Wearing an open-necked shirt, a suit and a white baseball cap with his slogan "Make America great again", Mr Trump was asked if he was worried about the volatility in financial markets following Britain's vote to leave the EU on Thursday.
"There's always turmoil no matter where you go, no matter what you do," he said.
He also met with News Corporation media mogul Rupert Murdoch and his wife Jerry Hall, giving them a tour of the Aberdeen course in a golf cart.
Mr Trump, whose mother was Scottish, was greeted by around a dozen protesters at the course waving Mexican flags, rainbow flags for Gay Pride day and signs that read "Donald stop the hating" and "Shame on you for ruining a beautiful landscape".
Asked about the protesters, Mr Trump compared them to rival candidates for the Republican nomination who he had defeated, such as Senator Ted Cruz.
"I have one or two that are contentious and that's fine because they lost, it's like some of the people I beat in the primaries," to win the Republican nomination for president, Mr Trump told reporters.
Mr Trump last year proposed a temporary ban on Muslims entering the US as a response to Islamist attacks in Paris and California, causing a furore in Europe.
In an article in a Scottish newspaper earlier this year, Mr Trump pointed to his determination to overcome local opposition to his golf course projects as an example of the leadership skills that Americans would get if he were to become president.
Top conservative columnist leaving Republican Party over Trump
Mr Trump is facing an increasing internal Republican revolt with prominent long-standing members of the party speaking out against his candidacy.
Influential conservative columnist George Will said he is leaving the Republican Party over Mr Trump's polarising campaign and urged others to follow suit, even if it means rival Democrats take the White House.
Mr Will, a Washington Post columnist, told a luncheon Friday: "This is not my party," according to the conservative PJ Media news website.
Henry Paulson, a Republican who was US Treasury secretary during the 2008 financial meltdown, on Friday called a Trump presidency "unthinkable" and said he will vote for Democrat Hillary Clinton.
"When it comes to the presidency, I will not vote for Donald Trump," Mr Paulson, who was chief executive of Goldman Sachs before becoming Treasury chief under Republican President George W Bush, wrote in an opinion piece in the Washington Post.
"I'll be voting for Hillary Clinton, with the hope that she can bring Americans together to do the things necessary to strengthen our economy, our environment and our place in the world.
"Simply put, a Trump presidency is unthinkable."
Mrs Clinton regained a double-digit lead over Mr Trump this week, according to a Reuters/Ipsos poll released.
The June 20-24 poll showed that 46.6 per cent of likely American voters supported Mrs Clinton while 33.3 per cent supported Mr Trump.
Another 20.1 per cent said they would support neither candidate.