Effects of explosion puffing drying at modified temperature and pressure on total flavonoids and water soluble saccharides of winter jujube (Zizyphus jujube Mill).

Effects of explosion puffing drying at modified temperature and pressure on total flavonoids and water soluble saccharides of winter jujube(Zizyphus jujube Mill) were studied in this paper.The total flavonoids extraction methods(alcohol assisted by ultrasonic wave-microwave and alcohol)were compared.Water soluble saccharides were extracted by hot water.The ability of eliminated the hydroxyl free radical of total flavonoids from puffing and un-puffing winter jujube was compared according to Fenton method.Water soluble saccharides was isolated by Sehpadex G-150 gel filtration.The results showed that the flavonoids extracted by alcohol assisted by ultrasonic wave-microwave was superior to that extracted by alcohol.The contents of total flavonoids and water soluble saccharides of winter jujube changed obviously during the explosion puffing drying.The total flavonoids content of fresh fruit,pre-dry and puffing dry winter jujube were 1.59%,0.71%,0.38% respectively.Ability of eliminated the hydroxyl free radical of puffing dry winter jujube was lower than that of fresh winter jujube.Water soluble saccharides and reduce sugar contents of fresh fruit,pre-dry and puffing dry winter jujube were 45.23%,55.84%,44.34% and 38.91%,47.29%,38.56%,respectively.There were more high molecule saccharides in fresh winter jujube fruits and more low molecule saccharides in puffing dry winter jujube by Sehpadex G-150 gel filtration showed.