What do the new berries in Pokémon Go do?

In the latest update, 0.57.2 for Android and 1.27.2 for iOS, Niantic not only released Generation 2 Pokémon, they released new berries as well.

Pokémon GO is in the process of being updated to version 0.57.2 for Android and 1.27.2 for iOS devices. Below are some release notes and comments from our development team.

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Added two new Berries.

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What do these new berries do?

Solution 1:

According to this article:

The Nanab Berry and Pinap Berry are the two new berry items in trainers’ arsenals. The Nanab Berry will slow Pokemon down so it’s less likely for them to run off, while Pinap Berries help players collect twice as much candy upon a successful catch.

It looks like the Nanab berry slows down pokemon to prevent them from escaping, and Pinap berry helps you to gain twice as much candy when you catch a pokemon.