The word "as" is commonly used as an adverb, for comparisons between one thing and another. In your text if it's used on its own ("not be extracted AS effectively"), I'd expect to see it compared with something else. For example: "may not be extracted as effectively as using a better quality juicing machine" If there's no comparison (whether stated or implied), then "as" is not being used correctly in the text.

Леда's answer about the "hidden" comparison is completely correct. It actually IS an "as...as" structure, but half of it is unsaid. Race A is not as fast as race B-->Race B is over within minutes, but race A is not as fast [=not as fast as race B]. Sam is not as smart as Jane--> Jane can solve all the math problems in the book, but Sam is not as smart [[=not as smart as Jane]], and sometimes he needs help

thank you. so here should be "that may not be extracted [as] effectively in home juicing (as …some professional juicing process)"

Home juicing won't be very effective. There is a "hidden" comparison with canned juice or whatever the text was about.