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1.
Bioresour Technol ; 406: 131024, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38914238

RESUMO

The rising prices of fishery derivatives limits their use in aquafeeds. Therefore, other alternatives are used to replace those ingredients. Among them, microalgae are of great interest both as an ingredient and as a potential stabilising agent against lipid oxidation. This study evaluates on the use of Nannochloropsis gaditana to prevent lipid oxidation in a set of 12 aquafeeds over 540 days of storage. Aquafeeds were formulated with/without 15 % N. gaditana combined with two antioxidants -butylhydroxytoluene (25-150 mg·kg-1) or vitamin E (500-3000 mg·kg-1). The effect of i) storage period, ii) presence of microalgae and iii) antioxidant addition on lipid oxidation was assessed. Results showed higher fatty acid degradation in diets lacking microalgae. The microalgae supplemented diets is enough for preserving feeds presenting the highest antioxidant effect at the end, without significant differences with the microalgae-supplemented feeds and those including antioxidants after 540 days of storage.

2.
Bioresour Technol ; 379: 129057, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37059341

RESUMO

This paper demonstrates a sequential partitioning method for isolating bioactive compounds from Chrysochromulina rotalis using a polarity gradient, replacing classic and hazardous solvents with greener alternatives. Seventeen solvents were evaluated based on their Hansen solubility parameters and for having a similar polarity to the solvents they would replace, four of which were selected as substitutes in the classic fractionation process. Considering the fatty acid and carotenoid recovery yields obtained for each of the solvents, it has been proposed to replace hexane (HEX), toluene (TOL), dichloromethane (DCM) and n-butanol (BUT) with cyclohexane, chlorobenzene, isobutyl acetate and isoamyl alcohol, respectively. In addition, cytotoxic activity was observed when the TOL and DCM solvent extracts were tested against tumour cell lines, demonstrating the antiproliferative potential of compounds containing, for example, fucoxanthin, fatty acids, peptides, isoflavonoids or terpenes, among others.


Assuntos
Ácidos Graxos , Tolueno , Solventes/química , Fracionamento Químico , Extratos Vegetais/farmacologia
3.
Bioresour Technol ; 342: 125922, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34547712

RESUMO

An amphidinol-prioritized fractioning approach was for the first time developed to isolate multiple specialty metabolites such as amphidinols, carotenoids and fatty acids using the biomass of the marine microalgae Amphidinium carterae. The biomass was produced in a raceway photobioreactor and the exhausted culture media were reused, thus fulfilling sustainability criteria employing a circular economy concept. The integrated bioactive compounds-targeted approach presented here consisted of four steps with which recovery percentages of carotenoids, fatty acids and amphidinols of 97%, 82% and 99 %, respectively, were achieved. The proposed process was proved to be a better extraction system for this microalga than another based on a sequential gradient partition with water and four water-immiscible organic solvents (hexane, carbon tetrachloride, dichloromethane and n-butanol). The proposed process could be scaled-up as a commercial solid-phase extraction technology well-established for industrial bioprocesses.


Assuntos
Dinoflagellida , Microalgas , Biomassa , Carotenoides , Fotobiorreatores
4.
Biotechnol Biofuels ; 14(1): 20, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446259

RESUMO

BACKGROUND: Microalgae have attracted considerable interest due to their ability to produce a wide range of valuable compounds. Pulsed Electric Fields (PEF) has been demonstrated to effectively disrupt the microalgae cells and facilitate intracellular extraction. To increase the commercial viability of microalgae, the entire biomass should be exploited with different products extracted and valorized according to the biorefinery scheme. However, demonstrations of multiple component extraction in series are very limited in literature. This study aimed to develop an effective lipid extraction protocol from wet Scenedesmus almeriensis after PEF-treatment with 1.5 MJ·kgDW-1. A cascade process, i.e., the valorization of several products in row, was tested with firstly the collection of the released carbohydrates in the water fraction, then protein enzymatic hydrolysis and finally lipid extraction. Biomass processed with high pressure homogenization (HPH) on parallel, served as benchmark. RESULTS: Lipid extraction with ethanol:hexane (1:0.41 vol/vol) offered the highest yields from the different protocols tested. PEF-treatment promoted extraction with almost 70% of total lipids extracted against 43% from untreated biomass. An incubation step after PEF-treatment, further improved the yields, up to 83% of total lipids. Increasing the solvent volume by factor 2 offered no improvement. In comparison, extraction with two other systems utilizing only ethanol at room temperature or elevated at 60 °C were ineffective with less than 30% of total lipids extracted. Regarding cascade extraction, carbohydrate release after PEF was detected albeit in low concentrations. PEF-treated samples displayed slightly better kinetics during the enzymatic protein hydrolysis compared to untreated or HPH-treated biomass. The yields from a subsequent lipid extraction were not affected after PEF but were significantly increased for untreated samples (66% of total lipids), while HPH displayed the lowest yields (~ 49% of total lipids). CONCLUSIONS: PEF-treatment successfully promoted lipid extraction from S. almeriensis but only in combination with a polar:neutral co-solvent (ethanol:hexane). After enzymatic protein hydrolysis in cascade processing; however, untreated biomass displayed equal lipid yields due to the disruptive effect of the proteolytic enzymes. Therefore, the positive impact of PEF in this scheme is limited on the improved reaction kinetics exhibited during the enzymatic hydrolysis step.

5.
Bioresour Technol ; 313: 123518, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32512427

RESUMO

The extraction of three families of compounds (carotenoids, fatty acids and amphidinols) from the biomass of two strains of Amphidinium carterae (ACRN03 and Dn241EHU) was improved by tuning cell disruption and solvent extraction operations. The extraction of carotenoids was evaluated using alkaline saponification (0%-60% KOH d.w.) at different temperatures (25-80 °C). High levels of carotenoids were obtained at 60 °C using freeze-dried biomass, not subjected to cell disruption methods. The ACRN03 strain required 20% KOH whereas the Dn241EHU strain did not require saponification since carotenoid degradation was observed. The extraction efficiencies were determined with a wide range of pure solvents and mixtures thereof. Two empirical non-linear equations were used to correlate extraction percentages for each family of compounds with the Hildebrand solubility parameter (δT) and the polarity index of the solvents (PI). Thresholds of δT and PI of around 20 MPa1/2 and 6, respectively, were determined for the extraction of amphidinols, consistent with antiproliferative activity measurements.


Assuntos
Dinoflagellida , Microalgas , Biomassa , Carotenoides , Ácidos Graxos , Solventes
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