The phrase "high quantities" refers to a large or large amounts of something. It means there is a lot of a particular item or substance. Full definition
Results concluded that many commercial baby foods contain high quantities of sugar and trans fats; both ingredients that are not considered to be healthy for adults, much less babies. (ethicalfoods.com)
The other fatty acids are found in higher quantities in certain plants and grains. (drsfostersmith.com)
For example, whole grains contain higher quantities of the essential amino acids legumes lack and vice versa. (cathe.com)