Determination of moisture
Objectives:
1. To determine the moisture content of selected food samples using drying oven method
2. To determine the moisture content of selected food samples using moisture analyzer.
Introduction:
Moisture content is one of the most commonly measured properties of food materials. The choice of an analytical procedure for a particular application depends on the nature of the food being analyzed and the reason the information is needed. In this experiment, cookies sample A(wheat) and sample B (butter) are used as a sample which have low moisture contents. However, in certain food likes meat and bakery product, both of it have higher moisture content. One of the way to determine a moisture content in meat from estimation of the apparent fat-free meat content, from the amount of nitrogen originating from the meat. (“Moisture in Peat”, 1990).
Moisture analysis is important for a number of different reasons, for examples economic reason. The cost of many foods depends on the amount of water they contain so, water is an inexpensive ingredient, and manufacturers often try to incorporate as much as possible in a food, without exceeding some maximum legal requirement. Analytical methods have been developed to measure the moisture content of foods that do not rely on direct measurement of the mass of water in a food. ( “Moisture content is”, n.d)
In this experiment, one of the method use to determine moisture content is oven drying. The sample is placed in the oven for a specific time and temperature. They are dried until their reached constant mass. The percentage of moisture content can be determined by performing some simple calculations. Another method is, distillation method (dean & stark). A known weight of food is placed in a flask with an organic solvent such as xylene or toluene. The organic solvent must be insoluble with water, have a higher boiling point than water and less dense than water. (Faichney, G.J. and G.A.
References: 1. Moisture in Peat.(976.03) Official Methods of Analysis. 1990. Association of Official Analytical Chemist. 15th edition. 2. Faichney, G.J. and G.A. White. 1983. Methods for the analysis of feeds eaten by ruminants. Commonwealth Scientific and Industrial Research Organization, Melbourne, Australia. 3. http://www.academia.edu/3607171/DETERMINATION_OF_WATER_MOISTURE_CONTENT_OF_FOODS 4. http://www.ndc.com/en/Moisture-Measurement-and-Moisture-Analysis.aspx 5. http://www.asdi.com/applications/additional/moisture-analysis