My mum taught me D.I.Y pineapple enzyme from 1 of her colleagues

酵素【jiaosu】 ferment; enzyme.
Fruits: Lemon & Pineapple (type: not ripe)
1-2 pkt Brown Sugar from Chinese Medical Hall (片糖)
1 empty glass container with lid (clean & wipe it dry with cloth, individual
preferably size of glass container)

The process:
* Lemon - cut off the top & bottom, Pineapple - cut off the top & bottom
then cut the rind off the sides in wide strokes trying to leave as much
flesh as possible while removing all of the "eyes."

1) cut Lemon & Pineapple in thin slices (on a cutting board. must be dry)
2) put it into the glass container
3) cut the Brown Sugar into half, put it on top of Lemon & Pineapple
Repeat no.1 to 3 steps until the glass container is filled.

Use Glad Cling Wrap (clear food wrap) cover the glass container,
then put the lid; closed tight & leave it for 21 days about 3 weeks.
(tip: leave it in kitchen cabinet)

After 21 days (3 weeks) then consume, 1 or 2 small cup before bed time.
[Note: if glass container have been shake; the taste might be concentrated.
might need to add water]

It's good for people who is malnutrition (營養不良); anemia (貧血); easy
weary (容易疲勞).
info from this web http://tw.knowledge.yahoo.com/question/question?qid=1306022607750

More info from websites:
http://www.diyhouse.com.sg/healthBoard/healthBoard7.asp
http://stephanietan.net/enzyme/pineapple-enzyme/

P.S: I find this is good for my health, no need to spend so much money to stay healthy. This is quite popular in Taiwan & Japan.