According to Official Guinness Records,
The most marshmallows caught in the mouth with a home-made catapult in one minute is 31, and was achieved by Ashrita Furman (USA) in Jamaica, New York, USA, on 24 April 2018.Ashrita also holds the record for the farthest distance propelling a marshmallow by compressed air.
For a complete list of 2018 records, please visit 2018 Guinness Records in United States.