Acidifying the raw materials could decrease the viscosity, which resulted in the improvement of fresh tea juice quality and the increase of juice extraction rate.

Enzymatic extraction was superior to heating and frozen extractions in juice extraction rate, while frozen extraction was better than enzymatic and heating extractions in the maintenance of nutrients.

The pineapple produced in Zhanjiang as the raw material and the single factor tests and orthogonal test were used to study the effects of enzyme pretreatment on extraction rate of pineapple juice.