Driftserfaringer fra pelagisk innfrysing

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The effect of freeze-chilling on quality changes of cod loins (Gadus morhua) during chilled storage

Fish is highly perishable and has a short shelf-life. Freeze-chilling involves freezing and frozen storage followed by thawing and chilled storage. It offers more sustainable logistic benefits as it enables the products to be held frozen and released into the chill chain as required. Freeze-chilling can offer consumers high quality fish products throughout the year. The study was performed in the industry and included industrial methods for thawing, filleting, packaging, and freezing. The effect of freeze-chilling and chilling on vacuum packed cod loins was evaluated by sensory evaluation, drip loss, and total viable counts (TVC). Loins were stored at 4°C for up to 14 days after thawing. Analyses were performed on day 0, 6, 10 and 14. The results indicated that cod loins worked well as freeze-chilled vacuum-packed loins during short-term chilled storage after thawing. Freeze-chilled samples kept acceptable quality based on the sensory score but had higher drip loss.acceptedVersio

Possibilities of ice slurry systems onboard fishing vessels

Rapid handling of seafood at low temperatures are important for the quality and shelf life of the catch. There are several different methods onboard fishing vessels, including no chilling, ice storage, refrigerated sea water (RSW) and ice slurry chilling. A refrigeration system is needed for the chilling methods and it is either located on land (when ice is brought on the ship) or installed on the ship. The main working fluid in fishing vessels globally is still R22, but there are efforts for providing systems with natural refrigerants, even if this should be done at a much faster rate. Most of the new systems on fishing vessels in Norway have either R717 or R744. The use of slurry systems has been investigated in this study. A few vendors have been contacted and an overview of the status of ice slurry system is given. It can be concluded that storing seafood with ice slurry gives longer shelf life, but is not used widely in the industry, mainly because of limited capacities and high costs. Not many of the ice slurry systems are operated with natural refrigerants either. There is clearly a potential for development, but for now there is no interest from the market and no incentives for that.acceptedVersio

Wild caught cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) chilled in slurry or flake ice and its effect on product quality.

Chilling is an essential preservation technology in fish-processing. Slurry systems offer seafood preservation at sub-zero temperatures with advantages like faster chilling, reduced physical damage and prolonged shelf life. The study was conducted on wild caught cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) in an industry setting. A seawater slurry at −2.0 ± 0.3°C was used, and cod and haddock were stored in ice or slurry for 8 days. The effect of chilling in seawater slurry compared to traditional flake ice, was evaluated by sensory evaluation (QIM) of whole fish, colour changes and texture of fillets, water content, water activity and water-holding capacity (WHC) in minced muscle. The results showed that chilling in slurry was faster, and gave lower temperatures compared to flake ice. However, slurry stored fish had worse QI-values and had yellower fillets compared to ice.acceptedVersio

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

Sustainability within food cold chain sectors in Norway

Food processing, storage, and distribution demand a considerable amount of energy and raw materials. Processes that are especially energy demanding includes cooling, freezing, drying and heating, but they are also necessary to ensure the quality and shelf life of the products. All actors within the food value chain are aware of the climate changes and the need for more sustainable activities and development. Many companies annually report their sustainability initiatives, reduction targets, goals towards carbon neutrality and evaluate their performance based on key performance indicators (KPIs). This paper presents results from a review done on Norwegian actors within dairy, meat, fish, fruit, and vegetable sectors. The companies set their goals according to the Paris Agreement to reduce their emissions significantly toward 2030 and become climate neutral by 2050. Some sectors such as meat and dairy have most of their emissions in the pre-processing stage (at farm level) and have significant challenges in meeting the Paris Agreement goals if the market demand continues to grow. However, it is more likely to achieve the reduction targets from post-harvest to retail stages. There are significant challenges in packaging, transport and the source of electricity and these challenges are addressed in research projects HighEff and ENOUGH. Solutions found within these two large consortiums with relevance for the Norwegian food value chain are also presented in the paper.publishedVersio

Energy consumption of ammonia refrigeration system on board a fishing vessel

When assessing the carbon footprint of seafood from capture fisheries, the fuel use during fishing operation is the major contributor to overall greenhouse gas emissions. While the necessary shift towards low-carbon fuels and advancement in propulsion technology has commenced, also a more efficient use of energy is a key strategy for reduction of the emissions. Furthermore, leakage of high-GWP refrigerants contributes to emissions and a transition towards natural refrigerants (NH3, CO2) is essential. Introducing efficiency measures depends on knowledge of current performance. Due to the wide range of different fishing vessels with different on-board processing equipment and different modes of operation, the performance needs to be evaluated for each fleet segment before proper advise can be given. This paper presents energy measurement results from a research cruise conducted during autumn 2020 on a combined purse seiner/pelagic trawler. The vessel's refrigeration system was instrumented with sensors logging the electrical input to frequency converters (compressors and seawater pumps) and temperatures on the RSW side, while the vessels mode of operation and fuel consumption was logged on a regular basis during the cruise. The results provide insight on the vessel's energy flow, performance of the refrigeration system and fuel intensity of the fishing operation, which gives valuable input for design of efficiency measures.acceptedVersio

Energy flow analysis of an industrial ammonia refrigeration system and potential for a cold thermal energy storage

There is an increasing effort to reduce energy demand at food processing plants, mainly to reduce the total carbon footprint. The energy demand of a fish processing plant (using ammonia as refrigerant) has been evaluated in this study. Results show that production follows a seasonal cycle throughout the year, with no (or very low) production in the spring (Mar-May), and peak production in the autumn (Sep-Nov). By investigating data from the plant's energy management system, it was revealed that the refrigeration systems are responsible for about 75% of the total electric power demand and the compressors for 90-95% of that. Because of the large discrepancy in energy demand over the year, and also daily variation within production periods, there is a good potential for installing a cold thermal energy storage. An initial evaluation on how a CTES system can be implemented at the plant is included, discussing type of storage, choice of PCM (e.g. solid CO2) and effect on heat production, but this evaluation will be developed further.Energy flow analysis of an industrial ammonia refrigeration system and potential for a cold thermal energy storageacceptedVersio

Veileder - Industrielle konsepter for refresh produkter av hvitfisk

En refresh-produksjon henviser til produkter som har vært fryst, lagret og tint en eller flere ganger gjennom verdikjeden fra fangst til butikk. En vanlig metode for en refresh-produksjon av hvitfisk er å produsere konsumentforpakninger av filet eller loins som fryses, transporteres og deretter tines nært utsalgsstedene [13,16,18]. En annen tilnærming er å fryse inn porsjoner i blokk eller IQF (individuelt raskt frosset), for deretter å tine og pakke produktene nært markedet (Se figur 1, s.4). Det norske fisket etter torsk er sesongbasert. Hovedtyngden av volumet landes i løpet av årets første måneder i perioden januar til april. Sesongvariasjonene skaper utfordringer for ferskfiskindustrien som er avhengig av jevn produksjon. Markedet ønsker stabile leveranser slik at forbrukerne kan tilbys torsk hele året. En løsning på dette er å fryse fisken i høysesong for deretter å tine og selge "refresh"-produkter utenfor sesong [4,13,18]. Refresh-produksjon kan gi flere fordeler knyttet til holdbarhet og matsvinn, mer miljøvennlig distribusjon, lavere distribusjonskostnader, jevn og høy kvalitet og mer stabile leveranser. Norsk industri ønsker også å øke andelen innenlands foredling fremfor å eksportere fisk til prosessering i utlandet. Refresh-produksjon kan bidra til dette. I dag er den kun en norsk industriell aktør som har en slik produksjon, men flere industriaktører er interessert i å starte opp. Skal det satses ytterligere på en slik produksjon, er det avgjørende at den beste teknologien og produksjonskonseptene blir benyttet. Fersk selvfangstet fisk eller fisk som man kjøper direkte fra fisker har selvsagt den ideelle kvaliteten så lenge den har blitt optimalt behandlet. Men, med utgangspunkt i råstoff av høy kvalitet og god kunnskap om innfrysing, lagring og tining kan man også produsere tinte produkter av høy kvalitet også utenom høysesong. Denne veilederen oppsummerer "best practice" for en refresh-produksjon basert på kunnskapsstatus og resultater fra FHF prosjektet ReFresh (Kartlegging og optimalisering av industrielle konsepter for refresh-produkter av hvitfisk, prosjektnr 901596).FHF - Fiskeri– og havbruksnæringens forskningsfinansieringpublishedVersio