Grind the pineapple slice to a fine paste and sieve it and keep aside.
Then put sugar in a pan and add water so that sugar sinks in it and bring to a boil.
Add the sieved paste and cook for 2-3 boils or 2-3 minutes.
Lastly add citric acid and salt and mix well.
Cool completely and store in an airtight container in the freezer compartment and use as required.