Protractor: find a text in a page

I've created this step definition to check if a given text exists in a web page. The code works properly but sometimes, expecially when I look for a long text, I get an error even if the text exists in the page.

The code is this:

this.Then(/^The text "([^"]*)" exists in page$/, function(myText, callback){

    browser.sleep(10000);

    var selectedElement = element(by.xpath("//*[. = '" + myText + "']"));

    expect(selectedElement.isPresent()).to.eventually.equal(true, "This text is not present in page").and.notify(callback);    

  });

Basically I do three things:

1. I wait 10 seconds to be sure that all elements of the DOM have been loaded.
2. I seach for an element(div, p, label or whatever) thet contains the text I'm looking for.
3. I check if the element is present oterwise I get an error.

Can you tell me if there is a better way to do this? It's correct to use browser.sleep() at the beginning of a step definition to wait for the DOM loading?

IMPORTANT: I'm not using Angularjs

Thank you in advance.