With Thanksgiving and Christmas now past and the new year just underway, the ice cream manufacturing industry is one of the few that could rely on production levels remaining profitably high in these challenging times. But while most people are familiar with what’s in the tub, this seemingly simple product brings into play a variety of complex hydrodynamic and thermodynamic processes, with as yet poorly known interactions.
Ice cream typically starts out life as a liquid or semi-liquid which promptly undergoes abrupt and rapid temperature changes and mechanical shearing as a result of a scraped heat exchanger. This modifies its viscosity, transforming it into a product with a texture as rigid as soft Italian ice cream. However, this progression varies over time and even within the heat exchanger. The interactions operating within the product remain largely poorly understood and controlled. As such, they pose a technological hurdle for manufacturers who are constantly striving to innovate and create new textures and products.
Fortunately, scientists at the French Public Agricultural and Environmental Research Institute (Cemagref), Antony, France, have developed a simulator, the size of a 100-ml yogurt cup, that mimics the entire production chain. Capable of simulating volumes in excess of 132 gallons/hour (500 liters), it can apply temperatures, speed changes and mechanical shearing intensities that these products undergo in industrial equipment.
Using this small prototype, describing and predicting the changes in flow behavior of products is now possible in extreme conditions, -40°C for example, while varying parameters such as duration, flow speed, pressure, temperature, scraping and rotor speed.
This offers manufacturers a new perspective on their processes, making it possible to test a large number of formulations in a short time, with obvious cost gains, in the search for new products with hitherto unknown properties, according to Cemagref.
The simulator itself was developed within the Sûreté, Innovation et Maîtrise de l’énergie dans les Procédés Frigorifiques (SIMPFRI) project, with financing from the Agence Nationale pour la Recherche (ANR). Altogether 14 different partners were involved, bringing together skills in hygienics, food safety, fluid mechanics, aerodynamics, thermodynamics and energetics.
Another simulator working on a similar principle to study cooking and cooling of milk-based desserts was patented in 2005, with Danone as the industrial partner.
Meanwhile Unilever R&D has opened its twin-sited Centre of Excellence Ice Foods, employing 130 scientists and engineers at Bedford, U.K., and Caivano, Italy. The idea is to bring together Unilever’s know-how in ice, freezing, ingredients and processing to achieve critical mass and promote cross-fertilization of new ideas.
The Centre is charged with developing appealing, tasty and wholesome ice-based foods — so the experts are focusing on using natural ingredients such as milk, fruit and cereals, while at the same time minimizing fat, sugar and calories. All this has to be done without compromising taste and enjoyment. Or, as the company puts it, “They will try to increase the pleasurable experience of ice cream and ice-based foods through the creation of new eating sensations and innovative formats.”
To deliver these innovations, the Ice Foods Centre is focusing on four main areas. The first is freezing, aeration of products and ice technology. This involves controlling ice crystals through the freezing process and keeping air in ice-based products to give different and new textures, flavor delivery or reduce fat and sugar levels. Another aspect is using ice as an ingredient to deliver new eating sensations and occasions, for example drinkable or fizzy ice.
The second area covers product shaping and forming. Here product design and processing technology is used to make, shape and assemble ice-based products for what Unilever describes as unique sensory experiences.
Third is the ice cream value chain — from cow to cone. This covers all the technical know-how needed to make ice cream: from raw materials and creative product formulation and design, to manufacturing and distribution to the shelves— around the world.
The final area is packaging and selling systems for ice-based foods. So the hunt is on for innovative packaging formats that are attractive and functional for the consumer, ease handling for customers, and are environmentally responsible. Selling systems that make products available when and where people want them is another focus here.
“We want to be a treasure trove of technologies for new innovations that wow our consumers,” explains Iain Campbell, director of the Centre of Excellence Ice Foods.
Seán Ottewell is Chemical Processing's Editor at Large. You can e-mail him at [email protected].
