Join collection of objects into comma-separated string

In many places in our code we have collections of objects, from which we need to create a comma-separated list. The type of collection varies: it may be a DataTable from which we need a certain column, or a List<Customer>, etc.

Now we loop through the collection and use string concatenation, for example:

string text = "";
string separator = "";
foreach (DataRow row in table.Rows)
{
    text += separator + row["title"];
    separator = ", ";
}

Is there a better pattern for this? Ideally I would like an approach we could reuse by just sending in a function to get the right field/property/column from each object.