Search Results (64)

In this study, we report the development of mixed gas composition for packaging dried apple slices in a modified atmosphere to extend their shelf life and maintain their quality. We used the response surface methodology to optimize oxygen and carbon dioxide concentrations in the mixture for packaging in a modified atmosphere based on the changes in mass, hardness, browning index, polyphenols, and vitamin C content during apple chip storage. Studies have shown that the optimal concentration of oxygen should be 2.663% and carbon dioxide 3.785% when packaging dried apple slices in a modified atmosphere to obtain minimal changes in the measured quality attributes. These findings can be applied in food processing and storage, providing a useful guideline for improving the preservation and nutritional value of dried fruits. Full article

The highly perishable nature of Rubus berries, particularly their susceptibility to water loss and earlier senescence, significantly limits their shelf life. In this study, we investigated the mechanistic role of modified atmosphere packaging (MAP) on the physiochemical quality, phenolic metabolism, and antioxidant potential of blackberries and raspberries during cold storage (2 ± 1 °C) for 12 and 10 days, respectively. Modified atmosphere (MA)-packed Rubus berries exhibited higher total phenolics accompanied by higher activities of shikimate dehydrogenase, and phenylalanine ammonia-lyase. Furthermore, MA-packed Rubus berries demonstrated lower hydrogen peroxide by maintaining higher catalase activity and delayed lipid peroxidation during the entire period of cold storage. Relatively higher levels of glutathione and ascorbic acid as well as the activities of enzymes involved in the ascorbate-glutathione cycle in MA-packed Rubus berries were also observed. Conversely, MAP reduced the respiration rate and weight loss while maintaining higher postharvest quality attributes in raspberries and blackberries than control fruit. In conclusion, MAP is an effective method for extending the cold storage life and maintaining the quality of Rubus berries. Full article

Composite biopolymer hydrogel as food packaging material, apart from being environmentally favorable, faces high standards set upon food packaging materials. The feature that favors biopolymer film application is their low gas permeability under room conditions and lower relative humidity conditions. However, most biopolymer-based materials show high moisture sensitiveness and limited water vapor permeability, which limits their application for food packaging. In this paper, a new packaging material derived from an edible oil industry byproduct (pumpkin oil cake) coated with a thin layer of paraffin wax was obtained. Compared to the film without wax coating, the new material showed reduced water sensitivity and significantly reduced water vapor transmission rate (56.98 ± 7.42 g/m² 24 h). The new material was tested for packing dry apricot slices under a modified atmosphere (100% N₂). Gas composition in PuOC/wax pouches’ headspace was minimally changed during 105 days of storage. The low moisture content (6.76–10.60%) of dried apricot slices was preserved throughout the storage period (p > 0.05), as well as high rehydration power (65–75%). Changes in sensorial properties during storage were minimal. Total phenol content was minimally reduced during storage, followed by antioxidant activity (FRAP and ABTS trial). The microbial profile of dried apricot slices showed that a safe product was obtained throughout the storage. Considering the results, the functionality of new material for packing dry apricots under a modified atmosphere was proven. Full article

Edible coatings are an innovative solution for food producers and suppliers looking for healthy alternatives that would be appealing to consumers seeking for ready-made products in fresh form. Low-processed horticulture products are expected to appear in more and more convenient form, ready to eat and completely safe. The application of edible surface films contributes to the extension of shelf life while maintaining strict hygiene standards. Properly selected coating components are not only able to slow down the decomposition processes but also inhibit microbial growth, thus preventing quality losses and eliminating any potential threats to health. The additional use of modified atmosphere packaging (MAP) can significantly increase the shelf life of fruit and vegetables both fresh and minimally processed. However, single treatments (edible coatings and MAP) are limited in maintaining the quality and shelf life of fresh and fresh-cut fruit and vegetables. Little is known about the synergistic effect of MAP and edible coatings, and more research is necessary. The synergic action means combined action—first applying the edible coating, then packing in MAP. Full article

The aim of this study was to analyze the influence of different packaging materials on the composition of the headspace (CO₂ and O₂) of rennet cheeses packed in unit packaging under different modified atmosphere (MAP) conditions during a storage period of 90 days at 2 °C and 8 °C. The packaging materials comprised different combinations of BOPP—biaxially oriented polypropylene; PET—polyester; PE—polyethylene; PP—polypropylene; EVOH—ethylene–vinyl alcohol copolymer; PET—polyethylene terephthalate; and PA—polyamide. As the properties of the packaging material (foil) affect the gas conditions inside the packaging, it is important to study whether the modifications, i.e., properties and thickness, of the foils will result in significant differences in the composition of the headspace of packed cheeses. The CO₂ content in the headspace of Gouda cheese packages ranged from 35% to 45%, while for Maasdamer and Sielski Klasyczny cheese, it varied between 55% and 65%. Throughout the storage period, the O₂ content in the headspace of cheeses packaged in tested foils (1–5) did not exceed 0.5%. The type of foil used did not influence the modified atmosphere packaging (MAP) conditions. Full article

Consumers are responsible for a large proportion of food waste, and food that has reached its use-by or best-before date is often discarded, even if edible. In this study on fresh chicken, the suitability of use-by dates currently used in the EU was evaluated by using microbial and sensory analyses. This was carried out by analyzing bacterial populations of chicken breast fillets (M. pectoralis major) at three different time points (use-by date, 2 days past use-by date, 4 days past use-by date) and two different storage temperatures (4 °C, 8 °C). A discrimination triangle test was performed to check for sensory differences between chicken breast fillets cooked at the three selected time points for both storage temperatures. A consumer preference test was also performed for chicken breast fillets that had been stored at the highest recommended temperature (4 °C) and after being cooked at the three time points. Changes in populations of total aerobic count (TAC), Enterobacteriaceae (EB), and lactic acid bacteria (LAB) were recorded over time. Despite large differences in bacterial counts at the selected time points, with TAC populations of approximately 6.5 and 8.0 log CFU/g at use-by date and four days after use-by date, respectively, storage for two or four extra days had no significant effect on the sensory parameters of cooked chicken compared with chicken consumed at its use-by date. Since the TAC populations were close to or above levels that are associated with spoilage, more work is needed to explore if shelf life can be extended. Full article

Globally, fresh vegetables or minimally processed salads have been implicated in several foodborne disease outbreaks. This work studied the effect of Lactiplantibacillus pentosus FMCC-B281 cells (F) and its supernatant (S) on spoilage and on the fate of Listeria monocytogenes and Escherichia coli O157:H7 on fresh-cut ready-to-eat (RTE) salads during storage. Also, Fourier transform infrared (FTIR) and multispectral imaging (MSI) analysis were used as rapid and non-destructive techniques to estimate the microbiological status of the samples. Fresh romaine lettuce, rocket cabbage, and white cabbage were used in the present study and were inoculated with L. pentosus and the two pathogens. The strains were grown at 37 °C for 24 h in MRS and BHI broths, respectively, and then were centrifuged to collect the supernatant and the pellet (cells). Cells (F, ~5 log CFU/g), the supernatant (S), and a control (C, broth) were used to spray the leaves of each fresh vegetable that had been previously contaminated (sprayed) with the pathogen (3 log CFU/g). Subsequently, the salads were packed under modified atmosphere packaging (10%CO₂/10%O₂/80%N₂) and stored at 4 and 10 °C until spoilage. During storage, microbiological counts and pH were monitored in parallel with FTIR and MSI analyses. The results showed that during storage, the population of the pathogens increased for lettuce and rocket independent of the treatment. For cabbage, pathogen populations remained stable throughout storage. Regarding the spoilage microbiota, the Pseudomonas population was lower in the F samples, while no differences in the populations of Enterobacteriaceae and yeasts/molds were observed for the C, F, and S samples stored at 4 °C. According to sensory evaluation, the shelf-life was shorter for the control samples in contrast to the S and F samples, where their shelf-life was elongated by 1–2 days. Initial pH values were ca. 6.0 for the three leafy vegetables. An increase in the pH of ca. 0.5 values was recorded until the end of storage at both temperatures for all cases of leafy vegetables. FTIR and MSI analyses did not satisfactorily lead to the estimation of the microbiological quality of salads. In conclusion, the applied bioprotective strain (L. pentosus) can elongate the shelf-life of the RTE salads without an effect on pathogen growth. Full article

During storage, raw meat is exposed to many external factors, which cause visible changes on the surface of the meat and which affect its water-holding capacity. This study aimed to determine the effect of oxygen content in modified atmosphere packaging (MAP) used for storing fresh pork on the colour, pH, value and water-holding capacity during refrigerated storage. The study also analysed the dynamics of changes in colour using the colour difference (ΔE) coefficient and sensory quality. In the study, slices of pork loin were packed in MAP using the following gas compositions: 55% O₂/40% CO₂/5% N₂ and 75% O₂/20%, CO₂/5% N₂; they were then stored for 15 days at a temperature of 4 °C. The colour of pork stored in MAP was significantly affected by time, but not by the proportion of oxygen. During storage, the meat’s lightness (L*), yellowness (b*), chroma, and hue angle increased, whereas its redness index (a*/b*) decreased. Significant differences in colour between freshly packed and stored samples were noted after days 7 and 9 in MAP containing 55% and 75% oxygen, respectively. The values of pH, free water, and purge and cooking loss were not affected by gas concentration but changed over time. Lowering the oxygen content from 75% to 55% in MAP opens the possibility of reducing the oxygen demand from the meat industry without compromising the quality of the meat. Full article

The effect of exposure of soft wheat buns to Ultraviolet-C radiation (UV-C, 253.7 nm) was studied as an alternative to conventional treatments to control fungal spoilage and prolong shelf life. To identify the most suitable operating conditions, the study included preliminary tests on the permeability of films to UV-C irradiation, and on treatment antifungal efficacy on target microorganisms (Penicillium digitatum and Saccharomycopsis fibuligera) in Petri dishes. A 125 µm T9250B film (Cryovac^® Sealed Air S.r.l), commercially available for long-life bread treated with ethanol and conditioned in a modified atmosphere, was selected to pack buns before the UV-C treatment. The study was carried out along with the observation of the fungal growth of buns artificially inoculated with suspensions of P. digitatum and S. fibuligera, treated under UV-C at a distance of 25 cm between bread and the 15 W UV-C source, in comparison to untreated buns used as control. Estimation of fungal growth as well as sensory evaluation was made 2, 4, 7, 10 and 14 days after the treatment. UV-C treated buns showed a noticeable reduction of fungal spoilage and kept a tender texture for up to two weeks after packaging. UV-C treatment represents a good opportunity for the bakery industry, reducing costs and ensuring a prolonged shelf life of a commercial product, respecting the health and hedonistic expectations of the customers. Full article

This study investigated cadaverine as a spoilage indicator in commercial beef products stored under conditions favourable for the growth of lactic acid bacteria. Samples included vacuum-skin-packed entrecotes (EB) aged up to 42 days and modified-atmosphere-packed (70% O₂ + 30% CO₂) minced beef (MB) stored at 5 °C. Two MB product lines were analysed: one stored aerobically two days post-slaughter before mincing and another stored for 14 days in vacuum packaging prior to mincing. Sensory assessment/evaluation and microbial analysis were performed throughout the shelf life of the products and compared to cadaverine levels measured using LC-MS/MS. Cadaverine concentrations in EB reached approximately 40,000 µg/kg on the “best before” date, while remaining below 50 µg/kg in both MB products on the corresponding date. While cadaverine concentrations in EB displayed a consistent increase, suggesting its potential as a spoilage indicator post-ageing, the low concentrations in MB, did not correlate with sensory assessments, revealing its limitations as a universal spoilage marker. In conclusion, it is necessary to conduct product-specific studies to evaluate the applicability of cadaverine as a spoilage indicator for beef products. Full article

High levels of carbon dioxide are known to inhibit the growth of microorganisms. A total of twenty strains of filamentous fungi and yeasts were isolated from habitats with enriched carbon dioxide concentration. Most strains were derived from modified atmosphere packed (MAP) food products or mofettes and were cultivated under an atmosphere of 20% CO₂ and 80% O₂. The influence of CO₂ on fungal cell membrane fatty acid profiles was examined in this study. Major changes were the increase in linolenic acid (C_18:3 cis 9, 12, 15) and, additionally in most strains, linoleic acid (C_18:2 cis 9, 12) with a maximum of 24.8%, at the expense of oleic (C_18:1 cis 9), palmitic (C_16:0), palmitoleic (C_16:1 cis 9) and stearic acid (C_18:0). The degree of fatty acid unsaturation increased for all of the strains in the study, which consequently led to lower melting temperatures of the cell membranes after incubation with elevated levels of CO₂, indicating fluidization of the membrane and a potential membrane malfunction. Growth was reduced in 18 out of 20 strains in laboratory experiments and a change in pigmentation was observed in several strains. Two of the isolated strains, strain WT5 and strain WR1, were found to represent a hitherto undescribed yeast for which the new genus and species Stenotrophomyces fumitolerans (MB# 849906) is proposed. Full article

Dates are highly perishable fruits, and maintaining their quality during storage is crucial. The current study aims to investigate the impact of storage conditions on the quality of dates (Khalas and Sukary cultivars) at the Tamer stage and predict their quality attributes during storage using artificial neural networks (ANN). The studied storage conditions were the modified atmosphere packing (MAP) gases (CO₂, O₂, and N), packaging materials, storage temperature, and storage time, and the evaluated quality attributes were moisture content, firmness, color parameters (L*, a*, b*, and ∆E), pH, water activity, total soluble solids, and microbial contamination. The findings demonstrated that the storage conditions significantly impacted (p < 0.05) the quality of the two stored date cultivars. The use of MAP with 20% CO₂ + 80% N had a high potential to decrease the rate of color transformation and microbial growth of dates stored at 4 °C for both stored date cultivars. The developed ANN models efficiently predicted the quality changes of stored dates closely aligned with observed values under the different storage conditions, as evidenced by low Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE) values. In addition, the reliability of the developed ANN models was further affirmed by the linear regression between predicted and measured values, which closely follow the 1:1 line, with R² values ranging from 0.766 to 0.980, the ANN models demonstrate accurate estimating of fruit quality attributes. The study’s findings contribute to food quality and supply chain management through the identification of optimal storage conditions and predicting the fruit quality during storage under different atmosphere conditions, thereby minimizing food waste and enhancing food safety. Full article

This multi-disciplinary paper aims to provide a roadmap for the development of an integrated, process-intensified technology for the production of H₂, NH₃ and NH₃-based symbiotic/smart fertilizers (referred to as target products) from renewable feedstock with CO₂ sequestration and utilization while addressing environmental issues relating to the emerging Food, Energy and Water shortages as a result of global warming. The paper also discloses several novel processes, reactors and catalysts. In addition to the process intensification character of the processes used and reactors designed in this study, they also deliver novel or superior products so as to lower both capital and processing costs. The critical elements of the proposed technology in the sustainable production of the target products are examined under three-sections: (1) Materials: They include natural or synthetic porous water absorbents for NH₃ sequestration and symbiotic and smart fertilizers (S-fertilizers), synthesis of plasma interactive supported catalysts including supported piezoelectric catalysts, supported high-entropy catalysts, plasma generating-chemical looping and natural catalysts and catalysts based on quantum effects in plasma. Their performance in NH₃ synthesis and CO₂ conversion to CO as well as the direct conversion of syngas to NH₃ and NH₃—fertilizers are evaluated, and their mechanisms investigated. The plasma-generating chemical-looping catalysts (Catalysts, 2020, 10, 152; and 2016, 6, 80) were further modified to obtain a highly active piezoelectric catalyst with high levels of chemical and morphological heterogeneity. In particular, the mechanism of structure formation in the catalysts BaTi_1−rM_rO_3−x−y{#}_xN_z and M₃O_4−x−y{#}_xN_z/Si = X was studied. Here, z = 2y/3, {#} represents an oxygen vacancy and M is a transition metal catalyst. (2) Intensified processes: They include, multi-oxidant (air, oxygen, CO₂ and water) fueled catalytic biomass/waste gasification for the generation of hydrogen-enriched syngas (H₂, CO, CO₂, CH₄, N₂); plasma enhanced syngas cleaning with ca. 99% tar removal; direct syngas-to-NH₃ based fertilizer conversion using catalytic plasma with CO₂ sequestration and microwave energized packed bed flow reactors with in situ reactive separation; CO₂ conversion to CO with BaTiO_3−x{#}_x or biochar to achieve in situ O₂ sequestration leading to higher CO₂ conversion, biochar upgrading for agricultural applications; NH₃ sequestration with CO₂ and urea synthesis. (3) Reactors: Several patented process-intensified novel reactors were described and utilized. They are all based on the Multi-Reaction Zone Reactor (M-RZR) concept and include, a multi-oxidant gasifier, syngas cleaning reactor, NH₃ and fertilizer production reactors with in situ NH₃ sequestration with mineral acids or CO₂. The approach adopted for the design of the critical reactors is to use the critical materials (including natural catalysts and soil additives) in order to enhance intensified H₂ and NH₃ production. Ultimately, they become an essential part of the S-fertilizer system, providing efficient fertilizer use and enhanced crop yield, especially under water and nutrient stress. These critical processes and reactors are based on a process intensification philosophy where critical materials are utilized in the acceleration of the reactions including NH₃ production and carbon dioxide reduction. When compared with the current NH₃ production technology (Haber–Bosch process), the proposed technology achieves higher ammonia conversion at much lower temperatures and atmospheric pressure while eliminating the costly NH₃ separation process through in situ reactive separation, which results in the production of S-fertilizers or H₂ or urea precursor (ammonium carbamate). As such, the cost of NH₃-based S-fertilizers can become competitive with small-scale distributed production platforms compared with the Haber–Bosch fertilizers. Full article

The quality changes of gutted rainbow trout in vacuum packaging (VP) and modified atmosphere packaging (MAP) with 40% CO₂ + 60% N₂ (MAP1), 60% CO₂ + 40% N₂ (MAP2), and 90% CO₂ + 10% N₂ (MAP3) were evaluated. The samples were stored at 3 ± 0.5 °C, and on days 1, 4, 7, 10, 13, and 16 of storage, microbiological, chemical, and sensory testing was performed. The aerobic plate count (APC) and psychrotrophic bacteria count (PBC) in VP fish exceeded the conventional limit of 7 log cfu/g on day 10, and in MAP1 and MAP2 fish on day 16, whereas in MAP3 fish, their number remained below that limit during the experiment. MAP significantly slowed down the growth of Enterobacteriaceae in trout, and the degree of inhibition increased with increasing CO₂ concentration in the gas mixture. The lowest lactic acid bacteria numbers were detected in VP fish, whereas the highest numbers were determined in trout packaged in MAP2 and MAP3. Significantly lower numbers of hydrogen sulfide-producing (H₂S) bacteria were detected in fish packed in MAP. Distinct patterns were observed for pH among treatments. The lowest increase in TBARS values was detected in VP and MAP3 fish, whereas in MAP1 and MAP2 fish, the TBARS values were higher than 1 mg MDA/kg on day 16 of storage when a rancid odor was detected. MAP inhibited the increase in total volatile basic nitrogen (TVB-N) content of trout compared to trout packaged in a vacuum. The sensory attributes of trout perceived by the sensory panel changed significantly in all experimental groups during storage. Based primarily on sensory, but also microbial, and chemical parameters, MAP has great potential for preserving fish quality and extending the shelf life of gutted rainbow trout from 7 days in VP to 13 days in MAP1 and MAP2, and to 16 days in MAP3. Full article

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. Full article