Obtención de astaxantina a partir de residuos de camarón fermentados
The objective of this thesis was to study various aspects on carotenoprotein extraction from shrimp residues, treated by enzymatic means in order to split the protein and pigment moieties. Purification and concentration of these two components by a membrane process in an enzymatic bioreactor was als...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2002 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:3b5919288 |
| Acceso en línea: | https://doi.org/10.24275/uami.3b5919288 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Carotenoides info:eu-repo/classification/LEM/Carotenoids info:eu-repo/classification/LEM/Proteins info:eu-repo/classification/LEM/Proteínas info:eu-repo/classification/cti/3 |
| Sumario: | The objective of this thesis was to study various aspects on carotenoprotein extraction from shrimp residues, treated by enzymatic means in order to split the protein and pigment moieties. Purification and concentration of these two components by a membrane process in an enzymatic bioreactor was also studied. Shrimp residues were subjected to lactic fermentation as a stabilizing method. Carotenoproteins were then extracted using a petroleum ether:acetone:water (1 5:75:19) system. The protein-pigment complex was dissolved in phosphate buffer. Four enzymatic treatments were tested: protease, protease:lipase, cellulase and ce1lulase:lipase. The efficiency of each treatment was evaluated by the amount of soluble protein and total xanthophylls in the extract. A treatment with a protease was carried out using 15 and 20 UP at pH 7 or 8 during 24 hours. The highest carotene and protein concentrations were obtained using 20 UP at pH 8 during 24 hours. The most efficient protease:lipase treatment, in terms of protein:pigment separation, was observed when a 15:lO (UP:UL) ratio was used during 12 hours. When 20 BG cellulase were applied for 24 hours at pH 5, the complex almost entirely dissociated; this splitting was improved when 20:lO (BG:UL) ratio was applied for 24 hours. Fifteen and 20 UP were applied on carotenoproteins dissolved into two solvent proportions, 15:75:1 O and 156525; when 20 UP were used in the 156525 solvent system during 24 hours, 83.1% of the pigments obtained as compared to the protease:lipase treatment on phosphate buffer. The hydrolysis of carotenoproteins with a protease was also studied in a membrane enzymatic bioreactor. Fifteen and 20 UP were applied during 16 hours; 83% of pigments were obtained when 20 UP were used during 14 hours, as compared to a hydrolysis using 15 UP for 24 hours in a model system. The volume concentration factor, using an ultrafiltration membrane, was 8.27 for soluble protein in the retentate; the concentration in the permeate by reverse osmosis of the pigments was 4.66. Carotenoprotein extraction yields were (mg / kg residue): 272.2 by solvent extraction; 1100-1 140 by hydrolysis with a protease; 1567 with a protease:lipase system, 1302 with a protease in an organic solvent; 769.7 with a cellulase; and 91 1.9 with a protease in a membrane enzymatic bioreactor. The pigment extracted from shrimp residues, a commercial synthetic pigment (Carophyll pinkMR) and 11 pigment standards were analyzed using an HPLC fitted with a reverse phase column; retention times and calibration curves were obtained. Values for astaxanthin and astacene were used as a reference for pigment stability; this was carried out during 8 weeks studying the effect of daylight, temperature and oxygen availability on astaxanthin degradation due to oxidation and subsequent astacene formation. Results showed that the natural pigment oxidized in a higher degree than the synthetic pigment. Daylight and high temperatures were the two most significant conditions in promoting astaxanthin oxidation. When factor interactions were considered, the most intense degradation occurred at daylight-high oxygen-high temperature conditions. Treatments including daylight and high oxygen were consistently the most oxidative ones. Amino-acid composition of the carotenoprotein obtained from fermented and nonfermented residues was studied. Carotenoproteins obtained for these two methods were rich in aspartate, glutamate and the essential amino-acids leucine and lysine. Carotenoproteins from fermented residues had higher concentration of phenylalanine, histidine, threonine and tryptophane; arginine and valine levels were higher in nonfermented residues. The molecular weight of the protein moiety was 260 kDa and it was obtained by electrophoresis. High concentrations of astaxanthin can be obtained by lactic fermentation followed by an enzymatic hydrolysis. This combined process is feasible to be applied to high shrimp residue volumes, such as those obtained in Mexico. The process can be carried out in a membrane enzymatic bioreactor recovering pigments and high protein concentrations. It is suggested that future studies in this topic will envisage enzymatic hydrolysis of carotenoproteins in a bioreactor, using protease:lipase and cellulase:lipase systems. Finally, considerations on process scaling-up as well as on improving pigment stability by polymer (excipient) and antioxidant addition are recommended for future studies. |
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