Olive fermentation yeast strains have probiotic potential, study finds

The research focused on the probiotic potential of 16 yeast strains from the north east of Portugal.

Researchers discovered that some yeast strains showed characteristics such as high antioxidant capacity and lipase activity and have now called for further testing to better understand the mechanism involved so the strains can be used in probiotic products.

Speaking to Nutra Ingredients, professor Elsa Ramalhosa, School of Agriculture, Polytechnic Institute of Bragança, Portugal, the author of the research, said: “The yeast strains with the highest probiotic potential could be applied in mixed starter cultures to obtain probiotic olives or other probiotic fermented vegetable products."​

Prospect of probiotic table olive​

“The next step in terms of research in this area will be to perform additional tests to these strains to better understand the mechanisms involved, taking into account their role in table olives fermentation and table olives characteristics, as well as to evaluate other probiotic properties to eventually produce a probiotic table olive.​”

This latest research comes amid a backdrop of consumers desiring an alternative to dairy probiotics, driven by an increasing number of people who are lactose intolerant and those that are scared off dairy products by the possible adverse effects of its cholesterol content.

“There is an interest in finding yeast strains with probiotic potential due to the numerous beneficial effects on human health, including prevention and treatment of intestinal diseases and immunomodulatory effects,”​ Professor Ramalhosa told us.

 “In addition, yeasts have the ability to produce natural antioxidants such as carotenoids, citric acid, ascorbic acid, tocopherols and glutathione that may retard the oxidative degeneration of lipids and improve the health of the host.”​

Study details​

The research involved 16 yeast strains usually found in green table olives.

They were tested for enzymatic activity; ability to grow at 37 degree centrigade; antimicrobial activity; autoaggregation capacity; antioxidant activity and survival in gastrointestinal tract conditions.

Of the 16 strains, a Saccharomyces cerevisia​e strain showed lipase activity, high ability to grow at the host temperature and high antioxidant capacity.

Strains Pichia guilliermondii​ and Candida norvegica​ showed an ability to survive in the human gastrointestinal tract conditions.

Yeast strain Candida norvegica​ demonstrated antimicrobial activity compared to Cryptococcus neoformans.​

“In this research we observed that some yeast strains had interesting characteristics such as lipase activity, high ability to grow at the host temperature and high antioxidant capacity and ability to survive to the human gastrointestinal tract digestion,”​ Professor Ramalhosa told us.

Source: Trends in Food Science & Technology​

Published online ahead of print: doi.org/10.1016/j.ifset.2017.06.003​​

"Probiotic potential of indigenous yeasts isolated during the fermentation of table olives from Northeast of Portugal."​

Authors:  Tatiane Oliveira, Elsa Ramalhosa, Luís Nunes, José A. Pereira, Eliane Colla, Ermelinda L. Pereira