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Nowadays, there is a growing interest on how to utilize fish materials remaining from the main production and considered as unappropriated for a direct human consumption. There are numbers of possible solutions to recover valuable nutrients from that matter and one of the most efficient is the production of fish protein hydrolysate. This article is devoted to overview existing information about the production of dried fish protein hydrolysates with a focus on dehydration process during production and equipment used for moisture removal. Drying step of the production is considered as the most energy demanding and, therefore, described in detail. Questions considering energy demands of the drying are highlighted in the article together with the proposals for the improvement of energy efficiency. This work also describes source of the raw material, the main steps of the technological scheme with the equipment used and valuable information on the intermediate state of fish protein hydrolysate between the process operations. Keywords Drying Á Fish protein hydrolysate Á Fish by-products Á Industrial drying systems Abbreviations P Pressure (Pa) pH Logarithmic measure of hydrogen ion concentration (dimensionless) T Temperature (°C)

various types of dry-cured ham are due to pig breed, feed of pigs, their weight and age, as well as differences in the production process. High-quality dry-cured hams, with a production length longer than 1 year, have distinct organoleptic characteristics: a rich, unique, and recognizable flavor and color in the range from rosy to maroon or brown red marbled with white fat. However, the sensorial, physical-chemical, aromatic, morphological, and textural characteristics of dry-cured ham vary significantly depending on the alterations in the technological process from producer to producer [1][2][3][4][5].The traditional technology for the production of dry-cured ham mainly consists of salting, postsalting (resting), and drying-ripening stages. In Northern Europe (Germany, Scandinavia), smoking is frequently applied. Salting and drying-ripening are the most important steps in the manufacture where the flavor of the final product is mainly formed.The duration of the postsalting and the drying-ripening stages varies depending on the type of dry-cured ham. The drying-ripening step lasts from 2-3 months to 2-3 years for the highest quality dry-cured hams. Increased time of ripening gives a higher degree of enzymatic degradation, contributing to taste and flavor of the final product and as a consequence of higher quality of dry-cured ham [6]. Shorter processing time allows faster production of drycured ham, but the quality characteristics will suffer. The technology for each particular kind of dry-cured ham is adjusted according to the desired priority: quality or high production capacity.During ripening, endogenous enzymes degrade proteins and lipids to amino and fatty acids correspondingly, which are mainly responsible for the flavor of dry-cured ham [7]. Free amino and fatty acids are further degraded and converted by enzymatic and chemical reactions, including oxidation, to volatile compounds. Free amino acids contribute Abstract Dry-cured ham is a traditional meat product highly appreciated by consumers. Production of dry-cured ham is a time-consuming process which varies between different ham types. There are many factors affecting the final characteristics of dry-cured ham. The quality of the raw material and the process conditions mainly influence the rate and the extent of biochemical reactions which are in turn responsible for the formation of specific flavor and texture. This review paper highlights the characteristics of the raw material, the enzymatic and chemical processes taking place during dry-cured ham manufacture and the compounds formed by these reactions. The rates of the enzymatic changes from fresh meat to the stage of final product are also described.

Aim of this thesis is to present an experimental investigation of standard R744 supermarket refrigeration system, with the high-pressure electronic valve (HPV), and refrigeration system with multi-ejector expansion pack on the same vapour compression rack. Comparison of the R744 multi-ejector refrigeration system, was carried out based on energy performance characteristics: refrigeration capacity, power consumption, COP, and exergy efficiency. Apart from the system performance comparison, influence of the pressure level in the flash tank on the system performance for both alternatives was analysed.The experimental results indicated COP and exergy efficiency improvement of the multiejector refrigeration system up to 7% and 13.7%, respectively. The multi-ejector system was able to operate in smaller range of the tanks pressure lift than the standard system dependent on the refrigeration load and the exit gas cooler section parameters. The highest values of COP and exergy efficiency were obtained by the multi-ejector refrigeration system for the tanks pressure lift value close to the limit value. The values of the overall compressor efficiencies were significantly differentiated, dependent on the operation module (cooling load and heat rejection conditions), which strongly influenced the values of COP and exergy efficiency. Therefore, it was not possible to clearly define the optimum pressure in the flash tank. It was concluded that improvement of compressors efficiencies utilized in the multiejector system will indicate high energy performance of the refrigeration system.

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Highlights Review of recent studies on heat delivery above 80 o C using vapour compression heat pumps  Recent advances in natural fluids as high temperature working fluids  Component development for high temperature heat pump operation  Proposed fluid mixtures, cycle variations, system design in high temperature domain