Optimising and scaling new fermented food products

SIMBA project partners, Minna Kahala (Luke) and Lena Decuyper (BBEPP), describe the work taking place to develop and refine new fermented food products.

Interest in plant-based foods as well as fermentation has increased in recent years for reasons including environmental concerns, health consciousness, nutritional needs, sensory issues and safety. In SIMBA, we have responded to this demand by applying microbial technologies to help produce easily used, plant-based foods with improved nutrient content for people.

Identifying promising food products

Fermentation is a sustainable processing technique that can alter the nutrient content of food by reducing the antinutrient content and producing bioactive compounds in plant-based products. At Luke, we have designed microbial starter mixtures to be used during the fermentation process. These mixtures have been assembled based on preliminary tests conducted with individual microbial strains from the microbe collections in Luke and SIMBA partners in NMBU. The most promising strains were added to starter mixtures and are now being used in the development of new product ‘prototypes’ based on pulses and cereals. Through fermentation, levels of antinutrients such as oligosaccharides that cause stomach discomfort, have been reduced. Furthermore, with the help of the assembled microbial mixtures, bioactive compounds such as vitamin B12 could be produced in the plant-based products in Luke’s laboratory scale experiments. Further information on the nutritional quality will be obtained after analyses are finished in Luke, NMBU and NIVA.

New food products we have developed include a fresh porridge-type fava bean-oat product, a pea-based yoghurt-type snack product and lentil-based fresh cheese-like product. The pea-based product was further tested in 5-liter laboratory scale fermenters and was selected for upscaling performed by colleagues in BBEPP.

Scaling Up

As a multipurpose pilot plant for the development and scale-up of bio-based processes, the Bio Base Europe Pilot Plant is involved in the SIMBA project to help partners bridge the gap in the innovation chain between lab research and industrial production lines. BBEPP is responsible for scaling-up starter cultures that will be used as the microbial consortium in the fermentation of peas. These cultures will improve the nutritional quality of the peas while also reducing the presence of inhibitors and increasing the vitamin B12 content. As scale-up partner, BBEPP also provides industrially relevant data and knowledge required for the Life Cycle Assessment and techno-economic analysis.

Firstly, BBEPP developed the cultivation protocols for producing eight starter cultures selected by Luke, all at bench scale using cost-efficient raw materials. Optimizing the cultivation of the strains has been a real challenge for certain bacteria due to the high biomass concentrations required for pea fermentation, their slow-growing characteristics and their sensitivity to product inhibition effects by the produced organic acids.

Secondly, BBEPP performed the scale-up to pre-pilot scale for the top-3 starter cultures, selected by Luke for their promising characteristics as microbiome for downstream use. Switching to bioreactors and more advanced process set-ups for strain cultivation facilitated greater control with more possibilities for fed-batch fermentation and cell recycling. Therefore, the team could mitigate against product inhibition effects and slow growth and meet cultivation targets for each of the strains.

Next Steps

In the coming months, BBEPP will demonstrate the actual pea fermentation process, using the upscaled starter cultures and industrially relevant equipment (150 L, see picture). The most challenging part of the process will be the transfer of the cultivated starter cultures to the main fermenter due to high risk for contamination. The team is currently designing the entire process in order to overcome this hurdle and achieve the SIMBA objectives.

In addition to process development and characterization of the nutritional quality of the fermented products, SIMBA partners will provide new information on the fermentation process with mixed microbial cultures by using new sequencing technologies. Sequencing of the DNA of the selected strains by NMBU colleagues will provide deeper information on the genomic content of these food grade starter strains. Furthermore, metatranscriptomic analysis of the microbial community present in fermentation process, which will be carried out by our SIMBA colleagues at UNIBI, will help to better understand the fermentation process, the functional activity of the microbial community. All this knowledge will provide the foundation for new tools to further advance fermentation of novel healthy plant-based products.

[Thumbnail image via Pexels]