1. Food additives
• Def.
– The substance that are added to foods by the
processor.
• Function
– Improve keeping quality
– Improve appearance
– Improve texture
3. • Nitrate and nitrite
– 1- to produce cured colour (combine with meat
pigment)
– 2- to retard bacterial growth
– 3- to alter flavour
• Starch
– Act as binding agent
4. Fig. 61: Two sausage cuts
One produced with salt only (right)
and the other with salt and small
amounts of nitrite (left)
Fig. 60: Pieces of cooked meat (pork)
4 pieces with common salt only
(right) and 3 with common salt
containing small amounts of nitrite
(left)
5. Fig. 88: Example of effect of functional
ingredients
Meat loaf cut, left with curing colour, centre
without colour, right with artificial colour
6. • Detection of nitrate
– Reagent
• Diphenylamine (0.5 gm) in Conc. H2SO4 (50 ml)
– Procedure
Small portion of well mixed sample
in porcelain dish
↓
Cover with few ml of the reagent
↓
Blue colour
indicate the presence of nitrate
7. • Detection of nitrite
– Reagents
• Reagent 1
– 1-naphthylamine reagent (0.1 gm in a mixture of glacial acetic
acid (30ml) and dist water (120ml) by heating, then filter.
• Reagent 2
– Sulphanilic acid reagent (0.5 gm of sulphanilic acid in mixture
of glacial acetic acid (30ml) and dist water (120ml) and filter.
8. • Procedure
Equal parts of reagent 1 and reagent 2 are added to
a small portion of well mixed sample
↓
Red colour
indicates the presence of nitrite
9. • Detection of starch
– Reagent
• Lugol’s solution (iodine 2gm + potassium iodide 4gm +
dist water 100ml)
– Procedure
Add few drops of lugol’s solution to a piece of well
mixed meat sample
↓
Blue colour
indicate the presence of starch
