Modified Atmosphere Research Articles

Atmosphere modification system for respiration analysis of recalcitrant seeds during storage

Abstract: The modification of atmosphere composition is a strategy to prolong the storage of organisms susceptible to senescence. Atmospheres with high levels of carbon dioxide could be applied to prolong the viability of recalcitrant seeds, which are in a constant process of deterioration due to intense metabolic activity. However, there is a need to develop methods that allow the standardized generation of these modified atmospheres to isolate the effect of low oxygen from high carbon dioxide. In this study, the generation of modified atmospheres was carried out by experiments with insufflated gas (IG) or compensated vacuum (CV), on recalcitrant Inga vera embryos as an experimental model. In IG, CO2 and N2 were uninterruptedly injected into a mixing chamber, in which the gases underwent turbulence to be homogenized and subsequently applied to the flasks where the embryos were incubated. In CV, the embryos were placed in flasks, from which a fraction of the air present inside was removed, and subsequently, the gases of interest were injected in defined fractions. The CV method proved to be more efficient and it was possible to restrict the respiratory metabolism of the Inga vera embryos by reducing respiration with the increase in carbon dioxide applied exogenously.

Unlocking color-tunable emission of Eu2+-activated phosphors through doping-free exploration of hidden sites

Reducing atmosphere modification (a doping-free strategy) leads to Eu2+ emission color changes from blue to cyan.

Physiology and biochemistry of naranjilla (Solanum quitoense Lam) fruit during postharvest and the main conservation strategies: A review

Naranjilla (lulo) is an Andean fruit that is very attractive for consumption due to its acid flavor and aroma, as well as its antioxidant, mineral, carbohydrate, and protein content. However, several aspects of the fruit´s pre-harvest and ripening postharvest are unknown, which results in deficiencies during the postharvest handling and conservation. The aim of this review was to present and describe the naranjilla fruit´'s main physiological changes, such as respiration pattern, ethylene production, firmness reduction, and pigment variation, as well as the main preservation technologies implemented during the postharvest period. Naranjilla fruit has been cataloged as a climacteric fruit but its respiratory rate is lower than other fruits in this group. During ripening, there are changes such as a color evolution from green to yellow hue for the pulp and peel, an increase in the concentration of soluble sugars, ascorbic acid, and ethylene production, as well as a reduction in firmness and acidity. Given the nature of its ripening, naranjilla is considered a perishable fruit. To preserve the fruits throughout the postharvest period, different technologies involving cooling, packaging in modified atmospheres (MAP), use of 1-methylciclopropene (1-MCP), UV-C and gamma radiation, and ozone application have been evaluated. From these technologies, refrigeration and MAP are the most often used commercially; they are efficient and relatively economical. More research is required to optimize the use of these technologies for naranjilla preservation.

Modified atmosphere packaging of flounder fillet: Modelling of package conditions and comparison of different flushing atmospheres for quality preservation

Modified atmosphere packaging (MAP) flushed in high CO2 concentration with high gas barrier layer is often applied to preserve fish at chilled temperatures. Dissolution of CO2 in fish product results in changes from the original CO2 concentration and volume of packages. Maintenance of the desired CO2 concentration under appropriate package volume is required for realising effectiveness in fish preservation and handling through distribution channel. In the present work, mathematical model for estimating package gas compositional changes along with volume decrease was developed by incorporating CO2 dissolution dynamics into gas mass balance equation, and it was then validated by 200 g flounder packages flushed with atmospheres of 30 or 60% CO2 and stored at 5°C. Then, the effect of different modified atmospheres (MAs) on preservation of the flounder fillets was examined for 100 g flounder packages stored at 10°C for 5 d. Package flushed with MA of CO2 60%/O2 30%/N2 10% was the best for preserving flounder fillet preservation, in terms of total aerobic bacteria inhibition and low volatile basic nitrogen content as major quality indexes.

The Fatty Acid Profile, and the Content of Vitamin A, Vitamin E and Cholesterol in Beef (M. longissimus lumborum) Stored Under Different Modified Atmospheres

Abstract The aim of this study was to analyze the fatty acid profile of intramuscular fat and the content of vitamin A, vitamin E and cholesterol in samples of the longissimus lumborum (LL) beef muscles and stored for 7, 14 and 21 days under modified atmospheres (MA): vacuum, 80% O2 + 20% CO2, 60% O2 + 30% CO2 + 10% N2, 40% CO2 + 60% N2, 30% CO2 + 70% Ar). The experimental factors, i.e., storage time (ST) and MA composition, had no significant effect on the proportions of individual saturated fatty acids (SFAs), but they significantly modified the proportions of individual unsaturated fatty acids (UFAs) and the fatty acid profile of intramuscular fat (IMF). The study demonstrated that in order to minimize the loss of total UFAs, samples of the LL muscle should be cold-stored in MA 40% CO2 + 60% N2 for up to 14 days; MA 30% CO2 + 70% Ar also effectively prevented the loss of total PUFAs and eicosapentaenoic acid (EPA). The losses of vitamins A and E were lowest when beef was packaged under oxygen-free MA, in particular MA 30% CO2 + 70% Ar. Prolonged storage (21 days) did not contribute to significant vitamin losses, but it induced a decrease in cholesterol concentration, which was lower in vacuum-packaged samples than in those packaged in MA containing 60% O2 and MA composed of 40% CO2 + 60% N2.

Assessment of the Spoilage Microbiota and the Growth Potential of Listeria monocytogenes in Minced Free-Range Chicken Meat Stored at 4 °C in Vacuum: Comparison with the Spoilage Community of Resultant Retail Modified Atmosphere Packaged Products

Although current diet and nutrition trends in developed countries led the poultry industry to shift to alternative breeding/production methods, such as organic and free-range, limited data on the microbiology of alternative compared to conventional poultry meat products exist. Therefore, this study assessed the evolution and composition of the spoilage microbiota and the growth potential of inoculated (3 log cfu/g) Listeria monocytogenes in freshly minced free-range chicken meat stored at 4 °C in vacuum packages (VP; four batches) for 0, 3, 5, 7, and 10 days. Additionally, two VP batches were compared with their resultant retail products stored in modified atmosphere packages (MAP 30:70 CO2/N2) at 4 °C to detect potential differences with the MAP spoilage community described previously. The initial pH of the VP minces was 6.0–6.1, except for one mince, designated VP + AA, which had initial pH 5.8 and was found to contain ‘external’ 1.26% L-lactate and 0.24% acetate associated with a vinegar smell during storage. The rest of the VP batches contained on average 0.75% L-lactate and 0.02% acetate on day 0. After 7 days at 4 °C, L-lactate decreased by at least 3-fold in VP and over 5-fold in VP + AA vs. minor decreases in MAP. Acetate increased 2-fold in all batches. D-lactate (ca. 0.02% on day 0) increased by 4-fold in VP batches only. Lactic acid bacteria (LAB) became the dominant spoilers in all samples. Only VP allowed a delayed 10-fold growth (>5.0 to 6.2 log cfu/g) of pseudomonads from day 7 to day 10 at 4 °C. Compared to VP, VP + AA and MAP retarded growth of LAB, pseudomonads, and enterobacteria by 1–2 log units, at final levels below 6.5, 4.5, and 3.0 log cfu/g, respectively. Enterococci, staphylococci, yeasts, and L. monocytogenes did not grow. Latilactobacillus sakei predominated in all spoiled VP batches (65.8% of 80 meat isolates) followed by Latilactobacillus fuchuensis (9.2%), Leuconostoc carnosum (6.6%), Carnobacterium divergens (6.6%), Latilactobacillus curvatus (5.3%), and Weissella koreensis (2.6%). VP + AA favored Latilactobacillus. Brochothrix thermosphacta was frequent in one VP batch. In conclusion, cold-stored (4 °C), minced, free-range chicken meat spoils more rapidly and offensively under VP than MAP or VP combined with acetate-containing (VP + AA) antimicrobial blends.

The exploration of dominant spoilage bacteria in blue mussels (Mytilus edulis) stored under different modified atmospheres by MALDI-TOF MS in combination with 16S rRNA sequencing

Few studies have addressed species-level identification of spoilage bacteria in blue mussels packed under modified atmospheres (MAs). We investigated the effect of MAs and seasons on the tentative species-level of dominant spoilage bacteria in blue mussels. Summer (s) and winter (w) blue mussels were stored at 4 °C in the atmospheres (%CO2/O2/N2): A40s (30/40/30), B60s (40/60/0), C60s (0/60/40), A40w (30/40/30), and D75w (25/75/0). In total, 122 culturable isolates were obtained at the final stage of shelf life, when mortality was high (56–100%) and total psychrotrophic bacteria counted >7 log CFU g−1. Biochemical properties were analyzed using gram reactions, catalase and oxidase activities, and salt tolerance tests. Culturable isolates were identified through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16 S rRNA gene sequence analysis. Spoilage potential tests were investigated by evaluating protease, lipase, and fermentation activities as well as gas and H2S production. The culturable isolates showed tolerance to varied salt concentrations. Psychromonas arctica, Pseudoalteromonas elyakovii, and Shewanella frigidimarina were dominating in specific MAs. Winter blue mussels resulted in a higher variation of spoilage bacteria, including S. frigidimarina, S. vesiculosa, S. polaris, Micrococcus luteus, Paeniglutamicibacter terrestris sp. nov., and Alteromonas sp.

Application of Modified Atmospheres to Control Stegobium paniceum and Lasioderma serricorne Infestation of Stored Chamomile and Coriander and Its Effect On Product Quality

AbstractMedicinal and spices plants are crucial, and they can become infested by several insects, such as drugstore beetle (Stegobium paniceum l.) and the cigarette beetle (Lasioderma serricorne), during storage. Therefore, the present study aimed to assess the effect of enriched modified atmospheres (MAs), with CO2 or N2, on L. serricorne and S. paniceum adults and larvae and their effect on quality of chamomile flowers and coriander seeds during storage. Various carbon dioxide and nitrogen gas concentrations were tested, including 40% CO2, 50% CO2, 60% CO2, 97% N2, and 98% N2. The larval mortality for S. paniceum reached 100% after 6 days of 60% CO2 and 8 days for the L. serricorne. At 98% N2 treatment, the complete mortality (100%) of S. paniceum and L. serricorne adults was recorded following 3 and 9 day exposures and of larvae following 10 day exposure.The quality parameters (weight loss percentage, germination, essential oil percentage, and color) of chamomile flower and coriander seeds treated with 60% CO2 and control were studied after 3 and 6 months of storage. The MAs had the lowest weight loss percentage, the highest lightness value, the lowest color changes, and the highest essential oil content of chamomile flower and coriander seeds compared with the control treatment. Additionally, the MAs induced a higher germination percentage of coriander seeds compared with the control. Treatment with CO2 increased some essential oils compounds, compared with control after 6 months of storage of chamomile. All compounds were decreased in coriander seeds treated with CO2, except for carvone and anethole, which were increased. In conclusion, our study recommends using MAs to control S. paniceum and L. serricorne during storage and maintain the quality of chamomile flower and coriander seed.

NIRS (Near Infrared Spectroscopy) classification of sliced Duroc dry-cured ham under various packaging systems and storage temperature and time

The potential of Near Infrared Spectroscopy (NIRS) was assessed for storage temperature discrimination (4 °C ± 2 vs. 20 °C ± 2) and for the prediction of the length of time that sliced Duroc dry-cured ham was in storage, considering the following packaging types; vacuum (n = 133) and modified atmosphere (MAP) (n = 133), without opening the package. The models, obtained by means of Partial least squares-discriminant analysis, indicated successful classification of the product according to storage temperature after validation (accuracy values of 100.00% in vacuum and between 92.00 and 100% in MAP). Furthermore, good accuracy was obtained for the assignments into storage times, with values comprised between 92.31% and 100.00% for samples under vacuum and between 91.00% and 97.00% for those under MAP, in both cases after validation. Thus, NIRS technology could help to support the preservation temperature traceability and the stocks of sliced dry-cured hams.

Enhancing the Shelf Life of Palak and Coriander through Modified Atmosphere Packaging under Diverse Storage Environments

Aim: Green leafy vegetables are renowned for their rich vitamin and mineral content as well as their nutritional value. However, these vegetables are highly perishable due to their accelerated rates of respiration and transpiration. The process of packing and the choice of packaging materials play a crucial role in extending their shelf life. The main aim of this study was to prolong the shelf life of two prominent leafy greens, Palak (Beta vulgaris L. var. bengalensis) and Coriander (Coriandrum sativum L.), using Modified Atmospheric Packaging (MAP) and various packaging materials. Study Design: The study employed an FCRD experimental design with 12 treatments and 3 replications. Place and Duration of Study: This study was conducted at Department of Vegetable Science, HC&RI, TNAU, Coimbatore during the year 2023. Methodology: Freshly harvested Palak and Coriander were collected, sorted, and prepared as 250-gram samples. Two packaging materials (LDPE and PP) and three gas compositions (G1, G2, G3) was employed. The vegetables were stored under both ambient (35±5°C) and refrigerated (5°C) conditions and their physiological loss in weight (PLW %) was monitored. The observations were taken every day up to the spoilage of the produce. Results: According to the research findings, vegetables could remain fresh under ambient storage for up to 4 days and under refrigeration for up to 15 days. In ambient storage conditions, Palak exhibited the longest shelf life in treatment T3 - G3M1 (4% O2, 5% CO2, LDPE), followed by T5 - G2M2 (6% O2, 5% CO2, PP). Meanwhile, Coriander showed better shelf life in treatment T2 - G2M1 (6% O2, 5% CO2, LDPE), followed by T6 - G3M2 (4% O2, 5% CO2, PP). Under refrigerated storage conditions, Palak exhibited an extended shelf life in treatment T9 - G3M1 (4% O2, 5% CO2, LDPE), followed by T12 - G3M2 (4% O2, 5% CO2, PP). For Coriander, the best results were achieved with treatment T12 - G3M2 (4% O2, 5% CO2, PP), followed by T8 - G2M1 (6% O2, 5% CO2, LDPE). Conclusion: Proper packaging and gas composition significantly increased the shelf life of these leafy greens, offering potential benefits for both producers and consumers. Palak had a longer shelf life when stored under refrigerated conditions, up to 14 days, while Coriander could be kept fresh for up to 12 days in the refrigerator. Gas composition G3 (4% O2, 5% CO2) was found to be effective and LDPE was generally the preferred packaging material in extending the shelf life of the vegetables.

Influence of sustainable packaging material and packaging conditions on physicochemical, microbiological, and sensorial properties of cheeses

The aim of this study was to evaluate the influence of different packaging materials [standard foil: BOPP (biaxially oriented polypropylene)/PET (polyester)/PE (polyethylene) for upper layer, and APET (polyethylene terephthalate)/PE for bottom layer; foil 1: PP (polypropylene)/PET/PE/EVOH (ethylene-vinyl alcohol copolymer)/PE upper layer, and PP/PE/EVOH/PE bottom layer; foil 2: PP/PET/PE/EVOH/PE upper layer, and PA (polyamide)/EVOH/PE bottom layer; foil 3: PP/PET/PE upper layer, and PA/EVOH/PE bottom layer; foil 4: PP/PET/PE upper layer, and PA/PE bottom layer; foil 5: PP upper layer, and PP/PP bottom layer] on the quality of 3 different ripening rennet cheeses packed under different modified atmosphere (MAP) conditions as reflected in particular physicochemical, microbiological, and sensorial changes. The changes were monitored during a period of 90 d of storage at 2°C or 8°C. For Gouda cheese, CO2 content of the headspace of the packages was in the range 35% to 45%, whereas for Maasdamer and Sielski Klasyczny cheeses it was 55% to 65%. Three-way ANOVA showed that the foil type influenced the moisture content of Gouda cheese stored for 90 d at 2°C and for Sielski Klasyczny cheese at 8°C, whereas the moisture content was not dependent on MAP conditions during storage. Moreover, the foil type had a significant effect on free fatty acid changes for Gouda and Sielski Klasyczny cheeses stored at 2°C for 90 d. Sensory attributes changed significantly over storage time at 2°C for all studied cheeses as affected by foil type, whereas there was no effect of MAP conditions. In general, the cheeses packed in standard foil and foil 4 were characterized by the highest values of mean sensory attributes. Time was the most significant factor influencing most changes in physicochemical and sensory attributes of cheeses stored at 2°C and 8°C. The storage temperature did not affect the moisture of the samples during storage. In general, we found an increase in the pH value during storage regardless of storage temperature. It was possible to decrease the thickness of the packaging material from initial 103 and 250 µm (standard foil; lid and bottom, respectively) to 98 and 100 µm (foil 4) without affecting sensory attributes of the product.

Estimating the Chlorophyll-a in the Nha Trang Bay using Landsat-8 OLI data

The pigment chlorophyll-a (Chl-a) is used to evaluate aquatic ecological health. Using remote sensing techniques to estimate this pigment and spatially mapping its distribution becomes essential for measuring and assessing water quality in coastal areas. Nha Trang Bay is famous not only for its scenery but also for its biodiversity values, especially the existence of coral reefs. In this study, Landsat-8 OLI was taken on June 3, 2015, and field measurements of Chl-a at 13 survey sites from June 6-8, 2015, were used to build a local algorithm to monitor the spatio-temporal distribution of Chl-a content in Nha Trang Bay. The ACOLITE processor was employed for the atmospheric modification of Landsat-8 OLI images to obtain atmospherically corrected surface reflectance products. Four types of simple regression models, including linear, exponential, logarithmic, and power models, were used to describe the relationship between the in-situ measurement of Chl-a and remote sensing reflectance of Landsat-8 OLI data. The results of correlation analysis have shown a statistically significant relationship between field measurement of Chl-a concentration and the remote sensing reflectance ratio of Landsat-8 band 3 versus band 2 using an exponential model with a coefficient of determination of 0.88 (p < 0.001) and root mean square error (RMSE) of 0.40 mg/m3. This empirical relationship was applied to map the spatial distribution of Chl-a concentration from 27 cloudless Landsat-8 OLI images from 2013 to 2021. The spatio-temporal distribution of Chl-a indicated that the Chl-a concentration in the Bay has a low value (less than 1 mg/m3). However, this concentration becomes high in the coastal areas (greater than 1 mg/m3) and the Cai and Tac rivers (greater than 2 mg/m3). It is also noted that the content of Chl-a in the rainy season is fairly higher than in the dry season, by an average of 0.68 mg/m3 and 0.53 mg/m3, respectively. This research highlights that Landsat-8 OLI data can be an effective and valuable tool in monitoring Chl-a for coastal areas.

The Potential of Soluble Gas Stabilization (SGS) Technology in a Simulated Post-Frying Cooling Step of Commercial Fish Cakes.

Soluble gas stabilization (SGS) technology is a novel way to increase the effectiveness of modified atmosphere (MA) packaging. However, SGS can be time-consuming and difficult to include in an existing process. This can be overcome by including CO2 in an existing processing step, such as the product's cooling step. A full factorial design was set up with SGS times (0.5, 1.0, and 2.0 h) and temperatures of fish cakes (chilled (0 °C) or during chilling (starting at 85 °C)) as factors. MA-packaged fish cakes were included as a control. The response was headspace gas composition at equilibrium. Headspace gas composition at equilibrium showed significantly (p < 0.05) less dissolved CO2 in hot fish cakes after 0.5 h than in cold cakes. Still, no significant differences were found between hot and cold at 1.0 and 2.0 h. Also, all SGS samples, regardless of time and temperature, had a higher content of CO2 compared to modified atmosphere packaging (MAP).

Chilling temperatures and controlled atmospheres alter key volatile compounds implicated in basil aroma and flavor.

Use of basil in its fresh form is increasingly popular due to its unique aromatic and sensory properties. However, fresh basil has a short shelf life and high chilling sensitivity resulting in leaf browning and loss of characteristic aroma. Moderate CO2 atmospheres have shown potential in alleviating symptoms of chilling injury in basil during short-term storage but its effect on the flavor volatiles is unclear. Moreover, studies on basil volatile profile as impacted by chilling temperatures are limited. We investigated the response of two basil genotypes to low temperatures and atmosphere modification, with emphasis on the volatile organic compounds responsible for basil aroma and flavor. Leaves were stored for 6 days at 5, 10, or 15°C combined with three different CO2 atmospheres (0.04%, 5% or 10%). Basil volatile profile was assessed using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Leaves suffered severe chilling injury and greater loss of aroma volatiles at 5°C compared to 10°C and 15°C. More than 70 volatiles were identified for each genotype, while supervised multivariate analysis revealed 26 and 10 differentially-accumulated volatiles for 'Genovese' and 'Lemon' basil, respectively, stored at different temperatures. Storage in 5% CO2 ameliorated the symptoms of chilling injury for up to 3 days in 'Genovese', but not in 'Lemon' basil. Both chilling temperatures and controlled atmospheres altered key volatile compounds implicated in basil aroma and flavor, but temperature had a bigger influence on the observed changes in volatile profile.

Development of an antimicrobial packaging system for fresh cape gooseberry (Physalis peruviana L.) fruits

An active antifungal packaging system combined with modified atmospheres (MAP) was proposed to preserve cape gooseberry. Initially, the antifungal effect of oregano essential oil, cinnamaldehyde, and 2-nonanone in the vapor phase was evaluated in vitro to determine the minimum inhibitory concentration (MIC) for Botrytis cinerea. Next, the better antifungal compound was included inside an active packaging system adsorbed in powdered bentonite. 100 ± 1 g of fruits were introduced in sealed polylactic acid (PLA) packages with a 0.058 mm perforation in the center forming a MAP and stored at 6 °C and 75 % RH determining fungal deterioration and changes in quality properties. From the in vitro tests, it was determined that cinnamaldehyde was the component with the highest antifungal capacity with a MIC of 2,38 µg per cm3 of headspace air. With the active packages combined with MAP, it was possible to obtain up to 42 days of shelf life.

Growth and Non-Thermal Inactivation of Staphylococcus aureus in Sliced Dry-Cured Ham in Relation to Water Activity, Packaging Type and Storage Temperature.

Dry-cured ham (DCH) could support the growth of Staphylococcus aureus as a halotolerant bacterium, which may compromise the shelf-stability of the product according to the growth/no growth boundary models and the physicochemical parameters of commercial DCH. In the present study, the behavior of S. aureus is evaluated in sliced DCH with different water activity (aw 0.861-0.925), packaged under air, vacuum, or modified atmosphere (MAP), and stored at different temperatures (2-25 °C) for up to 1 year. The Logistic and the Weibull models were fitted to data to estimate the primary kinetic parameters for the pathogen Log10 increase and Log10 reduction, respectively. Then, polynomial models were developed as secondary models following their integration into the primary Weibull model to obtain a global model for each packaging. Growth was observed for samples with the highest aw stored at 20 and 25 °C in air-packaged DCH. For lower aw, progressive inactivation of S. aureus was observed, being faster at the lowest temperature (15 °C) for air-packaged DCH. In contrast, for vacuum and MAP-packaged DCH, a higher storage temperature resulted in faster inactivation without a significant effect of the product aw. The results of this study clearly indicate that the behavior of S. aureus is highly dependent on factors such as storage temperature, packaging conditions and product aw. The developed models provide a management tool for evaluating the risk associated with DCH and for preventing the development of S. aureus by selecting the most appropriate packaging according to aw range and storage temperature.

Prevention of Chilling Injury in Pomegranates Revisited: Pre- and Post-Harvest Factors, Mode of Actions, and Technologies Involved.

The storage life of pomegranate fruit (Punica granatum L.) is limited by decay, chilling injury, weight loss, and husk scald. In particular, chilling injury (CI) limits pomegranate long-term storage at chilling temperatures. CI manifests as skin browning that expands randomly with surface spots, albedo brown discoloration, and changes in aril colors from red to brown discoloration during handling or storage (6-8 weeks) at <5-7 °C. Since CI symptoms affect external and internal appearance, it significantly reduces pomegranate fruit marketability. Several postharvest treatments have been proposed to prevent CI, including atmospheric modifications (MA), heat treatments (HT), coatings, use of polyamines (PAs), salicylic acid (SA), jasmonates (JA), melatonin and glycine betaine (GB), among others. There is no complete understanding of the etiology and biochemistry of CI, however, a hypothetical model proposed herein indicates that oxidative stress plays a key role, which alters cell membrane functionality and integrity and alters protein/enzyme biosynthesis associated with chilling injury symptoms. This review discusses the hypothesized mechanism of CI based on recent research, its association to postharvest treatments, and their possible targets. It also indicates that the proposed mode of action model can be used to combine treatments in a hurdle synergistic or additive approach or as the basis for novel technological developments.

Investigation into the Physicochemical and Textural Properties of an Iron-Rich 3D-Printed Hybrid Food

In the context of dietary transition, blending animal-source protein with plant-source protein offers a promising way to exploit their nutritional complementarity. This study investigates the feasibility of formulating an iron-rich hybrid food product blending plant-source and animal-source protein ingredients for iron-deficient populations. Using a commercial 3D-food printer, two different-shaped products composed mainly of pork and chicken liver and red lentils were designed. After baking at 180 °C with 70% steam, the 3D-printed products were packed under two different modified atmospheres (MAP): O2-MAP (70% oxygen + 30% carbon dioxide) and N2-MAP (70% nitrogen + 30% carbon dioxide) and stored at 4 °C. pH, water content, aw, lipid oxidation, heme iron and non-heme iron contents and textural properties were measured after 0, 7, 14 and 21 days in storage. After 21 days in storage, the 3D-printed hybrid products had an iron content of around 13 mg/100 g, regardless of the product form and packaging method. However, O2-MAP products showed significant (p < 0.05) time-course changes from day 0 to day 7, i.e., an increase in lipid oxidation, a decrease in heme iron content and an increase in product hardness, gumminess and chewiness. This work opens prospects for developing hybrid food products that upvalue animal by-products.

Change of Campylobacter, Escherichia coli and Salmonella counts in packaged broiler breast meat stored under modified atmosphere and vacuum conditions at 4 and 10 °C based on cultural and molecular biological quantification

Poultry on the European market is offered primarily as fresh meat and is usually sold at the retail level packed under either a modified atmosphere (MAP) or vacuum. Packaging is meant to retain product quality during retail offering and influences microbiological changes during storage. The focus of this study was to determine the influence of routinely used broiler meat packaging technologies on the change of Campylobacter , Salmonella and Escherichia coli counts on chicken breast meat. Chicken breast meat was inoculated with Campylobacter (5 log 10 cfu/g), Salmonella and E. coli (each at 4 log 10 cfu/g), packaged under MAP or vacuum conditions and stored at 4 and 10 °C over a period of 13 days. Cultural microbiological analysis was used together with quantitative viability real time PCR (v-qPCR) to assess the development of inoculated bacteria as well as the general hygiene and spoilage microbiota. The results showed a reduction of thermophilic Campylobacter spp. of about 2 log 10 cfu at the end of storage for MAP meat as compared to vacuum packed meat. However, this reduction was not observed by v-qPCR, where viable Campylobacter spp. counts remained almost at inoculation level. No change in cfu was observed for either Salmonella or E. coli . The results indicate that examination by culturing alone can lead to an underestimation of the Campylobacter spp. load on fresh broiler meat. Quantitative molecular biological analysis with live/dead differentiation is applicable for overcoming the limitations of culturing methods and therefore requires further verification through additional studies under retail conditions on different matrices. • MAP storage at 4 °C resulted in a 2 log reduction of cultured Campylobacter . • Reduction of Campylobacter count of cultural examination was not confirmed by qPCR. • No significant differences found for E. coli comparing qPCR and cultural results. • Storage temperature influenced the change in Salmonella counts.

Application of Cytokinin under Modified Atmosphere (MA) Delays Yellowing and Prolongs the Vase Life of Davallia solida (G. Forst.) Sw. Leaves

Cut leaves of Davallia solida are widely used in bouquet greenery. However, the leaves wilt and yellow after seven days. Postharvest applications of exogenous cytokinins (CKs), a plant growth regulator (PGR), preventing senescence in many green leafy plants, were studied by pulsing cut D. solida leaves with 6-benzylamiopurine (BA) at a concentration of 100 ppm, or thidiazuron (TDZ) at a concentration of 10 μM for 24 h, compared with distilled water as a control, and then placing the ferns in a controlled room (21 + 2 °C, 70–80% relative humidity (RH), under cool-white fluorescent lights for 12 h/d). Pulsing with BA and TDZ delayed leaf yellowing while preserving chlorophyll (Chl) content. This was due to reduced Chl-degrading enzyme activities on day 8 of the vase life of the leaves, resulting in longer display life of 11.1 and 11.5 days, respectively. TDZ delayed Chl breakdown on day 8 of the vase life of leaves more than was the case for BA. Subsequently, leaves were pulsed in 10 μM TDZ, or distilled water for 24 h, and then 10 leaves from each treatment were packaged in a 25 × 30 cm, 25-μm thickness BOPP bag. All the packages were stored at 10 °C in 10 h/d light for one, two and three weeks, then unpacked and placed in distilled water. Pulsing with TDZ before one-week storage delayed leaf yellowing, maintained Chl content and extended their vase life to 9.6 days compared with one-, two-, and three-week control leaves, which had a vase life of 6.2, 5.8, and 3.6 days, respectively. After one week, the relative fresh weight of the leaves and water uptake did not alter between the control and TDZ groups. The activities of Chl degradation enzymes in the leaves of D. solida pulsed with TDZ prior to storage were significantly suppressed, related to higher Chl content and a lower percentage of leaf yellowing than the control, resulting in a longer vase life of 9.0 days, while the control lasted 7.0 days. A 10 µM TDZ pulsing treatment significantly prevented the yellowing of D. solida fronds during the vase period or storage period, and one-week storage under MA with light conditions is recommended for retaining postharvest quality after storage.