International Proficiency Testing Program for stevia

Posted on 18 May 2011

The International Stevia Council (ISC) announced the launch of an independent Proficiency Testing Program (PTP) for stevia products.

There are currently a wide variety of analytical methods and reference standards being used within the industry to determine steviol glycoside content.

However, the quality of the analytical methods and reference standards are inconsistent across the industry.

This has resulted in inaccurate and inconsistent representation of product composition and purity levels.

In order to protect market viability of all stevia-based products, the stevia industry needs to address the challenge of ensuring that analytical methods and standards employed are appropriate and also meet minimum levels of accuracy.

The PTP is expected to allow participants to benchmark performance of their methods, analytical standards and analysts' competency in a statistically relevant, blind testing scheme managed in accordance with international quality standards.

Initially, samples will be limited to stevia-based sweeteners that comply with Joint FAO/WHO Expert Committee on Food Additives (JECFA) purity specifications (not less than 95% of the total of the nine named steviol glycosides, on a dry basis).

Successful proficiency testing programs exist in numerous industries, including corn-based sweeteners, sugar, food and botanicals industries.

The International Stevia Council has selected LGC Standards Limited as the vendor to administer the PTP.

"The PTP is open to any laboratory that wishes to participate in this testing scheme. Therefore you do not need to be a member of the International Stevia Council to participate, though you will enrol directly with ISC for participation," said president Carl Horn af Rantzien.

"Since this program is designed to provide inter-laboratory comparisons, you do not need to invest in new equipment or methods. Participants are requested, however, to commit to a minimum full year of PT rounds (four tests) to ensure the creation of trend analysis."