(611b) Energy Usage in Food Manufacture

The food industry, the largest manufacture sector globally and also one of the major contributors to GHG emissions, is facing significant environmental challenges that are building up pressure on food security. As the global population keeps growing, water, food and energy demand are expected to increase too - up to 50 % by 2050. A starting point to reduce such demand is to identify energy consumption hot spots in food manufacture operations. In this context, this work provides a comprehensive and updated database for energy processing usage – within the UK and globally. Specific energy consumption (SEC) data for products, processes and food distribution were collected from 44 literature sources based on product-based energy intensity metrics. To account for changes in technologies, processing and fuel efficiencies, and structural changes within sectors data was sorted in three groups: prior to 2000, 2000 - 2004, and 2005 – 2015.

Findings show that thermal processes consume most of the total processing energy – generated extensively from fossil fuels (e.g. > 65% average of the dairy sector), which shows potential for alternative technologies to be implemented. Emerging technologies are typically electric powered, so the energy could be supplied from renewable resources. Data also revealed that the most energy intensive food products are powders (instant coffee and milk powder), fried goods (French fries and crisps) and bread, all them products that involve phase-change in their manufacturing, such freeze-drying or drying. The ways in which many food processes are carried out require first the addition of water to the product followed by its removal (either by evaporation or sublimation), revealing water flow streams that can be optimised and recycled. In the meat and dairy processing sectors, energy and water use have increased due to a rise in hygienic standards and cleaning requirements, which represents an opportunity for hygienic design developments. The challenge here is to introduce energy and water-usage saving policies into the manufacturing protocols without either affecting the quality of the foodstuff or making it less safe. Developing food formulation with lower moisture contents could be a solution.

Energy use in the UK follows the same trends, although a lack of studies that assessed food products playing a central role to the UK – e.g. ready to eat meals, sandwiches – was also identified. An analysis of the relationship between energy density (calories intake), weekly consumption and processing energy use in the UK revealed that the some of the more demanded processed, nutrient-dense foods (e.g. cakes, cookies) require also higher amounts of energy during processing.

In terms of food distribution, a shift towards distributed supply systems – as opposed to centralised ones – and to local production has been identified. For example, more than 98% of all foods within the UK are transported by road, with increasing distances travelled in recent years. However, the environmental benefits of these changes are not always clear, which reveals the importance of global environmental assessment tools (such LCA, carbon and water footprint) that take the whole food chain into consideration.

Overall, this work reveals a series of needs and points towards current trends in food manufacturing that can help both stakeholders and policy makers to allocate resources more effectively and design new food manufacturing protocols that increase sustainability and security of food chains.