Nonthermal technologies, including high pressure processing, high voltage electrical discharge and pulsed electric fields, can contribute to these goals. Professor Anet Režek Jambrak, from the Faculty of Food Technology and Biotechnology at the University of Zagreb, Croatia, discusses how innovations in advanced thermal and nonthermal processing can help food producers be part of the circular economy.
What role can the food production sector play in helping to meet some of the UN’s Sustainable Development Goals?
“The latest UN Sustainable Development Goals promote the development of sustainable technologies. The food production sector can help by implementing low emission techniques; improving existing technology to become more sustainable; and focusing on developing ‘smart factories’. The Food and Drug Administration (FDA) was among the first regulatory agencies to request from the Institute of Food Technologists (IFT) a report on the effectiveness of microbial inactivation by alternative food processing technologies. The idea was to develop applications for novel nonthermal technologies, eventually in combination with advanced thermal technologies, to ensure food safety.”
What issues should food businesses think about when looking to achieve more sustainable processes?
“The aim of using alternative food processing technologies is to achieve the desired inactivation of microorganisms, reduce energy consumption, optimise time-consuming processes, and satisfy consumer requests. Nowadays, one of the biggest challenges is to scale up the readiness level of these novel technologies to an industrial level. The food industry should also focus on zero-waste processing, waste management and the sustainability of food packaging.
While thermal techniques have been used for decades, high-temperature processing can be responsible for the deterioration of nutritive, functional, and organoleptic properties. Therefore, several nonthermal techniques had been evaluated for their potential in food preservation. So far, only high-pressure processing has satisfied requirements in terms of microbial inactivation, when used alone in food preservation. The use of other nonthermal processing techniques is industrially viable only in combination with moderate heating, to ensure the required food preservation effect. In addition, the mechanisms underlying the inactivation of microorganism by novel technologies have not been fully elucidated and are still under study, with several proposed action plans still ongoing for each technique.”
What are nonthermal technologies, and how can these be made greener?
“Nonthermal technologies are sustainable if we use them to reduce or reuse food waste. It is very important here to perform life cycle assessments (LCAs), to confirm their sustainability. Novel nonthermal and improved thermal processing techniques can offer more efficient energy consumption and quality and impact positively on food quality.”
Can you give some of examples of how these technologies might be applied in practice?
“At DIL in Germany, the energy balance and LCA of pulsed electric fields and high-pressure processing technologies were recently compared to conventional thermal processing applied to the preservation of tomato and watermelon juices. At the pilot scale, both pulsed electric field and high-pressure processing technologies presented lower energy consumption expressed per litre of juice. At DIL, they are also producing pulsed electric field equipment in pre-treatments of potato to reduce oil consumption, and to speed up the frying process.
Ultra-high pressure homogenisation in the treatment of milk was also recently compared with common thermal treatment for milk. Upscaling showed a decrease in the carbon footprint of up to 88%. High-power ultrasound has also been applied to water treatments and dye removal. High voltage electrical discharge can be used for the extraction of bioactive compounds, while cold plasma can be used for surface cleaning and the production of plasma activated water (PAW) and plasma activated air (PAA).”
How can the sustainable production of bioactive peptides and biomolecules be beneficial for the food sector?
“This means that enzyme usage can be replaced by nonthermal processing. This could be useful because protein rich food waste can be used to process waste products, to obtain bioactive peptides and to process biomolecules.”
What are your predictions for food technology over the next three to five years?
“I predict that, especially in developed countries, more than 50% of food processing industries will have at least one alternative (nonthermal technique) in their processing line. Each industry should orient their production and management thinking towards lean area, digitalisation and green ways of processing. The aim is to reduce carbon, water and waste footprint and to be in line with SDGs and Agenda 2030. Less developed countries might not have enough funds to intervene in production. In my opinion, tackling climate change and the environmental impact on food processing should be a joint task.
Another point is waste and wastewaters in the food production sector. There should be a clear plan with a focus on reducing, reusing and recycling. Everything that can be reused should be reused. Companies should also prepare to recycle packaging for each food product, or develop edible packaging parts. Food technology will have to be built up with sensors to monitor processing, collect and analyse data, and to optimise food processing technology towards sustainable “green” production.”