Degradation Of Astaxanthin Research Articles

The Impact of Drying Techniques on Stabilizing Microencapsulated Astaxanthin From Shrimp Shells: A Comparative Study of Spray Drying Versus Freeze Drying

ABSTRACTThe research aimed to study how different drying methods (spray and freeze drying) affect the release kinetics of microencapsulated astaxanthin in various environmental conditions. Shrimp shell extract containing astaxanthin was encapsulated using different wall components (maltodextrin with different dextrose equivalents and modified starch) via a simplex lattice mixture design. The encapsulated extract was then subjected to storage at different temperatures (25°C ± 2°C and 2°C ± 4°C) and humidity conditions (52% ± 2% and 75% ± 2%), as well as exposure to UV light (four 15 W lamps, 254 nm, for 10 h). The release kinetics of astaxanthin were analyzed using various models (page, Newton Korsmeyer–Peppas model, Modified Henderson and Pabis, Diffusion approach, and Two‐term exponential). The evaluation results of correlation coefficient (R2), root mean square deviation (RMSE), and mean absolute percentage error (MAPE) values of different models showed that the astaxanthin degradation followed a two‐term exponential kinetics in both types of microcapsules. Astaxanthin degradation increased with higher temperatures, humidity, and UV light exposure. However, microcapsules with equal wall compound ratios exhibited better preservation of astaxanthin. The study also emphasized the significance of optimizing storage conditions and wall materials for microencapsulated astaxanthin, as well as the utility of the two‐term exponential model in enhancing stability and shelf life.

Effects of boiling, centrifuging and drying methods on bioactive compounds in Antarctic krill meal

SummaryBoiling, centrifuging and various drying techniques (vacuum freeze‐drying (VFD), vacuum drying (VD), hot‐air drying (HAD) and microwave drying (MWD)) were assessed for their impact on bioactive compounds in Antarctic krill meal. A comparison between the raw and boiling groups revealed a significant degradation and isomerisation of astaxanthin, accompanied by a 1.25‐fold and 1.32‐fold increase in saturated (SFAs) and monounsaturated fatty acids (MUFAs), respectively. Drying was the primary factor responsible for the reduction in phospholipids, α‐tocopherol and polyunsaturated fatty acid (PUFAs), in combination with the increase in thiobarbituric acid‐reactive substances. For different drying methods, it was found that HAD induced severe lipid oxidation. In contrast, the VFD, VD and MWD improved lipid quality, reducing thiobarbituric acid‐reactive substances (TBARS) by 13–22% and increasing phospholipids by 1.08–1.11 times compared to HAD. VD preserved higher levels of bioactive compounds. PLS‐DA analysis identified 13‐cis‐astaxanthin, α‐tocopherol and eleven fatty acids as key indicators for Antarctic krill meal.

Mechanism of color change in Antarctic krill oil during storage

Antarctic krill oil (AKO) is reddish-orange in color but undergoes changes during storage. To investigate the color deterioration and potential mechanisms involved, the changes in color, endogenous components (astaxanthin, fatty acids, and phospholipids), and reaction products (aldehydes, α-dicarbonyl compounds, and pyrroles) of AKO upon storage were determined. Although the visual color of AKO tended to darken upon storage, the colorimetric analysis and ultraviolet–visible spectrum analysis both indicated a fading in red and yellow due to the oxidative degradation of astaxanthin. During storage of AKO, lipid oxidation led to the formation of carbonyl compounds such as aldehydes and α-dicarbonyls. In addition, phosphatidylethanolamines (PEs) exhibited a faster loss rate than phosphatidylcholines. Moreover, hydrophobic pyrroles, the Maillard-like reaction products associated with primary amine groups in PEs accumulated. Therefore, it is suggested that the Maillard-like reaction between PEs and carbonyl compounds formed by lipid oxidation contributed to color darkening of AKO during storage.

Stability of electrostatically stabilized emulsions and its encapsulation of astaxanthin against environmental stresses: Effect of sodium caseinate-sugar beet pectin addition order

Two addition orders, i.e., the layer-by-layer (L) and mixed biopolymer (M) orders, were used to generate sodium caseinate - sugar beet pectin electrostatically stabilized o/w emulsions with 0.5% oil and varying sodium caseinate: sugar beet pectin ratios (3:1–1:3) at pH 4.5. Emulsion stability against environmental stresses (i.e., pH, salt addition, thermal treatment, storage and in vitro simulated gastrointestinal digestion) and its astaxanthin encapsulation against degradation during storage and in vitro digestion were evaluated. Results indicated that a total biopolymer concentration of 0.5% was optimal, with the preferred sodium caseinate-sugar beet pectin ratios for L and M emulsions being 1:1 and 1:3, respectively. L emulsions generally exhibited smaller droplet diameters than M emulsions across all ratios, except at 1:3. Lowering the pH to 1.5 substantially reduced the net negative charge of all emulsions, with only L emulsions precipitating at pH 3. M emulsions showed greater tolerance to salt addition, remaining stable up to 500 mM sodium and calcium concentrations, whereas L emulsions destabilized at levels exceeding 50 mM and 30 mM, respectively. All emulsions were stable when heated at 37 °C or 90 °C for 30 min. Astaxanthin degradation rates increased with prolonged storage, reaching 61.66% and 54.08% by day 7 for L and M emulsions, respectively. Encapsulation efficiency of astaxanthin in freshly prepared M emulsions (86.85%) was significantly higher compared to L emulsions (72.82%). M emulsions had 30% and 25% higher encapsulation efficiency of astaxanthin than L emulsions after in vitro digestion for 120 min and 240 min respectively. This study offers suggestions for interface design and process optimization to improve the performance of protein-polysaccharide emulsion systems, such as in beverages and dairy products, as well as their delivery effect of bioactives.

Stabilized Astaxanthin Nanoparticles Developed Using Flash Nanoprecipitation to Improve Oral Bioavailability and Hepatoprotective Effects.

In this study, we developed stabilized astaxanthin (AX) nanoparticles (sNP/AX) to improve the physicochemical properties, oral bioavailability, and hepatoprotection of AX. A flash nanoprecipitation technique was used with a multi-inlet vortex mixer to prepare the sNP/AX. Vitamins E (VE) and C (VC) were used as co-stabilizers with poloxamer 407 as a stabilizer to inhibit the oxidative degradation of AX during sNP/AX formation and storage. VC stabilized AX in the aqueous phase during the preparation, whereas VE markedly improved the storage stability of sNP/AX, as evidenced by the AX contents remaining at 94 and 81% after 12 weeks of storage at 4 °C and 25 °C, respectively. The mean sNP/AX diameter was 215 nm, which resulted in higher AX release properties than those of crystalline AX. Rats, orally administered sNP/AX (33.2 mg AX/kg), exhibited higher systemic exposure to AX, whereas oral absorption in the crystalline AX group was negligible. In the rat hepatic injury model, oral pretreatment with sNP/AX (33.2 mg AX/kg) markedly attenuated hepatic damage, as shown by the histopathological analysis and reduced levels of plasma biomarkers for hepatic injury. These findings suggest that strategically including antioxidative additives in the sNP/AX has the potential to improve the physicochemical and nutraceutical properties of AX.

Characteristics of LED light-induced geometrical isomerization and degradation of astaxanthin and improvement of the color value and crystallinity of astaxanthin utilizing the photoisomerization

The effects of light-emitting diode (LED) irradiation characterized by different emission wavelengths on the E/Z-isomerization and degradation of astaxanthin were investigated. LED irradiation slightly promoted Z-isomerization of astaxanthin, whereas the all-E-isomerization was highly efficiently promoted at specific wavelengths, especially at 365 nm. Astaxanthin isomers did not degrade significantly when dissolved in ethanol and subjected to LED irradiation conditions for 300 min. However, significant degradation was achieved when ethyl acetate was used for dissolution, and the samples were irradiated at the wavelength of 405 nm. The addition of α-tocopherol suppressed the photodegradation of astaxanthin. LED irradiation significantly affected the physical properties of astaxanthin Z-isomers. Irradiation with 365, 405, and 470 nm LEDs enhanced the color value (redness) and crystallinity of the Z-isomers via an all-E-isomerization reaction. These findings can contribute to the development of technologies that can arbitrarily control the E/Z-isomer ratio and physical properties of astaxanthin.

Astaxanthin-Loaded Pickering Emulsions Stabilized by Nanofibrillated Cellulose: Impact on Emulsion Characteristics, Digestion Behavior, and Bioaccessibility.

Astaxanthin (AX) is one of the major bioactives that has been found to have strong antioxidant properties. However, AX tends to degrade due to its highly unsaturated structure. To overcome this problem, a Pickering O/W emulsion using nanofibrillated cellulose (NFC) as an emulsifier was investigated. NFC was used because it is renewable, biodegradable, and nontoxic. The 10 wt% O/W emulsions with 0.05 wt% AX were prepared with different concentrations of NFC (0.3-0.7 wt%). After 30 days of storage, droplet size, ζ-potential values, viscosity, encapsulation efficiency (EE), and color were determined. The results show that more stable emulsions are formed with increasing NFC concentrations, which can be attributed to the formulation of the NFC network in the aqueous phase. Notably, the stability of the 0.7 wt% NFC-stabilized emulsion was high, indicating that NFC can improve the emulsion's stability. Moreover, it was found that fat digestibility and AX bioaccessibility decreased with increasing NFC concentrations, which was due to the limitation of lipase accessibility. In contrast, the stability of AX increased with increasing NFC concentrations, which was due to the formation of an NFC layer that acted as a barrier and prevented the degradation of AX during in vitro digestion. Therefore, high concentrations of NFC are useful for functional foods delivering satiety instead of oil-soluble bioactives.

Antioxidant addition improves cholesterol and astaxanthin stability in dry salted shrimp.

Traditional production of dry salted shrimp enhances cholesterol oxidation and astaxanthin degradation in the product. The aim of this study was to evaluate the effect of addition of the antioxidants butylhydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ) to cooked shrimp on the formation of cholesterol oxidation products (COPs) and astaxanthin degradation during solar drying of shrimp. The added antioxidants significantly inhibited COPs formation after the product was boiled in brine. Smaller amounts of COPs were formed in antioxidant-treated shrimps (~-23%) as compared to untreated samples. The antioxidants continued to significantly inhibit COPs formation (~-39%) during sun drying. Similarly, TBHQ and BHT reduced by 51.3% and 37.2%, respectively, the degradation rate of astaxanthin, favoring a higher retention of this carotenoid in the final product. The use of the antioxidants BHT and TBHQ in the preparation of dry salted shrimp significantly inhibited the formation of COPs after cooking raw shrimp and during direct solar drying. They also protected astaxanthin contained in the cooked shrimp from photodegradation. These results are technologically relevant because it is possible to prepare a product with a higher content of astaxanthin and lower the presence of hazardous COPs. © 2022 Society of Chemical Industry.

Development and validation of reliable astaxanthin quantification from natural sources.

Astaxanthin derived from natural sources occurs in the form of various esters and stereomers, which complicates its quantitative and qualitative analysis. To simplify and standardize astaxanthin measurement with high precision, an enzymolysis-based astaxanthin quantification method was developed to hydrolyze astaxanthin esters and determine free astaxanthin in all its diastereomeric forms. Astaxanthin standards and differently processed Haematococcus pluvialis biomass were investigated. Linear correlation of standards of all-E-astaxanthin was observed in a measurement range between extract concentrations of 1.0 μg/mL and 11.2 μg/mL with a coefficient of variation below 5%. The diastereomers 9Z-, and 13Z-astaxanthin, and two di-Z-forms were detected. In contrast to the measurement of standards, the observed measurement range was extended to 30 μg/mL in extracts from H. pluvialis. The nature of the sample had to be taken into account for measurement, as cell, respectively, sample composition altered the optimal concentration for astaxanthin determination. The measurement precision of all-E-astaxanthin quantification in dried H. pluvialis biomass (1.2-1.8 mg dried biomass per sample) was calculated with a coefficient of variation of maximum 1.1%, whereas it was below 10% regarding the diastereomers. Complete enzymolysis was performed with 1.0 to 2.0 units of cholesterol esterase in the presence of various solvents with up to 2.0 mg biomass (dry weight). The method was compared with other astaxanthin determination approaches in which astaxanthin is converted to acetone in a further step before measurement. The developed method resulted in a higher total astaxanthin recovery but lower selectivity of the diastereomers. The reliability of photometric astaxanthin estimations was assessed by comparing them with the developed chromatographic method. At later stages in the cell cycle of H. pluvialis, all methods yielded similar results (down to 0.1% deviation), but photometry lost precision at earlier stages (up to 31.5% deviation). To optimize sample storage, the shelf life of astaxanthin-containing samples was investigated. Temperatures below -20°C, excluding oxygen, and storing intact H. pluvialis cells instead of dried or disrupted biomass reduced astaxanthin degradation.

Degradation rate of astaxanthin from Haematococcus pluvialis

Astaxanthin is an antioxidant that is sensitive to environmental conditions. This study aimed to determine the effect of temperature and lighting on the concentration of astaxanthin, then derive the kinetic equation for its degradation. The half-life was calculated to determine the astaxanthin degradation time at which its concentration drops to half of its initial concentration. Standard astaxanthin was dissolved in acetone and left to stand under three different conditions. The results indicated that temperature and lighting can both cause degradation of astaxanthin. Degradation appeared to follow the second-order kinetics. The calculation showed that lower storage temperatures and less intense light exposure extended the astaxanthin half-life.

Combined effect of chitosan and bovine serum albumin/whey protein isolate on the characteristics and stability of shrimp oil-in-water emulsion.

The effect of bovine serum albumin (BSA) or whey protein isolate (WPI) at various concentrations (0.5%, 1.5%, and 3%; w/v) on the properties of shrimp oil-in-water emulsion was investigated. Both proteins at 1.5% showed the highest emulsifying properties. Moreover, the combined impact of chitosan (CS) at different levels (0.25%, 0.50%, 0.75%, and 1%; w/v) and 1.5% BSA or 1.5% WPI on emulsion properties was also studied. For the same protein used, those stabilized by BSA and WPI in conjunction with CS solution at 0.5% and 0.25% had the highest emulsion stability index, respectively. During storage for 28 days, the BSA-CSstabilized emulsion had higher turbidity, a*, b* but the lowest L* values compared to the WPI-CS counterpart (p<0.05). Emulsion stabilized by the BSA-CS complex showed higher stability, as witnessed by lower d32 and d43 and lower flocculation factor and coalescence index, but it had a lower negative charge than those stabilized by the WPI-CS complex (p<0.05). Oil droplets of the BSA-CS-stabilized emulsion showed a lower extent of size enlargement after storage. Rheological studies revealed viscous, shear-thinning, and non-Newtonian behavior of emulsions. Overall, emulsion stabilized by the BSA-CS complex had higher stability than that stabilized by the WPI-CS complex, and the former could maintain the stability of pigment in shrimp oil to some extent. PRACTICAL APPLICATION: Oil from shrimp hepatopancreas is a rich source of both astaxanthin and polyunsaturated fatty acids with health benefits. It can be used for the preparation of food emulsion, such as mayonnaise, with nutraceutical properties. However, emulsion stability determines the quality of the emulsion. The use of protein (bovine serum albumin) in conjunction with polysaccharides, especially chitosan at appropriate concentrations, was proven to improve shrimp oil-in-water emulsion during extended storage. Additionally, chitosan can act as an antioxidant to prevent the degradation of astaxanthin to some extent. This finding could be potentially beneficial to produce emulsion with high stability using protein-chitosan complexes.

Impact of Polymers as Precipitation Inhibitors on Physicochemical Properties of Spray-Dried Astaxanthin-Loaded Self-Microemulsifying Delivery Systems

Supersaturated astaxanthin (AST)-loaded self-microemulsifying delivery system (SMEDS) was developed and formulated with polymeric precipitation inhibitors (PPIs) to improve the dissolution profile of AST. Based on our preliminary in vitro polymer screening test, hydroxypropyl cellulose (HPC-L) and polyvinyl alcohol (PVA8/88) were selected as PPIs and studied further in this work. Microemulsions prepared from AST SMEDS (composed of AST, rice bran oil, Kolliphor® RH40, and Span® 20) were mixed with maltodextrin (MD) as a solid carrier and each PPI solution and then solidified using a spray drying technique. Particle size of spray-dried S-MD-HPC powder had larger circular equivalent (CE) diameter (14.69 ± 0.75 μm) than the other formula and showed particle agglomeration in SEM images. Spray-dried S-MD-PVA powder had 8.94 ± 0.37 μm CE diameter, and smooth surface of particles was observed. Amorphous phase transformation and chemical compatibility of both spray-dried powder formulations were detected by FT-IR, PXRD, and DSC. S-MD-HPC had marginally slower dissolution rate and release profile of AST compared to those of S-MD-PVA; however, both HPC and PVA polymers exhibited the ability for AST precipitation prevention and solubilization enhancement. Although AST degradation was caused by high temperature, physicochemical properties of the spray-dried AST SMEDS (S-MD-HPC and S-MD-PVA) powders after reconstitution were not significantly changed upon storage at 30°C/ RH 75%. This study illustrated a novel platform of spray-dried AST SMEDS in combination with HPC or PVA as a polymeric precipitation inhibitor for improvement of AST loading, solubility, and stability.

Monoglyceride oleogels for lipophilic bioactive delivery – Influence of self-assembled structures on stability and in vitro bioaccessibility of astaxanthin

The present study investigated the influence of self-assembled structures on stability and in vitro bioaccessibility of astaxanthin by modifying the structures with different processing conditions. The self-assembled structures of GMS oleogels were changed to produce smaller crystals and more compact network at higher glycerol monostearate (GMS) concentration and lower cooling temperature, resulting in higher hardness, oil binding capacity, and viscoelastic properties of oleogels. In the stability test, the highest retention ratio of astaxanthin was observed in oleogels formed at 4 °C and 10% GMS, indicating that the denser network structures were more effective to prevent the degradation of astaxanthin. During in vitro digestion, the self-assembled structures of oleogels and the nature of GMS molecules affected the lipolysis and micellization, which in turn regulated the bioaccessibility of astaxanthin. Collectively, GMS oleogels were effective delivery materials for improving the stability and bioaccessibility of lipophilic bioactives.

Krill oil microencapsulation: Antioxidant activity, astaxanthin retention, encapsulation efficiency, fatty acids profile, in vitro bioaccessibility and storage stability

Krill oil (KO) emulsions with a ratio of KO/arabic gum of 1:4 (w/w) were prepared and then spray dried. The effect of drying temperatures on antioxidant activity, astaxanthin retention, and microencapsulation efficiency was evaluated and microcapsules with better results were employed for further analysis. The encapsulation of KO in arabic gum was confirmed by using Fourier transform infrared spectroscopy. KO microcapsules showed eicosapentaenoic and docosahexaenoic content of 21% of the total fatty acids, low ω-6/ω-3 and SF/unsaturated FA ratios, and a bioaccessibility of 53.8% after 2 h of in vitro digestion. The effect of aw on color change and degradation of astaxanthin contained in KO microcapsules was evaluated during storage at 35 °C. Monolayer value was 3.7241 g H2O/100 g d.s. which corresponds to 0.4 of aw. The astaxanthin degradation rate increased considerably when the KO microcapsules were stored at an aw of 0.743, under these conditions the microcapsules showed drastic changes in the color parameters.

Thermal stability of astaxanthin in oils for its use in fish food technology

Astaxanthin is one of the inputs that most influences the final prices of salmonids on the market and is unstable due to its sensitivity to various factors, such as temperature, which cause the loss of its bioactivity during feed processing and storage. Dilocarcinus pagei is a native crab that is commonly found in fish culture ponds and presents an attractive reddish-brown coloration. The objectives of the present study were to evaluate this crab as a natural source of astaxanthin and to assess how the stability of this pigment was affected by different vegetable oils (soy and sunflower) and butylhydroxytoluene (BHT) presence over a range of temperatures used in feed processing technology like extraction, cooking, extrusion and storage. Individuals of D. pagei were collected and homogenized. Carotenes were extracted from different samples using acetone. The extractions were analyzed using High-Performance Liquid Chromatography (HPLC). The percentages of remaining astaxanthin dissolved in soy and sunflower oils with or without BHT (0.1%) were estimated before and after being incubated at 50 °C. Astaxanthin dissolved in both oils with BHT were exposed to different temperatures between 25 °C and 180 °C. Samples were taken at different intervals of time and astaxanthin was measured at λmax490 nm by a spectrophotometer. The degradation rate of astaxanthin at each temperature in both oils was estimated. The results showed that D. pagei would be an alternative as a natural source of astaxanthin since its concentration values (231.5 μg/g dry matter) are similar to those present in other species commercially exploited. The two-ways Analysis of variance (ANOVA) showed that the presence of BHT (P = 0.03) and the oils (P < 0.01) used as dissolvent affect the percentages of remaining astaxanthin independently of the oil used (P = 0.06). The astaxanthin degradation rates in sunflower were higher than those in soy oil at all tested temperatures, being significantly different (P < 0.05) at temperatures from 25 °C to 120 °C but not at 180 °C. The activation energies calculated for soy oil was 88.7 kJ/mol while for sunflower oil, it was 85.5 kJ/mol. Astaxanthin was more stable in soy oil than in sunflower oil. Moreover, commercial soy oil is a cheap ingredient and a good source of unsaturated fatty acids (ω3, ω6 and ω9). Thus, soy oil would be recommended as a solvent to extract the pigment.

Effect of oxidation and maillard reaction on color deterioration of ready-to-eat shrimps during storage

The mechanism of color deterioration in ready-to-eat (RTE) shrimps during storage was revealed for the first time. During storage, the appearance of the RTE shrimps gradually browned and blackened. Meanwhile, colorimeter analysis showed that the lightness decreased, but the redness and yellowness increased after storage. The peroxide and thiobarbituric acid value increased but the astaxanthin and phenol contents decreased after storage, indicating the occurrence of lipid and phenol oxidation. And the browning index, 5-hydroxymethylfurfural, pyrroles and pyrazine volatile compounds showed an upward trend after storage, indicating the occurrence of Maillard reaction. Correlation and principal component analysis showed that the composite effects of lipid oxidation, phenol oxidation, Maillard reaction and astaxanthin degradation led to the color deterioration of RTE shrimps, and the order of effect was Maillard reaction > lipid oxidation > phenol oxidation > astaxanthin degradation. Moreover, the lipid oxidation had a certain promoting effect on Maillard reaction and phenol oxidation.

The Effect of the Solvent Nature and Lighting on Isomerization and Oxidative Degradation of Astaxanthin

Astaxanthin and its esters, which are classified as secondary carotenoids, are synthesized under stress conditions in Haematococcus pluvialis cells that undergo transformation from vegetative cells to hematocysts. Stress factors can affect not only the rate and the direction of synthesis, but also the conformational changes in the pigment molecule, causing conversion of trans-isomers to cis-isomers. The aim of this study was to evaluate the effects of different factors (the polarity of the medium and light) on the process of trans–cis isomerization of astaxanthin. Investigation of the formation of 9-cis- and 13-cis-isomers from all-trans astaxanthin solutions at 50°C showed that medium polarity solvents stabilized cis-isomers more efficiently than highly polar solvents. Nonpolar solvents did not contribute to the stabilization of cis-isomers. The presence of π-bonds in the solvent molecule also stimulated isomerization. Analysis of the effects of the solvent refractive index on polarizability of astaxanthin revealed differences between the dependencies for polar and nonpolar solvents. Supposedly, solvents of medium polarity facilitate the process of trans–cis astaxanthin isomerization by decreasing the energy of the torque and stabilizing the cis-conformation of the molecule due to diminished dipole–dipole repulsion between the methyl groups in the polyene chain and the ionone ring. Exposure of astaxanthin solutions to light at 25°C induced formation of cis-isomers, which were more abundant within the first 4 h of exposure than after 6 h or later. Exposure to irradiation for longer periods caused astaxanthin decomposition and formation of degradation and oxidation products.

Formation, characterization, and application of chitosan/pectin-stabilized multilayer emulsions as astaxanthin delivery systems

Multilayer emulsions were formed by sequential electrostatic deposition of anionic (pectin) and cationic (chitosan) biopolymers onto anionic saponin-coated lipid droplets. These emulsions were then tested for their ability to encapsulate and protect a hydrophobic nutraceutical (astaxanthin). The impact of chitosan and pectin concentration, pH, and ionic strength on the formation and stability of the multilayer emulsions was examined. Multilayer emulsions containing small uniform particles were produced using 2.5% lipid droplets, 0.05% chitosan, and 0.0125% pectin. The physical stability of the astaxanthin-loaded emulsions after exposure to heating, pH, and NaCl was determined. The multilayer-coatings improved the chemical stability of the encapsulated astaxanthin, as well as the aggregation stability of the lipid droplets at elevated ionic strengths and temperatures. Astaxanthin degradation during storage was 3- to 4-fold slower in multilayer emulsions than conventional ones. The multilayer emulsions developed in this study may be useful for encapsulating, protecting, and delivering hydrophobic carotenoids, which may aid in the development of more efficacious functional foods, supplements, and medical foods.

Effects of Ergothioneine-Rich Mushroom Extract on the Oxidative Stability of Astaxanthin in Liposomes.

Ergothioneine-rich crude extracts of Pleurotus cornucopiae were used as a source of antioxidative components to control the effects of lipid oxidation in astaxanthin-containing liposomes. This study aimed to elucidate the interactions of liposomal astaxanthin and lipids with ergothioneine-rich mushroom extract (ME) under radical oxidation-induced conditions to provide a better understanding of the agricultural and postharvest applications of this strategy. Azo compounds (2,2'-azobis(2-methylpropionamidine) dihydrochloride and 2,2'-azobis(2,4-dimethylvaleronitrile) were used as hydrophilic and lipophilic radical initiators, respectively. Results of this study demonstrate that the presence of ME significantly delayed the oxidative degradation of astaxanthin and controlled the progress of lipid oxidation in a liposomal system. The lipid hydroperoxide formation was significantly suppressed, while polyunsaturated fatty acids were protected from degradation. In addition, Crude ME also demonstrated more potent DPPH radical scavenging activities and EC50 than the equimolar concentrations of ergothioneine alone, which suggested the presence of additional compounds with antioxidative properties.

Kinetics of Astaxanthin Degradation in Three Types of Antarctic Krill (Euphausia superba) Oil during Storage

AbstractThree types of Antarctic krill oil (KO), namely, phospholipid‐type krill oil (PKO), whole krill oil (WKO), and triacylglycerol‐rich krill oil (TKO), were stored at three different temperatures (−20, 4, and 25 °C) with or without oxygen to investigate the effects of temperature and oxygen on astaxanthin (AST) degradation during storage. Additionally, the influence of fatty acid composition on AST degradation in the three types of KO was compared. The results revealed that the degradation of AST followed first‐order kinetics, and the temperature dependence of the reaction was well explained by the Arrhenius relationship. A high storage temperature led to faster AST degradation. AST degradation rates under nitrogen were lower than those under an oxygen atmosphere. The higher degradation rate of AST in PKO is ascribed to its higher level of polyunsaturated fatty acids (PUFA) in comparison to WKO and TKO. This is the first time the energy of activation of AST degradation was evaluated to determine how the fatty acid composition of the oil matrix and storage atmosphere affect the reaction kinetics.