scholarly journals Microwave-Assisted Solid Extraction from Natural Matrices

2021 ◽  
Author(s):  
Valeria Cavalloro ◽  
Emanuela Martino ◽  
Pasquale Linciano ◽  
Simona Collina

The extraction of secondary metabolites from plants, and natural sources in general, is a cornerstone in medicinal chemistry and required the development of sustainable extraction techniques. Microwave-Assisted Solid Extraction (MASE) is a promising extractive methodology being more effective than traditional extraction techniques. It offers higher and faster extraction performance ability with less solvent consumption and protection toward thermolabile constituents. For these reasons, MASE resulted in a suitable extractive methodology in all aspects, including economical and practical, compared to traditional extraction techniques, especially over Soxhlet or solid–liquid extraction. In this chapter, a brief theoretical background about the use of microwave energy for extraction has been presented for better understanding. Then, the potential of MASE for the extraction of secondary metabolites from natural resources, for evaluating the plant productivity and for evaluating the quality of the natural matrices will be reviewed. The discussion is supported by reporting recent applicative examples of MASE applied to the extraction of the most representative chemical classes of secondary metabolites, with a special focus on some drugs or compounds of pharmaceutical and nutraceutical interest.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1766
Author(s):  
Laura Benassi ◽  
Ivano Alessandri ◽  
Irene Vassalini

In this work, we assess three different methods for the extraction of pectin from waste orange peels, using water as extracting solvent. “Hot-water”, Rapid Solid Liquid Dynamic (RSLD) and microwave-assisted extractions have been compared and evaluated in terms of amount and quality of extracted pectin, as well as embodied energy. This analysis provides useful guidelines for pectin production from food waste according to green procedures, enabling the identification of acidic “hot-water” as the most sustainable extraction route.



2014 ◽  
Vol 30 (6) ◽  
Author(s):  
Jibrin Mohammed Danlami ◽  
Agus Arsad ◽  
Muhammad Abbas Ahmad Zaini ◽  
Hanizam Sulaiman

AbstractResearchers have shown that techniques such as microwave-assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction developed for extraction of valuable components from plants and seed materials have been successfully used to effectively reduce the major shortcomings of the traditional method such as Soxhlet extraction. These include shorter extraction time, increase in yield of extracted components, decrease in solvent consumption, and improvement of the quality of extracts. This review presents a detailed description of the principles and mechanisms of the various extraction techniques for better understanding and summarizes the potential of these techniques in the extraction of oil from plants and seed materials. Discussions on some of the parameters affecting the extraction efficiency are also highlighted, with special emphasis on supercritical fluid extraction. A comparison of the performance of traditional Soxhlet extraction with that of other extraction techniques is also presented.



2018 ◽  
Vol 28 (3) ◽  
pp. 1027-1030
Author(s):  
Gergana Todorova - Markova

The article is focused on the communication with children with special educational needs. The main topic is alternative communication with children with sensory disorders and multiple disabilities. It explores the phenomenon of communication, citing current definitions developed by a number of authors, which place the emphasis on different aspects of this complex and multilayered process, with a special focus on alternative communication with the groups of special needs children mentioned in the title.The issue is investigated from a special pedagogical and from a social perspective.The author is especially interested in the exploration of the multiple strata of communication (the universal, functional and specific levels). Apart from the different forms, contents, methods and means of communication (the last of which is most commonly discussed in Bulgaria), the article is focused primarily on the important methodological issues related to this topic.One of these basic questions of methodology is the attempt not to place at the center of this process its bi-directional nature, its algorithm or code (sign language, Braille writing system, etc.), but instead to focus on the personalities of those involved in the interaction, their initiative, relationship and goals manifested in different communication situations (mutual influence, emancipation and therapy). Particular emphasis is given to therapy, i.e. the way of influencing the communication behavior of children with sensory disorders and multiple disabilities. It is not viewed as a unilateral process (stimulus-response), but as an interactive one, based on mutual influence. The relationship between the communicators is of utmost significance.Communication is characterized by a number of specific features. Those can mostly be found in the specificity of the communication situations (for example the interactive situations in the following pairs of communicators: deaf – hard of hearing; deaf – deaf; deaf-blind – deaf, etc.), in the presence of an intermediary (for example a sign language interpreter) and above all in the personalities of the communicators. They change the quality of communication. It is for this reason, and not just because of the different means of communication, that this interaction is defined as “alternative”, or more precisely, it is an alternative to the communication of children without disabilities.Based on the analyzed information, the author formulates a number of inferences and recommendations. The main conclusion is the following:When discussing alternative communication with children with special educational needs, the focus should shift from the specific means of communication towards the equally socially important quality of the complex process of communication, which is centered on the personality of the handicapped child.



2020 ◽  
Vol 27 (11) ◽  
pp. 1836-1854 ◽  
Author(s):  
Elena Ancheeva ◽  
Georgios Daletos ◽  
Peter Proksch

Background: Endophytes represent a complex community of microorganisms colonizing asymptomatically internal tissues of higher plants. Several reports have shown that endophytes enhance the fitness of their host plants by direct production of bioactive secondary metabolites, which are involved in protecting the host against herbivores and pathogenic microbes. In addition, it is increasingly apparent that endophytes are able to biosynthesize medicinally important “phytochemicals”, originally believed to be produced only by their host plants. Objective: The present review provides an overview of secondary metabolites from endophytic fungi with pronounced biological activities covering the literature between 2010 and 2017. Special focus is given on studies aiming at exploration of the mode of action of these metabolites towards the discovery of leads from endophytic fungi. Moreover, this review critically evaluates the potential of endophytic fungi as alternative sources of bioactive “plant metabolites”. Results: Over the past few years, several promising lead structures from endophytic fungi have been described in the literature. In this review, 65 metabolites are outlined with pronounced biological activities, primarily as antimicrobial and cytotoxic agents. Some of these metabolites have shown to be highly selective or to possess novel mechanisms of action, which hold great promises as potential drug candidates. Conclusion: Endophytes represent an inexhaustible reservoir of pharmacologically important compounds. Moreover, endophytic fungi could be exploited for the sustainable production of bioactive “plant metabolites” in the future. Towards this aim, further insights into the dynamic endophyte - host plant interactions and origin of endophytic fungal genes would be of utmost importance.



Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 787
Author(s):  
Minaxi Sharma ◽  
Rajeev Bhat

Natural pigments improve aesthetic value as well as antioxidant potential of a food product. This study was designed to determine the effects of green extraction techniques on carotenoids, polyphenols and antioxidant activities of pulp and peel of two varieties of pumpkin (Cucurbita maxima). Innovative green extractions (IGE; Ultrasound and Microwave-Assisted Extractions) synergised with corn oil (used as green solvent) were compared with conventional extraction (CE; hexane/isopropyl alcohol; 60:40, v/v). Results showed total carotenoids to be almost double on employing IGE (PM2-UAE-peel = 38.03 ± 4.21; PM4-UAE-peel = 33.78 ± 1.76 µg/g) when compared to conventional extraction (PM2-CE-peel = 19.21 ± 4.39; PM4-CE-peel = 16.21 ± 2.52 µg/g). Polyphenolic contents ranged between 510.69 ± 5.50 and 588.68 ± 7.26 mg GAE/100 g of extract in IGE, compared with conventional extracts (269.50 ± 2.17 to 318.46 ± 6.60 mg GAE/100 g) and percent inhibition of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) ranging between 88.32 ± 1.51 and 93.53 ± 0.30% in IGE when compared with conventional extraction (50.61 ± 1.44 to 57.79 ± 2.09%). Further, oxidative stability of carotenoids extracts from IGE (protection factor = 1.59 ± 0.01 to 1.81 ± 0.05) were found to be significantly higher (p < 0.05) than conventional extracts. Based on results, this study supports the use of innovative green extraction techniques to obtain bioactive pigments like carotenoids. It is anticipated that results generated will find potential applications in food, pharmaceutical and cosmetic industries.



2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Izabela Grabowska ◽  
Radosław Antczak ◽  
Jan Zwierzchowski ◽  
Tomasz Panek

Abstract Background The United Nations Convention on the Rights of Persons with Disabilities [1] highlights the need to create proper socioeconomic and political conditions for persons with disabilities, with a special focus on their immediate living conditions. According to the Convention, these conditions should be built to ensure that persons with disabilities have the potential to enjoy a high quality of life (QoL), and this principle is reflected in the notion of livable areas. The crucial aspect of this framework is the relationship between the individual QoL and the environment, broadly understood as the socioeconomic as well as the technical conditions in which persons with disabilities function. Methods The basic research problem was to assess the relationship between individual QoL for the population with disabilities as a dependent variable and livability indicators as independent variables, controlling for individual characteristics. The study used a dataset from the EU-SILC (European Union Statistics on Income and Living Conditions) survey carried out in 2015 in Poland. The research concept involved several steps. First, we created a variable measuring the QoL for the entire population with disabilities. To measure the multidimensional QoL, we used Sen’s capability approach as a general concept, which was operationalized by the MIMIC (multiple indicators multiple causes) model. In the second step, we identified the livability indicators available in the official statistics, and merged them with survey data. Finally, in the last step, we ran the regression analysis. We also checked the data for the nested structure. Results We confirmed that the general environmental conditions, focused on creating livable areas, played a significant role in shaping the QoL of persons with disabilities; i.e., we found that the higher the level of the local Human Development Index, the higher the quality of life of the individuals living in this area. This relationship held even after controlling for the demographic characteristics of the respondents. Moreover, we found that in addition to the general environmental conditions, the conditions created especially for persons with disabilities (i.e., services for this group and support for their living conditions) affected the QoL of these individuals. Conclusions The results illustrate the need to strengthen policies aimed at promoting the QoL of persons with disabilities by creating access to community assets and services that can contribute to improving the life chances of this population.



Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 103
Author(s):  
Jin Mark D. G. Pagulayan ◽  
Aprille Suzette V. Mendoza ◽  
Fredelyn S. Gascon ◽  
Jan Carlo C. Aningat ◽  
Abigail S. Rustia ◽  
...  

The study aimed to evaluate the effects of process parameters (time and raw material weight (RMW)) of conventional (boiling for 10–45 min) and microwave-assisted (2–8 min) aqueous extraction on the color quality (i.e., lightness (L*), chroma (C*), and hue (H°) of anthocyanin –based colorants of red and Inubi sweet potato (Ipomoea batatas L.) leaves. Using response surface methodology, it was found that RMW and boiling time (BT) and microwave time (MT) generally had a significant (p < 0.05) effect on the color quality of the extract from both extraction methods. The effects were found to vary depending on the extraction method and variety of the leaves used. Both extraction methods produced a brown to brick-red extract from the Inubi variety that turned red-violet to pink when acidified. The red sweet potato leaves produced a deep violet colored extract that also turned red-violet when acidified. It is recommended that the anthocyanin content of the extracts be measured to validate the impact of the methods on the active agent. Nevertheless, the outcomes in this study may serve as baseline data for further studies on the potential of sweet potato leaf colorants (SPLC) as a colorant with functional properties.



Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 114
Author(s):  
Tiziano Zarra ◽  
Mark Gino K. Galang ◽  
Florencio C. Ballesteros ◽  
Vincenzo Belgiorno ◽  
Vincenzo Naddeo

Instrumental odour monitoring systems (IOMS) are intelligent electronic sensing tools for which the primary application is the generation of odour metrics that are indicators of odour as perceived by human observers. The quality of the odour sensor signal, the mathematical treatment of the acquired data, and the validation of the correlation of the odour metric are key topics to control in order to ensure a robust and reliable measurement. The research presents and discusses the use of different pattern recognition and feature extraction techniques in the elaboration and effectiveness of the odour classification monitoring model (OCMM). The effect of the rise, intermediate, and peak period from the original response curve, in collaboration with Linear Discriminant Analysis (LDA) and Artificial Neural Networks (ANN) as a pattern recognition algorithm, were investigated. Laboratory analyses were performed with real odour samples collected in a complex industrial plant, using an advanced smart IOMS. The results demonstrate the influence of the choice of method on the quality of the OCMM produced. The peak period in combination with the Artificial Neural Network (ANN) highlighted the best combination on the basis of high classification rates. The paper provides information to develop a solution to optimize the performance of IOMS.



Author(s):  
Arja Rautio ◽  
Natalia Kukarenko ◽  
Lena Maria Nilsson ◽  
Birgitta Evengard

Climate change in the Arctic affects both environmental, animal, and human health, as well as human wellbeing and societal development. Women and men, and girls and boys are affected differently. Sex-disaggregated data collection is increasingly carried out as a routine in human health research and in healthcare analysis. This study involved a literature review and used a case study design to analyze gender differences in the roles and responsibilities of men and women residing in the Arctic. The theoretical background for gender-analysis is here described together with examples from the Russian Arctic and a literature search. We conclude that a broader gender-analysis of sex-disaggregated data followed by actions is a question of human rights and also of economic benefits for societies at large and of the quality of services as in the health care.



2006 ◽  
Vol 61 (5-6) ◽  
pp. 347-350 ◽  
Author(s):  
Rilka M. Taskova ◽  
Holger Zorn ◽  
Ulrich Krings ◽  
Henning Bouws ◽  
Ralf G. Berger

Different techniques were compared for their effectiveness in the disruption of the rigid cell walls of Basidiomycetes. Grinding under liquid nitrogen, stirred glass bead milling and enzymatic cell lysis were applied to the mycelia of Pleurotus sapidus and Lepista irina grown submerged. Each of the disruption procedures was evaluated by testing the quantity and quality of released intracellular metabolites: DNA, RNA, enzymes, and secondary metabolites. The most suitable method for nucleic acid isolation was grinding under liquid nitrogen, while bead mill homogenization was the superior technique for isolation of active enzymes. A new effective method is proposed for isolation of secondary metabolites with the aid of bead milling of fungal mycelia.



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