پديد آورندگان :
صداقت، ناصر نويسنده , , رستگاري، مريم نويسنده دانشگاه فردوسي مشهد , , خشنودي نيا، سارا نويسنده , , شريف، علي نويسنده ,
چكيده فارسي :
هدف از اين پژوهش طراحي ظروف خودگرم‌كننده و بررسي اثر ميزان و نوع تركيبات گرمازا بر دماي توليد شده، مي‌باشد. شش تركيب بازي-اسيدي هيدروكسيدسديم+ اسيد سيتريك، هيدروكسيدسديم+ اسيد تارتاريك، هيدروكسيد پتاسيم+ اسيد سيتريك، هيدروكسيد پتاسيم + اسيد تارتاريك، اكسيدكلسيم + اسيد سيتريك و اكسيدكلسيم + اسيدتارتاريك به نسبت 1: 5/1 در سه ميزان 150، 200 و 250 گرم تهيه و در فضاي خالي بين دو جداره‌ي قوطي‌هاي طراحي شده، تعبيه شدند. آب به ميزان 75/0 وزن تركيب گرمازا نيز در لفاف قرار داده شد و در فضاي مذكور جاسازي شد. براي تعيين بهترين ميزان و نوع تركيب، دماي جدار قوطي و غذا (كنسرو لوبيا و كنسرو خاوياربادنجان) و همچنين پروفايل دما-زمان تركيبات مختلف ترسيم گرديد. نتايج نشان داد، ميزان تركيب قليا-اسيد بر حرارت توليدي موثر است و بهترين نتيجه در ميزان 250 گرم حاصل شد. نوع تركيب تاثير معني‌داري (05/0 > p) بر حرارت توليدي داشت. بهترين تركيب هيدروكسيدسديم- اسيدسيتريك بود. بين انتخاب اسيدسيتريك و اسيدتارتاريك تفاوت معني‌داري ديده نشد. با مقايسه ميزان و سرعت گرم شدن در كنسرو لوبيا وكنسرو خاوياربادنجان نتايج نشان داد گرماي ايجاد شده در كنسرو بادنجان به طور معني‌داري بيش تر از كنسرو لوبيا است. پروفايل دمايي نشان داد 6 دقيقه طول مي‌كشد تا دما به حداكثر خود برسد، 6-10 دقيقه نيز دما ثابت باقي ماند. به اين ترتيب مشخص شد، تركيبات گرمازا انتخاب شده به خوبي توانستند حرارت مناسبي براي گرم كردن مواد غذايي ايجاد كنند و بهترين تركيب گرمازا هيدروكسيدسديم - اسيدسيتريك به ميزان 250 گرم بود.
چكيده لاتين :
Introduction: Self-heating packaging (SHP) is an active packaging with the ability to heat food contents without external heat sources or power. Packets typically use an exothermic chemical reaction and then woul be useful for military operations, natural disasters, or whenever conventional cooking is not available. These packages are often used to prepare main courses such as meat dishes, which are more palatable when hot.The system consists of three compartments that are separated within the can: the first is the packaged food item; the second, exothermic chemical material(such as calcium hydroxide); and in the third, water. Once the calcium hydroxide is dissolved within the water, it generates, in just 3 minutes, a large amount of heat (up to 60 degrees Celsius), which heats the food item that is located in the first compartment of the can and allows for it to remain hot for up to 20 minutes.For consumption,consumer must remove a seal on the base of the can to reveal the activation button. Pressing the button activates the heater. After 2-3 minutes, the contents of the can must be lightly shaken to ensure contents are at an even temperature. Setting the can upright, the consumer opens the package and enjoys a hot food or beverage.
The present study would focuse on finding the new exothermic chemical materials for reducing cost or producing upper temperature.Therefore, the main objectives of this study were to determine the effect of type and amount of heat-producing compositions on heat-produced and temperature profiles of self heating cans.
Material and methods: In this study,the designed self-heating canswere consisted of twoseparated compartments within the can.The first section of can was used for putting of food and the second section was used for storage of exothermic chemical materials. A misture of 6 exothermic chemical materials alkali-acidic, (Sodium hydroxide+citricacid ,Sodiumhydroxide+tartaric acid , potassium hydroxide +citric acid, potassium hydroxide +tartaric acid, Calcium oxide+citricacid and Calcium oxide+tartaric acid) was selected. alkalian-acidic composition was mixed in the ratio 1:1.5 and mixture weighing 150, 200 and 250 g were used in this investigation and placed in the free space between cans. For added degree of heat insulation using of glass wool as label outer of cans. Cans wall andcanned food (canned beans and eggplant caviar) temperature were investigated to determine the best combination of level and type of heat-producing composition. In addition, Time-Temperature profiles of each combination were plotted.
Results&Discussion: Observations indicated that amount of Heat-producing compositions had significant effect on heat-generated and the best result was obtained with 250g of Heat-producing compositions(p < 0.05). In the other words,the most amount of Heat-producing compositions is used, more heat-generatedwill produce and this results was adapted with the resultsofCarvalho et al., 2007 and James, 1996.Mixture type also had significant effect (p < 0.05) on investigated parameter and mixture of Sodium hydroxide and citric acid produced the most heat. However, type of acidic composition (citric or tartaric acid) had no significant effect on heat-produced. After mixing sodium hydroxide (NaOH) and tartaric acid, a mixture of sodium hydroxide (NaOH) and citric acid, potassium hydroxide (KOH) and tartaric acid, potassium hydroxide (KOH) and citric acid, calcium oxide (lime) and tartaric acid and Finally, calcium oxide (lime) and citric acid to produce the highest to the lowest temperature respectively.
Compare the speed and amount of heating in two canned food items revealed that eggplant caviar have a higher rate of heating than Canned Beans. Uniform texture than canned beans, canned eggplant caviar leads to better heat transfer and increase the rate of warming eggplant caviar has been created. In canned beans, bean shells on the seeds, such as an insulator practice and therefore has a longer period of time warming the canned. In addition, results of quantitative analysis of time-temperature profile showed that it takes about 6 minutes to reach its maximum temperature.
Conclusion: It was concluded that these compositions, especially sodium hydroxide - citric acid, have a good potential to be used asHeat-producing compositions in self-heating Cans. There was no significant difference between the selectionof Citric acid and tartaric acid.The profile of temperature showed 6 minutes needs that temperature reaches its maximum and 6-10 minutes, the temperatures remained stable.This time relatively acceptable time to warm up and stay warm for canned foods.
