دراسة عملية لتصميم و تصنيع جهاز لإزالة الكولسترول من اللحوم المفرومة باستخدام ثاني أوكسيد الكاربون فوق الحرج

الملخص EN

A device to remove cholesterol from minced meat by using supercritical CO2 has been designed and manufactured.

This device removes cholesterol and part of the fat from the meat and operates by static and dynamic methods .

This device consists of a pump run by compressed air that increases CO2 pressure to supercritical pressure , and from a CO2 cylinder size 20 kg .

It also consists of three units : the first unit separates cholesterol and fat from the meat , the second unit separates cholesterol and part of the fat from supercritical CO2 , and the third unit absorbs cholesterol only by using Calcium carbonate .

Other Components of the device are the cooling unit, heating unit, pressure and temperature gauges and control valves distributed among the parts of the device , in addition to the safety valve .

The parameter of the device performance such as pressure, temperature, time, density, viscosity,and compression coefficient were measured , and cholesterol percentages in fresh minced meat were calculated before and after supercritical CO2 treatment in both the static and dynamic methods .

Moreover, the chemical , micrological , and sensory characteristics and the storage period of samples which undergo the pressure, temperature, and time conditions have been measured as well is studying the economical quality of the manufactured device .

The results have shown the maximum time to get the supercritical pressure for CO2 75,85,and 95 bar by using a pressure increasing pump was 35,40,55 minutes respectively and the density of supercritical CO2 increased by increasing the pressure, and decreased with high temperatures .

The highest value was 667.525 kg\ m 3 at 95 bar pressure and a temperature of 35 Celsius.The viscosity of supercritical CO2 increased by increasing the pressure and decreased with high temperatures .

The highest value get 52.71×10-6 Pa.

sec.

at 95 bar pressure and a temperature of 35 Celsius and the compression coefficient of supercritical CO2 increased at high temperature and decreased by increasing pressure.

The highest value was 0.6607 at 75bar pressure and a temperature of 55 Celsius , and the highest loss ratio of fat and cholesterol by using supercritical CO2 were 92.72 and 61.96 % for fat and 87.10 and 70.69% for cholesterol respectively and the percentages of moisture, protein, fat and ash in fresh meat samples untreated with supercritical CO2 were 74.43, 19.1, 4.48, 1.21 % respectively, while in fresh meat samples which have been treated with supercritical CO2 have reached 72.50, 22.1, 1.56, 3.4 and 71.67 , 22.78, 0.4, 4.1 % by using dynamic and static methods respectively .

The cholesterol loss ratios of samples treated with supercritical CO2 were 72.28 and 89% by using the dynamic and static methods respectively by using the static and dynamic methods at 95 bar pressure , a temperature of 35 Celsius, and 80 minute hold time .

The microbiological tests result of meat treated with supercritical CO2 have shown that there were no colonies in the total count of bacteria, coliform bacteria, gold aurous, and yeasts and molds where the result was zero.

The detection has shown a negative value about the existence of Salmonella.

The results sensory evaluation of barker made by meat that is treated with supercritical CO2 have shown that the dynamic method samples are may accepted among experienced arbitrators followed by the static method samples at 95 bar pressure , a temperature of 35 Celsius, and 80 minute hold time .