Relevance of cathepsins activity and texture in slightly acidic electrolyzed water-slurry iced mackerel(Pneumatophorus japonicus)

The incorporation of SAEW and SI can effectively maintain the characteristics of texture in marine fish.This study aimed to investigate the relevance of cathepsin activity for texture and the establishment of a shelf-life model of mackerel(Pneumatophorus japonicus)stored at 4◦C.Before the cold storage,mackerel samples were exposed to flake ice(Control),slurry ice(SI),and slightly acidic electrolyzed water-slurry ice(SAEW-SI),respectively.Then the TVC,K-value,cathepsin activity,texture,and sensory attributes were investigated.The results showed that the TVC and K-value of samples in SAEW-SI group was significantly lower by approximately 1 log CFU/g and 17%than those in Control group(P<0.05).Meanwhile,there was a tendency to first increase and then decrease on the activities of cathepsin B,D and L.Results of texture profile analysis(TPA)clarified that SAEW-SI can markedly suppress the decrease of hardness,springiness and chewiness(P<0.05).During the experimental period,the highest sensory scores were obtained in SAEW-SI group.In addition,the heat map of correlation analysis suggested that texture attributes(hardness)were negatively correlated with cathepsin B(r=-0.66),cathepsin D(r=-0.49),and cathepsin L(r=-0.69),respectively.According to the principal component analysis(PCA)and analysis of linear regression,SAEW-SI treatment could effectively maintain mackerel quality and extend the estimated shelf-life of mackerel by at least 5 days compared to Control group.Therefore,SAEW-SI could be suggested as a novel strategy for cold-chain transportation in seafood industry.

Liquid dehumidification-assisted evaporative supercooling method for ice slurry production

Due to the fact that the conventional ice slurry production system using supercooled water suffers from ice block and depends heavily on electric power,a novel ice slurry production system is proposed.The new system consists of two major parts：the evaporative supercooling process and the liquid dehumidification process.The classical diffusion-control equation is improved by introducing an impact factor into the simulation analysis in the evaporative supercooling process.Meanwhile,experiments are carried out by adopting the particle analyzer to detect the radii and the velocities of the droplets,and an infrared camera to examine the temperature profile of the physical process.It is found that the theoretical conclusion agrees well with the experimental results.Compared with the conventional system,the new system can alleviate the burden on electric power and raise efficiency.These improvements are essentially attributed to the reutilization of the inner waste heat generated from the system itself.

Slurry ice as an alternative cooling medium for fish harvesting and transportation:Study of the effect on seabass flesh quality and shelf life

The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass(Dicentrarchus labrax)to retain flesh quality and extend shelf life,compared with conventional flake ice.Fish was slaughtered and transported in different mixtures of slurry ice and conventional flake ice(C:slaughtered and transported in 100%flake ice-Control samples,SC:slaughtered in 100%slurry ice and transported in 100%flake ice,S50:slaughtered and transported in 50%slurry ice-50%flake ice,S100:slaughtered and transported in 100%slurry ice)and subsequently stored under controlled isothermal conditions at 0℃for shelf life modelling and flesh quality evaluation(proteolytic enzymes).The replacement of conventional flake ice with slurry ice as a slaughtering method led to improved quality stability during subsequent refrigerated storage and shelf life extension,in terms of microbial growth,flesh quality and sensory degradation of fish.Based on microbial growth,the shelf life of C samples was found to be 19 days,whereas the shelf life of S50/S100 and SC was 21 and 25 days,respectively,showing that the replacement of flake ice with slurry ice resulted in 2–6 days shelf life extension of whole sea bass stored at 0℃.The use of slurry ice at slaughter and flake ice in transportation was accompanied by low activities and late peaks of all four enzymes that is expected to lead to delayed proteolytic degradation and extended freshness.

Ice Slurry Formation in a Cocurrent Liquid-Liquid Flow

A new technique for ice slurry production was explored. Multiple small water-drops were formed in another immiscible chilled liquid by a single-nozzled atomizer and frozen in the fluidized bed by direct contact heat transfer. Experiments were conducted to investigate the dynamic behaviors of the ice crystal making system. The results demonstrate that the ice crystals could be produced continuously and stably in the vertical bed with the circulating coolant of initial temperature below -5℃. The size distribution of the ice crystals appears non-uniform, but is more similar and more uniform at lower oil flow rate. The mean ice crystal size rests seriously with the jet velocity and the oil flow rate. It decreases with decreasing the oil flow rate, and reaches the maximum at an intermediate jet velocity at about 16.5 m.s y. The ice crystal size is also closely related to the phenomenon of drop-coalescing, which can be alleviated considerably by reducing the flow rate or lowering the temperature of the carrier oil. However, optimization of liquid-liquid atomization is a more effective approach to produce fine ice crystals of desired size.

A novel ice slurry producing system with vacuum freezing

A novel vacuum ice slurry producing system with jet-pumps was proposed to deal with the problems of high energy consumption and ice blockage.In this novel system,one steam driven by a jet-pump was used to create vacuum in a hermetic vessel where water was sprayed through a nozzle to produce ice slurry,while the other steam was used to provide enough cold energy to make the left vapor in the hermetic vessel condense.Mathematical models of this novel system were established and theoretical simulation on the performance characteristics was also implemented based on the MATLAB program.Results show that the novel system is feasible and practicable,and the system performance is affected by many factors,such as the temperature of the generators,condensing temperature,evaporation temperature,and the cooling load of the refrigerator sub-system.The findings are helpful to improve the performance of ice slurry producing system.

Effect of Liquid versus Ice Slurry Ingestion on Core Temperature during Simulated Mining Conditions

Miners in Australia frequently perform physically demanding work under high ambient temperatures and humidity, often whilst wearing personal protective equipment, leading to heat-related illnesses. This study investigated effects of replacing 100% and 50% sweat losses with 5% carbohydrate liquid or ice-slurry solution on core temperature during simulated mining conditions. Five randomized treadmill trials were performed with: no fluid replacement (NF), 100% (100 ICE) and 50% (50 ICE) sweat loss replaced with ice-slurry (~-1°C) solution and 100% (100 LIQ) and 50% (50 LIQ) sweat loss replaced with liquid (~+4°C) solution. Time to exhaustion was longer in 100 ICE followed by 100 LIQ, 50 ICE, 50 LIQ and NF. Change in rectal temperature was least in 100 ICE followed by 100 LIQ, 50 ICE, 50 LIQ and NF. Ingestion of ice-slurry resulted in longer time to exhaustion and slower rates of change in rectal temperature. It is recommended that ice-slurry drinks be provided to personnel to lower heat strain during hot working conditions.

Numerical study on critical flow velocity of ice slurry in the pipe of ice source heat pump system

The traditional evaporator of water source heat pump system is easy to freeze when the water source temperature is too low in winter.A novel ice source heat pump system is proposed,which can use low temperature surface water to supply heat to buildings.One of the key problems for safe transportation is velocity range of ice slurry in ice outlet pipeline.In order to study the critical flow velocity of ice slurry in the pipe,an Euler model of horizontal straight pipe and 90°elbow pipe were established by Fluent software.The influence of five factors on the critical flow velocity of two kinds of pipes,including initial ice packing fraction,ice particle size,pipe diameter,length of straight pipe and radius curvature of elbow was studied.It found that the initial ice content should be controlled from 10%to 15%.The inlet flow rate was 20%higher than the critical flow rate under the most unfavorable condition.Ice particle size was less than 0.2 mm.The total length of ice discharge pipeline was less than 50 m.Curvature radius of the bend should be met the minimum requirements of the specification of the pipe used.

Analysis of ice slurry production by direct contact heat transfer of air and water solution

In this paper, a novel system using direct contact heat transfer between air and water solution was proposed to generate ice slurry. The heat transfer process and the system performance were studied; energy efficiency coefficients of 0.038, 0.053, and 0.064 were obtained using different solutions. An empirical relationship between the volumetric heat transfer coefficient U v and the main parameters was obtained by fitting the experimental data. The U v calculated from the empirical formula agreed with the experimental U v quite well with a relative error of less than 15%. Based on the empirical formula, a laboratory-scale direct contact ice slurry generator was then constructed, with practical application in mind. If the air flow rate is fixed at 200 m 3 /h, the ice production rate will be 0.091 kg/min. The experimental results also showed that the cold energy consumption of the air compressor accounted for more than half of the total amount. To improve the system energy efficiency coefficient, it is necessary to increase the air pipes insulation and the solution's thermal capacity, and also it is appropriate to utilize the free cold energy of liquefied natural gas (LNG).

Numerical simulation on flow of ice slurry in horizontal straight tube

Numerical simulation on flow of ice slurry in horizontal straight tubes was conducted in this paper to improve its transportation characteristics and application.This paper determined the influence of the diameter and length of tubes,the ice packing factors(IPF)and the flow velocity of ice slurry on pressure loss by using numerical simulation,based on two-phase flow and the granular dynamic theory.Furthermore,it was found that the deviation between the simulation results and experimental data could be reduced from 20%to 5%by adjusting the viscosity which was reflected by velocity.This confirmed the reliability of the simulation model.Thus,two mathematical correlations between viscosity and flow velocity were developed eventually.It could also be concluded that future rheological model of ice slurry should be considered in three sections clarified by the flow velocity,which determined the fundamental difference from single-phase fluid.

Research progress of mobile cold storage using ice slurry

The demand for cooling,such as that of products,spaces,and processes,has increased with the development of urbanization.Cold storage can shift the valley time of electric power to cold energy.Compared to the fixed cold storage routine,mobile cold storage can eliminate site limitations.Ice slurry,as a new functional fluid,has recently become a new source of technology in our social lives.First,the research status of ice slurry mobile cold storage is summarized.Applications in the engineering field,such as space cooling,fisheries,pipeline cleaning,firefighting,and other real scenarios,are listed.Subsequently,key issues are summarized to understand the theoretical basis of ice slurry mobile cold storage,including flow,heat transfer,and loss in the mobile cold storage process-related ice slurry.Both tap water ice slurry and binary ice slurry are distinguished and discussed.Finally,beneficial policy analyses and market prospects for its promotion are presented.In summary,ice slurry mobile cold storage is a popular research topic with broad prospects for energy storage.