It came as it emerged a politician who quit the Liberal Democrats amid a row over far-right social media posts is to stand for the SNP in a Highland Council ward.
Drew Millar left the Lib Dems while being investigated for allegedly sharing material from the group Britain First, which he denies.
Ms Tortolano, a 61-year-old tour guide, commented on an article about award-winning Nigerian-born rapper Bemz, who moved from London to Stranraer when he was 14.
Bemz, 27, whose real name is Jubemi Iyiku, previously told The Scotsman: “I never really experienced racism until I came to Stranraer.”
He described being called a monkey and other names and said a friend’s mum was spat on in the face.
The musician posted a link to the article in October 2021, the headline of which read: “Black History Month: ‘I never knew what racism was until I moved to Scotland’.”
Responding, Ms Tortolano wrote: “What a load of s***.”
Scottish Conservative MSP Pam Gosal said: “This is a highly inoffensive tweet that seeks to rubbish the lived experience of someone else.
“She’s effectively telling this man that the racism he experienced in Scotland was imagined.
“This is an example of Scottish exceptionalism at its worst – an ignorant belief that racism is a problem that exists only in other countries, not in Scotland."
In a statement issued by the SNP, Ms Tortolano said: “I can only apologise for what was a stupid comment from me.
“I reacted to a headline without reading the story.
“I in no way dismiss the experiences that any individual has of racist behaviour in Scotland.
“I’d apologise not only to the individual involved but to any else offended by my thoughtless tweet.”
Ms Tortolano is standing for the Bannockburn ward in the May 5 elections.
She has now deleted her Twitter account.