FDE 310- FOOD MATERIALS LABAROTORY
Determination of Moisture, Total Solid, Soluble Solid and Ash Contents
Burcu BAŞAK
Büşra KARAHAN
Elif Gökçen SAKAR
Merve Aylin AYDOĞDU
Özge Nur ÖNDER
INTRODUCTION
A refractometer is an optical device that takes advantage of the fact that light passing through a liquid bends or refracts. The refractometer is a tool. It is used to help you select higher quality of foods containing more vitamins and minerals. They are also used to determine the concentration of dissolved solids in a solution. Cooking oil, molasses, syrup, and other thick liquids require a refractometer calibrated to read 30-90 Brix. Refractometer also is used in wine making. (Harrill, 1998) refractometer is also used
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It can be determined by using oven technique. First of all, a known mass of butter is dried in an oven at 102 ° for 1 hour. After drying process, dried sample is put in desiccators to cool samples. Then, the sample is reweighted and the final mass which is_completely dried part. (Panda. H, 2013) Why do you keep samples for moisture determination in a sealed container before use?
To prevent the higher amount of evaporation caused by the moisture content, food samples must be put into the desiccator to take the correct results. Temperature is an important parameter when measuring the soluble solid content of a solution by using a refractometer? Why?
Temperature is an essential parameter because the index of refraction is affected by temperature. The speed_of light in a liquid will increase when the temperature increases. For instance, according to Hanson (2006), when there is 1°C increasing_in temperature, many organic_liquids the index of refraction decreases by nearly %0.05
What are the advantages and disadvantages of both instruments in measuring total soluble solid content? Refractometer advantages: İnexpensive instrument
Refractometer
A characteristic property can help identify a substance. A characteristic property will never change even when the volume of a substance is varied. A characteristic property also does not change when a substance changes state in matter. A physical property cannot identify a substance. A physical property will change when the volume of a substance is varied. It can also change when the substance changes state in matter. For example, if the volume and mass of a substance changes then the physical appearance will also change. However, the density, which is a characteristic property, will not change at all. The boiling point of a substance is the temperature that a substance changes from a liquid to a gas. The boiling point of a substance is a characteristic property because the boiling point of a substance will never change even when the volume and mass changes. The only thing that will change is the time that it takes to reach that temperature. If the mass and volume of the substance is small, then it will take a small amount of time for the substance to reach the temperature. However if the mass and volume of the substance is larger, then it will take a longer time to reach the temperature. The purpose of this lab was to see if when the volume of a substance changes so does the boiling point.
However, the measured densities lied below the accepted densities of 0.933 g/mL, 0.900 g/mL, and 0.888 g/mL for methyl acetate, ethyl acetate, and propyl acetate respectively. Refractive indices increased across all groups, including Group 6, from the methyl acetate sample to the propyl acetate sample just as expected from the theoretical refractive index values of the pure liquids. In addition, the refractive index % error calculations of Group 6 indicate that samples 1,3, and 5 produced refractive index values relatively close to the theoretical refractive indices of methyl acetate, ethyl acetate, and propyl acetate respectively. Although no distillation produces a perfectly pure liquid, the lack of relatively constant temperatures seen in the data and plots makes it unlikely that the samples collected by the class distillations had a high level of purity. Evaporation from the samples due to a lack of properly fitting test tube caps also reduced the usefulness of the density and refractive index calculations for determining the closeness of the obtained samples to the pure
Using the scopula, take a small amount of the substance and add it to the spot plate. Add deionized water to the section with the substance. Stir to see if the substance dissolves or not. Record your observations.
To calibrate the thermometer that I bought from Irvine Valley College, I followed the steps given by my Astronomy 20 teacher, Roy McCord. First, I purchased distilled water. I then found a reliable source, to research the point at which water freezes and boils in Celsius. Water freezes at 0°C and boils at 100°C.
To conduct the experiment, sample solutions will be placed next to a light source, which would be a white LED, with a diffraction grating, which will split and diffract light beams in different directions, between the samples and the detector, the cell phone camera, which will be used to collect images that will then be analysed using a computer software program that measures the amount of light that will be transmitted through the sample. The same samples will then be tested in a commercial spectrophotometer to see how much accuracy there would be using a cell-phone spectrophotometer.
on how long it takes to heat up. If we heat a large volume of water it
My interest into becoming an optometrist had begun when I was in high school; it happened in an unconventional way. It was not through watching videos, or someone explaining to me what optometry was, but rather, seeing the power of it firsthand. There was a point in my life where I felt emotions that I was unable to comprehend at the time. Seeing a family member on an operating table was the most petrifying moment that I have gone through, especially when the person on the table was my father. My father had to get a chalazion removed from his right eyelid. The doctor told my family that my father would be susceptible to certain health risks because of his diabetes and the severity of his cyst. This procedure was the hardest thing I have had to deal with in my life because it made me feel helpless. Usually, when my dad needs help he always asks me, but this time I could not do anything. It is interesting to think that something so small had such a big affect on my life.
The purpose of the lab was to show the effect of temperature on the rate of
7.) After you have heated them to the right temperatures, pour the excess water into a dry evaporating dish. ( Be sure not to get any of the substance in your solution. )
Our task was to investigate what the optimum ratio of solute to solvent that will produce the maximum cooling/heating effect?
Using three test tubes with samples in instead of two test tubes with samples in.
The primary goal of this experiment was to determine which types of glassware are the most accurate and precise in measuring substances. Another goal of this experiment was to help familiarize ourselves with the different types of glassware, and how we should handle the laboratory equipment. The accuracy and precision of a particular type of glassware is important because it allows for accurate measurements when performing different experiments. It also allows us to differentiate between glassware that is better for containing substances versus glassware that can deliver substances more accurately. In order to measure the accuracy and precision of the different types of glassware, we first chose seven different types of glassware. The general
The mixture was then cooled. Vacuum filtration was then performed on the mixture. This was done by carefully rinsing the precipitate mixture over moist, pre-weighed filter paper into a Büchner flask under vacuum. The residue was then moistened with ethanol while the flask was still under vacuum. The residue and filter paper were placed on a pre-weighed watch glass and weighed. They were then placed in a drying oven for about fifteen minutes and then reweighed. They were reweighed after a further five minutes in the oven and then again after another five minutes, so as to ensure the precipitate had been fully dried.
Operation: A hydrometer is a measurement instrument used to measure the relative density of liquids, the ratio of a density of a liquid to the density of water.
Equation (3) is the one used to calculate the index of refraction (nacrylic) of acrylic from each angle of incidence (θ1) and angle of refraction (θ2).