Sterols Biosynthesis in Algae

Sterols are secondary metabolites, they are considered bioactive, due to their recognized activity as antioxidants, anticarcinogenic, cardiovascular protectors, and antiviral capacity. These triterpenoids can be found in a wide range of concentrations in different algae strains, being the variations related to external factors. In the world, there are millions of algae, some strains have the ability to produce high-value phytosterols, like stigmasterol, and sitosterol, however, others could lead to cholesterol production. For this reason, understand the principal factors involved in sterols biosynthesis, allows us to appoint the algae strain for industrial application and escalating these specific compounds production. Some algae are capable to produce sterols from mevalonic acid pathway, other strains present the methylerythritol 4-phosphate (MEP), or 1-deoxy-D-xylulose-5-phosphate (DOXP) as the main pathway, each one is responsible for the production of plans of intermediary compounds. In this sense, this chapter summarizes current knowledge of the biosynthetic pathways responsible for different sterols formation, as well as, describe main sterols that could be isolated from algae metabolism

Adding Blends of NaCl, KCl, and CaCl 2

The effect of a 50% reduction of NaCl and its replacement by KCl, CaCl2, and a blend of KCl and CaCl2 (1 : 1) on lipid oxidation of dry fermented sausages was investigated. We found that a 50% reduction in NaCl decreased the intensity of the reactions to lipid oxidation, while treatments with added CaCl2 resulted in increased lipid oxidation during manufacture and storage. Fatty acid composition also changed owing to the presence of KCl and CaCl2, showing a decrease in saturated, monounsaturated, and polyunsaturated fatty acids after 30 days of storage. Furthermore, a decreased intensity of L⁎ and increased b⁎ values were found in salamis with CaCl2. These results suggest that using CaCl2 as a substitute for NaCl increases the intensity of oxidative reactions while the addition of KCl could be a good alternative to reduce the NaCl content in fermented meat products

Adding Blends of NaCl, KCl, and CaCl 2 to Low-Sodium Dry Fermented Sausages: Effects on Lipid Oxidation on Curing Process and Shelf Life

The effect of a 50% reduction of NaCl and its replacement by KCl, CaCl 2 , and a blend of KCl and CaCl 2 (1 : 1) on lipid oxidation of dry fermented sausages was investigated. We found that a 50% reduction in NaCl decreased the intensity of the reactions to lipid oxidation, while treatments with added CaCl 2 resulted in increased lipid oxidation during manufacture and storage. Fatty acid composition also changed owing to the presence of KCl and CaCl 2 , showing a decrease in saturated, monounsaturated, and polyunsaturated fatty acids after 30 days of storage. Furthermore, a decreased intensity of * and increased * values were found in salamis with CaCl 2 . These results suggest that using CaCl 2 as a substitute for NaCl increases the intensity of oxidative reactions while the addition of KCl could be a good alternative to reduce the NaCl content in fermented meat products

Neuroprotective potential of terpenoid-rich extracts from orange juice by-products obtained by pressurized liquid extraction

Pressurized liquid extraction (PLE) conditions were optimized to improve the recovery of orange (Citrus sinensis) by-products terpenoids. The neuroprotective potential of the PLE extracts were tested against a set of in-vitro assay (antioxidant (ABTS), reactive oxygen/nitrogen species (ROS/RNS)) as well as enzymatic tests (acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and lipoxygenase (LOX)). Gas chromatography coupled to high-resolution mass spectrometry (GC-q-TOF-MS) analysis revealed a higher enrichment in mono- and sesquiterpenoids of the PLE extracts with the highest neuroprotection capacity. In-silico molecular docking analysis showed the specific interaction of representative terpenoids with enzymes active sites. The results demonstrate that the selected extract at 100 °C and 30 minutes possesses high antioxidant (ABTSIC50 = 13.5 μg mL−1; ROSIC50 = 4.4 μg mL−1), anti-cholinesterase (AChEIC50 = 137.1 vg L−1; BChEIC50 = 147.0 μg mL−1) and anti-inflammatory properties (against IL-6 and LOXIC50 = 76.1 μg mL−1), with low cytotoxicity and protection against L-glutamic acid in cell models.J.D.S.-M. would like acknowledge The Ministry of Education and Vocational Training for a FPU predoctoral grant FPU17/01876. G.A.-R. and A.V. would like to acknowledge the Ministry of Science and Innovation (MICINN) for their “Juan de la Cierva-Incorporación” postdoctoral grants IJC2019-041482-I and IJC2018-037560-I, respectively. The authors also thank the support from the AGL2017-89417-R project (MINECO).Peer reviewe

Development of sustainable processes for extraction of bioactives from algae

Trabajo presentado al V Congresso de Óleos e Gorduras - International Meeting on Fats and Oils, celebrado en Brasil del 10 al 12 mayo de 2022.Peer reviewe

Green microsaponification-based method for gas chromatography determination of sterol and squalene in cyanobacterial biomass

Sterol analysis of complex matrices can be very laborious. To minimize the existing drawbacks, a new micro-method of sterols and squalene determination in cyanobacteria was developed and applied to monitor their production of Phormidium autumnale cultured heterotrophically. Sample extraction/saponification and GC analysis of the target compounds were optimized separately using Plackett-Burman design (PB) followed by a central composite rotational design (CCRD). The most influential variables were identified to maximize compound recovery. Chloroform presented the highest capability to extract all target compounds with a horizontal shaker table (HST) for homogenization in the saponification step. For the pretreatment, a small amount of chloroform was used for 90 min at 50 °C and 6 min for the saponification time. The sample introduction in the GC injector was studied by evaluating pressure and injector temperature. High response for sterols and squalene were obtained between 19 and 23 psi and at 310 °C of injection temperature. The new method was able to determine different sterol concentrations: 0.2–0.6 mg kg−1 of squalene, 5–18 mg kg−1 of stigmasterol, 6 mg kg−1 of cholesterol, and 3 mg kg−1 of β-sitosterol, showing high analytical performance and fulfilling all steps, thus proving to be a promising technique.This work was supported by the Institutional Internationalization Program CAPES-PRINT nº 41/2017 and financed by CAPES – Brazilian Federal Agency for Support and Evaluation of Graduate Education within the Ministry of Education of Brazil. Additionally, we are grateful to the financial support by the National Council for Scientific and Technological Development (CNPq) – Brazil; PQ-2018, Process: 311125/2018-2 and Universal (MCTI/CNPq) 1/2016 Process: 428691/2016-1.Peer reviewe

Phytosterol-rich compressed fluids extracts from Phormidium autumnale cyanobacteria with neuroprotective potential

Phormidium autumnale (P. autumnale) is a cyanobacteria with an unknown metabolic system, since only few studies have been reported. Among the produced metabolites, sterols profile is important considering the ability to this cyanobacterium in producing such compounds and their important benefits for human health. In this study, compressed fluid technologies were evaluated to obtain phytosterol-rich extracts from P. autumnale cyanobacteria for investigating their potential neuroprotective properties. A preliminary study was performed by comparing gas-expanded liquid extraction and supercritical fluid extraction using ethanol as a co-solvent. The following steps were optimized using a two-level factorial design and considering solvent composition and pressure as experimental factors. The bioactive potential of the optimized compressed fluid extract was tested using in vitro bioactivity assays, including acetylcholinesterase, lipoxygenase inhibition, and antioxidant capacity. The supercritical fluid multi-optimization response presented optimum phytosterol enrichment conditions at 266.3 bar of pressure and 7% of ethanol. Moreover, the optimized extract had higher in-vitro neuroprotective activity than the non-enriched extract, presenting the biochemical half maximal inhibitory concentration (IC50) values of 65.80 μg mL−1 for acetylcholinesterase, 58.20 μg mL−1 for lipoxygenase inhibition, and 7.40 μg mL−1 for antioxidant activity. In-silico molecular docking analyses showed the specificity of sterol interaction with acetylcholinesterase active sites. These results provide evidence for further exploring P. autumnale as a source of bioactive phytosterols, demonstrating that compressed fluid technologies are powerful tools to obtain phytosterol-rich extracts.The authors would like to thanks CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) and CAPES-PRINT (PRINT-Programa institucional de Internacionalização) - Edital n° 41/2017 for the scholarship process (88887.363435/2019-00). G.A.-R. and M.B. would like to acknowledge the Ministry of Economy and Competitiveness (MINECO) for their “Juan de la Cierva-Formación” postdoctoral grants FJCI-2015-25504 and FJCI-2016-30902, respectively, and MICIU for their “Juan de La Cierva-Incorporación” IJC2019-041482-I and IJC2018-037830-I postdoctoral grants, respectively.Peer reviewe