Preserving pork: Spanish scientists innovate yeast-based nitrite alternative to extend meat shelf life

16 Jul 2024 --- The F&B industry is increasingly swapping out chemical preservatives in meats for natural substitutes due to their associated health risks. Amid this, Spanish researchers have examined the potential of yeast as a “natural preservative” in Iberian pork loin, which traditionally uses nitrites and salt as preservatives.

This comes after the EU’s recent regulations on the use of nitrites and nitrates in foods like meat, fish and cheese to secure their preservation and microbiological safety.

The yeast — Debaryomyces hansenii LRC2 — is present in the pork loin itself, say the scientists. The meat industry can use the alternative to maintain the properties of Iberian pork loin through nitrite and salt reduction.

A decade ago, a team at the University of Cordoba’s Microbiology Area in Spain led by Professor José Ramo conducted this study. They isolated a collection of yeasts that developed inside the loin during its maturation process. They found that these microorganisms impacted the characteristics of the final product.

“We have seen that, through the application of this yeast, we can prevent other unwanted microbes from appearing,” explains Ramos, confirming that this yeast results in enhanced food safety for the pork loin and longer shelf lives.

Targeting mold
The team evaluated the yeast strain’s potential as a preservative by conducting a volatile compound inhibition assay and achieved mold inhibition rates surpassing 75% in all studied conditions. This strengthened the hypothesis of its potential preservative effect in cured meat products, highlights the study.

The study says application of natural yeast-based alternatives is a feasible option for the new meat industry needs.This is because the yeast’s volatile compounds are responsible for the pork loin’s aroma but are also capable of “inhibiting fungi that can harm the product.”

“In that phase, we tested the yeast with a fungus, face to face, without them touching, and the fungus grew less,” explains Helena Chacón, first author of the study.

The findings are published in the journal Food Control.

Verifying food safety
The team verified the yeast’s protective quality in the final product and inoculated it with a battery of Iberian pork loins from the Navalpedroche company, located in the Valle de los Pedroches, a valley in southern Spain recognized for the quality of its meat products.

“In this process, as it is industrial work, the ISO standards for food quality and microbiology were observed,” details Francisco J. Ruiz, another researcher who worked on the project. 

“Using this yeast, in particular, allowed us to lower the levels of nitrite and salt, maintain food safety and the characteristics of the Iberian pork loin. At the flavor level, however, we did not fully meet the market’s needs.”

Meeting taste expectations
The crux of the matter in meat products is the taste, observe the researchers. 

Although the specialized panelists and regular consumers who tried the Iberian pork loin with fewer preservatives and inoculated with the yeast reported that “it was good,” their scores were lower due to a “loss of sensory quality.”

“Having managed to preserve the pork loin’s characteristics and increased its shelf life, as well as having adapted it to European standards by lowering its nitrites and salt, the pending task is to improve the taste,” underscore the scientists.

“To do this, the team is working with other complementary strains to maintain 100% of the Iberian pork loin’s flavor.”