Convenience foods more like their fresh counterparts

People are forced to increasingly rely on convenience foods due to time constraints. EU-funded scientists are developing novel technologies for safer, tastier foods that retain their natural characteristics after preservation.

Availability of convenience foods that do not compromise on nutrition and flavour is becoming equally or more important to consumers than simply minimising time spent in the kitchen. EU-funded scientists initiated the project ''Processing raw materials into excellent and sustainable end products while remaining fresh'' (PRESERF) to investigate three novel food preservation techniques.

Freezing and thawing alters the texture and nutritional value of products such as leafy vegetables and soft fruit by disrupting cell structure. Pulsed electric fields (PEFs) reversibly open cell walls and enable subsequent vacuum infusion of substances (cryoprotection agents) that protect against the harmful effects of freezing. Scientists have studied both processes individually and are now optimising combinations to maintain cell structure and viability after freezing.

Drying is an effective preservation technique that alters the structure, nutritional content and physical appearance of food. Use of supercritical carbon dioxide (CO2) rather than hot air or freeze drying showed promising potential for mild, economical drying. Preliminary observations indicated equal or better preservation of structure and the restoration of characteristics after rehydration in soups and sauces. Lower energy consumption and enhanced preservation of bioactive compounds was found in comparison to conventional drying techniques.

Supercritical CO2 can also be used for pasteurisation to kill and prevent the growth of new microbes in food without affecting aroma or texture. Microbial inactivation was effective in all three foods tested with faster inactivation occurring at higher temperatures.

PRESERF has developed a novel methodology and indicators for life cycle assessment (LCA) of sustainability, with preliminary studies currently under way. The two CO2-based processes will be developed for pilot plant testing. Equipment designs are being finalised and construction is due to commence.

In the end, technologies have the potential to increase the quality, safety and preservation of a variety of solid food products. At the same time, they reduce the environmental impact of processing technologies all along the food preparation chain. Combined with reduced costs for manufacturers, enhanced competitiveness is sure to follow.

Related link:
http://cordis.europa.eu