Objective: To identify the impact of sugarconcentration on freezing temperature

Background

Freezingis a common method used to preserve food. In the freeze process, water isconverted from fluid to solid. Once this happens, cost-free water is no longeravailable for chemical reactions and microbial growth. Hence, food spoilage dueto microbial task is delayed. “Delayed” is the correct term to usage heresince microbes such together bacteria space not killed by freezing. They deserve to resumegrowth and task when the food is thawed. That is why frozen foods items must bekept frozen to ensure food safety. Return microbes are successfully controlledduring freezing, enzymes room less influenced and may be energetic even in ~ freezingtemperatures result in alters in color, texture, flavor and aroma overtime. Food texture might be the many damaged the the sensory properties. This isparticularly true if the food is frozen slowly. Slow freezing have the right to causetextural damages due to the expansion of ice cream crystals in foods items such as ice-cream,and frozen fruits and also vegetables. Once ice crystals are large in ice-cream, youexperience a grainy texture. This commonly happens in home-made ice-cream thatis frozen in the kitchen freezer. Fruits and vegetables that room frozen slowlytend to obtain soggy and also drain water. This is since the ice cream crystals prosper largeenough to damages the cell walls so that they can no longer hold its contentintact.

Due to thenegative results caused by sluggish freezing, food manufacturers prefer to freezefoods quickly using different freezing methods. These approaches may incorporate blastfreezing through cold air, or immersion freezing with cryogenic (“extremely cold”)fluids (liquid nitrogen and carbon dioxide) to temperature of 0oC or below. The lower the temperature, thelonger the food can be preserved.

Onefactor affecting final temperature after freezing is the amount of dissolvedsolids in the food i.e. Salt and also sugar content. These solids minimize the meltingpoint the water leading to it to frozen at reduced temperatures, hence improving thekeeping top quality of the food material. In this lab you will certainly observe the effectof street on the temperature that food after ~ freezing.




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Materials and also Equipment

Four 300 ml beakersFour digital thermometers sugar WaterDigital lab scale

Method

Collect 4 300 ml beakers or accessible containers about the very same sizePrepare 250 ml the sugar/water remedies with sugar concentrations the 0% (no sugar), 5%, 15%, 35% street respectively, and pour them into each beaker. Make sure to brand them accordingly.Place a digital thermometer in each container. Note: rotate off the battery power on the thermometer throughout freezing enable to sit for at the very least 40 minute in the freezerRemove beakers indigenous the freezer, check and also record temperatures. Note: you can also store the beakers in the freezer overnight to observe larger differences in temperature due to freezing
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Beakers (Left to right – 0%, 5%, 15%, and 35% street solution) ~ removal native freezer overnight (12 hours). Notice how freezing temperature (oC) autumn with enhancing sugar concentration.

LaboratoryQuestions

Record the temperature the the solutions and also draw a bar graph reflecting sugar concentration matches temperature (5 points)Based ~ above the graph what was the impact of street concentration top top the temperature the the street solution? (2 points)Explain the reason for the distinction in temperatures. (3 points)Using your feeling of touch, observe the structure of the frozen solutions.

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Do you notice any difference in hardness? record your observations and discuss exactly how sugar affect the capacity of water to freeze. (5 points)Based on her observations, what result do girlfriend think sugar content would have on the toughness that ice-cream? (5 points)