Try this:
using Sitecore.ContentSearch.Linq; // GetResults on IQueryable
var index = ContentSearchManager.GetIndex("sitecore_web_index");
using (var context = index.CreateSearchContext())
{
var query = context.GetQueryable<SearchResultItem>()
.Where(item => item.Content == "banana");
var results = query.GetResults();
var totalResults = results.TotalSearchResults;
var topTenResults = results.Hits.Take(10);
...
}
To get more info about sitecore and linq you can watch this session and look at this repo.