2.3. Milk analysis
2.3.1. Fat, protein and lactose contents
Fat content of the milk was determinated through the Gerber
method following the procedure of Marshall (1993) by using
92% H2
SO4 (specific gravity 1.825) and Isoamyl alcohol.
Moreover, the protein content was estimated by following
the Kjeldahl method. The percent of nitrogen estimated was
multiplied by factor (6.38) to get protein percentage AOAC,
2000. Lactose content was measured by enzymatic hydrolysis
of lactose to glucose and b-galactose in the presence of galactosidase and water. Galactose oxidized by NAD and resultant
NADH formed is measured spectrophotometerically at
340 nm by following the instructions of AOAC, 2000.
2.4. Vitamins
2.4.1. Vitamin C content
Vitamin C in fresh milk was determined by titrimetric method
(Bosset and Eberhard, 1991). Ten grams of fresh milk sample
was mixed with 20 mL of 10% Meta phosphoric acid and
40 mL of distilled water at 50 C was added into a 100 mL long
neck amber glass flask and was set on an agitator for 5 min.
After that, the volume of the resultant adduct was made up
to the mark with distilled water and collected filtrate in a conical flask. Ten milliliters of filtrate was mixed with 5 mL of
10% acetic acid and 10 mL of 2% Meta phosphoric acid in
a beaker. It was titrated against 2,6-dichlorophenolindophenol
indophenol sodium salt dihydrate and the volume used was
noted to determine vitamin C contents by the following
formula.
2.3. Milk analysis
2.3.1. Fat, protein and lactose contents
Fat content of the milk was determinated through the Gerber
method following the procedure of Marshall (1993) by using
92% H2
SO4 (specific gravity 1.825) and Isoamyl alcohol.
Moreover, the protein content was estimated by following
the Kjeldahl method. The percent of nitrogen estimated was
multiplied by factor (6.38) to get protein percentage AOAC,
2000. Lactose content was measured by enzymatic hydrolysis
of lactose to glucose and b-galactose in the presence of galactosidase and water. Galactose oxidized by NAD and resultant
NADH formed is measured spectrophotometerically at
340 nm by following the instructions of AOAC, 2000.
2.4. Vitamins
2.4.1. Vitamin C content
Vitamin C in fresh milk was determined by titrimetric method
(Bosset and Eberhard, 1991). Ten grams of fresh milk sample
was mixed with 20 mL of 10% Meta phosphoric acid and
40 mL of distilled water at 50 C was added into a 100 mL long
neck amber glass flask and was set on an agitator for 5 min.
After that, the volume of the resultant adduct was made up
to the mark with distilled water and collected filtrate in a conical flask. Ten milliliters of filtrate was mixed with 5 mL of
10% acetic acid and 10 mL of 2% Meta phosphoric acid in
a beaker. It was titrated against 2,6-dichlorophenolindophenol
indophenol sodium salt dihydrate and the volume used was
noted to determine vitamin C contents by the following
formula.
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