When using shortcuts, you can use the text renderer () and then use the variable to save the object. If you need to dynamically update this text, you only need to use the attr () function and update.
http://jsfiddle.net/6GKCJ/2/
var title = chart.renderer.text('Total fruits consumption', 100, 90) .css({ fontSize: '12px' }) .add(); $('#btn').click(function(){ title.attr({ text:'newText' }); });
source share