Modified Atmosphere Research Articles

Effect of modified atmosphere packaging on the extension of storage life and quality maintenance of pomegranate (cv. 'Bhagwa') at ambient and low temperatures.

Pomegranates (cv. 'Bhagwa') packed in four semi-permeable films (Cryovac® BDF-2001, D-955, RD-106 and normal LDPE) were stored at ambient temperature (25-30°C, 60-70% RH) and low temperature (8°C, 80-85% RH) to study the effect of modified atmosphere (MA) packaging on storage life extension and quality maintenance. O2 and CO2 levels generated inside MA packs differed significantly with the film type wherein extremely high CO2 (> 70%) and low O2 (1% or less) were observed in BDF film during 3weeks at ambient temperature and 3months at 8°C. Moderate O2 (3-8%) and CO2 (7-11%) were maintained in D-955 film, whereas very high O2 (18-20%) and low CO2 (2-4%) were maintained in RD-906 film. Significantly low weight loss of 0.73 and 0.52% was observed in MA packed (D-955) fruits after 3weeks at ambient and 3months at 8°C respectively compared to 19.0 and 17.8% in non-packed fruits. Fruits packed in D-955 film also retained original peel colour (L*, h° and C*), whereas colour was adversely affected in fruits packed in low permeable BDF film. MA packaging maintained peel thickness and peel moisture, significantly higher than non-packed fruits at both temperatures. TSS, acidity, sugars, antioxidants and sensory qualities were better in D-955 and LDPE packed fruits at both ambient and 8°C storage, whereas quality was adversely affected in BDF film packed fruits. MA packed (D-955 and LDPE) fruits had less spoilage up to 3weeks at ambient (5.5 and 8.3%) and 3months at 8°C (2.8 and 9.7%). Quality got deteriorated by 4weeks at ambient temperature and 4months at 8°C with enhanced spoilage. Pomegranate fruits cv. 'Bhagwa' can thus be stored safely for 3weeks at ambient and 3months at 8°C storage by MA packaging in D-955 or LDPE film with least weight loss and maintenance of nutritional quality.

Quality, sensory and volatile profiles of fresh‐cut big top nectarines cold stored in air or modified atmosphere packaging

SummarySolid‐phase microextraction (SPME) GC‐MS was used to investigate the volatile organic compound (VOC) profile of fresh‐cut ‘Big Top’ nectarine samples, stored in unsealed bags (AIR) or packed in active modified atmosphere (MAP) after 8 days of cold storage. Nectarine slices were also subjected to sensory and quality analysis after harvest and at the end of the storage. MAP preserved the overall quality, the appearance and the olfactory properties of nectarine slices during storage, while AIR samples showed symptoms of dehydration and browning. Sixty VOCs were identified in total in the headspace of the fresh nectarines and cold‐stored fruit slices samples. Principal component analysis performed on VOCs allowed to differentiate fresh nectarines from cold‐stored samples, with lactones and terpenes mainly related to fresh samples, and ester compounds positively correlated to AIR or MAP samples. Partial least square regression models allowed to identify a pool of VOC predictors of olfactory sensory descriptors.

Influence of Modified Atmosphere Packaging on Postharvest Quality of Baby Spinach (Spinacia oleracea L.) Leaves

The aim of the current study was to determine the influence of modified atmospheric pressure on the quality of baby spinach during storage. Treatments consisted of control [(normal air) (78% N2; 21% O2)], modified atmosphere (MA) (5% O2; 15% CO2; balance N2), storage temperature (4, 10, and 20 °C), and number of days after storage (0, 3, 6, 9, and 12). Parameters recorded are gas composition, weight loss, sensory quality, minerals and trace elements (Mg, Fe, and Zn), flavonoids, and antioxidant activity. The results of this study demonstrated that in the headspace gas there was overall reduction in O2 and increase in CO2 levels over the storage period. After 6 days of storage, all samples in normal air irrespective of the storage temperature were found to fall short of acceptable marketability with regard to visual appearance. The total antioxidant activity and flavonoids were well maintained under controlled atmosphere (CA) at 4 °C when stored for 9 days.

A High-level Atmospheric Management Program Plan for the New Millennium

The recent renewed interest in the field of weather modification has led to the conception of the following high-level national program plan designed for implementation during the new millennium. It is conceived that any atmospheric management program plan, whether it is as laid out in this paper or otherwise, must pursue a comprehensive agenda of fundamental and applied research and development efforts directed toward the goal of optimizing the technologies used to manage atmospheric processes and conditions. The Atmospheric Management Program (AMP) described in this paper would contain tasks organized under five activities: Atmospheric Modification Monitor/ Analysis Prediction System Development, Glaciogenic and Non-Glaciogenic Seeding Technology Research/ Development, Applications Research/ Development, Atmospheric Modification Professional Development/ Public Outreach, and Program Management and Support.

Some Reflections on Hailstorms and Hail Suppression

The Weather Modification Association (WMA) has this wonderful journal as a tool to promote the sharing of new and old ideas and insights between members. I would like to use it now to share some reflections on the subject of hailstorms and hail suppression. These reflections come from one who has been only peripherally involved in the study of hail development in hailstorms, and who has learned a little about transport and dispersion of seeding material in flanking cells, but one who has not been directly involved in hail suppression operations. I have had the opportunity to work for 15 years now with a wonderful observing platform that routinely penetrates hailstorms as a participant in collaborative convective storm field programs with various goals. These programs have included participants who have made fundamental contributions to the understanding of hailstorms and hail suppression. I have learned a great deal about hail from being around these folks at meetings, during field operations, sharing meals, and on long road trips. The following thoughts are offered in an effort to continue the discussions that seem to have waned since the demise of the National Oceanic and Atmospheric Administration (NOAA) Federal/State Cooperative Program in Atmospheric Modification Research.

Impact of Unit Operations From Farm to Fork on Microbial Safety and Quality of Foods.

Unit operations modify material properties aiming to produce uniform and high-quality food products with greater acceptance by the increasingly demanding consumers or with longer shelf life and better possibilities of storage and transport. Microorganisms, including bacteria, molds, viruses, and parasites, may have different susceptibilities to unit operations employed during food processing. On-farm (cleaning, selection and classification, cooling, storage, and transport) and on-factory unit operations (heating, refrigeration/freezing, dehydration, modification of atmosphere, irradiation, and physical, chemical, and microbial-based operations) are commonly employed throughout food production chain. The intensity and combination of unit operations along with food composition, packaging, and storage conditions will influence on the dominance of specific microorganisms, which can be pathogenic or responsible for spoilage. Thus, in the context of food safety objective (FSO), the knowledge and the quantification of the effects caused by each step of processing can enable to control and ensure the quality and safety of manufactured products.

Model for the Effect of Carbon Dioxide on <i>Listeria Monocytogenes</i> in Fresh-cut Iceberg Lettuce Packaged Under Modified Atmosphere

Model for the Effect of Carbon Dioxide on <i>Listeria Monocytogenes</i> in Fresh-cut Iceberg Lettuce Packaged Under Modified Atmosphere

MODIFIED ATMOSPHERE FOR THRIP DISINSECTION ON CUT LOTUS FLOWERS

MODIFIED ATMOSPHERE FOR THRIP DISINSECTION ON CUT LOTUS FLOWERS

SURFACE RADIATION BALANCE AND THE LAND USE IN THE AMAZON REGION

The goal of this study is to verify the relationship between the change in land use and occupation and the balance of surface radiation in the Macapá Metropolitan Area (RMM), which is placed in the Legal Amazon Northeast, due to the fact of the fast urbanization of the area. The development of the urban areas causes changes on the cover and use of the soil which could have a direct effect on the surface energy balance that may result in atmospheric modification in a local, or even regional, scale. In order to verify the RMM urban development, were used images from LANDSAT TM and OLI/TIRS of five different periods. Therefore, through the supervised classification MAXVER, it was possible to verify an expansion of the build-up area, the class of soil that covers the urban sheet, between 1986 and 2015. The data collected showed the biggest thermal changes took place further from the city, due to changes in the use of the soil in the isolated region of the RMM, Since the expansion of the urban network of the RMM occurs in the SW and S directions, with emphasis on the Fazendinha district, which is located between the center of Macapá and the center of the city of Santana.

Tailoring microstructure and photovoltaic effect in multiferroic Nd-substituted BiFeO3 ceramics by processing atmosphere modification

This study highlights significant effects of processing atmosphere ratio (O2/N2) on microstructure, impurity phases, atomic hybridization, band gap, and photovoltaic properties in (Bi0.93Nd0.07)FeO3 (BFO7Nd) ceramics. A Rietveld-refinement analysis indicates increased oxygen and bismuth vacancies in the specimens processed in the O2-rich atmosphere (hereafter called O2-rich-atmosphere specimens). In the matrix containing mainly Fe3+ ions, Fe4+ cations were identified with O2 concentration decreasing in the atmosphere by Fe K/L-edges synchrotron X-ray absorption. Oxygen K-edge absorption reveals reduced hybridizations of the O 2p–Fe 3d and the O 2p–Bi 6sp orbitals in the O2-rich-atmosphere specimens. Photovoltaic effects in the ITO/BFO7Nd/Au heterostructures under near-ultraviolet irradiation (λ=405nm) exhibit strong dependences on O2/N2 ratio. A p-n-junction model was used to describe open-circuit voltage and short-circuit current density as functions of irradiation intensity. The calculated carrier densities (in BFO7Nd ceramics) and p-n-junction widths (in the dark) are ∼1023m−3 and a few hundred nanometers, respectively.

Antifungal resistance and physicochemical attributes of apricots coated with potassium sorbate‐added carboxymethyl cellulose‐based emulsion

SummaryAntifungal effectiveness of potassium sorbate (KS) incorporated into edible coating composed of carboxymethyl cellulose and candelilla wax blend (CMC‐CnW) was tested on apricots inoculated with fungi. The efficiency of KS‐added coating was higher than KS‐free formulation. The antifungal action of KS‐free coating was likely associated with a reduced access of oxygen to the infection sites and, consequently, modification of the gaseous atmosphere within the fruit tissues. Rhizopus nigricans as the fastest growing fungus was the most resistant to the coating treatment. In turn, KS‐loaded coating was very effective against Botrytis cinerea and Monilinia fructigena. Coating significantly delayed softening of apricots. The results of this study demonstrate that KS can be incorporated into coating to control common fungal diseases of apricots. Nevertheless, the CMC‐CnW coating treatment inhibited the respiratory functions and caused deterioration in the fruit sensory quality.

Extreme condition nanocarbon formation under air and argon atmospheres during detonation of composition B-3

Novel nanocarbons synthesized by extreme conditions produce products with various chemical and physical properties. Herein through high explosive detonation of Composition B-3 (40% TNT, 60% RDX), pressures and temperatures not classically attainable in laboratory syntheses provide access to interesting carbon allotropes. For example, detonations of Composition B-3 are regularly used to synthesize the now commercially-available nanodiamond (3–5 nm spherical diamond particles) through quenching of the detonation by ice collars at high pressures and temperatures. Detonation conditions of Composition B-3, in this study, were modified by altering the atmosphere (air versus Ar) without quenching, consequently directing nanocarbon formation. X-ray scattering and microscopy elucidate that detonations performed in air produced spherical hollow core-shell nanocarbons, whereas detonations in Ar produced elongated nanocarbons. Although morphology bifurcates, spectroscopy reveals that both major detonation products are comprised of sp2 hybridized carbon. As expected from air atmosphere detonations, surface functionalization is dominated by CO bonding. The absence of oxygen in the Ar atmosphere detonations may propagate extended sheets of graphene that either stack together due to electrostatics or fold upon itself. This work demonstrates that modification of the detonation atmosphere provides an alternative route for the production of new and interesting nanocarbons.

Modified Atmosphere Packaging for Mango and Tomato: An Appraisal to Improve Shelf Life

In the present study modified atmospheric (MA) packages, having package size of 19 × 19 cm2 for a fill weight of 500 ± 100 g were developed for the experimental purpose. The storage study of MA packages was performed at 10 ± 1, 18 ± 1 and 27 ± 1 °C temperatures, considering low-density polyethylene (LDPE) packaging film with 0.1, 0.05, 0.025 and 0.0125% perforations. The performance of film packages was evaluated for their ability to establish equilibrium condition at target levels and to extend the shelf life of the packaged fruit and vegetable. It was observed that ratio of the respiration rate of O2 and CO2 prominently depends upon the perforation rate and variations in storage temperature. The LDPE packages having 0.0125% perforations have maintained the respiration rate the most in both the cases of O2 and CO2 up to 90 h at 0.89 ml kg−1 at a refrigerated temperature of 10 °C. The results showed that LDPE film with 0.0125% perforation was found best suitable for packaging both tomato and mango.

Combined Foliar Spray of Boron, Calcium, and Silicon can Influence Quality and Shelf Life of Cherry Tomato in Modified Atmosphere Packaging

This study was analyzed the effects of boron (B), calcium (Ca), silicon (Si) on quality and shelf life of ‘Unicorn’ cherry tomato at the light red maturity-stage. The storage conditions were modified atmosphere packaging (MAP) by oxygen transmission rate (OTR) packaging film at 5oC, 11oC, and 24oC. Respiration and ethylene production were the lowest in B + Ca + Si -treated tomato fruits. The lowest fresh weight loss and the longest shelf life resulted from the B + Ca + Si treatment. And the firmness was enhanced by B + Ca + Si treatment at harvest time, and it was retained after storage at 5oC, 11oC, and 24oC. Significantly lower soluble solids, lycopene, and color development were found at B + Ca + Si-treated tomato fruits compared with control after storage. Moreover, the highest titratable acidity and vitamin C content were observed in B + Ca + Si-treated tomato fruits after storage. From the above results, it was concluded that B + Ca + Si combined treatment can delay the maturity of cherry tomato after harvesting, and retained the firmness and prolong the shelf life.

Chlorine Dioxide Gas Retain Postharvest Quality and Shelf Life of Tomato during Modified Atmosphere Packaging Storage

While surface sterilization can minimize the postharvest loss of fruits and vegetables, it depends on concentration, treatment duration, storage condition, and crops. This study was conducted to investigate the consequences of chlorine dioxide (ClO 2 ) gas on post-harvest quality and shelf life of tomato fruits during the modified atmosphere packaging storage. Tomato fruits of light red maturity stage were harvested at Gangwon province in the Republic of Korea . Fruits were dipped in fungal suspension and, afterward, some of them were sterilized with NaOCl, while others were sterilized with ClO 2 gas. On the final storage day, the 5 ppm ClO 2 gas 12 hours treated tomato fruits showed the least carbon dioxide and ethylene, and the utmost oxygen concentration. The least fresh weight loss, prolonged shelf life and the most suppressed fungal incidence were obtained by the 5 ppm ClO 2 gas 12 hours treatment. As compared to other treatments, the 5 ppm ClO 2 gas 12 hours treatment yielded higher firmness, titratable acidity and vitamin C, and lower soluble solids. Therefore, the 5 ppm ClO 2 gas 12 hours treatment may be useful to prevent fungal incidence as well as to retain the postharvest quality and increase the shelf life of tomato fruits.

Evaluation of antibacterial activity of two natural bio-preservatives formulations on freshness and sensory quality of ready to eat (RTE) foods

The antibacterial activity of two natural antibacterial formulations based on lemongrass essential oil/citrus extract/lactic acid for F2 (with ratio of 0.01:0.1:1) and oregano/citrus extract/lactic acid for F6 (with ratio of 0.01:0.1:1) was studied against several pathogens (Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium) and non-pathogenic bacteria (Listeria Innocua, Escherichia coli ATCC 25922, and Salmonella enterica).The in vitro inhibition capacity (IC %) of F2 and F6 formulations demonstrated their high antimicrobial potential against pathogenic and non-pathogenic bacteria. In addition, in vitro minimum inhibitory concentration (MIC) of F2 and F6 formulations exhibited a lower MIC (higher antibacterial properties) against pathogenic and non-pathogenic bacteria compared to sodium benzoate.Furthermore, in situ antimicrobial capacity of two natural formulations (F2 and F6) was assessed on ready to eat vegetables and fruits (pre-cut red peppers, cranberries and pre-cut/pre-fried potatoes) against targeted bacteria; it's important to mention that peppers and cranberries were frozen and then thawed before treatment and storage, however pre-fried potatoes were fresh.The in situ results showed that both coatings allowed a significant reduction (P ≤ 0.05) of pathogenic bacteria in cranberries (e.g. in presence of F2 formulation: 1.5, 2.3, 1.7 log reduction of L. monocytogenes, E. coli and S. Typhimurium populations, respectively) and in red peppers (1.3, 0.85 and 2 log reduction of L. monocytogenes, E. coli and S. Typhimurium in presence of F6). Results obtained on pre-fried sliced potatoes packed under modified atmosphere (MA), showed that F2 allowed a 0.5 and 1.5 log reduction of E. coli and S. Typhimurium respectively at day 10. On the other hand, F6 allowed a 0.5 and 1.1 log reduction of E. coli and S. Typhimurium respectively at day 10. The sensory analysis of red peppers and potatoes treated with F2 and F6 formulations suggested that both formulations were acceptable in terms of organoleptic attributes. Therefore, their sensorial attributes could be accepted for further commercialization.

Characterization of Extracellular Polymeric Substances Produced by Pseudomonas fragi Under Air and Modified Atmosphere Packaging.

Extracellular polymeric substances (EPS) play an important role in bacterial biochemical properties. The characteristics of EPS from 2 strains of Pseudomonas fragi cultured in meat aerobically (control) and in modified atmosphere packaging (MAP) were studied. The amount and components of EPS, the surface properties, and the effect on biofilm formation of several spoilage organisms were evaluated. The results showed that MAP inhibited the growth of the P. fragi strains. Compared with the control, more loose and less bound EPS (containing protein and carbohydrate) were produced by P. fragi in MAP samples. MAP also caused increased cell autoaggregation and surface hydrophobicity. After the removal of the EPS, the surface property changes were strain-dependent, suggesting that membrane compositions were also changed. In addition, the EPS displayed significant antibiofilm activity on Pseudomonas fluorescens and Serratia liquefaciens. In conclusion, P. fragi strains not only modified the amount, components, and surface properties of EPS but also changed the cell membrane compositions to adapt to MAP stress. Moreover, EPS may play an important role in microbial community competitions.

산소투과도를 달리한 MA 필름으로 포장한 딸기 ‘매향’의 모의 수출 조건에서 품질 고찰

This study was conducted to determine types of oxygen transmission rate (OTR) films suitable for modified atmosphere (MA) storage treatment of strawberries (cv. ‘Maehyang’) for export and examination related changes in quality of strawberries during simulated shipping distribution conditions (2oC for 10 days~8oC for 11 days). Strawberries were packed by 1,300, 10,000, 20,000, and 30,000 cc/m2·day·atm OTR films for MA storage treatment and perforated film as the control for MAP. Fresh weight loss rate was less than 0.5% in OTR films except for the perforated film. Carbon dioxide and oxygen content in packages prevailed in permissible range for strawberries under recommended CA/MA conditions (i.e., CO2: 15~20%, O2: 5~10%) at 10,000 cc, 20,000 cc, and 30,000 cc OTR films. Ethylene content in OTR films did not reveal significant differences during storage. The 1,300 cc OTR film revealed highest off-flavor and lowest fungal incidence rate by sensory evaluation. The firmness, soluble solids, and visual quality were preserved the highest at 10,000 cc OTR film. In conclusion, 10,000 cc OTR film preserved the highest quality and extended shelf-life by 13 days if compared with conventional distribution conditions.

Effect of temperature abuse and improper atmosphere packaging on volatile profile and quality of rocket leaves

Abstract This study aimed to investigate the effect of temperature abuse and improper packaging on volatiles profile, vitamin C and sensorial attributes of rocket leaves packaged in modified atmosphere. Leaves packed in suboptimal conditions (high ratio of product weight/bag surface) were stored for 10 days at 0 and 5 °C, and for 8 days at 15 °C. Rocket leaves were kept in macroperforated bags in order to prevent modification of atmosphere within the headspace (as control). The packed rockets at 0 °C retained ascorbic acid content while it decreased during storage at higher temperatures. The main losses in the appearance and vitamin C content were observed when the O 2 level reached about 0 kPa corresponding to the highest CO 2 accumulation in the bag (25 kPa). The off-odors from dimethyl sulfide (DMS), dimethyl disulfides (DMDS) and other volatiles were produced at 5° and 15 °C, changing the initial headspace fingerprint, which was best preserved at 0 °C. Results of this work showed that improper packaging condition may decrease the shelf-life of rocket leaves compared to storage in air, inducing loss of appearance score, the production of off-odors and the degradation of Vitamin C. No additional benefit was obtained by optimal gas composition when bags were stored at 0 °C, indicating that the use of low temperature was effective to slowing down degradation reactions.

Alchemilla vulgaris AND Filipendula ulmaria EXTRACTS AS POTENTIAL NATURAL PRESERVATIVES IN BEEF PATTIES

Alchemilla vulgaris (AV) and Filipendula ulmaria (FU) are European medicinal plants possess bioactive compounds that exhibit many pharmacological benefits in human. The present work aims to assess two plants ethanolic extract; AV and FU of their antioxidant activities as natural preservative in beef patties. All plant samples were analysed using total polyphenol content (TPC), their antioxidant activities using Trolox Equivalent Antioxidant Capacity (TEAC), Ferric Reducing Antioxidant Power (FRAP), color and TBARS (Thiobarbituric acid reactive substances) analysis to measure their potential as synthetic preservative in muscle food. The antioxidant activity of FU and AV extracts measured with TEAC were 88.46 and 68.21 mmol of Trolox (TE)/g Dry Weight (DW) respectively. Whereas, FRAP assay were 44.6 and 40.12 mmol of TE/g DW for FU and AV extracts. The effect of lipid oxidation of beef patties were measured with adding 0.1% (w/w) of lyophilise FU and AV and Butylated hydroxytoluene (BHT) packed in modified atmosphere (MAP) (80% v/v O2 and 20% v/v CO2) for 14 days storages. FU and AV treated samples showed no significant different compared with BHT (p>0.05). Beef patties treated with 0.1% (w/w) FU showed minimum changes in red color and formation of metmyoglobin throughout storages (p<0.05). These results indicate that these edible plants extract are promising sources of natural antioxidants and can potentially be used as functional preservatives in meat products.