A study of USDA shows almost all olive oil passes these commonly used standards, even when the rarely used sensory standard finds that the oils are not fit for human consumption.
Evaluated 21 olive oil samples sold to the restaurant and catering sectors based on the voluntary standards of the United States Department of Agriculture (USDA) and tests that have been adopted by the International Organization for Standardization (ISO).
Analysis found that:
• All but one of the 15 “extra virgin” samples passed the most commonly used USDA chemistry standards (free fatty acidity, peroxide value, and ultraviolet absorbence) to test quality;
• Despite this high passage rate, 60 percent of the samples failed the USDA “extra virgin” sensory standard, which is a standard rarely used for quality-control purposes in the foodservice and restaurant sectors. Some of the oils were so defective that they were classified by sensory panels as “not fit for human consumption” under the USDA standard;