Philadelphia, PA—Scientists from Chr. Hansen, the University of Copenhagen, and Cornell University have developed predictive models that evaluate the effects of a bioprotective culture on yogurt spoilage, according to an article in the Journal of Dairy Science.
Spoilage of yogurt by yeast poses a problem for the dairy industry that includes economic losses from wasted product, the article pointed out. Understanding the effects of factors such as storage conditions, yeast species, and bioprotective cultures on yeast spoilage can help yogurt producers make decisions that improve quality and minimize loss.
Between 11 percent and 25 percent of dairy products are wasted globally, in part due to fungal spoilage, the article noted. One method to reduce fungal spoilage is to add food cultures known to have bioprotective effects that delay growth of unwanted microorganisms during shelf life.
The authors of this study were the first to develop Monte Carlo simulation models to estimate yogurt spoilage caused by yeast that included the initial contamination level, different yeast species, storage conditions, and the addition of food cultures with bioprotective effects.
“These predictive models allowed for prediction of yogurt spoilage caused by different yeast species, as well as the effect of including bioprotective culture in a yogurt product to reduce yeast spoilage,” said first author Line Nielsen, Ph.D., department of food science, University of Copenhagen. “Such models can help yogurt producers understand how different parameters influence product quality and use these results to support decision-making in yogurt quality management.”
The models from this study are able to predict the amount of spoiled product when four common spoilage yeast strains are present in a production (Debaryomyces hansenii, Yarrowia lipolytica, Saccharamyces cerevisiae, and Kluyveromyces) at different storage temperatures with or without a bioprotective culture containing Lacticaseibacillus rhamnosus over a 30-day storage period, it was authored.
Although the researchers found the effect of the bioprotective culture was most pronounced at 7 degrees Celsius for all yeasts compared to 16 degrees C, the yeast strain had the largest effect on the efficacy of the bioprotective culture.
