Andronicos Sideras, 55, is accused of mixing horsemeat with beef before selling it on through his company Dinos & Sons.
Two men who ran FlexiFoods - a meat suppliers linked to Dinos & Sons - have admitted passing horsemeat off as beef.
Mr Sideras denies one count of conspiracy to defraud.
The discovery of horsemeat in processed beef products sold by a number of UK supermarket chains in 2013 resulted in a series of product recalls.
The plot to pass horsemeat off as beef only came to light after horse identification chips were found in the meat by inspectors.
Ulrik Nielsen, 58, the owner of FlexiFoods, and his "right-hand man", Alex Beech, 44, have already admitted their involvement in the conspiracy.
Mr Sideras, of Southgate, north London, told the court in that in 2012 he agreed to store horsemeat for FlexiFoods.
He admits he relabelled the shipment because the packaging had been damaged during transit, but denies purchasing, selling or using the horsemeat.
The trial continues.
A businessman has denied being part of a conspiracy to pass off horsemeat as beef, claiming he was only storing the product for another company.