acid, and flavor profile of cucumbers; the control samples without cold shock showed higher weight loss and MDA levels. Results of this study confirmed that CS-PMAP has potential use in the storage of cucumbers.

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.

Effect of Modified Atmosphere Packaging (MAP) and UV-C Irradiation on Postharvest Quality of Red Raspberries

Red raspberries (Rubus idaeus L.) are highly appreciated by consumers. However, their postharvest shelf life scarcely exceeds 5 d under the refrigeration temperatures usually applied during commercialization, due to their high susceptibility to dehydration, softening and rot incidence. Thus, the objective of this study was to investigate the ability of UV-C radiation (UV1: 2 kJ m−2 and UV2: 4 kJ m−2), passive modified atmosphere packaging (MAP) with transmission rates (TR) for O2 and CO2 of 1805 mL d−1 and 1570 mL d−1 (MAP1), and 902 mL d−1 and 785 mL d−1 (MAP2), respectively, and the combination of both technologies to prolong raspberries’ shelf life at 6 °C. Their influence on respiration, physicochemical parameters, and microbiological and nutritional quality was assessed during 12 d of storage. The combination of 4 kJ m−2 UV-C radiation and a packaging film with O2 and CO2 transmission rates of 902 mL d−1 and 785 mL d−1, respectively, produced a synergistic effect against rot development, delaying senescence of the fruit. The UV2MAP2 and MAP2 samples only showed 1.66% rot incidence after 8 d of storage. The UV2MAP2 samples also had higher bioactive content (1.76 g kg−1 of gallic acid equivalents (GAE), 1.08 g kg−1 of catechin equivalents (CE) and 0.32 g kg−1 of cyanidin 3-O-glucoside equivalents (CGE)) than the control samples at the end of their shelf life. Moreover, the mass loss was minimal (0.56%), and fruit color and firmness were maintained during shelf life. However, the rest of the batches were not suitable for commercialization after 4 d due to excessive mold development.

Sprouting of Chayote Fruit as Influenced by Passive Modified Atmosphere Packaging and Different Postharvest Chemical Treatments

Chayote is one of the vegetable crops in the Philippines with inadequate local information on its sprouting inhibition or promotion upon application of some postharvest treatments. Newly harvested chayote fruit were applied with either passive modified atmosphere packaging (MAP) using cling wrap, 1-methylcyclopropene (1-MCP) (500 and 2500 μL·L-1), ethephon (100 and 500 μL·L-1) or gibberellic acid (GA3) (100 and 500 μL·L-1) and stored at ambient conditions (26.51±1.38 °C and 81.11±7.03% relative humidity) to evaluate its sprouting and other postharvest characteristics. Results revealed that untreated chayote sprouted in 13.5 days while passive MAP delayed the onset of sprouting by eight days. Sprouts were longest when treated with 500 μL·L-1 ethephon and shortest when fumigated with 2500 μL·L-1 1-MCP. 1-MCP promoted the occurrence of decay and higher weight loss resulting in faster deterioration of quality and shorter shelf life. Starch content did not vary. Cling-wrapped fruit maintained its quality longer because of delayed sprouting and lesser weight loss but also promoted an early onset of decay.

Effects of active and passive modified atmosphere packaging on biochemical properties of cut Dendrobium orchid flowers

Optimal storage conditions are essential to preserving the quality of postharvest produce and cut flowers during transportation, especially to overseas destinations. As a result, this research investigated the effects of active and passive modified atmosphere packaging (MAP) on the biochemical properties of cut Dendrobium Sonia orchid flowers. In active MAP, the orchid flowers were wrapped in MAP plastic film filled with 5 % carbon dioxide (CO2) and 2 % oxygen (O2). Meanwhile, in passive MAP the flowers were stored inside MAP plastic film without filling with 5 % CO2 and 2 % O2. The experimental MAP plastic films were polyethylene, low density polyethylene, high density polyethylene, polypropylene, and polyvinyl chloride films. The biochemical parameters included storage life, respiration rate, ethylene production, internal O2 and CO2, anthocyanin content, protein degradation, and electrolyte leakage. The results showed that the average storage life of orchid flowers under passive MAP condition was 9–15 days, depending on the plastic film types. The longest storage life of 15.66 days was achieved with polypropylene film. The storage life of orchid flowers in active MAP was 9.33 days on average. Without MAP (control), the storage life was 7 days under normal atmosphere condition (0.03 % CO2 and 21 % O2). The experiments also demonstrated that MAP efficiently reduced respiration rate, ethylene production, anthocyanin degradation, protein degradation, and electrolyte leakage. Unlike existing research on MAP which focused primarily on extending the shelf life of fresh produce or cut flowers, this study comparatively investigated the biochemical properties of cut orchid flowers stored in MAP environment, in addition to the storage life.