coefficient of variation CV 2, the bulk sample was considered marginally homogenous. Therefore this bulk was acceptable for next step in this research.
Since the others bulk samples were prepared with the same mixing condition and mixing equipment, they were assumed having the same homogeneity as bulk
chocolate filled milk powder with Iron Ferrous Sulphate 10 DV FMP IS10.
B. Selection of iron type based on chemical, micro and sensory evaluation
There were 7 bulk prototype of chocolate filled milk powder available for these researches which were control, Fe sulphate, Fe fumarate and Fe pyrophosphate with
10 and 20 Daily Value DV. 1. Chemical, microbiology and sensory evaluation of powder based product.
All prototype samples in 30g packing format were analysed for chemical, microbiology and organoleptic properties.
Table 10 Result of chemical, microbiology and sensory evaluation for all samples
AW Max. 0,2
0,147 ± 0,001 0,146 ± 0,002 0,146 ± 0,003 0,151 ± 0,003 0,147 ± 0,002 0,145 ± 0,003 0,150 ± 0,004 Moist KFMax. 2,0
1,46 ± 0,03 1,40 ± 0,04
1,25 ± 0,03 1,24 ± 0,03
1,42 ± 0,05 1,40 ± 0,06
1,39 ± 0,05 Fe
Min. 8,7 or 17mg100g 0,78 ± 0,07 9,53 ± 0,11
18,63 ± 0,26 9,42 ± 0,14
18,36 ± 0,19 9,44 ± 0,16
18,85 ± 0,24 Vit. C Min. 50
mg100g 97,2 ± 4,2 102,3 ± 4,4
104,3 ± 3,6 102,0 ± 4,3
105,5 ± 3,9 95,7 ± 4,4
95,1 ± 4,0 TPC
Max. 3000 cfug 188 ± 15,0
285 ± 12,9 123 ± 9,6
98 ± 9,6 101 ± 13,1
78 ± 9,6 44 ± 4,8
Color Min. 80 in Aroma Min. 80 in
20DV 10 DV
20DV 10 DV
Iron Ferric Pyrophosphate 20DV
Analysis Target Unit
Control 10 DV
Iron Ferrous Sulphate Iron Ferrous Fumarate
Brown Chocolate
100 in 100 in
100 in 100 in
100 in 100 in
100 in 100 in
100 in 100 in
100 in 100 in
From Table 10 it shows that the result of analysis iron content for 10 DV fortification was at average 9.42 - 9.53 mg100g and 18.36
– 18.85 mg100g for 20DV fortification which were higher than that of expected. One of the reason was
because the presence of iron inbound from the non iron fortified chocolate filled milk powder, which has average value 0.78 mg100gr.
From Table 10 it shows that all bulk samples have Vitamin C min. 50 mg100g, Fe min. 8.7 or 17.3 mg100g, AW max 0.2 and TPC max. 3000 as well as organoleptically
were acceptable. Based on above data, all samples were confirmed acceptable for further analysis and the good TPC result above shown that the bulk was made and
packed under hygienic condition. The color of all powder samples, as described in Table 11, shown in Figure 7.
2. Sensory evaluation of reconstituted product All prototype samples in 30g packing format were reconstituted with 150 mL of
water, and analysed for chemical pH and organoleptic properties.
Figure 7 Powder color for all samples Table 11 Result of sensory evaluation for all samples
0 min 15 min
0 min 15 min 0 min 15 min 0 min 15 min 0 min 15 min 0 min 15 min 0 min 15 min pH at 20C
6,3 - 6,9 6,65
6,65 6,65
6,64 6,65
6,65 6,65
Color Min. 80 in
Brown Brown 100 in 33 in 83 in 33 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Milky Min. 80 in
Milky Milky
100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in - Chocolate Min. 80 in Sp. Choco Sp. Choco 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Metalic Min. 80 in
Absent Absent 100 in 67 in 100 in 50 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Rancid Min. 80 in
Absent Absent 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
Color Min. 80 in
Brown Brown 100 in 0 in 83 in 0 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Milky Min. 80 in
Milky Milky
100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in - Chocolate Min. 80 in Sp. Choco Sp. Choco 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Metalic Min. 80 in
Absent Absent 100 in 67 in 100 in 50 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Rancid Min. 80 in
Absent Absent 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
Color Min. 80 in
Brown Brown
0 in 0 in 0 in 0 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Milky Min. 80 in
Milky Milky
100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in - Chocolate Min. 80 in Sp. Choco Sp. Choco 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Metalic Min. 80 in
Absent Absent 100 in 67 in 100 in 17 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
- Rancid Min. 80 in
Absent Absent 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in 100 in
Hot reconstitution 80C Taste
Taste
Taste Warm reconstitution 45C
Iron Ferous Sulphate Iron Ferous Fumarate
10DVFMPIF10 20 DVFMPIF20 Iron Feric Pyrophosphate
10DVFMPIP10 20 DVFMPIP20 Cold reconstitution 15C
Analysis Target
Unit Control FMP ref
20 DVFMPIS20 10DVFMPIS10
From Table 11, it is shown that against reference, both Iron Ferrous Sulphate 10 DV FMP IS10 and 20 DV FMP IS20 are not acceptable, due to greyish
colorisation as shown in Figure 8 when observed just after reconstitution at 80°C. And on observation of 15 minutes after reconstitution, not only greyish colorisation was
detected but also metallic taste.
Figure 8 Color of reconstituted control Iron Ferrous Sulphate 10DV FMPIS10 and 20DV FMPIS20
3. Greyish colorisation and metallic taste in reconstituted milk when using iron Sulphate
The pH of reconstituted chocolate filled milk powder is 6.6. At that pH, the anthocyanin will transform to blue color, and mix with the white color of milk and brown
color of cocoa, it could give grey colorisation Refer to chapter II page 23, the concentration of anthocyanin in reconstituted
chocolate filled milk powder is approx. 0.675 mgL and refer to Visual Detection Thresholds VDT data shown in page 19, this concentration is considered below the
VDT. Therefore the greyish colorisation is not detected in reference sample. Iron sulphate has high solubility 25.6 g100 mL, while iron fumarte has very low
solubility 0.63rg100 mL and iron pyrophosphate is insoluble, when reconstituted, the iron will form metal ions which will intensify the color of anthocyanin. Therefore iron
sulphate will cause greyish colorisation in reconstituted chocolate filled milk powder. The solubility is increased when temperature increase, therefore when hot water
80°C is applied for reconstitution, the greyish colorisation is more obvious. The detected metallic taste found in reconstituted chocolate filled milk powder is
also caused by the high solubility of iron sulphate, which more obvious when iron concentration is higher.
C. Stability evaluation of iron fortified chocolate filled milk powder
