Preparation And Characterization Of Astaxanthin From Antarctic Red Yeast

Astaxanthin is a kind of terpenoid unsaturated compound,which belongs to ketone carotenoid.Due to its strong antioxidant capacity and a variety of special functional characteristics,it has been widely used in animal husbandry,medicine,cosmetics,health care products and other aspects.Synthetic pigments are banned in the market now,and natural astaxanthin cannot meet the needs of the development of modern food industry.In this paper,the fermentation and culture conditions and extraction of astaxanthin from Antarctic red yeast were optimized,and the stability and antioxidant function of astaxanthin were further studied.Based on the traditional fermentation conditions,the fermentation of red yeast was optimized in terms of medium and culture conditions.2 % molasses and 0.5 %yeast powder were used as carbon and nitrogen sources,inoculation volume was 250 m L conical bottled 50 m L,p H 3.0 at 20 ?,under the condition of yeast cell density,the biggest increase by about 25.15% compared with the traditional training.Orthogonal experiment was carried out according to the results of single factor experiment,and the results of orthogonal experiment were successfully verified to be consistent with the results of single factor experiment.Lycopene,a precursor substance that can increase the density of yeast cells and increase the yield of astaxanthin,was further screened out.The optimal release time was determined to be24 h after the start of culture,and the optimal release mass was 40 ?g.It was determined that the extraction amount of astaxanthin was the highest when acid-heat method was used to break the wall of yeast cells,and the extraction amount of astaxanthin was the highest when chloroform-methanol?1:1?was used as the extraction agent.However,considering the safety of astaxanthin in later application,anhydrous ethanol was used as the extraction agent in subsequent experiments.Prawn the influence factors of green pigment extraction research showed that when the extraction temperature was 40 ?,the extraction time was 15 min,extraction liquid ratio was 1:2,extracting 2 times of extracting astaxanthin highest amount.The stability of astaxanthin under different light and temperature conditions was studied.The experimental results showed that astaxanthin was stable at low temperature and dark.The effects of Na⁺,K⁺,Cu²⁺,Zn²⁺,Fe²⁺ on the stability of astaxanthin were verified.The antioxidant function of astaxanthin was studied by comparing the scavenging capacity of astaxanthin,VC and VE on superoxide anionfree radicals and DPPH free radicals.The experimental results showed that the scavenging ability of various antioxidants to superoxide anion radicals was in the order of strong to weak at the same mass concentration: astaxanthin ? V_C > V_E.The scavenging ability of DPPH radical was in the order from strong to weak:astaxanthin > V_E > V_C.Astaxanthin has good scavenging effects on free radicals,which verified its good antioxidant function.The above studies finally optimized the cultivation of Antarctic erythrocytes and the extraction of astaxanthin,and studied its stability and antioxidation function,providing reference for the industrial production of astaxanthin and the theoretical study of its subsequent use and preservation.