Hazard Assessment In Flour Fortification
There are two types of safety concerns in fortifying flour. The first is
that the standard be set at a level low enough to guarantee that no one will
consume chronically dangerous levels of any micronutrient over the long run,
while still being set high enough to provide beneficial intake levels. One way
of assessing this is from the new Upper Levels (UL) set by the National Academy
of Sciences, shown in the Table below.
This UL is set at a level lower than the No Observed Adverse Effect
Level, so it should not be interpreted as meaning that higher levels are
unsafe. It does mean that any intake below it is safe. The amounts of fortified
flour or maize meal that anyone person could consume on a regular basis will
vary greatly depending on the person's size and what other food is available.
But it can be surmised that hardly anyone will consume his or her caloric
requirement of 2000 kcal/day entirely from flour or meal, which amounts to 540
grams. The table below shows the level of each micronutrient that would have to
be in flour for the UL to be exceeded at that consumption on a regular basis
corrected for the highest retention given in the Table below
Maximum safe levels in flour
| Nutrient |
Upper Level (UL)
From the
Food and Nutrition Board
of the U.S. Institute of Medicine, 2001 |
Amount needed in flour for
540 grams (2000 kcal)
to exceed UL |
| |
mg/day |
ppm |
| Iron |
45 |
83 |
| Zinc |
40 |
74 |
| Calcium |
2500 |
4630 |
| Selenium |
0.4 |
0.74 |
| Iodine |
1.1 |
2.0 |
| Folate |
1 |
2.6 |
| Vitamin B 1 |
none |
|
| Vitamin B2 |
none |
|
| Niacin |
35* |
72 |
| Vitamin B6 |
100 |
206 |
| Vitamin B12 |
none |
|
| Vitamin A |
3.0 or
10,000
IU |
6.2 mg/kg or
20,600 IU/kg |
| Vitamin D |
0.050 or
2,000 IU |
3,700 IU/kg |
| *The UL
for niacin is based on its vasodilatation effect, which is less of a problem
with niacinamide. The Scientific Committee for Food in the European Union has
proposed a UL for nicotinic acid of 10 mg and a separate UL for niacinamide of
900 mg. Thus the later form poses no safety limitations in common food
fortification practice. |
| |
| Source: Fortification
Handbook |
The other safety concern relates to the chance of acute toxicity if
flour was accidentally over fortified. Because of the high cost of
fortification premixes, no mill could tolerate having excessively high amounts
used over extended periods. Normal QC testing would quickly show a problem. Any
over-fortification would, thus, be for a short period and involve a small
amount of flour. This could happen if the fortification feeder was kept running
after the flour stopped flowing. Equipment and procedures for preventing that
will be discussed in
Implementation.
Also, there are some built-in mechanisms that would prevent such flour from
actually being sold or consumed. Highly overfortified flour would show an
off-color, from the iron and riboflavin as well as an off-flavor, making it
unacceptable to consumers.
A fifty-year experience with flour fortification has proven it to be
very safe with hazards that can be easily prevented by established QA and QC
procedures.
|