Superchilling of organic food

The present report is a part of the ERA-NET project SusOrganic: Development of quality standards and optimised processing methods for organic produce. The superchilling concept and the state-of-art of the technology are summarized with focus on potential implementation for small scale organic production. Production of processed organic food is mostly carried out by small and medium enterprises in demanding, competitive market conditions due to competition from highly cost-efficient large scale producers of conventional products and producers of locally grown food without certification requirements. The superchilling concept can be applied for organic meat and fish products, hereby helping the producer to supply the market with high-quality organic products. The extended shelf life of superchilled products will be beneficial during storage with respect to production and seasonal variations and transportation in order to reach new and far-distant markets. Strict control of the chilling process as well as storage temperature and time, is necessary in order to apply the concept. For these reasons, it might be difficult to apply superchilling towards the end of the cold chain at the retailer or consumer without significant alterations to the cold chain

Cold thermal energy storage for industrial CO refrigeration systems using phase change material: An experimental study

Refrigeration systems in industrial food processing plants are large users of electric energy and often show high peak power consumption. Cold thermal energy storage (CTES) technology integrated into refrigeration systems can reduce the peak power requirement and achieve peak shifting by decoupling the supply and demand of the refrigeration load. This paper presents the design and performance of a CTES unit consisting of a pillow plate heat exchanger (PP-HEX) immersed into a low-temperature phase change material (PCM) as the storage medium. It is one of the first experimental investigations featuring a large-scale technical solution that allows for coupling the evaporation and condensation processes of the refrigeration system with the melting and solidification of a low-temperature PCM in the same heat exchanger. The charging and discharging performance of the plates-in-tank CTES unit was extensively tested using CO as the refrigerant and a commercial PCM with phase change temperature of -9.6 °C. The charging time was found to be mainly affected by the refrigerant evaporation temperature, while the discharging rate and discharged energy over the cycle was higher when increasing the refrigerant condensing temperature. Using a plate pitch of 30 mm resulted in the highest mean discharge rate and total discharged energy over the cycle with 9.79 kW and 17.04 kWh, respectively. The flexible CTES-PCM unit can be adapted to fit several refrigeration load characteristics and temperature levels by changing the PP-HEX geometry and type of PCM used as the storage medium.publishedVersio

Evolution of proteolytic and physico-chemical characteristics of Norwegian dry-cured ham during its processing

Proteolytic activity and physico-chemical characteristics were studied for Norwegian dry-cured ham at four different times of processing: raw hams, post-salted hams (3 months of processing), hams selected in the middle of the production (12 months of processing) and hams at the end of the processing (24 months). Cathepsin H activity decreased until negligible values after 3 months of processing, whereas cathepsins B and B + L were inactive at 12 months. AAP was the most active aminopeptidase whereas RAP and MAP were active just during the first 12 months of processing. Proteolysis index reached a value of 4.56 ± 1.03 % with non-significant differences between 12 and 24 months of ripening. Peptide identification by LC-MS/MS was done and two peptides (GVEEPPKGHKGNKK and QAISNNKDQGSY) showing a linear response with the time of processing were found. Unfreezable water content and glass transition temperature were investigated using differential scanning calorimetry (DSC) technique with non-significant differences in the temperature of glass transition for 12 and 24 months of processing.The work was supported by the Research Council of Norway (project 225262/E40 – DryMeat)Peer reviewe

Superchilling of organic food. Part 2: Storage test with superchilled organic salmon and pork chops

Superchilling of organic salmon and pork chop was investigated and the potential of the concept was documented for the organic sector, especially SMEs.Relative shelf life extension of 14 days compared to chilled product, were documented for both products. The colour of the product showed no significant changes between the superchilling and conventional chilling processes. However, the superchilled products shod an increased drip loss and reduced water holding capacity, whic was caused by the partial freeze damage. The shelf life of the superchilled product will depend mainly on sanitation, processing and cold chain conditions and not on the organic origin of the product. The performed investigations demonstrated the potential of the superchilling concept for organic products. The needed technology is available at the market and implementation of the technology for the organic production lines is possible

Description of atmospheric freeze-drying of brown seaweeds (Saccherina Latissima) with respect to thermal properties and phase transitions

[EN] Thermal properties of brown seaweeds (Saccharina latissima) were determined using DSC technique in the temperature range between -150.0 and 50.0 °C. The following phase transitions were detected: glass transitions, incipient point of ice melting and freezing point. The ice content and amount of unfrozen water was detected by analysis of the melting peak. The ice content reduction in the product was predicted for different moisture contents and temperatures for atmospheric freeze-drying processMobility of the scientists from Murmansk State Technical University was provided by financial support of SIU, High North Programme 2015 (HNP-2015/10053)Tolstorebrov, I.; Eikevik, T.; Petrova, I.; Bantle, M. (2018). Description of atmospheric freeze-drying of brown seaweeds (Saccherina Latissima) with respect to thermal properties and phase transitions. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1695-1702. https://doi.org/10.4995/IDS2018.2018.7696OCS1695170

Modelling of Crystallization During Freeze-Concentration of Hydrolysates

Dewatering of fish protein hydrolysates is energy intensive process. The freeze concentration is one of the solutions, which provide high quality of concentrate, energy efficiency and sustainability of the hydrolysate production. This study investigates two important aspects: crystallization of water in fish protein hydrolysates and separation of the ice from the concentrate. The processes were modelled using Modelica tools and MATLAB. The models were validated via experimental campaign and literature review. When the influence of the following factors were taken into account: refrigeration temperature, fluid flow, concentration of solids and ice fraction.acceptedVersio

Application Of Refrigeration Technologies For Energy Efficient Production Of Fish Protein Hydrolysates

Fish protein hydrolysate (FPH) is one of the most efficient and sustainable way to recover the valuable nutrients from fish remaining materials and has a widespread application. However, the production of FPH demands intensive heating and cooling loads in the temperature range between 0 and 90 ⁰C. In addition, the stabilization of FPH using conventional moisture removal techniques like spray drying and evaporators is energy intensive due to low solid content. This study investigates application of refrigeration technologies and heat pumps to determine sustainable and energy efficient methods for processing and stabilization of FPH. The freeze concentration, vacuum-concentration and freeze-drying processes were investigated in combination with energy recovery at high temperatures (heating and sterilization). The overall comparison of production lines with respect to the energy savings of different techniques was presented.acceptedVersio

Investigation of influence of pre-treatment and low-temperature on drying kinetics, sorption properties, shrinkage and color of brown seaweeds (Saccharina Latissima)

[EN] Drying kinetics of Saccharina latissima (raw and blanched) at low temperatures (10.0, 25.0 and 38.0 °C) was studied. The effective moisture diffusivity coefficient varied due to temperature alterations in the range between 1.4 and 4.5 10-10 m2/s for raw and 0.91 and 2.56 10-10 m2/s for blanched seaweeds. Significant changes in structural properties and chemical composition resulted in a much longer drying time of blanched seaweeds, when compared with raw. Drying temperature of 38.0 °C resulted in more brown color, when compared with other samples. Sorption characteristics of dried raw seaweeds depended on salt content and showed high accumulation of moisture at relative humidity of air of 80.0 %. The blanched seaweeds showed linear accumulation of moisture within increasing of relative humidity of drying air from 20.0 to 80.0 %, but high level of hysteresis was determined between sorption and desorption isotherms. The shrinkage development within dewatering of blanched and raw samples was also studied.Mobility of the scientists from Murmansk State Technical University was provided by financial support of SIU, High North Programme 2015 (HNP-2015/10053)Tolstorebrov, I.; Eikevik, T.; Petrova, I.; Shokina, Y.; Bantle, M. (2018). Investigation of influence of pre-treatment and low-temperature on drying kinetics, sorption properties, shrinkage and color of brown seaweeds (Saccharina Latissima). En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 683-690. https://doi.org/10.4995/IDS2018.2018.7694OCS68369

Description of atmospheric freeze-drying process of organic apples using thermo-physical properties

[EN] his study discusses the influence of temperature and total moisture content on ice fraction in organic apples during atmospheric freeze-drying process. The ice formation of glass transition events were described by Clausius-Clapeyron and Gordon Taylor equations. The obtained data is essential for design the drying process and for understanding the limiting factors.This work was done in a frame of SusOrganic project “Development of quality standards and optimized processing methods for organic produce” financed by ERA-NET and NFR (502000972) and BLE (2814OE006). Mobility of the scientists from Murmansk State Technical University was provided by financial support of SIU, High North Programme 2015 (HNP-2015/10053).Tolstorebrov, I.; Eikevik, T.; Petrova, I.; Shokina, Y.; Bantle, M. (2018). Description of atmospheric freeze-drying process of organic apples using thermo-physical properties. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1703-1710. https://doi.org/10.4995/IDS2018.2018.7697OCS1703171