A baby food pouch can look right at month one and taste wrong at month nine. Nothing on the line catches that.

Baby meat puree is the hardest case in the spouted pouch family. High protein, high fat, a 10 mm spout, hot fill, then 121 °C. Fat oxidises slowly. Protein browns slowly. Neither shows up in a leak test.

By the time a parent opens it, the pouch is nine months old and the complaint is a smell.

The barrier question is not about the film alone. It is about the filled volume. How much oxygen was left in the headspace at the moment of sealing. Whether the spout carries a barrier layer of its own or is a plain PP tube with a cap on top. And how much barrier came back out of the retort with you.

Flat film has no spout hole, so flat film data cannot answer any of it.

Three things are worth having in writing. Headspace oxygen measured on your filling line. What the spout contributes to total OTR. And whether the shelf-life study ran on filled pouches or on film.

What oxygen level does your filler leave in the headspace?