Impact of high hydrostatic pressure processing on fruit granule qualities in carrot nectar

The quality of fruit granule containing beverage is highly affected by the inside granule. The effect of different pressure( 300,400,500 MPa) influence on polyphenol oxidase,peroxidase activity,total phenol content,total antioxidant value and browning was studied using high hydrostatic pressure process,dealing with three different fruit granule types( apple,water chestnut,pear) carrot nectar.Research also involved 400 MPa pressure influence on different granule size( 6,8,10 mm) in carrot juice.The results showed that different pressure had no significant effect on properties of polyphenol oxidase in apple and water chestnut,and pear enzyme activity was positively correlated with the pressure.The activity of peroxidase in apple and pear was inhibited by pressure.Total phenol content had varying degrees of decline by high hydrostatic pressure process.Total antioxidant value was generally a downward trend with pressure rise,and the pear flesh had a better resistance to adverse environment.High hydrostatic pressure processing was effective in anti-browning. The effect of different particle size on the activity of PPO was related to the type of fruit under 400 MPa.