امكان سنجي استفاده از تترادكان به عنوان ماده تغيير فاز دهنده براي حفظ دماي گوشت طي نوسانات دمايي

چكيده انگليسي :

The Feasibility of Using Tetradecane as a Phase Change Material to Maintain Meat Temperature During Temperature Fluctuations Neda Omidi Arjenaki n omidi@ag iut ac ir August 29 2016 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Nafiseh Soltanizadeh Soltanizadeh@cc iut ac ir Nasser Hamdami Hamdami@cc iut ac irAbstractHigh temperature fluctuation during cold transportation of food materials such as meat increases thepossibility of spoilage which results in poisoning the consumers Using phase change materials PCM isan interesting method for decreasing the temperature fluctuation throughout the transport chain untilconsumption So in this study tetradecane was used as a PCM to evaluate the tempreture changes as wellas feasibility of the PCM for meat temprtature maintainance during temprtature fluctuations 12 5 oC andenporsure to environment temprtature 30 oC Firstly its melting temperature and latent heat of fusionwere determined using differential scanning calorimetry DSC to find out its heat storage behavior Aluminum was used as a model system to evaluate the effectiveness of PCM in controlling thetemperature variations Based upon the heat capacity of aluminum and meat the required weight ofaluminum that is equivalent to 100 gram meat was calculated and two pieces of aluminum withdimensions of 13 8 1 cm and 13 8 1 5 cm were cut and placed in polystyrene packages Appropriatequantity of tetradecane to prevent the temperature fluctuation during two hours was calculated and afterpackaging in polyethylene film was put in three positions of over beneath and over beneath of thealuminum piece The polystyrene packages were covered with polyvinylchloride film and were placed inrefrigerated incubator until the temperature of aluminum and tetradecane decreased to 0oC Twotemperature of 12 5 oC as temperature fluctuation and 30 oC as ambient temperature was selected forevaluation of tetradecane effectiveness A k type thermocouple and a data logger R3100 Supcon China was used to record temperature of aluminum at time intervals of half a second and the rate of itschange in different aluminum thickness and PCM positions was compared Also to investigate the effectof PCM on controlling the temperature fluctuation and its impact on the quality of food materials meatwas used in a similar way Firmness and drip loss were evaluated as two important qualitative propertiesof meat Results showed that the position of tetradecane has a significant effect on the heating ratepatterns and the best results were obtained by placing PCM over beneath the aluminum followed byPCM placed beneath the aluminum The minimum and maximum yields of tetradecane at 30 oC wereattributed to placing the PCM over the aluminum with 4 3 and placing it over beneath the aluminumwith 62 yields respectively Decrease in aluminum thickness results in more rapidly temperaturealteration at 12 5 oC but at 30 oC the total time is dramatically increased So the thickness is an effectivefactor in temperature changes The temperature time plots showed that the position of tetradecane has asignificant effect on the temperature control of meat during incubation at 12 5 oC but using PCM at thestorage temperature of 30 oC hasn t an effective role in delaying the meat temperature increasing Generally the best result was obtained by placing the PCM over beneath the meat at 12 5 oC Tetradecanealso has a significant effect on quality attributes of meat in terms of firmness and drip loss It can beconcluded that using tetradecane as a phase change material the thermal variations could be controlledabout 5 hours which in turn could delay the quality loss of meat in transportation chain Keywords cold chain meat phase change materials tetradecane

اميدي ارجنكي، ندا

امكان سنجي استفاده از تترادكان به عنوان ماده تغيير فاز دهنده براي حفظ دماي گوشت طي نوسانات دمايي

زنجيره سرما , گوشت