Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV-vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO₂ modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO₂ enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans.     

Quantification of astaxanthin in shrimp waste hydrolysate by HPLC

In the present study, a simple and rapid reversed-phase HPLC method for the determination of astaxanthin in shrimp waste hydrolysate has been developed and validated. The analytical procedure involves the direct extraction of astaxanthin from the lipid fraction with methanol. The analytical column, SS Exil ODS, was operated at 25C. The mobile phase consisted of a mixture of water:methanol:dichloromethane:acetonitrile (4.5:28:22:45.5 v/v/v/v) at a flow rate of 1.0 mL/min. Detection and identification were performed using a photodiode array detector (lambda(detection) = 476 nm). The proposed HPLC method showed adequate linearity, repeatability and accuracy.     

Quantification of astaxanthin in salmons by chemiluminescence and absorption after TLC separation

Astaxanthin is a keto-carotenoid, belongs to the chemical class of terpenes and is a yellow lipid soluble compound. The compound is present in marine animals like salmons and crustacean. Its colour is due to conjugated double bonds and these double bonds are responsible for its antioxidant effect. Its antioxidant activity is ten times stronger than other carotenoids and nearly 500 fold stronger than vitamin-E. We present a new thin layer chromatography (TLC) method to measure astaxanthin on TLC-plates (Merck, 1.05554) in the visible absorption range as well as by using chemiluminescence. For separation a solvent mixture of cyclohexane and acetone (10?+?2.4, v/v) was used. The RF-value of astaxanthin is 0.14.The limit of detection in vis-absorption is 64?ng / band and the limit of quantification is 92?ng/band. In chemiluminescence the values are 90?ng / band and 115?ng/band. The method offers two independently working measurement modes on a single plate which increase the accuracy of the quantification.     

测定雨生红球藻中虾青素及其它色素含量的高效液相色谱法

建立了一种分离和测定雨生红球藻中虾青素和其它色素的反相高效液相色谱法 ;含有雨生红球藻细胞的培养液经离心分离 ,匀浆破碎 ,用甲醇 -二氯甲烷 (体积比3∶1)提取色素 ,提取液用HPLC分离测定 ;分析柱为Nova_PakC18(300mm×3.9mmID ,5μm)柱 ,流动相为水、甲醇和丙酮 ,流速1.0mL/min ,用二极管阵列检测器在250～700nm波长范围扫描 ,在476nm处进行检测 ;虾青素、多种类胡萝卜素和叶绿素在30min内得到较好分离 ,其中游离虾青素、斑蝥黄质和 β_胡萝卜素的检出限分别为3.56、1.36和29.4μg/L,这3种类胡萝卜素分别在质量浓度为1.99～31.7mg/L、2.44～39.0mg/L、2.25～36.0mg/L范围内与峰面积线性关系良好 ,相关系数分别为0.9993、0.9987和0.9778;该法的精密度 (RSD为0.09 %～2.97% )和回收率(96%～102 % )均符合方法学要求 ,可以用于研究和测定雨生红球藻中虾青素和其它色素的含量     

Integrated ultrasound-assisted liquid biphasic flotation for efficient extraction of astaxanthin from Haematococcus pluvialis

The purpose of this investigation is to evaluate the implementation of ultrasound-assisted liquid biphasic flotation (LBF) system for the recovery of natural astaxanthin from Haematococcus pluvialis microalgae. Various operating conditions of ultrasound-assisted LBF systems such as the position of ultrasound horn, mode of ultrasonication (pulse and continuous), amplitude of ultrasonication, air flowrate, duration of air flotation, and mass of H. pluvialis microalgae were evaluated. The effect of ultrasonication on the cellular morphology of microalgae was also assessed using microscopic analysis. Under the optimized operating conditions of UALBF, the maximum recovery yield, extraction efficiency, and partition coefficient of astaxanthin were 95.08 ± 3.02%, 99.74 ± 0.05%, and 185.09 ± 4.78, respectively. In addition, the successful scale-up operation of ultrasound-assisted LBF system verified the practicability of this integrated approach for an effective extraction of natural astaxanthin.     

虾青素全合成及选择性环氧化的量子化学计算研究

虾青素(astaxanthin)又名虾黄质、龙虾壳色素,是一种类胡萝卜素。在自然界,虾青素具有最强的抗氧化性,有很大的应用价值。目前虾青素合成国内外有几条路线,本文根据虾青素国内合成工艺对虾青素中间产物进行路线的优化,并对关键步骤α-紫罗兰酮选择性环氧化进行量子化学计算研究。     

NaOH皂化反相高效液相色谱法测定雨生红球藻中虾青素

建立了一种雨生红球藻中虾青素酯皂化的反相高效液相色谱方法。采用二极管阵列检测器（DAD）在476nm处进行检测,虾青素在15min内得到了较好的分离。虾青素的含量在1～15mg／L范围内与峰面积具有良好的线性关系,相关系数为0．9993;方法的检出限为0．049mg／L,RSD为3．27％,及回收率为100．7％。应用本法测定出雨生红球藻中虾青素的总含量为9．79～24．70mg／L。     

A Green Deep Eutectic Solvent-Based Ultrasound-Assisted Method to Extract Astaxanthin from Shrimp Byproducts

The extraction of valuable compounds from waste products using green and inexpensive solvents is a significant strategy for sample preparation. Accordingly, in the present study, the use of deep eutectic solvents, an emerging green approach, was used to extract astaxanthin, a well-known and widely-used antioxidant, from shrimp byproducts. After evaluating different combinations of extraction conditions and deep eutectic solvents, an ultrasonication method was established and optimized by a systematic investigation of the influencing factors. A comparison of the amount of astaxanthin (102 μg g^{? 1} ) extracted using a traditional organic solvent, ethanol, showed that more astaxanthin (146 μg g^{? 1} ) was obtained using the reported eco-friendly method. The excellent properties of deep eutectic solvents highlight their advantages as promising inexpensive green solvents for the extraction and determination of a range of bioactive compounds from natural products.     

光镊拉曼光谱法分析红法夫酵母内虾青素含量

建立一种用激光镊子拉曼光谱法快速定量红法夫酵母细胞内虾青素含量的方法。测定不同浓度虾青素标准品溶液的拉曼光谱,取其1 520cm-1峰峰高绘制虾青素标准曲线;取不同氮源、碳源的红法夫酵母细胞,一部分用激光镊子拉曼光谱法测定,一部分用紫外-可见分光光度法测定;最后分析两者间的相关性。结果表明虾青素标准曲线的相关系数到达0.998 3。在单位质量红法夫酵母虾青素含量与单位体积红法夫酵母发酵液虾青素产量方面,对比激光镊子拉曼光谱法与紫外-可见分光光度法,两种方法所得数据具有良好的相关性,其相关系数分别达到0.917 7和0.905 4,表明激光镊子拉曼光谱法能够达到紫外-可见分光光度法的测定效果,是定量分析红法夫酵母细胞内虾青素的更有效方法。