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The Cross-Talk between Bioremediation and Valuation of Residues of the Olive-Oil Production Chain
Published in Sanjay K. Sharma, Bioremediation, 2019
Ana Filipa Domingues, Inês Correia Rosa, Ruth Pereira, Joana Luísa Pereira
Although when heavily concentrated as in OOMW, polyphenols drive severe toxic effects in different biological receptors (see Section 6.2.3), when used in appropriate doses, these compounds have potential benefits to human health (Gebreyohannes et al. 2016). The benefits of polyphenolic compounds present in OOMW, such as flavonoids and carotenoids, relate to their high activity as antioxidant, anti-inflammatorie, antiallergic, antiviral and antitumor compounds (Aggoun et al. 2016; El-Abbassi et al. 2012; Obied et al. 2005). Among them, hydroxytyrosol is the one with greater antioxidant activity given its great ability to protect cells against oxidative stress (Aggoun et al. 2016; El-Abbassi et al. 2012; Kalogerakis et al. 2013). Antioxidant compounds act through the chelation or scavenging of free radicals, such as the superoxide anion, hydrogen peroxide or the hydroxyl radical preventing them to impair biomolecules such as proteins, lipids and DNA.
Extraction, Isolation and Utilisation of Bioactive Compounds from Waste Generated by the Olive Oil Industry
Published in Quan V. Vuong, Utilisation of Bioactive Compounds from Agricultural and Food Waste, 2017
J. Lozano-Sánchez, I. Cea Pavez, E. González-Cáceres, H. Núñez Kalasic, P. Robert Canales, A. Segura Carretero
With regard to conventional extraction technologies, several methodologies have been reported to provide phenolic enriched extracts, mainly in hydroxytyrosol, from olive by-products. The main systems for recovering the phenolic compounds include resin chromatography, membrane technologies (filtration and reverse osmosis) and solid-liquid or liquid-liquid solvent extractions. Among these processes, resin chromatography has proved a convenient and effective way for isolating phenolic compounds from aqueous solutions. This technique was applied by using different kinds of polymeric adsorbents. A patented system proposed to purify hydroxytyrosol from OMWW includes two-step chromatographic treatment. The process uses a nonactivated ion-exchange-resin chromatographic method, followed by a second treatment on an XAD-type absorbent non-ionic resin which concentrates and completely purifies the hydroxytyrosol by means of elution with a methanol or ethanol: water dissolution (from 30–33 per cent). The final concentration in the obtained solution is at least 75 per cent of hydroxytyrosol, followed by removal of the polar organic solvent to produce a solid containing 95 per cent by weight of hydroxytyrosol. The patented system may also be applied to two-phase pomaces, three-phase pomaces and stones when subjected to a steam explosion process (Fernandez-Bolanos et al. 2002).
Waste frying oil hydrolysis and lipase production by cold-adapted Pseudomonas yamanorum LP2 under non-sterile culture conditions
Published in Environmental Technology, 2021
Senba Komesli, Sumeyya Akbulut, Nazli Pinar Arslan, Ahmet Adiguzel, Mesut Taskin
Data summarized in Table 5 indicate that oil concentration significantly affected lipase activities in the media. This result is consistent with those reported in previous studies [50,51]. The maximum lipase activity in both sterile (75.7 U/L) and non-sterile (78.2 U/L) media could be attained at a waste frying oil concentration of 40 mL/L. Concentrations over 40 mL/L gradually decreased the lipase activity, probably due to the presence of some inhibitory compounds inside waste frying oil. This is because it has been documented that olive oil contains some antimicrobial compounds such as tyrosol, hydroxytyrosol dihydroxy phenyl glycol and oleuropein [52]. Furthermore, it is well known that many physical and chemical changes in oil structure occur during the frying process [13]. Therefore, it was considered that new compounds arising after the frying process might have also restricted the lipase activity in the test bacterium.
Isolation, identification and optimization of enhanced production of laccase from Galactomyces geotrichum under solid-state fermentation
Published in Preparative Biochemistry & Biotechnology, 2021
Khadijeh Pourkhanali, Gholam Khayati, Farhang Mizani, Fereshteh Raouf
In order to produce cost effective and efficient laccase enzyme under solid-state fermentation, the selection of appropriate lignocellulosic substrate should be considered. Among SSF substrates used for fungal laccase production, wheat straw was found to be superior due to its high protein, hemi-cellulosic and lignin content.[30,36–38] Also, it is reported that the olive leaf is a natural nitrogen source and when supplemented with an organic nitrogen source like yeast extract, it can be an effective substrate for laccase production. In addition, olive leaves contain phenolic compounds such as hydroxytyrosol and oleuropein which can act as natural inducers for the production of laccase.[18] Thus equal proportions of OL and WS were used as the solid substrate in our experiments.
Biosynthesis, characterization and antioxidant activity of oleuropein-mediated silver nanoparticles
Published in Inorganic and Nano-Metal Chemistry, 2020
Nusret Genc, Ilyas Yildiz, Radia Chaoui, Ramazan Erenler, Cengiz Temiz, Mahfuz Elmastas
Plants have been used extensively from ancient times due to their significant bioactive contents.[6–12] The olive tree known as Olea europaea L. belongs to the Oleaceae family, is native to warm temperature regions of the world. Olive leaves have been employed for their medicinal properties for years. Olive oil has a preventive effect and it significantly declines the risk of cancer. In addition, consumption of olive oil decreases the considerable the risk of developing breast cancer as well as digestive system cancer.[13] The olive oil contains phenolic acids and derivatives, phenolic alcohols, secoiridoids, lignans, and flavonoids.[14] Oleuropein is found in olive leaves as a major product.[15] Oleuropein is an ester of hydroxytyrosol including an oleosidic skeleton and a carbohydrate group. Oleuropein has been reported to have antioxidant, anticancer, anti-inflammatory, cardioprotective, cardioprotective, hepatoprotective effects.[15–17] Paramagnetic nano-oleuropein was synthesized and it revealed the inhibition of AGS cancer cells.[18] Although the antibacterial activity of the olive leaves-mediated silver nanoparticles was investigated,[19] there was not any study on silver nanoparticles using oleuropein as a natural product isolated from olive leaves. Herein, silver nanoparticles using oleuropein were synthesized, characterized and their antioxidant activity was investigated.