ABE 2 2nd Exer
Mampusti, Joemar M. 2012-39654
ABE 2 T-1L
Laboratory Exercise No. 2
Dockage Determination and Thickness Grading
Introduction:
Dockage is a factor of grading grains. It refers to the impurities in the paddy which can be separated through sieves and other cleaning devices. Dockage may be classified also as underdeveloped and shriveled kernels that are difficult to remove with recleaning and/or rescreening. Dockage determination is crucial for its precise development (Atungulu, 2013). Other importance include to protect processing equipment; separate the unripe and underdeveloped grains; be able to adjust hullers more precisely for minimum grain breakage in milling and be able to mill grain lots separately. Thickness grading on the other hand is used to separate the grains according to its thickness. By this we are able to classify the grain and achieve better results. The difference in thickness between mature and immature paddy may be considered. This means 1.75 mm slotted sieve are used in Philippine varieties.
Materials
1. Equipments/ Instruments
a. Bates Aspirator
b. Assorted sieves (4/64 to 6/64 and 12/64)
c. Slotted sieve (1.75 mm)
2. Working sample : 1000 grams of unclean paddy
Methods
Steps:
1. The composite sample of paddy to be tested is obtained.
2. The sample is divided into 500 gram samples.
3. Using the 12/64, the large impurities are separated from one sample.
4. Using the 4/64 to 6/64, the small impurities are now separated.
5. The light impurities are separated using the bates aspirator.
6. Using the same sample, the immature grains are separated
7. The percent purity and impurity are calculated.
8. The percent mature and immature grains are calculated.
9. The data is recorded on the worksheet.
Results and Discussion
Sample calculation formulas: % Large impurities = Grams Large impurity/grams sample(500) Average= Sum of observation/ No. of observationss
Table 1. Dockage determination
Sample
Large impurities
Small impurities
ABE 2 T-1L
Laboratory Exercise No. 2
Dockage Determination and Thickness Grading
Introduction:
Dockage is a factor of grading grains. It refers to the impurities in the paddy which can be separated through sieves and other cleaning devices. Dockage may be classified also as underdeveloped and shriveled kernels that are difficult to remove with recleaning and/or rescreening. Dockage determination is crucial for its precise development (Atungulu, 2013). Other importance include to protect processing equipment; separate the unripe and underdeveloped grains; be able to adjust hullers more precisely for minimum grain breakage in milling and be able to mill grain lots separately. Thickness grading on the other hand is used to separate the grains according to its thickness. By this we are able to classify the grain and achieve better results. The difference in thickness between mature and immature paddy may be considered. This means 1.75 mm slotted sieve are used in Philippine varieties.
Materials
1. Equipments/ Instruments
a. Bates Aspirator
b. Assorted sieves (4/64 to 6/64 and 12/64)
c. Slotted sieve (1.75 mm)
2. Working sample : 1000 grams of unclean paddy
Methods
Steps:
1. The composite sample of paddy to be tested is obtained.
2. The sample is divided into 500 gram samples.
3. Using the 12/64, the large impurities are separated from one sample.
4. Using the 4/64 to 6/64, the small impurities are now separated.
5. The light impurities are separated using the bates aspirator.
6. Using the same sample, the immature grains are separated
7. The percent purity and impurity are calculated.
8. The percent mature and immature grains are calculated.
9. The data is recorded on the worksheet.
Results and Discussion
Sample calculation formulas: % Large impurities = Grams Large impurity/grams sample(500) Average= Sum of observation/ No. of observationss
Table 1. Dockage determination
Sample
Large impurities
Small impurities
References: Atungulu ,Griffiths, et al. “Determination of Dockage for Accurate Rough Rice Quality Assessment.” American Society of Agricultural and Biological Engineers(2013). N.p, Web. Grigg, Brandon, and Terry Siebenmorgen. “Impacts of Thickness Grading on Milling Yields of Long-Grain Rice”. American Society of Agricultural and Biological Engineers(2013). N.p, Web.