Is the use of
results in the sentence below correct? Should
higher quality have article
the or not?
X results higher quality of products.
You can say "results in". For example, "Better testing results in higher quality products."
If you want to use "of" for some reason, then "higher quality" becomes the object, and as it is singular, you need an article. "Better testing results in a higher quality of product." You'd normally use "a" and not "the" as we are talking about higher quality as a general attribute, not one particular higher quality.