A relatively new method of food production, high pressure processing (HPP) removes the need to use heat and preserves the quality of ingredients, while reducing waste.
One key challenge for manufacturers today is upholding a system of food production that can keep pace with the world’s growing population. By 2050, a 60% increase in food production will be required to feed an estimated 9.3 billion people, the Food and Agriculture Organization (FOA) estimates.
For manufacturers, this means producing more food than ever before, via means that are quick, efficient, safe, and sustainable. High pressure processing – often referred to as the acronym HPP – may well be a solution to this challenge. Inactivating bacteria by exposing raw materials to high pressure, this food processing technique replaces the need to use heat, and subsequently extends the shelf life of food products. The result? Fresher produce with less waste.
So, how can manufacturers use high pressure processing in practice … and why should they?
It is estimated that anywhere between 25-40% of the food we produce globally is wasted in the post-harvest chain, never reaching the consumer’s plate. As well as the clear financial loss this incurs, large-scale food waste also heightens the risks associated with global food insecurity, such as hunger and malnutrition.
Using high pressure processing in food production is advantageous in that it preserves the fresh produce characteristics of ingredients, in turn extending the shelf life of food. This method is particularly beneficial for manufacturers of fresh foods such as fruit and vegetables, which make up a significant proportion of the total food waste due to their short shelf-lives.
A recent investigation into the effect of high-pressure processing (400 and 600 MPa, for two or five min, 20 °C) compared to conventional autoclave, or thermal, processing (96°C for 45 minutes) on cauliflower found that the technology has clear potential in increasing shelf life, while preserving a high level of quality. In terms of the cauliflower’s texture, high pressure processing did not cause any change from the control sample, compared to the autoclave samples which saw a significant reduction in texture.
As texture is a key driver of the consumer taste experience, the benefits that this method offers in preserving the original texture of an ingredient renders high pressure processing a valuable technique for manufacturers in the ready-made meals space, for instance.
High pressure processing consists of using compressed water as a pressure medium to remove bacteria, yeast, and mould from food and drink products, replacing the need for heat, as is the case with the more traditional method of thermal processing.
Comparatively, this method requires only one tenth of the energy needed to heat one litre of water from 45°C to 50°C. The water can also be reused over time, making high pressure processing an energy-efficient and sustainable alternative to traditional thermal processing.
As the recent results of a four-year long analysis by the food research institute, Nofima, into the effects of six new processing technologies on food show, high pressure processing can help manufacturers to implement more sustainable and efficient food production practices, while also making cost-savings by reducing energy and water consumption.
“With the use of new processing technologies, the food industry will be able to provide food with a long shelf life and of high quality. For most newer technologies, the process takes place at low temperatures and with short holding times. This means that the nutritional content is better taken care of, and it also results in a higher sensory quality the products,” said Tone Mari Rode, senior scientist at Nofima.
“In addition, the use of newer technologies could increase sustainable food production as many of the new technologies use less electricity and less water than traditional food processing.”
Nevertheless, it is worth noting that the relatively complex and expensive equipment required as part of this production method may be a stumbling block for smaller, more cost-conscious manufacturers.
Across all four food groups included in Nofima’s analysis, high pressure processing was found to have a notable effect on the shelf life of food ingredients, specifically in yoghurt, chicken, and cauliflower. The digestibility and texture of various ingredients were also significantly affected by the technology, with clear effects observed in the egg, dairy, and meat ingredient groups.
Changes to the colour, rancidity, and nutritional value of ingredients were also observed as part of the study, yet to a lesser extent than the abovementioned properties. A closer look at the nutritional value of fruit and vegetables treated by high pressure processing in some studies, showed that this method was better able to preserve antioxidant capacity than thermal techniques.
All in all, high pressure processing may offer the greatest opportunities for the meat sector, specifically chicken meat, which had effects in all six property categories measured as part of the analysis, the study found.
As part of the analysis, Nofima carried out a survey and a series of scientific consumer studies among Norwegian consumers to explore the consumer acceptance of these innovative processing technologies.
In light of the responses, Nofima suggests two key advantages that manufacturers should emphasize when marketing products that have been treated via high pressure processing. The first refers to the benefit of reduced food waste during processing, while the second centres around the longer quality retention of products processed via this method.
Conversely, manufacturers using high pressure processing are advised to avoid referring to environmental sustainability when communicating such products to consumers.
