Refrigeration systems in dairy processing offer some of the best potential for making efficiency improvements, as they are the biggest consumer of refrigeration energy in food manufacture, according to new research.
Early findings of a project being led by researchers at the University of Bristol suggest that milk production alone totalled 6.762Mt in the UK 2005, using a huge 240GWh of energy if it is chilled from 37°C down to 4°C.
Scientists in the Food Refrigeration Process Engineering Research Centre (FRPERC) at the University said the second most important sector was probably meat, where chilling processes are likely to account for 60GWh/year. Similarly, 654,000t of fish required 6GWh to cool.
However, the researchers said that other major refrigeration energy consuming food sectors would be difficult to identify. They reported that many fruits and vegetables were now being refrigerated, but that the primary cooling was carried out before product reached the UK.
“The largest single component by weight in household food and drink consumption is soft and alcoholic drinks,” said FRPERC researcher Mark Swain. “Although most, if not all, are consumed chilled, the refrigeration more often takes place at the point of sale or consumption rather than in manufacturing.”
The next stage of the three-year £1M study, funded by the Department for Environment, Food and Rural Affairs (DEFRA), will involve identification of the proportion of product that is frozen, or heated and re-cooled, stored and transported.
“It has become very clear in the first month of the project that there is a dearth of measured real data on energy consumption of refrigeration systems in the food manufacturing,” said Swain. “Far more detailed data is required to identify the critical 10 areas with the highest potential to make energy savings.”
On a related matter, Tara Garnett, co-ordinator of the University of Surrey-based Food Climate Research Network, has disputed some of the findings of a new study from the Agribusiness and Economic Research Unit at Lincoln University in New Zealand, which concluded that apples, dairy, onions and sheep meat from New Zealand caused significantly less environmental damage than that produced in the UK - even after transport had been taken into consideration.
According to Garnett: “The data given for UK sheep meat production and UK dairy (milk solids) production are quite starkly at odds with recent research undertaken by the Silsoe Institute at Cranfield University and published by DEFRA.”
For more details on the FRPERC research email m.j.swain@bristol.ac.uk