High Pressure Processing (HPP) - Articles and news items

Making low-fat yoghurts creamier through dynamic pressure processing

Latest issue / 4 January 2012 / Mark A.E. Auty, Vivian L. Gee and Christian I. Ciron, Teagasc Food Research Centre

Improving creaminess in food products, whilst simultaneously decreasing fat, remains a challenge for food manufacturers worldwide. Yoghurts are inherently perceived as healthy food products and can be made even healthier by reducing fat. However, reducing fat in yoghurt without compromising desirable textural characteristics like creaminess is difficult to achieve. One approach is to add fat replacers such as modified starch, polysaccharide-based hydrocolloids or microparticulated proteins. Fat replacers or fat mimetics can improve texture but have the disadvantage of requiring labelling as ‘additives’. An alternative approach is to modify the textural attributes of yoghurt through processing. In this article, high quality low-fat natural yoghurts using industry standard formulations were produced using high dynamic pressure (microfluidisation) technology.

The definition of ‘creaminess’ can be used in reference to product appearance, flavour and/or texture. It is a meta-descriptor that is constantly evolving and transforms when used in context with different products and can vary between individuals. It has been defined as “possessing the textural property producing the sensation of the presence of a miscible, thick, smooth liquid in the oral cavity”1. Fat contributes to mouthfeel and flavour and fat particle size affects micro – structural, rheological, and ultimately, the sensory properties of a variety of milk products, including yoghurt. (more…)

Packaging challenges for novel processed food

Issue 5 2010 / 4 November 2010 / Nathalie Gontard, Valérie Guillard, Miguel Mauricio Iglesias, Stéphane Peyron & Sana Raouche Joint Research Unit Agropolymers Engineering and Emerging Technologies – UMR 1208 Montpellier SupAgro, INRA and Salvatore Iannace, Institute of Composite and Biomedical Materials, National Research Council of Italy and Giuseppe Mensitieri & Ernesto Di Maio, Dept. of Materials and Production Engineering, University of Naples Federico II

In the last few years, the fast development of novel processing methods for food preservation to improve safety, quality and shelf life of packaged foods gave place to important gaps of knowledge that must be filled in the area of suitable packaging materials. In particular, in the European Project NovelQ (more…)

Hygienic design of novel processing equipment

Issue 5 2010 / 4 November 2010 / Edyta Margas & John Holah, Campden BRI and Alexander Milanov & Lilia Ahrné, SIK

The hygienic design of food processing equipment is a critical factor in determining the quality and safety of foods produced. It involves the selection of suitable materials of construction, their fabrication into a functional piece of equipment, the ability of constructed equipment to produce food hygienically and the maintenance of hygienic conditions throughout the equipment’s working life. There is a significant amount of guidance and information available on the principles of hygienic design for traditional food processing equipment (from the European Hygienic Engineering Design Group; www.EHEDG.org), but the nature of NP techniques such as High Pressure Processing (HPP) and Pulsed Electric Field (PEF) may impose other additional stresses on the equipment surfaces, their construction materials and their fabrication. (more…)

High-Pressure and Pulsed Electric Field: What do the consumers think?

Issue 2 2010 / 12 May 2010 / Nina Veflen Olsen (Nofima Mat) and Anne-Mette Sonne (MAPP)

New products and processing techniques are continuously being developed within the food industry. While food scientists may focus on the technical novelty and applaud the progress of science, consumers are often more conservative and sceptical about changes. From earlier experiences with gene modification and irradiation, we have learnt that advantages that new processing technologies offer do not guarantee the success of a product in the market place. Consumer acceptance depends on whether they perceive specific benefits associated with the product,1,2 which means identifying factors that influence consumer acceptance is important.

Within NovelQ (see www.novelQ.org for more information), consumer acceptance of novel foods has been investigated. Conventional processing techniques such as pasteurisation lose the fresh characteristics associated with the raw ingredients of plant origin (taste, aroma, texture, healthy ingredients). New treatments, which extend shelf-life without compromising these attributes, are therefore desirable. Two such treatments are High Pressure Processing (HPP) and Pulsed Electric Fields (PEF). Whether consumers will accept food processed using these novel technologies has been investigated within NovelQ. Consumers’ acceptance of apple juice treated with PEF and HPP was compared with their view of pasteurised and fresh apple juices in four European countries: Norway, Denmark, Hungary and Slovakia, using three methods: 1) focus group analysis, 2) MEC-analysis and 3) Conjoint analysis. (more…)

Product innovation by high pressure processing

Issue 2 2009 / 1 June 2009 / Dr. Volker Heinz, Dr. Achim Knoch & Thomas Lickert, German Institute of Food Technologies (DIL)

Application of thermal heat in today’s industrial scale food production and preservation is still the most commonly used processing technique, yet thermal treatment of foods affects their physical and chemical properties severely, which is often not intended but inevitable in order for sufficient preservation. Usually, sensorial appearance (colour, flavour, structure) and nutritional value undergo significant changes due to distinct heat sensitivity of the majority of raw materials.

High Pressure Processing (HPP) is an emerging novel processing technology for the gentle preservation of foods and is currently taking steps out of its R&D environment into industrial scale applications.

The principle of function of hydrostatic pressure is based on ‘Le Chatelier-Braun principle’, after which changes in pressure are owed to changes in volume. Reactions, phase transitions and changes in formation which are accompanied by reduction in volume occur preferably under pressure, whereas ones accompanied by an increase in volume are inhibited. Due to the isostatic principle, all molecules and atoms are subjected to the same amount of pressure at exactly the same time, unlike thermal treatment where temperature gradients exists. (more…)

New Food Digital Issue 1 2009

Past issues / 7 May 2009 /

Featuring:

• What does the industry need from science and technology?
  Steven Walker, Director-General, Campden BRI
• Inactivating enzymes by high intensity pulsed electric field
  Mariana Morales-De la Peña & Olga Martín-Belloso, University of Lleida
• High hydrostatic pressure processing uniformity in the picture
  Tara Grauwet et al, Katholieke Universiteit Leuven
• Creating Shared (more…)

High-pressure – meat processing and milk gels

Issue 1 2009 / 20 February 2009 / Professor Vibeke Orlien, Associate Professor Food Chemistry, University of Copenhagen

Consumers prefer food products, convenience products and ready-to-eat meals to have the taste of being freshly made. Moreover, it must be nutritious, safe, of high quality and originate from sustainable production. High-pressure (HP) technology can be utilised to its full potential as a minimal processing method to address consumers preferences and reflect the human ethics of natural, tasty, clean-label and eco-friendly products. For example, it is possible to produce chicken meat with improved oxidative stability and high water holding capacity and neutral milk gels with less sugar. The future new type of HP-food products may be just around the corner.

The perspective of producing high quality foods with an extended shelf-life by use of HP technology is based on the ability to inactivate bacteria and enzymes concomitantly with a minimum loss of nutritional and sensory quality. Investigations on the effects of pressure on microbial inactivation are reported in literature and HP-treatment is being used worldwide in the food industry as a preservation step in the production of cured meat products and fresh juices and other fruit-based products without destroying flavour and vitamins. The prospective of new types of food products by use of HP is due to the specific actions of pressure on food constituents. As a minimal process technology, HP does not break covalent bonds and thereby protects the small chemical constituents like flavour compounds and vitamins. Hence, HP affects only non-covalent bonds and can be used to modify macromolecules, like proteins, and thereby to change the functionality of food proteins. (more…)