Olives with yeast cells

Olive Phenols: Nature's Tiny Warriors Against Yeast?

Elliot Brynn in Science & Nature December 2025 • 4 min read.

"Unlocking the potential of olive compounds to combat yeast growth in food and beyond."

Olives are packed with phenolic compounds, natural substances known for their health benefits. While their ability to fight bacteria and fungi is well-documented, scientists are now looking into how these compounds affect yeasts.

A new study investigates the antimicrobial effects of five olive phenolic compounds—tyrosol, hydroxytyrosol, oleuropein, luteolin, and apigenin—on two common yeast species: Aureobasidium pullulans and Saccharomyces cerevisiae. The goal? To see if these natural compounds could offer a way to control yeast growth, particularly in food-related scenarios.

Researchers used various methods, including optical density measurements, yeast colony forming units, and mid-infrared spectroscopy, to track how the phenolic compounds impacted yeast populations. The findings suggest that olive phenols could indeed be a promising tool in the fight against unwanted yeast.

Olive Phenols vs. Yeast: The Showdown

The study revealed that all five phenolic compounds tested had an effect on both yeast species. Concentrations of 200 ppm (parts per million) and higher showed significant antimicrobial activity. However, the effectiveness of lower concentrations varied depending on the specific phenolic compound.

Mid-infrared spectroscopy provided additional insights. Exposure to most of the phenolic compounds (except tyrosol) caused changes in the 1200–900 cm-1 range, an area related to the carbohydrates in the yeast structure. Tyrosol and luteolin also caused changes in regions associated with amides (1750–1500 cm-1) and fatty acids (3600–3000 cm-1).

Here's a breakdown of how each compound fared:

Tyrosol: Higher concentrations were needed to impact yeast growth.
Hydroxytyrosol: Effective at inhibiting yeast, with concentrations as low as 12.5 ppm showing some effect.
Oleuropein: Extended the lag phase of yeast growth, particularly at 50 ppm.
Luteolin: Demonstrated high antimicrobial activity, leading to a 4-log reduction in yeast count at 400 and 200 ppm.
Apigenin: Similar to luteolin, it showed strong antimicrobial effects, especially at higher concentrations.

The study indicates that A. pullulans, a yeast found naturally on olives, was more sensitive to tyrosol and hydroxytyrosol compared to S. cerevisiae. This suggests that the source of the yeast might influence its response to these compounds.

A Natural Solution for Food Spoilage?

Since olive phenolic compounds demonstrate effectiveness against yeasts, they could potentially be used in food applications where yeast growth is a problem. Think of extending the shelf life of certain products or preventing spoilage caused by yeast contamination.

The researchers also suggest that FTIR spectroscopy is a valuable tool for monitoring and characterizing the antimicrobial activity of phenolic compounds on yeasts. This method can complement traditional microbiological techniques, offering a deeper understanding of how these compounds interact with yeast cells.

While further research is needed, these findings highlight the potential of olive phenols as natural antimicrobial agents. They could offer a safer and more sustainable alternative to synthetic preservatives, opening new avenues for food preservation and other applications.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1007/s13197-018-3468-4, Alternate LINK

Title: Characterization Of Antimicrobial Activities Of Olive Phenolics On Yeasts Using Conventional Methods And Mid-Infrared Spectroscopy

Subject: Food Science

Journal: Journal of Food Science and Technology

Publisher: Springer Science and Business Media LLC

Authors: Canan Canal, Banu Ozen, A. Handan Baysal

Published: 2018-10-25

Everything You Need To Know

What are olive phenols, and which ones were studied?

Olive phenols are natural compounds found in olives, known for their health benefits and antimicrobial properties. The study focused on five specific olive phenolic compounds: tyrosol, hydroxytyrosol, oleuropein, luteolin, and apigenin. These compounds were tested for their effects on two common yeast species, Aureobasidium pullulans and Saccharomyces cerevisiae, to determine their potential in controlling yeast growth, particularly in food applications.

Why is it important that olive phenols can affect yeast?

The study's findings are significant because they suggest that olive phenols, specifically tyrosol, hydroxytyrosol, oleuropein, luteolin, and apigenin, have antimicrobial effects against yeast. This is important because it opens the possibility of using these natural compounds to control yeast growth in food and other applications. The effectiveness varied, with some compounds like luteolin and apigenin showing strong activity even at lower concentrations. This could lead to natural alternatives for preventing food spoilage and extending shelf life.

What specific types of yeast were studied, and what were the differences in their responses?

The study investigated the impact of olive phenols on two types of yeast: Aureobasidium pullulans and Saccharomyces cerevisiae. Aureobasidium pullulans is naturally found on olives. The research revealed that A. pullulans was more sensitive to tyrosol and hydroxytyrosol than S. cerevisiae, implying that the yeast's origin can affect its response to these compounds. The study used methods like optical density measurements, yeast colony forming units, and mid-infrared spectroscopy to assess the effects.

How did the concentrations of olive phenols affect the yeast growth?

The study used various concentrations of olive phenols, measured in parts per million (ppm). Concentrations of 200 ppm and higher of the olive phenolic compounds showed significant antimicrobial activity. However, the effectiveness of lower concentrations varied depending on the specific compound. Hydroxytyrosol showed some effect at concentrations as low as 12.5 ppm, while oleuropein, even at 50 ppm, extended the lag phase of yeast growth. Luteolin and apigenin demonstrated high antimicrobial activity, even leading to significant reductions in yeast count at higher concentrations.

What insights did the study gain from using mid-infrared spectroscopy?

Mid-infrared spectroscopy provided insights into how olive phenols interacted with yeast at a molecular level. Exposure to most phenolic compounds (except tyrosol) caused changes in the 1200–900 cm-1 range, associated with the carbohydrates in the yeast structure. Tyrosol and luteolin caused changes in the regions of amides (1750–1500 cm-1) and fatty acids (3600–3000 cm-1). These observations indicate how the olive phenols might be disrupting the yeast's cellular structure and metabolic processes, supporting their antimicrobial effects.