Search engine and site indexing

I have inserted in the catalog some products with the word 'aluminium', sometimes in the description, some in the specification and some in the keywords.
The problem is that if I make a search in the site looking for the word 'aluminium' the only results come from those products where the word is in the description and not from the others places.
I have already activated the plugin 'Search - Eshop'.
The site is www.pramashop.com

Hello Andrea,

The keyword can be searched in product sku, product name, product short description, product description, product tag.

Sincerely, Giang

Hi Giang,
I would like to suggest as new implementation the possibility to index also 'Specification' and 'Keywords'.
The page source code is good enought for the crawling by Google and other search engines, but is a nonsense that the inside engine doesn't index those datas.
It Will be a good implementation.... believe me!!!

Hi Andrea,

Thank you for suggesting that. I will consider to add it in the future.

Sincerely, Giang