Four fire engines and around 25 firefighters tackled a fire at a market on Grand Avenue in the City of London.
A refrigeration unit was destroyed by fire. Around 15 pig carcasses were also destroyed. There were no reports of any injuries.
Sprinklers fitted in the unit helped contain the fire.
A London Fire Brigade spokesperson said: "Sprinklers are the only fire safety system that detects a fire, suppresses a fire and raises the alarm.
“They save lives and protect property and they are especially important where there are vulnerable residents who would find it difficult to escape, like those with mobility problems.”
The Brigade was called at 1815 and the fire was under control by 1918. Fire crews from Islington, Shoreditch, Soho and Whitechapel fire stations attended the scene.
The fire is believed to have been accidental and involved a refrigerator.