Determination of Moisture Content

Introduction

     Moisture content in simple terminologies means water contents; it is the amount of water found in any agricultural produce. Many of the agricultural produce harvested from field has some level of moisture present in them and we need to determine the amount of water they possessed before we can determine how to handle, process and store them. Moisture content has been the major reason while some agricultural produce get spoilt most of them leading to what we call agricultural loss.      The amount of moisture present in any Agricultural produce determine the number of days it going to use on ground after harvesting; some produce under the cereal and legume category have less moisture present in them when harvested while produce under the category of fruit and vegetable have high moisture level.      However, the knowledge of moisture content helps in the design of farm machines like drying bin, storage structures, heat exchangers and handling equipment. It helps to determine the temperature that every agricultural produce need to be subjected to during preservation and processing.

Why do we need to determine the moisture content of Agricultural produce?

     As earlier said in the introduction, agricultural produce when harvested has high amount of moisture present in it which doesn’t make it stay much longer when harvester without adequate storage facilities especially the fruits and vegetables. The knowledge of determination of moisture content helps us to determine the following:

1. The amount of moisture in the agricultural produce
2. The temperature the produce should be subjected too during handling, processing and preservations.
3. Storage temperature either permanent or temporary.
4. It helps in processing technique; like in the feed mill the amount of moisture present in the maize is a factor during milling.
5. It also helps in packaging technique.

Methods of determining moisture content:

1. Direct method ;- oven drying method
2. Indirect method :- Resistance method

Objective(s) of the Experiment

     The objective of this experiment is to determine the moisture content of selected agricultural produce

Equipments and Materials Needed

The equipments and materials needed for the oven drying method are listed below:

1. Oven
2. Moisture can
3. Selected produce
4. Weight meter
5. Recording paper

Procedures

1. Get a known weight of the selected agricultural produce about 10g.
2. Put the 10g inside the moisture can of known weight.
3. Place the moisture can with material on a weighing scale and record the weight observed. Place the material with moisture can inside the oven that has been set to 1040C for 24hrs.
4. Remove from the oven and record the new observed weight.

Results and Calculations

     Moisture content of agricultural produce can be calculated in two ways:

1. Dry Basis
2. Wet basis

Dry Basis

Wet Basis

Notes

Mass of total produce (Mt) = Mass of dried produce (Md) + Mass of Water (Mw)
These two bases can be converted one to another with the formula below;

Discussion and Conclusion

     Note that equation 4 can be re-adjusted to calculate for MCdb.

References

1. Mohsenin, N.N. (1980). “Physical Properties of Plants and Animal Materials”. Gordon and Breach, science publishers, inc. One Park Avenue. New York.
2. Tiamiyu, W.M, Ajao, S., Sanusi, B. and Ukpabi G. (2017). “Determination of Physical Properties of Brown Beans”. Department of Agricultural Engineering, OAU. OAU, ife Nigeria.

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