Flushing

In food processing and packaging, the displacement of air — typically oxygen — from a container or package by an inert gas such as nitrogen or carbon dioxide before sealing. Gas flushing extends shelf life by slowing oxidation and inhibiting aerobic spoilage organisms; it is the basis of modified-atmosphere packaging. Typical gas mixes — 100% nitrogen for snacks, CO₂/nitrogen blends for meats and cheeses — are matched to the product: CO₂ inhibits microbes but can collapse packs as it dissolves, while nitrogen is inert filler. Residual-oxygen targets below 1–2% are verified by headspace analysers as part of packaging quality control.