The Effects of Freezing and Thawing of Saccharina latissima and Alaria esculenta

publishedVersio

NMR approach for monitoring post-mortem changes in Atlantic salmon fillets stored at 0 and 4°C

High resolution NMR technique has been used to monitor post-mortem changes in salmon (Salmo salar) fillets upon storage at 4 and 0 °C. Thirty-one different fish metabolites influencing freshness and taste properties have been unequivocally assigned by NMR using either available standard compounds or ad hoc acquired 2D 1H–1H TOCSY and 1H–13С HSQC spectra. The monitored fish metabolites include amino acids, dipeptides, sugars, vitamins, biogenic amines, as well as different products of the ATP degradation. The detection and monitoring of biogenic amines by NMR, upon fish storage, is information of interest for consumers, since some of these compounds are toxic. The data from this study shows that NMR spectroscopy also provides the amount of all metabolites necessary for the calculation of the K-index used to express fish freshness. A good correlation was found between the K-index increase and the formation of the undesired biogenic amines. The metabolite concentrations and the K-index found in this work were compared and found coherent with literature data. The performed study reveals the strengths and the suitability of the NMR approach to monitor different biochemical processes occurring during fish storage and qualitatively and quantitatively characterise fish metabolites determining fish quality

Upgrading Marine Oils from Cod (Gadus morhua) On-Board the Deep-Sea Vessels—From Waste to Value

Significant amounts of marine raw material are lost on-board the deep-sea vessels due to fast quality degradation. Optimal on-board handling and processing strategies can upgrade these resources from waste to food ingredients rich in nutrients such as omega-3 fatty acids. The objective of this study was to investigate the effect of raw material freshness and sorting on the quality, composition and yield of oil produced thermally from cod (Gadus morhua) residuals on-board a commercial trawler. Oil was produced from whole viscera fractions with liver or out-sorted livers right after a catch and after chilled storage for up to 6 days. The results showed that significantly higher oil yields could be obtained if the raw materials were stored for 1 day or longer. However, an undesired emulsion was formed when viscera were stored for 4 days. All oils were rich in health beneficial omega-3 fatty acids, but viscera oils had generally lower quality with higher levels of free fatty acids and oxidation products. However, out-sorting of the liver was not necessary to meet guidelines for high-quality fish oil. Both viscera and liver could be stored for up to 2 days at 4 °C prior to oil production and still meet quality criteria for food applications. These results demonstrate a large potential in upgrading currently wasted marine raw materials into high-quality food ingredients.publishedVersio

Fra restråstoff til verdifulle råvarer

Laying hens are commonly not slaughtered and utilized for food purpose. Slaughtered hens may be hydrolyzed (e.g. at 50°C for 1-2 hours, with additions of enzymes)to produce soluble proteins and oils. Sediments after such hydrolysis are valuable fertilizers, whereas the oil and proteins are valuable food ingredients of high quality

Superchilling of food: A review

a b s t r a c t Food preservation is very important for the safety and the reliability of the product. Superchilling as used for preserving foods, has been defined as a process by which the temperature of a food product is lowered to 1-2°C below the initial freezing point. Fresh and high quality food products are in great demand worldwide. Temperature is a major factor determining the shelf life and quality of food products. Fish and meat are perishable food commodities, where better and more advanced preservation technology is needed. Deterioration of these foods mainly occurs as a result of chemical, enzymatic and bacteriological activities leading to loss of quality and subsequent spoilage. Storing food at superchilling temperature has three distinct advantages: maintaining food freshness, retaining high food quality and suppressing growth of harmful microbes. It can reduce the use of freezing/thawing for production and thereby increase yield, reduce energy, labour and transport costs. The study on the growth mechanism of ice crystals, modelling and computer simulation of foods during superchilling and superchilling storage is needed

Biomass soaking treatments to reduce potentially undesirable compounds in the edible seaweeds sugar kelp (Saccharina latissima) and winged kelp (Alaria esculenta) and health risk estimation for human consumption

acceptedVersio

The Effect of Sous-Vide Cooking Parameters, Chilled Storage and Antioxidants on Quality Characteristics of Atlantic Mackerel (Scomber scombrus) in Relation to Structural Changes in Proteins

Svrha je ovog istraživanja bila utvrditi utjecaj kuhanja u vakuumu (sous vide) pri različitim temperaturama te dodatka dvaju komercijalnih antioksidanasa (ekstrakta ružmarina i smjese ekstrakta ružmarina i askorbil palmitata) na kakvoću atlantske skuše (Scomb¬er scombrus) tijekom hladnog skladištenja. Fileti skuše tretirani su antioksidansima i kuhani u vakuumu 10 ili 20 min pri 70 ili 80 °C, te skladišteni 1, 3, 9 ili 15 dana pri (0±1) °C. Pomoću višestruke regresijske analize praćene su promjene u udjelu suhe tvari i pepela, kalo, oksidacija i topljivost proteina te promjene u teksturi kuhanih fileta skuše kuhanih tijekom skladištenja. Zaključeno je da dulje vrijeme hladnog skladištenja najviše smanjuje kalo, vjerojatno jer denaturirani proteini ponovno apsorbiraju vodu koju su otpustili tijekom kuhanja. Istovremeno se povećala karbonilacija proteina u uzorcima skuše, čime se smanjila topljivost proteina te povećala čvrstoća mišića ribe. Međutim, utvrđeno je da se dodatkom antioksidansa karbonilacija proteina u ispitanim uzorcima smanjila.The aim of the present study is to assess the influence of different sous-vide time-temperature regimes and use of two types of commercial antioxidants (rosemary extract and rosemary extract with ascorbyl palmitate) on quality parameters of Atlantic mackerel (Scomber scombrus) during chilled storage. The mackerel fillets were treated with the antioxidants, exposed to sous-vide cooking at 70 and 80 °C for 10 and 20 min, and further stored for 1, 3, 9 and 15 days at (0±1) °C. Changes in dry matter and ash, cook loss, protein oxidation and solubility, as well as texture parameters in sous-vide cooked mackerel during storage, were assessed by application of multiple regression analysis. It was revealed that duration of chilled storage had the highest contribution to the decrease in cook loss due to a possible reabsorption of water released during cooking by unfolded proteins. At the same time, this parameter increased protein carbonylation in mackerel samples, resulting in a decreased protein solubility due to aggregation of proteins and subsequent toughening of the fish muscle. However, the use of antioxidants has shown to be highly efficient in decreasing the protein carbonylation in the analysed fish samples

Effect of high-pressure pretreatment on enzymatic hydrolysis of a mixture of rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) rest raw material

IntroductionFish rest raw material generated from the fish processing industry may be a useful resource for recovery of added value compounds. The application of non-thermal novel technologies can improve the extraction. High-pressure processing (HPP) has long been used for the preservation and extension of the shelf life of seafood. It also constitutes a promising technology for the increased recovery of valuable compounds, such as lipids and proteins. The objective of this study was to assess the yield and the chemical composition of the fractions obtained after enzymatic hydrolysis on a mixture of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) rest raw material pretreated by high-pressure (HP).MethodsSix different pretreatments were applied prior to enzymatic hydrolysis; 600 MPa x 8  min, 600 MPa x 4  min, 400 MPa x 8  min, 400 MPa x 4  min, 200 MPa x 8  min, 200 MPa x 4  min.Results and discusssionThese applied pretreatments did not yield higher oil extraction compared to the control. However, the fish protein hydrolysates (FPH) contained higher amount of protein when compared to the FPH obtained from the control

Effect of Cold Plasma on Meat Cholesterol and Lipid Oxidation

Cold atmospheric plasma (CAP) is a novel non-thermal technology with potential applications in inactivating microorganisms in food products. However, its impact on food quality is not yet fully understood. The aim of this research is to study the impact of in-package plasma technology on the stability of cholesterol and total lipid in four different types of meat (beef, pork, lamb and chicken breast). Additionally, any changes in the primary or secondary lipid oxidation, which is undesirable from a health perspective, is investigated. CAP was not found to have any impact on the cholesterol or lipid content. However, higher peroxide and thiobarbituric acid reactive substances (TBARS) values were found for the treated samples, indicating that plasma can induce the acceleration of primary and secondary lipid oxidation. Finally, color was not affected by the treatment supporting the suitability of the technology for meat products