How can we get user's specific posts / tweets based on keywords using Facebook / Twitter API

Can we get any posts / tweets posted by a specific user based on set of keywords from facebook / twitter using the REST API?

Example

For example user X has posted a post in Facebook like: "I liked the the cheese burger at xyz stall, New york.". The same is tweeted in the Twitter.

And the same user is logged in to our app either using Facebook login or Twitter login (Our application is basically a street food search kind). When the user is logged in, we will have "cheese, burger, veg" etc keywords in our DB as predefined keywords. So we will search for the posts and tweets based on these keywords in the user's Facebook / twitter profile posted by the user and get them and show them on our app.

Is that really possible? If yes then please point me the relevant APIs for them.