The Characterization On The Structure Of The Red Carotenoids In The Natural Red Yolk Of Duck's Egg And Its Bioactivities Evaluation

The natural red yolk of duck's eggs is produced by the laying duck in the lake areas, the yolk is natural red with the chrominance reaching up to and/or above RYCF (Roche Yolk Color Fan ) 15 and it is popular with the people. In the laying duck breading areas such as Honghu, Jianli, Xiantao and Tianmen city in Hubei Province, the culturists are used to feeding fresh pondweeds, various grain to the laying ducks, and feeding the ducks in the aqueduct lakes, reservoirs, trenches, ponds and swamps etc. It is reported that the color of the yolk of fowl is related to the caroteniods in the feedstuff (Bailey, C. A. and Chen, B. H., 1989; H. Hencken, 1992; A. Blanch, 1999). Not only is it an important kind of natural pigments, caroteniods also has extensive biologic activity, such as preventing tumor, anti-oxidation, eliminating free radical, and so on (Wang Yeqin, Li Qinshen, 1997; Peng Guanghua, 2002; Paola Vitaglione, 2002), At the same time, with the increasing worry about the safety of synthesized pigments, many countries prohibit producing red yolk eggs with artificial synthesized pigment through adding synthesized pigment into the feedstuff. Therefore, it has great economic significance and development prospect to research into red pigments of natural red yolk and its natural biologic resources (H. Hencken, 1992; Britton G, 1985). The new investigation indicates that it has not been reported as yet about the characteristics, composition, structure and its sources of the red pigments in natural red yolk.In this study, The extraction, separation, purification of the carotenoids in natural red yolk of duck's eggs were studied; The characteristic, structure and bioactivities of the red carotenoids and its sourcesin the red yolk of duck's eggs were analyzed and identified by means of chromatogram, UV-VIS, HPLC/MS/MS and high-resolution mass spectrum; And to appraise the bioactivities of carotenoids from natural red yolk of duck's eggs, laser scanning confocal microscope, flow cytometer were preformed in this paper. The main results are as follows:1 Separating and purifying the red carotenoids from the carotenoids extract of natural red yolk of duck's eggs1.1 The extraction of carotenoids from natural red yolk of duck's eggsFor extracting the carotenoids of freeze-dried red yolk power the optimum conditions were performed by petroleum ether-acetone=2:lv/v, red yolk power: solvent = 1:4 w/v, extracting 3 times, 60min per time, 40?. The content of carotenoids in the freeze-dried common yolk power of duck's eggs (RYCF 6 or so) is 4.5mg/100gi in the freeze-dried natural red yolk power of duck's eggs (RYCF15 or above) is 9.25mg/100g.1.2 Separating and purifying the red carotenoids from the carotenoids extraction of natural red yolk of duck's eggsUsing MgO and kieselguhr (MgO: kieselguhr=l:2w/w) or silica gel as the column filling, load the carotenoids extract of red yolk of duck's eggs on the column to firstly wash with petroleum ether-acetone (96 : 4 v/v) and remove the neutral grease and cholesterol from the extraction. Then wash the red and yellow pigments with acetone, collect and condense it, the degreased carotenoids pigments of natural red yolk can be obtained.The degreased carotenoids pigments of natural red yolk was separated on the 0.75mm prepared silica gel plate. Using the developing agent (A) petroleum ether-acetone (17:4 v/v) or (B) petroleum ether-acetone- methanol (8 : 2 I 1 v/v), one red zone R can obtained. Using the developing agent (C) n-hexane-acetoacetate-acetone- methanol = 27 : 4 : 2 : 2 (v/v/v/v), three zone R1, R2 and R3 can be obtained. Scratch and collect the red zone of R and Rl, R2, R3 and use for structure analyses.1.3 The stability of carotenoids from natural red yolk of duck's eggsThe extract of carotenoids pigments should be kept in the dark as much as possible, and,ideally, they should be stored at low temperatures under nitrogen gas. Peroxide-free solvents must always be employed. They may also undergo trans-cis isomerism during handling. The carotenoids pigments are unstable when they com...