Revalorisation potential of agricultural waste materials into a sustainable source of health-promoting dietary fibre

Challenges

Agricultural and food production side stream materials represent an under-utilised resource that has great revalorisation potential - the process by which surplus food is transformed into a value-add product. Plant-based materials are rich in non-digestible carbohydrates and therefore a potential novel source of dietary fibre, an essential component of a healthy diet.

Dietary fibre is well-recognised for its health benefits despite intakes in the UK being below current recommendations. Key to these health benefits are the microbes in the intestine that play a crucial role in converting fibre to beneficial compounds. Dietary fibre is not digested in the upper intestine and constitutes the main nutrient source for the resident microbes in the large intestine, the gut microbiota. An appropriate supply of fibre is important for health maintenance, as its microbial fermentation leads to the production of metabolites that play an important role in maintaining gut and systemic health. Thus, short-chain fatty acids produced by the gut microbiota have been implicated in the prevention of several diseases, including colorectal cancer, inflammatory diseases, metabolic syndrome, and type 2 diabetes.

Soluble fibre is largely removed during food production processes, such as during the manufacture of juices. The human microbiota has limited capacity to efficiently break down the residual complex insoluble material in its native state. However, the way the material is processed is highly likely to have a major impact on its fermentability by the gut microbiota. The surface structure of the fibre particle dictates how easily the microbes can attach and gain access to the different fibre components to initiate their deconstruction. More work is needed to obtain proof-of-concept results that can inform the development of agricultural waste materials into novel sustainable fibre ingredients, which can be used by the food industry for the reformulation of diets to enhance their health-promoting properties. 

Questions

Solutions

We investigate whether food production waste materials can be developed into a novel source of fibre, thus improving the sustainability of agricultural practice. This project also identifies opportunities for innovation in the Scottish food and drink sector and expands on effective pathways to increase fibre in the Scottish diet. Waste materials from different crops will be ground into flours with different surface structures and incubated with defined microbial consortia to compare their fermentability and metabolite formation. The results are guiding the selection of the best-performing materials to be subjected to fermentation with human faecal microbiota to assess fermentability and metabolite production by the complete microbial community.

This project is:

• Identifying waste materials for fermentation analysis with complete faecal microbiota. 
• Seeking ethical approval in place for faecal microbiota incubations. 
• Gathering evidence of the effect of particle surface structure of agricultural waste materials on fermentability, microbiota composition and metabolite formation by the gut microbiota