You may not change the quote string with writetable directly.
However, you can add a single quote to your string before writing.
% create a small table
str = ["A", "B", "C D"]';
num = [1 2 3]';
t = table(str, num)
% No quotation marks
writetable(t, 'test.txt')
type test.txt
% double quotation marks
writetable(t, 'test1.txt', 'QuoteStrings', true)
type test1.txt
% single quotation marks
t.str = "'"+t.str+"'";
writetable(t, 'test2.txt')
type test2.txt
