A study published in Food Control found that only three out of 29 samples of avocado oil met both quality and purity standards. Nearly 70% of the oils tested were rancid or diluted.

One of the biggest clues that a liquid isn't what it claims to be is its color. Virgin avocado oil should be a bright green, in keeping with the green-hued fruit's flesh.

Refined versions of the oil will look lighter in color, indicating it has undergone processing. So, for more flavor and freshness, opt for the bold color.

Once purchased, keep an eye on the color and any changes in texture as you cook, as this can be a clue the oil is reaching the end of its prime.

Store the avocado oil in a cool, dark place along with other ingredients to extend its shelf-life, which should be about six months.