Iskanje po katalogu digitalne knjižnice

Opis: H. pluvialis is a unicellular freshwater alga containing many bioactive compounds, especially carotenoids, which are the strongest antioxidants among the pigments. This study evaluates the composition and content of carotenoids and other pigments in both stages of algae life cycle, especially in the green vegetative stage, less studied in comparison to the red stage. To determine the composition and content of carotenoids, a combination of HPLC-DAD and LC-QTOF-MS was used. The content of carotenoids in the green vegetative stage was significantly lower than in the red vegetative stage. In the green vegetative stage, 16 different carotenoids and other pigments were identified. Among the total 8.86 mg g−1 DW of pigments, 5.24 mg g−1 DW or 59% of them were chlorophyll a with its derivatives, and 3.62 mg g−1 DW or 41% of them were free carotenoids. After the transition from the green to the red stage, the carotenoid composition was replaced by secondary carotenoids, astaxanthin and its esters, which predominated in the whole carotenoid composition. In addition to free astaxanthin, 12 astaxanthin monoesters, 6 diesters and 13 other carotenoids were determined. The majority of 37.86 mg g−1 DW pigments were monoesters. They represented 82% of all pigments, and their content was about 5 times higher than both, diesters (5.91 mg g−1 DW or 12% of all) and free carotenoids (2.4 mg g−1 DW or 6% of all). The results of the study contribute to the data on the overall pigment composition and content of H. pluvialis algae and provide the basis for further improvement of cultivation of the H. pluvialis algae.
Ključne besede: antioxidants, astaxanthin, chlorophylls, bioactive compounds, algae, Haematococcus, life cycle, pigment composition, secondary carotenoids
Objavljeno v DKUM: 21.05.2024; Ogledov: 172; Prenosov: 13
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Opis: Plastic production and its end-of-life management pose a significant environmental footprint. The mitigation strategies of the plastic industry are comparatively attainable than the other hard-to-abate sector. However, the involvement of different stakeholders is needed. The life cycle analysis proposed in this study allocated the environmental footprint to stakeholders based on the game theory concept. It addresses the limitation of previous approaches that do not guarantee the stakeholders from different stages will participate in the initiatives with the lowest net environmental footprint due to the dissatisfaction or imbalance in the allocated unburdening footprint (benefit) and burdening footprint. The applicability of the proposed approach is demonstrated through a plastic recycling case study. An allocation of 82 % of environmental benefit to the producer, 14 % to the manufacturer, and 4 % to the user are suggested to achieve efficiency (lowest external interference) and stable cooperation (participation in recycling). This work serves as an initial assessment in demonstrating the integration of the game theory concept in environmental footprint allocation or Life Cycle Assessment.
Ključne besede: plastic production, environmental footprint, life cycle
Objavljeno v DKUM: 18.04.2024; Ogledov: 155; Prenosov: 4
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Opis: Japanese knotweed is an invasive alien plant species with characteristic rapid expansion in Europe and North America and resistance to extermination. It displaces autochthonous biodiversity and causes major damage to infrastructure, thus causing global ecological and economic damage. The Japanese knotweed plant is usually eradicated using various chemical, biological, or mechanical techniques, which at a large scale include heavy equipment, usually followed by incineration. Therefore, excavation is preferred to eradication techniques, and as a biomass waste recovery method due to the extraction of high-value biocompounds. This is supported by the fact that the Japanese knotweed possesses various bioactive compounds with beneficial effects on human health. Its rhizome bark extract produces strong and stable antioxidant activity over time, as well as apoptotic, antibacterial, and other beneficial activities. In this work, an environmental impact assessment, including greenhouse gas footprint, acidification, eutrophication, and ecotoxicity for extraction route of the Japanese knotweed rhizome bark, is performed. A comparative case study between the lab-based and proposed pilot-scale production of active added-value extract was evaluated. The results show the pilot-scale production exhibits lower environmental burdens, mainly due to greater electricity requirements for the lab-scale alternative.
Ključne besede: Japanese knotweed rhizome bark extract, invasive alien plant species, bioactive compounds, lab-scale, pilot-scale, life cycle assessment (LCA), environmental burden assessment
Objavljeno v DKUM: 19.03.2024; Ogledov: 236; Prenosov: 17
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Opis: Food supply chains have a significant impact on the environment, using large amounts of fossil energy resources and other non-renewable resources. Energy is directly and indirectly needed in all the steps along the food supply chain. This paper explores energy-related indicators in food supply chains and life cycle assessment within sixty-six research papers, gathered from the Web of Science database. Furthermore, a quantitative content analysis was carried out to assess the research trends and future opportunities regarding energy-related topics. The results revealed that a holistic perspective is needed, as energy-related indicators should be included in the use and end-of-life stages, not only in the production processes, and that the inclusion should follow the life cycle assessment methodology. The current research topics are energy issues related to production processes and environmental impacts. Improvements are possible in extending research areas to renewable resources, whole lifecycle perspectives, and socio-economic consequences.
Ključne besede: energy, food supply chain, life cycle assessment, Leximancer
Objavljeno v DKUM: 05.12.2023; Ogledov: 368; Prenosov: 5
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Opis: The seafood processing industry generates substantial amounts of waste, particularly from the shells of crustaceans. These shells currently hold limited to no value within the food sector, and the current methods of disposal can have negative impact on the natural bioecology. However, these shells still contain valuable compounds such as polymers, minerals, and polyphenols, which could be further utilized. Extracting these compounds using a biorefinery approach, which emphasizes sustainability, could be a viable solution. This master thesis aims to assess the environmental implications, using the Life Cycle Assessment methodology, of a shrimp shell biorefinery process, to produce valuable products, like proteins, chitin, astaxanthin and calcium carbonate. The laboratory-scale biorefinery process was initially upscaled to both pilot and industrial scales, based on equipment design. Also, a comparison between the calculated power demand of units and the power demand of units, derived from Aspen Capital Cost Estimator, was also done. For the laboratory, pilot and industrial sized process, the energy consumption was determined combined with the environmental impact assessment, such as global warming, eutrophication, acidification, ecotoxicity potentials and other. The functional unit was the production of 1 kg of chitin, where the capacity of the laboratory process was linearly scaled up. The evaluation of energy consumption revealed significant disparities among the different scales. Specifically, the upscaled laboratory process exhibited significantly higher energy consumption per kg of chitin (5,882.1 kWh) in comparison to the pilot (62.3 kWh) and industrial (21.1 kWh) scales. This outcome underscores the inadequacies of employing a linear scale-up in environmental analysis. Notably, centrifugation dominated electrical energy consumption at the laboratory-scale and industrial-scale, while refrigeration took over this role at the pilot-scale process. Related to impact assessment it was found that both pilot- and industrial-scale processes demonstrated lower overall environmental impacts, compared to the laboratory-scale process in all evaluated categories. Acidification, photochemical oxidation, eutrophication and global warming potential exhibited the most significant variations, with reductions ranging up to 97 %, while ozone layer depletion displayed only a 17 % decrease. Importantly, all three scales also exhibited some positive effects (unburdening the environment) due to the use of shrimp shell materials, with particularly noticeable improvements in the category of terrestrial ecotoxicity.
Ključne besede: Shrimp shells, Biorefinery, Process design, Life cycle assessment (LCA), Circular bioeconomy, Process Scale-up
Objavljeno v DKUM: 04.10.2023; Ogledov: 473; Prenosov: 0
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