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Abstract: Haematococcus pluvialis, a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents—methyl tert-butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)—and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g−1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g−1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters.
Keywords: astaxanthin diesters, astaxanthin monoesters, carotenoids, Hematococcus pluvialis, astaxanthin diesters, solvent extraction
Published in DKUM: 22.11.2024; Views: 0; Downloads: 5
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Abstract: This research showcases the use of hydrothermally extracted solutions from poultry feathers and wool as ecofriendly and versatile textile finishes. These solutions, derived from waste biomass containing the keratin biopolymer, were obtained through environmentally conscious hydrothermal degradation processes. Initially, the study focused on analysing the chemical parameters and properties of both dialysed and non-dialysed solutions extracted from feathers and wool. The investigation tracked primarily the presence of keratin within these solutions. Upon application to polyester textiles as the reference material, the presence of these solutions on the fabric surface was confirmed successfully. A thorough physicochemical analysis of the treated textiles involved various analytical techniques. These encompassed surface composition analysis via X-ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), assessment of wettability through Contact Angle measurements, determination of surface charge using surface zeta potential, and examination of the thermal and flame-retardant properties via Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and calorimetric tests. In addition, the colour, UV radiation transmission and antioxidant activity were evaluated using standard tests. The remarkable effects of the treatment have been observed in the exceptional antioxidative action, fire resistance, UV protection and enhanced hydrophilicity of these innovative multifunctional textiles. This approach holds significant implications across research, economics and society, enriching Material Science by deepening the understanding of materials and their multifaceted properties. Moreover, it promotes resource efficiency, opens new sustainable textile market prospects, and contributes to social impact by supporting environmental sustainability, engaging communities and ensuring health and safety benefits.
Keywords: poultry feathers and wool, hydrothermal extraction, polyester, finishing, green, multifunctionality
Published in DKUM: 03.09.2024; Views: 43; Downloads: 13
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Keywords: supercritical fluid extraction, ultrasound-assisted extraction, hemp, ginger, turmeric, cardamom
Published in DKUM: 08.05.2024; Views: 234; Downloads: 13
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Abstract: Helichrysum italicum (family Asteraceae), due to its various beneficial health effects, represents an important plant in the traditional medicine of Mediterranean countries. Currently, there is a renewed interest in this medicinal plant, especially in investigations involving the isolation and identification of its bioactive compounds from extracts and essential oils, as well as in experimental validation of their pharmacological activities. In this paper, we review the current knowledge on the beneficial health effects of Helichrysum italicum extracts, essential oils, and their major bioactive polyphenolic compounds, ranging from antioxidative, anti-inflammatory, and anticarcinogenic activities to their antiviral, antimicrobial, insecticidal, and antiparasitic effects. This review also provides an overview of the most promising extraction and distillation techniques for obtaining high-quality extracts and essential oils from Helichrysum italicum, as well as methods for determining their antioxidative, antimicrobial, anti-inflammatory, and anticarcinogenic activities. Finally, new ideas for in silico studies of molecular mechanisms of bioactive polyphenols from Helichrysum italicum, together with novel suggestions for their improved bioavailability through diverse encapsulation techniques, are introduced.
Keywords: Helichrysum italicum, polyphenolic compounds, biological effects, extraction methods, distillation methods, encapsulation methods
Published in DKUM: 15.03.2024; Views: 327; Downloads: 11
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Abstract: Red beetroot is well known for its high proportion of betalains, with great potential as functional food ingredients due to their health-promoting properties. The objective of this study was to investigate the influence of processing techniques such as Soxhlet, cold, ultrasound and supercritical fluid extraction on the betalains content and its antioxidant, anti-inflammatory and antihyperglycemic activities. Whilst Soxhlet extraction with water has provided the highest yield, the highest content of total phenolics was found in an extract prepared using Soxhlet extraction with 50% ethanol. Amongst eight phenolic compounds detected in the extracts, protocatechuic acid was the most abundant. The concentrations of total phenolics ranged from 12.09 mg/g (ultrasound extraction with 30% methanol) to 18.60 mg/g (Soxhlet extraction with 50% ethanol). The highest anti-inflammatory activity was observed for cold extraction with 50% methanol extract. The high radical scavenging activity of supercritical fluid extracts could be a consequence of nonphenolic compounds. The chemometrics approach was further used to analyse the results to find the “greenest” method for further possible application in the processing of beetroot in the food and/or pharmaceutical industry. According to the standard score, the best extraction method was determined to be Soxhlet extraction with 50% ethanol.
Keywords: red beetroot, supercritical fluid extraction, antioxidant activity, anti-inflammatory activity, antihyperglycemic activity, chemometric approach
Published in DKUM: 18.08.2023; Views: 436; Downloads: 37
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