1. DETERMINATION OF WATER CONTENT AND ASH CONTENT
SMK Negeri 13 Bandung

2. Water in human body
70% of human body consist of water (47 liter per adult)
2,5 liter of water should be replaced in human body each day
Function of water in human body could never be replaced bay other substance.
 Carrier of food and metabolism waste
 Media of various reaction
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3. Water in food Water is an important component in food. It influences :
- Appearance
- Texture
- Taste
- Acceptability (Freshness and durability)
Water content in food are various
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4. Types of water based on the bonding
Actually there is no certain term for water in food
 “Bound Water”
Water molecule bounded to other molecules by high energy hydrogen bonding
Water molecules bound each other, exist in micro capillar, has different properties with pure water
Water bounded physicaly in material matrix tissue like membrane, capillar, fiber, etc
Water unbound in material tissue (pure water)
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5. Types of water Teknologi dan Rekayasa Ambition Water
Water intrust to food material causes volume expanding  water is not component of material
Crystal Water
Water bounded in food or non food in form of crystal
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6. DETERMINATION OF WATER CONTENT
Method
Drainage Method (Gravimetric Method)
Destilation Method (Deanstark)
Chemical Method (Karl Fischer Titration and Ca-carbide method)
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7. Gravimetric Method for Determination Of Water Content
Principle is evaporating the water in material by heating method ( oC), the difference of weight before and after heating (lost matter) is water
Material with high content of sugar, protein or fat (meat, egg, soybean sauce, etc) attacked and damaged by heat. Evaporation process should be carried out in vacuum oven.
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8. Destilation Method for Determination Of Water Content
This is the determination of high water content material and contain volatile matter like milk and vegetable.
Determination of water content with distillation is evaporating water with carrier liquid chemical substance. The carrier liquid should be :
a. higher boiling point
than water,
b. lower density than
water
c. insoluble (cannot mixed
with) water.
Ex : toluene, xylol, heptane
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9. Chemical Method for Determination Of Water Content
Determination of water content chemically, those are Calcium carbide method and Karl Fischer titration
Calcium carbide method for determination of water content
Water content determination based on volume of ethylene gas produced by reaction of calcium carbide with water
This method used for material like soap, flour, vanilline powder, butter and juice
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10. Chemical Method for Determination Of Water Content
Karl Fischer Titration for Determination of Water Content
Karl Fischer method is designed to determine water content in substance, utilizing the quantitative reaction of water with iodine and sulfur dioxide in the presence of a lower alcohol such as methanol and an organic base such as pyridine
There are two determination methods different in iodine providing principle : the volumetric titration method and the coulometric titration method
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11. ASH or MINERAL CONTENT
In most of food stuff 96% are water and organic substance  The rest is minerals
Mineral known as ash or inorganic material residue from burning of organic compound
Ash content commonly oxide of metal
When dissolved in water, ash forms alkaline solution
Minerals existence in human body :
link to organic substance
 in form of free ion
Has function as developer and arranger
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12. MINERAL IN HUMAN BODY
There are 14 mineral unsure needed by human body to have good health and optimal growth
Macro unsure  found in human body in high percentage
example : Na,Cl,Ca,P, Mg,S
Micro Unsure (Trace element) found in human body in low percentage
example : Fe,I,Mn,Cu,Zn,Co,F
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13. Determination Ash/Mineral Content
Determination of total ash content
Purpose :
1. to determine the processing is
good or not
2. to determine the material used in
production process
3. as nutrient parameter
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14. Determination of ash Direct method
Heating all materials at high temperature around oC and then weigh the residue. Available for any sample (Mineral, soil or food)
2. Indirect method
Add chemical reagent into material
before the incineration process
The indirect method available for
any sample which is high % of NaCl
Example : H2SO4 reagent  sulfate ash
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15. Determination of ash method
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