Degradation Of Astaxanthin Research Articles

Kinetics of Lipid Oxidation and Degradation of Flaxseed Oil Containing Crawfish (Procambarus clarkii) Astaxanthin

AbstractFlaxseed oil (FO) containing crawfish (Procambarus clarkii) astaxanthin (FOA) was evaluated for lipid oxidation and astaxanthin degradation. The FOA was analyzed for astaxanthin content, free fatty acids (FFA), peroxide value (PV), fatty acid methyl esters (FAMEs) profile, and color. The amount of extractable astaxanthin in the crawfish byproducts was 3.02 mg/100 g of crawfish byproducts. FOA and FO had a similar alpha‐linolenic acid (ALA) content (on a weight% basis). The FO was lighter and more yellow in color than FOA. The oxidation rate of FOA was lower than that of FO. When FO and FOA were heated to 30 °C, both oils exhibited minimal lipid oxidation with increasing heating time, whereas FO, when heated to 40, 50, 60 °C, had a higher lipid oxidation rate than FOA with increasing the heating time from 0 to 4 h. Astaxanthin was an effective antioxidant agent in FO when it was heated from 30 to 60 °C. The degradation of astaxanthin in FOA could be described by first order reaction kinetics. Astaxanthin was stable in flaxseed oil at 30 and 40 °C, while its stability decreased significantly at 50 and 60 °C. The rate of astaxanthin degradation in FOA was significantly influenced by temperature.

Extraction of shrimp astaxanthin with flaxseed oil: Effects on lipid oxidation and astaxanthin degradation rates

Astaxanthin extracted from shrimp (Litopenaeus setiferus) byproducts using flaxseed oil (FO) was evaluated for the kinetics of lipid oxidation of FO containing astaxanthin (FOA) and astaxanthin degradation. The FOA was analysed for astaxanthin content, free fatty acids (FFA), peroxide value (PV), fatty acid methyl ester profiles (FA), and colour. The amount of extractable astaxanthin in the shrimp byproducts was 4.83 mg 100 g−1 of shrimp waste. FOA and FO had similar alpha-linolenic (ALA) content. The FO was lighter and more yellow in colour than FOA. The oxidation rate of FOA was lower than that of FO. When FO and FOA were heated to 30 °C, both oils exhibited minimal lipid oxidation with increasing heating time, whereas FO, when heated to 40, 50 and 60 °C, had a higher lipid oxidation rate than FOA with increasing heating time from 0 to 4 h. Astaxanthin was an effective antioxidant agent in FO when it was heated from 40 to 60 °C. The degradation of astaxanthin in FOA could be described by first order reaction kinetics. Astaxanthin was stable in FO at 30 and 40 °C, while significant increases in degradation were observed at 50 °C and 60 °C. The rate of astaxanthin degradation in FOA was significantly influenced by temperature.

Preventing the thermal degradation of astaxanthin through nanoencapsulation

The encapsulation of astaxanthin into polymeric nanospheres by solvent displacement was compared for three chemically diverse polymers, namely; poly(ethylene oxide)-4-methoxycinnamoylphthaloylchitosan (PCPLC), poly(vinylalcohol-co-vinyl-4-methoxycinnamate) (PB4) and ethylcellulose (EC). Although capable of forming nanospheres themselves, EC could not encapsulate astaxanthin at all, whilst PB4 yielded a poor encapsulation efficiency. In contrast, PCPLC yielded reasonably good encapsulation efficiency (98%) at a loading of 40% (w/w). Moreover, the freeze-dried astaxanthin-encapsulated PCPLC nanospheres showed good dispersibility in water yielding stable aqueous suspensions of 300–320 nm nanoparticles. A steady release of astaxanthin from the nanospheres up to a maximum of ∼85% payload over 60 min was also demonstrated, at least in acetone. NMR analysis indicated that after a two-hour-heating at 70 °C in an aqueous environment, PCPLC nanoencapsulated astaxanthin showed minimal heat degradation of olefinic functionality in contrast to that of the unencapsulated pigment molecules which were almost completely destroyed.

Redox processes in pressurised smoked salmon studied by resonance Raman spectroscopy

Non-thermal food preservation technology is based on the application of high pressures up to 600 MPa. Here we report a resonance Raman (RR) spectroscopic analysis of smoked salmon meat after high pressure processing. High quality spectra, which can be obtained even from packed salmon without spectral interference of the packing foil, allow determining pressure-dependent irreversible changes of the main RR-active components of salmon meat, astaxanthin and myoglobin/haemoglobin. High pressure-treatment causes a decrease of the relative RR intensities of astaxanthin as probed with 514 nm excitation which is in line with a slight attenuation of the originally intense red colour of the salmon meat. 413-nm excited RR spectra indicate a heterogeneous broadening of astaxanthin bands accompanied by the formation of deoxy-myoglobin or deoxy-haemoglobin. The results suggest that pressure-treatment facilitates the oxidative degradation of astaxanthin coupled to the reduction of metmyoglobin (methaemoglobin).

Kinetics of astaxanthin degradation and color changes of dried shrimp during storage

Dried shrimp is a high value fishery product of Thailand. Since it is known that drying and storage conditions affect the color changes of dried shrimp, but the quantitative information on this aspect is still very limited, the objective of the present study was to investigate the long-term effects of drying air temperature (80, 100, 120 °C) and various storage parameters, namely, storage atmosphere (air, vacuum) and storage temperature (4, 15, 25 °C), on the kinetics of astaxanthin degradation and of color changes, in terms of CIELAB parameters L ∗, a ∗ and b ∗, of dried shrimp during 16-week storage. In addition, the relationship between astaxanthin retention ratio and color retention ratio of dried shrimp was established. The degradation of astaxanthin and color loss was found to follow a first-order kinetic reaction; the temperature dependence of reaction constants was found to be well explained by the Arrhenius relationship. Drying shrimp at higher temperature led to lower astaxanthin degradation during storage than drying at lower temperatures. Storage of dried shrimp under vacuum atmosphere at low temperatures enhanced the retention of astaxanthin in dried shrimp. Good correlations between astaxanthin degradation and color changes were also observed.

Selective Extraction of Free Astaxanthin from Haematococcus Culture Using a Tandem Organic Solvent System

A novel tandem solvent process of dodecane and methanol was developed for the selective extraction of free astaxanthin from red encysted Haematococcus culture. The process consists of dodecane extraction for astaxanthin mixture from the culture (stage 1) and methanol extraction for free astaxanthin from the dodecane extract (stage 2). In the first stage, astaxanthin mixture was directly extracted to dodecane from the culture broth without cell harvest process, followed by a rapid separation of the dodecane extract and the culture medium containing cell debris by simple settling. In the second stage, free astaxanthin was selectively collected to methanol from the dodecane extract, accompanied with saponification of astaxanthin-esters by the addition of NaOH to methanol. During saponification, use of the optimum NaOH concentration (0.02 M) and low temperature (4 degrees C) reaction minimized the degradation of free astaxanthin, resulting in a total recovery yield of free astaxanthin of over 85%. The free-astaxanthin-containing methanol extract was also simply separated from dodecane by gravity settling, after which the astaxanthin-free dodecane was effectively recycled to the first stage, yielding a stable extractability of astaxanthin mixture during repeated extraction. Our results indicate the potential of the proposed tandem solvent process as an alternative extraction technology for the high-value antioxidant Haematococcus astaxanthin.

Interactions between irradiance and nutrient availability during astaxanthin accumulation and degradation in Haematococcus pluvialis.

Fully synchronised germination of Haematococcus pluvialis astaxanthin-replete aplanospores was induced by transfer to nitrogen-sufficient conditions under either high or low light intensities, and growth, pigment content and nitrogen consumption were monitored during the cell cycle. No germination of the aplanospores was achieved in the absence of nitrate, even when cells were transferred at low light intensities. On the other hand, cell density and chlorophyll concentration increased dramatically and astaxanthin concentration decreased in N-sufficient cultures due to the germination of 100% of the aplanospores, as demonstrated by flow cytometry. No significant effect of light intensity was observed on the degradation of astaxanthin during germination. In germinated cultures, nitrogen was depleted more rapidly under high light conditions, which resulted in earlier entry into the aplanospore stage and accumulation of astaxanthin. Germination of aplanospores accompanied by astaxanthin degradation could also be obtained in the dark in nutrient-sufficient conditions although at a much lower efficiency. The results demonstrate that nutrient availability is the main factor controlling the transition between red and green stages of H. pluvialis, with astaxanthin being accumulated only when cell division has ceased. High light levels accelerate the process by increasing the rate of nutrient depletion and providing more energy for astaxanthin synthesis.

Hydrolysis kinetics of astaxanthin esters and stability of astaxanthin of Haematococcus pluvialis during saponification.

The reaction kinetics for the hydrolysis of astaxanthin esters and the degradation of astaxanthin during saponification of the pigment extract from the microalga Haematococcus pluvialis were investigated. Different concentrations of sodium hydroxide in methanol were used for the saponification under nitrogen in darkness at ambient temperature (22 degrees C) followed by the analysis of astaxanthins and other carotenoids using an HPLC method. The concentration of methanolic NaOH solution was important for promoting the hydrolysis of astaxanthin esters and minimizing the degradation of astaxanthin during saponification. With a higher concentration of methanolic NaOH solution, the reaction rate of hydrolysis was high, but the degradation of astaxanthin occurred significantly. The rate constants of the hydrolysis reaction (first order) of astaxanthin esters and the degradation reaction (zero-order) of astaxanthin were directly proportional to the concentration of sodium hydroxide in the saponified solution. Although the concentration of sodium hydroxide in the saponified solution was 0.018 M, complete hydrolysis of astaxanthin esters was achieved in 6 h for different concentrations (10-100 mg/L) of pigment extracts. Results also indicated that a higher temperature should be avoided to minimize the degradation of astaxanthin. In addition, during saponification, no loss of lutein, beta-carotene, and canthaxanthin was found.

Singlet Oxygen and Peroxyl Radicals Regulate Carotenoid Biosynthesis in Phaffia rhodozyma

Carotenoids have recently received considerable interest because of their potential in delaying or preventing degenerative diseases such as arteriosclerosis, cancer, and aging. In this study we show that the active oxygen species singlet oxygen (1O2) and peroxyl radicals differently affect carotenoid composition and biosynthesis in the yeast Phaffia rhodozyma. Photochemical generation of 1O2 with rose bengal or alpha-terthienyl induced carotenoid accumulation. In contrast, peroxyl radicals derived from t-butylhydroperoxide (tBOOH) or H2O2 decreased the content of astaxanthin and increased beta-carotene by approximately 4-fold, suggesting end product feedback regulation by astaxanthin or inhibition of biosynthetic enzymes. 14C labeling of carotenoids during oxidative stress supported the possibility of end product regulation. Carotenoids were bleached by 8 mM tBOOH within 6 h when carotenogenesis was inhibited by thymol. When treated with peroxides, a previously unreported pigment in P. rhodozyma was formed. The carotenoid had a mass of 580 Da and a molecular formula of C40H52O3. Chemical derivatizations combined with mass and absorbance spectroscopy tentatively identified the carotenoid as dehydroflexixanthin (3,1'-dihydroxy-2,3,3',4'-tetradehydro-1',2'-dihydro-beta,psi-caro tene-4-one). This study provides the first report of induction of astaxanthin biosynthesis by 1O2, probable feedback control by astaxanthin, and the oxidative degradation of astaxanthin to novel pigments in P. rhodozyma.