胆盐和游离脂肪酸影响离体小肠细胞类胡萝卜素吸收的研究

用黄鸡小肠细胞进行了 β-胡萝卜素和黄体素的体外吸收试验 ,研究类胡萝卜素浓度、胆盐和游离脂肪酸对这两种类胡萝卜素吸收的影响。结果发现 :β-胡萝卜素和黄体素的吸收均呈浓度依赖性 ;牛磺胆酸钠极显著促进黄鸡离体小肠细胞类胡萝卜素的吸收(P<0.01) ,其促进 β-胡萝卜素和黄体素吸收的最佳浓度分别为3mM和10mM ;游离脂肪酸极显著促进了类胡萝卜素的吸收(P<0.01) ,其中油酸对类胡萝卜素的促吸收作用大于硬脂酸 ,促进 β-胡萝卜素和黄体素吸收的最佳油酸/硬脂酸比率分别为100 :0和3 :1。牛磺胆酸钠和游离脂肪酸影响 β-胡萝卜素吸收的动态变化模式与它们对黄体素的显著不同     

Evaluation of β‐carotene assimilation in leopard geckos (Eublepharis macularius)

Although leopard geckos (Eublepharis macularius) are commonly kept under human care, their vitamin requirements are largely unknown. Many invertebrate preys display a low vitamin A concentration; thus, gut‐loading insects with vitamin A or carotenoids is a common practice. The objective of this prospective experimental study was to investigate whether dietary supplementation with β‐carotene, including prey gut‐loading, leads to sufficient vitamin A hepatic storage and prevents epithelial squamous metaplasia development in leopard geckos. Ten clinically healthy female leopard geckos were randomly divided in two groups with various supplementations: a group receiving vitamin A supplementation and a group receiving β‐carotene. Insects were gut‐loaded continuously with a supplement containing vitamin A or β‐carotene, depending on the group. Oral supplementation with cod liver oil or carrot juice was administered weekly to each lizard from “vitamin A group” and “carotenoid group” respectively. After 10 weeks of supplementation, surgical hepatic biopsies were obtained in three geckos of each group while the two remaining geckos were euthanized to undergo complete necropsy. Hepatic vitamin A concentration was determined for each lizard (n = 10) by ultra‐performance liquid chromatography. Histopathology revealed hepatocellular vacuolization and vitellogenic follicles in five females. Epithelial squamous metaplasia was not observed in any of the geckos. Hepatic vitamin A concentration was significantly higher in the carotenoid‐supplemented group than in the vitamin A‐supplemented group (p = 0.03). Our results suggest that in leopard geckos, dietary supplementation with β‐carotene allows sufficient vitamin A hepatic storage.     

红叶石楠提取类胡萝卜素的工艺条件研究

在单因素试验基础上,采用正交试验优化红叶石楠绿叶中类胡萝卜素的提取工艺条件,并用柱层析分离纯化粗提液中的类胡萝卜素。结果表明,在40℃下以丙酮∶乙醇=1∶1为提取剂,料液比1∶10,浸提时间1.5 h,类胡萝卜素含量可达51.26μg/g。该类胡萝卜素粗提液经过柱层析法初步分离纯化,纯化倍数可达1.41。     

类胡萝卜素吸收研究进展

关于类胡萝卜素的吸收机制说法不一,目前体外培养的细胞模型被广泛用于类胡萝卜素的吸收研究。本文主要从细胞水平上讨论了类胡萝卜素的吸收研究进展,并详细讨论了类胡萝卜素吸收机制方面研究较多的选择性吸收及吸收过程中的相互影响。细胞对β-胡萝卜素的摄入和分泌表现出浓度依赖性、时间依赖性和饱和性;对不同类胡萝卜素的吸收表现出选择性;类胡萝卜素在吸收过程中表现出相互影响。上述研究结果表明,类胡萝卜素的吸收可能是一个有载体参与的易化运输过程。     

Calanus oil as a natural source for flesh pigmentation in Atlantic salmon (Salmo salar L.)

The present study was to understand how efficiently the astaxanthin in Calanus oil is utilized for flesh colouration in Atlantic salmon ( Salmo salar ). Postsmolts of the fish (309 g) were held at 7.9 °C and they were fed diets containing 20 or 60 mg astaxanthin per kilogram feed derived from a synthetic source or from Calanus oil for 181 days. Besides growth and feed intake assessments, at day 81 and 181, fish flesh were subjected to colour analysis and astaxanthin determination. Growth and feed performance did not vary between the groups. There were significant differences in the amount of astaxanthin in muscle between almost all groups both at day 81 ( P  < 0.05) and at day 181 ( P  < 0.001). However, a notable similarity between fish receiving 20 mg astaxanthin from the synthetic source and those receiving 60 mg astaxanthin from Calanus oil ( P  > 0.05) at day 181 indicated that comparable amounts were deposited only with the greater level of the natural source. Tristimuli colorimeter a* values support the analytical results at day 181. Although Calanus oil did serve as a natural dietary pigment source for farmed salmon, its inclusion level should provide more than 60 mg astaxanthin per kilogram feed to achieve colouration preferred by the market.     

母乳中VA与婴幼儿健康研究进展

母乳中含有多种VA,如视黄醇、β-胡萝卜素、β-隐黄质、α-胡萝卜素、番茄红素及叶黄素等,且母乳初乳、过渡乳和成熟乳中VA的含量不同,但总体上VA含量随着泌乳期的延长而降低。如母乳中含量最高的VA视黄醇,其在初乳、过渡乳、成熟乳中的含量分别为478～1 920、440～1 270、178～825 μg/L。母乳中VA含量除受泌乳时间影响外,还与地域、乳母膳食及母乳脂肪含量等有关。本文重点介绍不同国家/地区母乳中VA的种类、含量、影响因素及其健康作用（视觉健康、免疫健康和生长发育等）,以期为婴幼儿配方乳粉的发展提供参考。     

Synthetic Biology and Metabolic Engineering for Marine Carotenoids: New Opportunities and Future Prospects

Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations.     

Pigmentation of gilthead seabream, Sparus aurata (L. 1875), using Chlorella vulgaris (Chlorophyta, Volvocales) microalga

A feeding experiment was conducted over 9 weeks with seven groups of 30 (fish per group) unpigmented gilthead seabream, Sparus aurata (L. 1875) (initial mean weight = 145.2 ± 12.3 g). Three experimental diets were prepared by adding to a basal diet free of carotenoid (final pigment content of around 40 mg per kg feed): (i) a biomass of the carotenogenic Chlorella vulgaris (Chlorophyta, Volvocales); (ii) a synthetic astaxanthin; and (iii) a mixture (1:1) of microalgal biomass and synthetic astaxanthin. At 3‐week intervals, five fish were sampled from each tank for total carotenoids analysis in skin and muscle. The carotenoid pigments (total amount = 0.4%) identified in the carotenogenic alga were lutein (0.3%), β‐carotene (1.2%), canthaxanthin (36.2%), astaxanthin, free and esterified forms (55.0%), and other pigments (7.3%). Carotenoid pigments were significantly deposited in the four skin zones studied during the feeding trial: the forefront between the eyes, the opercule, along the dorsal fin and in the abdominal area. In the muscle, regardless of the astaxanthin source, the amount of carotenoids measured was very low (less than 1 mg kg^?1) and differences not significant. Moreover, no muscle pigmentation was evident, and there was no variation in the amount of carotenoid analysed in skin tissue, through the trial, for each treatment. It was concluded that supplementing the feed with C. vulgaris would be an acceptable practice in aquaculture to improve the market appeal of the gilthead seabream.     

银杏叶类胡萝卜素的研究

银杏叶和提取黄酮(GBE)生产过程中的废弃物含有的类胡萝卜素主要为叶黄素、紫堇新质、隐黄质、新黄质和其他胡萝卜素,是天然的着色剂,如能加以利用,是银杏产业资源综合利用和循环经济发展的途径之一。