Strategies to understand and reduce the spoilage potential of low and non-alcoholic beverages

Fermented beverages are considered to be products which are 'safe for human consumption', for the primary reason that pathogenic organisms are not associated with the final product. However, in recent years, consumer preferences have led to the growth in popularity of 'no or low alcohol beverages' (NABLAB's). This category reflects a rapidly growing market within the brewing sector, expanding from <0.1% of all products in 2015 to 5% global consumption at the current time and further growth expected to reach ~33% by 2025.

Although often designed to mimic alcoholic beverage flavour profiles, NABLAB's are fundamentally different in terms of their composition and are at higher risk of microbial contamination due to the relatively high concentration of nutrients, elevated pH, milder carbonation levels and reduction in ethanol1. Consequently, reports of spoilage in NABLAB products have dramatically increased, an issue highlighted by a recent major product recall by Diageo.

In this project we aim to fully understand the microbial risks associated with production of NABLAB's across the brewing process, including the potential for contamination by organisms previously considered to be of low threat. We aim to select for organisms capable of thriving in the NABLAB environment and analyse their physiology and growth preferences with the ambition of preventing contamination via a targeted approach. This topic will be addressed through 4 work packages as described below:

WP1 - Identification of key contaminants (0-12 months)
This will be conducted via a series of site surveys focused on raw materials, the manufacturing process, storage and transport of products, and goods at point of sale. To achieve this, we will develop a metagenomic based strategy (MinION) using current expertise within the brewing group at UoN, to fully capture the microbiome at each process stage. Microbes will also be isolated using standard microbiological techniques for WP2.

WP2 - Characterisation of microbes (9-18 months)
To understand spoilage potential, BioLog Phenotype Microarray analysis will be used to assess microbial growth in NABLAB's under a range of conditions. The aim is to understand the biology of microorganisms, including their resilience to antimicrobials (hop compounds, sulphites and benzoates), their tolerances to beer properties (alcohol, pH) and their nutritional requirements (sugars and essential ions). We already have extensive expertise in the application of Biolog PM technology to analyse for the effect of growth inhibitors and in modelling microbial population dynamics2-3.

WP3 - Relationship between product and spoilage potential (18-27 months)
Here we aim to determine if all NABLAB products have the same spoilage potential and to identify key attributes (nutritional or compositional) which enhance or prevent contamination. We will use the metagenomic approach developed in WP1 to track spoilage over time and to determine the impact of multiple organisms on spoilage over time through population monitoring.

WP4 - Maximising the impact of preservative strategies (24-36 months)
Learnings from WP3 and WP4 will be applied to key products in order to enhance current preservation strategies using a targeted approach. The goal is to reduce dependency on artificial preservatives and to enhance natural characteristics to prevent microbial growth and spoilage.