Rearch Of Carotenoids, Polyphenols And Antioxidant Activity Of Sea-buckthorn Wines During Fermentation

Northwestern China is the largest producer of sea buckthorn. Sea buckthorn has demonstrated to have potential beneficial effects on health and so it’s called "king of natural vitamins." Though sea buckthorn wine has a function of anti-cancer and anti-aging, the biggest drawback is its lack of wine’s aroma.As far as we know, little has been reported on the distribution of aroma compounds in sea buckthorn and its wine.The isolated strain in the brewing process has an ability of degrading β- carotene. In this experiment a new formula preparation of a synthetic medium was put forward; this study showed the chemical properties of the enzyme of β- carotene degradation bacteria; different methods were used to extract carotenoids in sea buckthorn juice; the changes of different wine varieties(wine, add bacteria, add enzyme) and different antioxidant activity were determined; HPLC method to simultaneously detect ten major polyphenols in sea-buckthorn were established and the composition and distribution of phenolic in sea-buckthorn wines were analyzed. The main results are as follows:1. The β-carotene- degrading Staphylococcus sp. was screened from sea-buckthorn,and the nutritional requirements of this Staphylococcus growth by single components deficiency analysis in chemically defined medium were determined. The results showed that the six amino acids Arg、Leu、Trp、Thr、Cys、Pro and two inorganic salts K2HPO4、Na NO3 were essential for chemically defined medium.2. The optimum temperature of the active peptide was 60℃ and the enzyme was discovered to be relatively thermo stable. The enzyme was found to be more acid resistant, showing higher activity at p H3.5. Ferrous iron was identified as the potent inhibitor of enzyme while ferric ion and aluminum ion were the promoter of enzyme. Km and Vmax of the enzyme are 10.208 μmol/L and 0.8033/(min·L),respectively.3. By extracting the carotenoids of sea buckthorn juice using four different methods and saponification was selected. The optimum conditions for saponification were obtained: in the saponification time 30 min, saponification temperature 90 ℃, p H3.5 under saponification conditions, the availability of sea buckthorn juice extracted carotenoids among the largest yield to 61.44%.4. 10 kinds of polyphenols were extracted by HPLC method from sea buckthorn wine at the same time. Adding degrading bacteria can make total phenolic in sea buckthorn wine(9.817mg/m L) have a significant increase compared to the ordinary sea buckthorn wine(9.033mg/m L).5. The content of polyphenols and flavonoids in different wines were determined. The results showed that the wines have a high ability of DPPH scavenging capacity and reducing power, in this work, only in vitro the antioxidant of sea buckthorn wine activity detected, preliminary further study needs to be done whether it still has the antioxidant activity in vivo.