IN Brief:
- Research found substantial variation in bacterial spore levels between plant ingredient types and between samples from the same source.
- Suppliers are being urged to monitor highly heat resistant thermophilic spores and Bacillus cereus in ingredients intended for beverages.
- Stronger ingredient specifications and predictive models could reduce spoilage, overprocessing, and avoidable product waste.
NIZO Food Research and an industrial alliance of beverage manufacturers, ingredient specialists, and technology suppliers have issued new guidance on controlling bacterial spores in plant based ingredients used for shelf stable drinks.
Ripple Foods, Royal FrieslandCampina, Tetra Pak, SPX Flow, HP Hood, HAS Green Academy, Wageningen University & Research, and 11 industry partners contributed to the work, which examined microbial contamination in pea, oat, almond, faba bean, and coconut derived ingredients.
Although the researchers found no previously unknown or unusually resistant microorganisms, contamination differed considerably between ingredient groups and between samples from the same source. Several identified species could still cause spoilage or create food safety concerns when ingredient selection, processing, and storage controls were inadequate.
Particular attention was given to spore forming organisms capable of surviving the thermal processes used for low acid beverages distributed at ambient temperature. Suppliers are being encouraged to monitor highly heat resistant spores from thermophilic bacteria and Bacillus cereus, maintaining consistently low levels before ingredients reach beverage plants.
Improved methods for detecting and enumerating spores were developed alongside new data on heat resistance, germination, and growth. Predictive models produced through the programme can help product developers identify critical control points and set more realistic ingredient specifications before recipes move into commercial production.
Such specifications increasingly need to describe more than a total plate count. The identity, concentration, and resistance of the organisms present can determine whether an ingredient is suitable for a particular ambient beverage, even when broader microbiological results appear acceptable.
Natural variation reaches the processing line
Plant ingredients can pass through cultivation, harvesting, storage, milling, extraction, concentration, drying, and transport before arriving at the beverage factory. Conditions at every stage influence the final microbial profile, while apparently similar batches can reach the processor with markedly different spore loads.
Raw-material variability complicates thermal validation because a scheduled heat process must account for the product formulation and the challenge presented by the incoming ingredients. Increasing the thermal load can provide an additional safety margin, but excessive treatment may damage flavour, colour, protein functionality, texture, and nutritional quality.
More precise microbiological data allows process engineers to set time and temperature combinations against a defined hazard rather than compensate for uncertainty. Homogenisation, deaeration, aseptic storage, filler hygiene, and downstream distribution conditions can then be considered as part of one validated system.
Low acid drinks require especially careful control because the formulation provides fewer intrinsic barriers to microbial growth. Protein, fat, starch, minerals, fibre, and suspended particles can also alter heat transfer, creating different treatment requirements across oat, pea, almond, coconut, and blended products.
An ingredient carrying an excessive spore load can shorten production runs, increase fouling, complicate cleaning, and force a more severe thermal process. Even where the finished drink remains safe, spoilage may produce swollen packs, sediment, flavour deterioration, or a shorter commercial shelf life.
Incoming-material approval therefore affects production efficiency as well as microbiological performance. Better control upstream can support longer runs, more predictable commissioning, and fewer interventions when a new formulation moves from pilot scale into continuous manufacture.
A broader European effort to strengthen regional protein production is also drawing attention to the processing capacity and quality systems behind the raw-material base. The EU protein strategy links crop availability with investment in extraction, fractionation, and food manufacturing, but additional supply will still require consistent specifications if it is to support dependable ambient beverage production.
Shared methods tighten supplier relationships
No single participant controls the complete microbiological risk. Crop production affects the organisms carried into storage, ingredient processing determines which contaminants survive, and beverage formulation influences how they behave during heating and shelf life.
Shared analytical methods should make it easier for ingredient suppliers and drink manufacturers to agree meaningful limits. Results produced using incompatible enrichment, incubation, or enumeration procedures can otherwise create disputes over whether a batch meets specification.
Routine monitoring also gives suppliers a clearer view of process drift. Changes in crop origin, storage duration, dryer performance, cleaning, or transport conditions may appear in spore data before customers encounter failures in finished products.
Processors, meanwhile, can use supplier histories to distinguish occasional outliers from a systemic control problem. That evidence can support purchasing decisions, audit priorities, and the level of verification required when material arrives at the factory.
Tighter specifications will carry a cost, particularly where ingredients require additional testing or where only a limited number of suppliers can meet the required standard. Those costs have to be weighed against the much larger losses associated with rejected batches, destroyed stock, curtailed shelf life, or a market withdrawal.
As plant based beverage portfolios expand, manufacturers are handling more protein sources, blends, fortification systems, flavours, and pack formats. A thermal process validated for one formulation cannot be assumed to protect another, particularly when ingredient microbiology and product composition both change.
The consortium’s work provides a common scientific basis for aligning those variables. Its practical effect will depend on suppliers introducing routine spore monitoring, processors updating purchasing specifications, and product teams incorporating microbiological variation into formulation and thermal validation from the beginning of development.
Ambient plant drinks are now expected to deliver the same consistency in safety, flavour, texture, and shelf life as established beverage categories. Reaching that standard requires control to begin with the ingredient rather than at the entrance to the heat-treatment system.
