Detection and Identification of Food-Borne Yeasts: An Overview of the Relevant Methods and Their Evolution

Abstract

The presence of yeasts in food is not unexpected, as they are part of the microbiota of raw materials, employed as starter cultures in numerous fermentation processes, and also play a role in spontaneous fermentation. Nevertheless, they have the potential to induce spoilage, which can lead to significant quality issues, and certain yeasts have the ability to cause infections in humans and animals, posing a food safety risk. The detection of yeasts in food, determination of their cell number, as well as identification and typing, are therefore often tasks during the examination of certain food categories. The methods employed to achieve these objectives are diverse, encompassing both conventional culture-based techniques and more recent, genome-based studies. The objective of this study is to provide a summary article that presents the methods suitable for testing food-derived yeasts. The article will highlight the advantages, disadvantages, and potential difficulties of their applicability. Moreover, a comprehensive review of nucleic acid-based, culture-dependent and culture-independent molecular yeast identification techniques was conducted, encompassing scientific articles from the past five years (2020-2024). The search was based on the Science Direct database using the keywords "yeast and molecular identification and food".

Keywords: culture-based techniques; molecular methods; qualitative analysis; rapid detection; yeasts.

Figure 1

The impacts of foodborne yeasts. (The images illustrate the macro- and micromorphological diversity, as well as the enzymatic and biocontrol activity of yeasts. Own photographs.).

Figure 2

Life cycle of the evolution of standards for enumeration of viable yeasts and moulds from 1987 to the present and with a focus on the future [61,62,63,64].

Figure 3

The principle of ATP luminescence.