They are used as a vegetable.
You only eat the peeled centre part of the shoot, which is white and hairless. They have a crisp texture with a mild, sweetish flavour, almost like artichoke hearts.
Bamboo Shoots can be bought fresh at some ethnic markets, or bought in cans, packed in water. The canned ones will be light yellow because they have already been cooked by boiling. The canned ones are available whole or already sliced. Purists say the canned ones are a different food item altogether from the fresh ones.
Fresh Bamboo Shoots should be firm, and not too long. Old ones or long ones will be more woody; soft ones are stale, and will taste awful and bitter. The longer you leave fresh ones standing without cooking them, the more bitter they will become, so cook them as soon as you can. The bitterness comes from the “hydrocyanic acid” in them interacting with starches and sugars in the shoots; the more time it has to react, the more bitterness is produced.
To peel the shoots, slice them lengthwise part of the way into the centre, then peel off the layers until only the centre remains. Some advise wearing gloves to avoid the tiny black bristles on the outside of the shoots that can irritate your hands. Place peeled shoots in salted water until ready to use.
Older Bamboo Shoots can still be used but are more work. Peel them as above, then slice them up — this will help more bitterness to be leeched out. Place in a pot of cold, salted water, and bring just to the boil. Drain, then repeat the process another two times.
When using canned Bamboo Shoots, you many notice a white residue on the shoots. This is an amino acid that collects when they are boiled. Drain the sprouts and rinse well with fresh water to remove this. Put unused ones in fresh water, and store in sealed container for up to a week in fridge; change the water daily.
Some people advise to also blanch canned Bamboo Shoots to get rid of the processed taste.
Bamboo Shoots must be cooked first before eating to destroy a toxin in them called “hydrocyanic acid” that can cause cyanide poisoning. The acid also makes them bitter.