Suppose I have an online shopping system and many users are registered to it. I want a feature that when I add a new product or there's a promotion for a particular product, my Google plus page gets updated in the sense that the details of the product are published there automatically. It will only be used for back-office purpose. 

The problem is that I cannot share on the Business Page, it gets posted on my user profile. 

How can I achieve posting on google plus page via a web application?