In the following examples, study how the core of each sentence is singled out.
In the first example, the two clauses introduced by “which” give added information about the nouns they come after. The information that comes between the two dashes refers to “producer”. Crossing out these noun modifiers, we’ll get to the main idea “The powder is the result of years of research.”
Example 1
The powder is the result of years of research which has led to a technique which enables its producer General Foods Ltd. –to encapsulate harmless carbondioxide gas under pressure inside a flavoured sugar-based coating.