a half opened avocado
Why You Should Avoid Cutting Avocados With Metal Knives
Using a metal kitchen knife to cut avocados can speed up the fruit's oxidation process, causing it to brown more quickly due to the contact with metals which are prone to rusting.
To slow down browning, it's recommended to use a ceramic knife instead, although it's still best to cut the avocado right before using it to minimize exposure to air.
To prevent avocado browning, it's best to minimize contact between the fruit and the knife, leaving the pit intact for as long as possible and avoiding dicing or cross-hatching.
If meal prep is necessary, opt for a ceramic knife, make limited cuts, and store the avocado with sliced onions to combat oxidation with the sulfites in alliums.