The family of 54-year-old Gloria Burgos, found beaten to death in Bermondsey Street's Goode Foods cafe on Monday, have joined police in appealing for witnesses.
A delivery man found the body of Mrs Burgos – a Colombian national who lived in SE1 – when he went to her Goode Foods sandwich bar at the corner of Bermondsey Street and Morocco Street at about 10pm on Monday.
She was pronounced dead at the scene and a post-mortem gave cause of death as blunt trauma to the head and upper body.
An incident room is open at Lewisham under DI Clive Heys from the Homicide and Serious Crime Command.
Her family has joined police in appealing for any witnesses or information.
"Gloria was a loving wife, daughter, mother to three children and wonderful grandmother to her five grandchildren," said her daughter and son Elizabeth and Richard Burgos.
"Our mother was extremely hardworking and very good-hearted. She put her heart and soul into running her sandwich bar and was deeply respected by all in the community.
"She was known for her great coffee and positive nature and her motto was 'the best ingredient is love'.
"She is deeply missed by all our family and friends and we want to send thanks to everybody for the support we have received over the past few days.
"Please if anybody has any information about what happened to our mother, could they contact the police, however small they believe the information is."
The number to ring with any information is 020 8721 4868 or Crimestoppers anonymously on 0800 555 111.
A man was arrested on Wednesday at an address in south east London on suspicion of murder. He remains in custody at a south London police station.