Expert’s view: Monika Leukert about selenium-enriched yeast

How to choose selenium-enriched yeast?

When it comes to selecting the best organic selenium (Se) source, it can be tricky as there are more and more options on the market. Monika Leukert gives us five tips for choosing the best Se-enriched yeast.

1. Light beige color

For selenized yeast, color matters! A light color is the result of continuous control of the whole production process and reveals a high-quality product. In contrast, a darker brown color might be a sign of less digestible selenized yeast.

2. Certificate of analysis

Make sure you get a certificate of analysis for each production batch. This is a proof of good control of the production process to ensure batch-to-batch consistency and a guarantee of the composition of the product. Content analysis of both the total Se and selenomethionine (SeMet) of each production batch is crucial to guarantee a high-quality product to the users.

3. A combination of several organic Se forms

Se-enriched yeast should contain more than 98% of organic Se according to European Union regulations. Nevertheless, animals’ Se metabolism involves different forms of Se, and Barbé et al. (2017) has shown the bioavailability of Se-enriched yeast appears more important when it combines several forms of Se such as SeMet and selenocysteine.

4. High SeMet level

Even though it is not the only organic Se compound in selenized yeast, SeMet level is a good quality tracker of the fermentation process and Se absorption by the yeast. For example, to be sold in the EU as a nutritional feed additive, SeMet levels should be >63% of total Se.

5. Reliable bioavailability studies

It is important to make sure the Se from the animals’ diet is well assimilated. Bioavailability studies should consider two factors: the concentration in the animals’ blood, milk, eggs or muscle; and the Se transfer rate, which is the most reliable measure to assess Se assimilation.

 

To see these tips in an image, browse our interactive infographics!