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Future food: Safety and shelf-life of reformulated food products.

Primary Supervisor: Dr Helen Onyeaka, School of Chemical Engineering

Secondary supervisor: Dr Taghi Miri

PhD project title: Future food: Safety and shelf-life of reformulated food products

University of Registration: University of Birmingham

Project outline:

Food Reformulation has been defined as the “reduction of the amount of negative nutrients in (processed) foods such as energy, salt, saturated (and trans) fat and sugar”. The World Health Organisation recently challenged the private sector to improve the food supply and reduce levels of energy density, trans fat, saturated fat, sodium and added sugar in their products. Therefore, food reformulation has been high on the agenda of public health communities, governments and food companies. But this trend has raised the question of whether food safety and healthy nutrition are compatible (Walls et al., 2019).

Concern about microbiological stability and safety of reformulated food is a challenge for the Food Technology as adjusting recipes is risky. In 1989, there was a large foodborne outbreak of botulism due to contaminated hazelnut yoghurt. This was due to insufficient thermal treatment and the replacement of sugar by aspartame. This case illustrates the dangers of changing a traditional formulation.

Therefore, we teamed up the food engineering and food safety groups together to produce novel reformulated food as well as investigate their safety. Currently, we achieved reduced-fat and low-fat mayonnaise, reduced-fat and reduced-sugar chocolate and reduced-salt bread and are working to extend the variety of the product.

In this project, we will measure and control the key parameters such as pH, water content, water activity, process/storage humidity-temperature. Furthermore, we will investigate the Safety (microbial growth) and Shelf-life (microbial stability) of the reformulated foods. We will also explore the possibility of using hurdle technology to produce even higher quality food while ensuring its safety

Exact project details will be agreed between supervisors and students at a later date.


  1. Walls, H., Baker, P., Chirwa, E. and Hawkins, B. (2019) 'Food security, food safety & healthy nutrition: are they compatible?', Global Food Security.
  2. Evanuarini, H., Nurliyani, I. and Hastuti, P. (2015) 'Characteristic of Low Fat Mayonnaise Containing Porang Flour as Stabilizer', Pakistan Journal of Nutrition, 14(7), pp. 392-395.
  3. Gurtler, J.B., Doyle, M.P. and Kornacki, J.L. (2014) The microbiological safety of low water activity foods and spices. Springer.

BBSRC Strategic Research Priority: Sustainable Agriculture and Food: Microbial Food Safety

    Techniques that will be undertaken during the project:

    We typically use:

    • molecular biology;
    • microscopy (light/fluorescence / confocal / Raman);
    • flow cytometry;
    • chemical and biological assays;
    • pulse-field gel electrophoresis (PFGE);
    • bioreactor culture; and
    • several inactivation techniques such as ohmic and microwave heating and ultra-sonication.

    Contact: Dr Helen Onyeaka, University of Birmingham