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Ítem Mixotrophic growth of a highly acidic habitat microalga for production of valuable fatty acids(2024) María Robles; Carol Ostojic; Mari Carmen Ruiz‑Domínguez; María Cuaresma; Carlos Gonzalo; Virginia Obregón; Juan Luis Fuentes; Alejandra Bartolomé; Carlos VílchezPhotoautotrophic algal cultivation is challenging due to the shadowing effect produced by an increase in the number of cells; under such circumstances, mixotrophic growth might be an efficient alternative. We grew cultures of the autochthonous acidotolerant microalga Elliptochloris sp. on crude technical glycerin or glucose bubbled with either only air or air containing 2.5 % (v/v) CO2. We found that CO2 strongly influenced the production of Elliptochloris sp., as higher growth occurred in mixotrophy with CO2-enriched air compared to that with only air. Mixotrophy with CO2-enriched air allowed to reach higher biomass productivities and facilitated an increase in the relative abundance of saturated fatty acids. Nevertheless, mixotrophy with only air resulted in an increase of both saturated and unsaturated fatty acids, but biomass productivities were lower. These results, along with the limited biological contamination facilitated by low pH, suggest that this microalga might be attractive for large-scale production within the circular economy model.Ítem Fucoxanthin from marine microalga Isochrysis galbana: optimization of extraction methods with organic solvents•(2019) Elena Medina; Pedro Cerezal; Juan Morales; Mari Carmen Ruiz-DomínguezFucoxanthin was the carotenoid studied from the marine microalga Isochrysis galbana for its importance in preventing obesity and diabetes. In this manner, seven solvents were used to fucoxanthin extraction, highlighting methanol and ethanol with 6.282 and 4.187 mg/g, respectively. However, petroleum ether and n-hexane were the worst solvents for fucoxanthin extraction, obtaining approximately 12-folds less content. Extraction time was another relevant parameter in improve fucoxanthin extraction where 10 min was the best time reaching 7.464 mg/g under 100% ethanol. Finally, we propose the use of I. galbana as natural source of fucoxanthin, a bioactive compound useful for food industry.Ítem Application of microencapsulated anthocyanin extracted from purple cabbage in fermented milk drinks(2019) Carolina Espinosa Álvarez; Javiera López Contreras; Darling Escobar Rodríguez; Diana Jiménez Rondón; Waldo Bugueño Muñoz; Pedro Cerezal MezquitaMicroencapsulation protects different bioactive compounds (anthocyanins) from environmental factors, increasing their half-life. In this study, the extraction and microencapsulation conditions for purple cabbage anthocyanins were determined, in addition to stability of the natural pigment obtained in a fermented milk beverage. Scalded was used for enzymatic inactivation in purple cabbage (Brassica oleracea L. ssp. Capitata f. Rubra) leaves, the extraction of bioactive compounds was carried out using green technologies (microwaves), concentrating the anthocyanin solution and mixing with wall materials such as maltodextrin, inulin and gum arabic for microencapsulation and addition to fermented milk beverage. The color stability was determined for 8 days; the ΔE of the beverage was slightly perceptible by the human eye. The concentration of anthocyanins was 199 mg/L with a solution of water and 2% acidified ethyl alcohol at 880 W of power for 90 s; the best drying performance was 58.9%.Ítem Some physical characteristics of the O/W macroemulsion of oleoresin of astaxanthin obtained from biomass of Haematococcus pluvialis(2019) Carolina Espinosa Álvarez; Carolina Jaime Matus; Pedro Cerezal MezquitaMacroemulsions facilitate the solubilization, stability, bioaccessibility, and bioactivity of compounds with low solubility, as is the case of the emulsion developed from astaxanthin oleoresin (10%). In this study, some characteristics of the physical behavior of the macroemulsion with astaxanthin oleoresin that are in close relationship with stability were determined. One of them was the viscosity at 5, 10, 20 and 30°C. Another, corresponded to observing the size variation of the micelles, observed under the microscope for 8 days and finally, the color was determined in CIEL*a*b* system for 34 days. The results showed that the macroemulsion behaved like a shear thinning fluid up to 20°C, becoming a shear thickening fluid at 30° C. In addition, the macroemulsion presented stability in the color as time elapsed; observing some slight variations that may be due to flocculation and coalescence. Both affect the viscosity at low temperatures.Ítem Determining the Potential of Haematococcus pluvialis Oleoresin as a Rich Source of Antioxidants(2019) Mari Carmen Ruiz Domínguez; Carolina Espinosa; Adrián Paredes; Jenifer Palma; Carolina Jaime; Carlos Vílchez; Pedro CerezalHaematococcus pluvialis is known to be a natural source of antioxidants for numerous applications. In this study, an oleoresin rich in carotenoids extracted by supercritical CO2 treatment of H. pluvialis was extensively characterized for its antioxidant capacity. Carotenoid content, fatty acid profile, total phenol content, antioxidant capacity, and viscosity of the oleoresin were determined with the aim of ascertaining the potential of the oleoresin in terms of its antioxidant content for food applications. The oleoresin contained 96.22 mg/g of total astaxanthin (which includes free astaxanthin and astaxanthin esters) and mostly included unsaturated fatty acids (~78% of total fatty acids). High total phenol content and ferric reducing antioxidant potential indicated high antioxidant capacity, but oxygen radical absorbance capacity was lower compared to the oleoresin samples obtained from other species. The oleoresin was a non-Newtonian fluid since it had shear-thinning (pseudoplastic) and shear-thickening (dilatant) flow. Therefore, the H. pluvialis oleoresin is a potential alternative in developing functional ingredients for designing healthy food products. To the best of our knowledge, this is the first study that has reported an extensive characterization of the antioxidant properties of a microalgal oleoresin obtained by means of supercritical CO2 fluid extraction.Ítem Stability of Lutein Obtained from Muriellopsis sp biomass and used as a natural colorant and antioxidant in a mayonnaise-like dressing sauce(2019) Pedro Cerezal Mezquita; Juan Morales; Jenifer Palma; Maria Del Carmen Ruiz; Marjorie JáureguiLutein is present in higher plants and algae. It may confer protection against the progression of chronic and eye diseases. Currently, lutein supplements are supplied to the world market in the form of capsules. We obtained a lutein oleoresin from the biomass of the microalgae Muriellopsis sp. This was added to a home-made mayonnaise. The samples were stored for three months at 5 ± 2°C. The lutein content was quantified by high-performance liquid chromatography (HPLC), and the antioxidant concentration was determined by the total polyphenol content (Folin-Ciocalteau) and the oxygen radical absorbance capacity (ORAC). Pigment degradation followed a first-order kinetics, with k = 0.0068 days-1, and t½ = 102 days. The chromatic coordinates L*, a*, b* indicated high pigment stability in the matrix. These results indicate that, due to its high antioxidant capacity, lutein derived from the Muriellopsis sp could represent a potential substitute for pigments, such as β-carotene, in oily matrices.Ítem Rapid Green Extractions of C-Phycocyanin from Arthrospira maxima for Functional Applications(2019) Mari Carmen Ruiz Domínguez; Marjorie Jáuregui; Elena Medina; Carolina Jaime; Pedro CerezalCyanobacteria are a rich source of bioactive compounds, mainly in the Arthospira sp., and one of the most interesting components in recent years has been C-phycocyanin (C-PC). There have been several conventional methods for their extraction, among which stand out: chemical products, freezing-thawing (FT); enzymatic, and maceration (M); which have come to be replaced by more environmentally friendly methods, such as those assisted by microwaves (MW) and high-pressure homogenization (HPH). The aim of the research was to use these two “green extraction processes” to obtain C-PC from cyanobacteria Arthrospira maxima because they improve functionality and are fast. Extractions of C-PC were studied by means of two experimental designs for MW and HPH, based on a response surface methodology (RSM) employing, firstly, a factorial design 33: power (100, 200, and 300 W), time (15, 30, and 60 s), and types of solvents (distiller water, Na-phosphate buffer and, distiller water: Na-phosphate buffer (Ph 7.0; 1:1, v/v); and secondly, two factors with different levels: Pressure (800, 1000, 1200, 1400, and 1600 bar) and, types of solvents (distilled water, Na-phosphate bu er (pH 7.0) 100 mM and, Na-phosphate buffer:water 1:1, (v/v)). Optimum C-PC content was achieved with the HPH process under Na-phosphate solvent at 1400 bar (291.9 ± 6.7 mg/g) and the MW method showed improved results using distilled water as a solvent at 100 W for 30 s (215.0 ± 5.5 mg/g). In the case of conventional methods, the freeze–thawing procedure reached better results than maceration using the buffer (225.6 ± 2.6 mg/g). This last one also did not show a significant difference between solvents (a range of 147.7–162.0 mg/g). Finally, the main advantage of using green extractions are the high C-PC yield achieved, e ectively reducing both processing times, costs, and increasing the economic and functional applications of the bioactive compound.Ítem Use of phycobiliproteins from atacama cyanobacteria as food colorants in a dairy beverage prototype(2020) Alexandra Galetović; Francisca Seura; Valeska Gallardo; Rocío Graves; Juan Cortés; Carolina Valdivia; Javier Núñez; Claudia Tapia; Iván Neira; Sigrid Sanzana; Benito Gómez-SilvaThe interest of the food industry in replacing artificial dyes with natural pigments has grown recently. Cyanobacterial phycobiliproteins (PBPs), phycoerythrin (PE) and phycocyanin (PC), are colored water-soluble proteins that are used as natural pigments. Additionally, red PE and blue PC have antioxidant capabilities. We have formulated a new food prototype based on PBP-fortified skim milk. PBPs from Andean cyanobacteria were purified by ammonium sulfate precipitation, ion-exchange chromatography, and freeze-drying. The stability of PE and PC was evaluated by changes in their absorption spectra at various pH (1–14) and temperature (0–80 °C) values. Purified PBPs showed chemical stability under pH values of 5 to 8 and at temperatures between 0 and 50 °C. The antioxidant property of PBP was confirmed by ABTS (2,20-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical ion scavenging, and FRAP (Ferric Antioxidant Power) assays. The absence of PBP toxicity against Caenorhabditis elegans was confirmed up to 1 mg PBP/mL. Skim milk fortified with PE obtained a higher score after sensory tests. Thus, a functional food based on skim milk-containing cyanobacterial PBPs can be considered an innovative beverage for the food industry. PBPs were stable at an ultra-high temperature (138 °C and 4 s). PBP stability improvements by changes at its primary structure and the incorporation of freeze-dried PBPs into sachets should be considered as alternatives for their future commercializationÍtem Chemical Profiling, Antioxidant, Anticholinesterase, and Antiprotozoal Potentials of Artemisia copa Phil. (Asteraceae)(2020) Maria José Larrazábal-Fuentes; Carlos Fernández-Galleguillos; Jenifer Palma-Ramírez; Javier Romero-Parra; Kevin Sepúlveda; Jorge González; Adrián Paredes; Jorge Bórquez; Mario J. Simirgiotis; Javier Echeverría; Alexandra GaletovićArtemisia copa Phil. (Asteraceae) (known as copa-copa) is a native species of Chile used as an infusion in traditional medicine by Atacameños people in the Altiplano, highlands of northern Chile. In this research, we have investigated for the first time the cholinesterase inhibition potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the chemical profiling of the infusions prepared from the aerial parts of A. copa by high resolution spectrometry. In addition, total phenolic, total flavonoid content, antioxidant (DPPH, FRAP, and ORAC) and antiprozoal activity were tested. Artemisia copa showed good inhibitory activity against AChE and BChE (3.92 ± 0.08 µg/ml and 44.13 ± 0.10 µg/ml). The infusion displayed a total phenolics content of 155.6 ± 2.9 mg of gallic acid equivalents/g and total flavonoid content of 5.5 ± 0.2 mg quercetin equivalents/g. Additionally, trypanocidal activity against Trypanosoma cruzi was found (LD50 of 131.8 µg/ml). Forty-seven metabolites were detected in the infusion of A. copa including several phenolic acids and flavonoids which were rapidly identified using ultrahigh performance liquid chromatography orbitrap mass spectrometry analysis (UHPLC-Orbitrap-MS) for chemical profiling. The major compounds identified in the infusions were studied by molecular docking against AChE and BChE. The UHPLC-MS fingerprints generated can be also used for the authentication of these endemic species. These findings reveal that A. copa infusions can be used as beverages with protective effects.