The cryogenic freezing process provides an alternative of great interest to the conventional freezing, enhancing high-quality products of the Italian culinary tradition. The virtuous case of “tortellino” and the many possibilities offered, from pizzas to hamburgers
Tortellini are one of the most renowned and appreciated food products in Italy and in the world, feather in the cap of a culinary tradition that is also exported and consumed all over the world. If we consider the total fresh pasta market, which includes filled pasta, egg pasta, semolina pasta and gnocchi, Circana data (total Italy – data April 2024) report a turnover amounting to 900 million Euros, in a growth phase.
However, the most important issue is the following: how exporting them worldwide, keeping the excellence standards unchanged? The question was asked by four outstanding realities in the Italian gastronomic panorama, united to carry forward a project dedicated to filled pasta and to export one of the delicacies of the made in Italy all over the world, fully preserving quality. The collaboration has involved SIAD Group, together with the University of Gastronomic Sciences of Pollenzo, in an initiative that saw the collaboration of Modena company “Il Matterello”, producer of fresh pasta, ideated by the food and technological consulting company Tortellinice. The latter has decided patenting a cryogenic freezing process for tortellini, to enhance the properties and characteristics of the product and of the recipe itself.
Tortellini and cryogenic freezing: the comparison with the fresh product is winning
Concerning the cryogenic aspect, Siad was called as process specialist. «The target of the project conceived by Tortellinice was testing and developing at best the characteristics of the cryogenic freezing process, patent subject», Luca Bellocchio, Process Technologist for cryogenic systems of SIAD, explains. Since the project ideation, the company itself has been active, first of all implementing the pilot plants for tests.
Once obtained the first flattening results, they have proceeded to the following phase, which saw the active involvement of Pollenzo University to assess the full conformity in the comparison with a fresh product, until the final tasting.
After the cryogenic freezing process, the two samples of pasta (fresh and frozen) have been boiled in the same typology and quantity of broth. Once drained and seasoned, they were subjected to tasters. Three samples were subjected to each taster, two naturally identical to each other (two fresh and one frozen), asking to identify the different one. At the end of the tasting, the involved subjects did not find any difference in the products subjected to tasting.
Hence, they then proceeded to industrialize the process and the relative plant, for the cryogenic freezing process, with storage in cryogenic cabinet that operates with liquid nitrogen.
The advantages are noteworthy, starting from a shelf life of 12 months in freezer. The interest aroused by the project is confirmed by the demands in various parts of the world, from the United Kingdom to Arab Emirates.
Cryogenics: process characteristics
Bellocchio in person explains how the cryogenic freezing process is characterized and how it is specifically applied by SIAD: «The process provides for the implementation of a freezing plant, which can be made with cryogenic cabinets (for batch productions) and/or linear tunnels (for productions in continuous).Moreover, there are various alternative solutions devised to grant the so-called IQF (Individual Quick Freezing), by means of rotary tunnels, churns or liquid-nitrogen immersion tunnels, useful not only to freeze and to preserve the product quality, but also to ensure that each single piece is frozen individually».
The plant must provide for a storage of liquid nitrogen upstream (sometimes also of liquid CO2 as an alternative, if the application enables it), equipped with appropriate insulations to ensure the sealing and to minimize the heat losses connected with the management of the cryogenic fluid in its interior. An insulated, pressurized supply pipeline of liquid nitrogen assures that the product is supplied as a liquid to the point of use, to optimize the freezing process and inherent consumptions. «Fundamental element is the integration of safety systems to analyse the oxygen content inside work areas, in order to ensure the safety of operators themselves at any time».
A valuable alternative to standard freezing
«The cryogenic freezing was born as an alternative to mechanical freezing and it features several advantages, the first of which is a valuable freezing that succeeds in enhancing the characteristics of high-quality products, such as the “tortellino”».
The cryogenic freezing process (which operates even at work temperatures of -80°C/-90°C, sometimes also lower in case of specific processes), allows further preserving the product quality in comparison with mechanical freezing techniques with refrigerating cycles (which typically work at -30°C/-40°C minimum). This happens because it does not allow the growth of macro-crystals inside the product: the lower the work temperature, the lower the degree of interstitial ice growth. The result is therefore a phenomenon of micro-crystallization, which prevents the product from the risk of breaking the cellular membranes, excluding the release of nutritional substances and of fragrances.
The role of electronics in the cryogenic freezing
Electronics is a precious element in the cryogenic freezing: from the components to the PLC used, also in stand-alone modality, to digitize processes and to make it for an optimal scientific and analytical conservation process – in full compliance and compatibility with the dictates of industry 4.0 –, besides managing the product flow phases in the plant, too.
Sensors are fundamental, too: besides the temperature analysis, they play a fundamental role to measure the rate of residual oxygen in work areas, as already said, to ensure high safety conditions for workers in production areas and to intervene, in case of phenomena of under-oxygenation of work areas, automatically and promptly stopping the delivery of liquid nitrogen until the restoration of the ideal conditions.
Possibilities and advantages offered for food
In addition to the cryogenic freezing for the “tortellino”, there are many applicative cases indeed at disposal that demonstrate the goodness of this process. «In recent months/years the world of frozen pizzas and “pinsas” has lived a relevant boost, both in the version with seasoning and as pre-cooked bases», the Siad specialist further explains.
Other products worth highlighting are the hamburgers (or other cuts of meat) for the packaging in skin, which is emerging as alternative to the packaging in a protective atmosphere. In this case, we are dealing with the so-called “crusting” processes: a surface freezing (obtained just through a fast cooling that does not penetrate to the product core and therefore obtainable with the low nitrogen temperature) which allows stiffening the surface and minimizing deformations and browning of the meat once vacuum-packed with the skin method, which slightly heats the product in pressing phase.
An advantage offered by the cryogenic freezing concerns the possibility of being complementary and being used alongside other traditional techniques, making cooling process more efficient and reducing the so-called “bottlenecks”, which are typical of this step inside the manufacturing chain.
