Flour Millers Tool Kit
►Introduction
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►Operations
►Quality
►Marketing
Definitions
Enrichment / Fortification
• Adding vitamins and minerals to flour during the milling process
• May include nutrients naturally in the grain or additional nutrients
• Addition may meet or exceed natural levels
• Designed for mass populations
Supplementation
• Nutrients provided in liquid or pill form
• Usually in doses higher than found in fortified food
• Designed for specific target groups (i.e. women or children)
►Introduction
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Flour Millers Tool Kit for Fortification
Table of Contents
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Section 1: Introduction to Flour Fortification
Section 2: Procuring Premix
Section 3: Mill Set-up
Section 4: System Operation
Section 5: Assuring Quality Control
Section 6: Advocacy and Marketing
Click on the arrows above to go directly to the first page of each section.
In the rest of the Tool Kit, click on the text at the bottom of each page to go to the
first page of that section.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 1:
Introduction
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Why Fortify?
Overview of Fortification Process
Fortification’s Public Health Impact
Minerals and Vitamins Used in Flour Fortification
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Why Fortify?
Health and Economic Benefits
• Prevent iron deficiency, neural tube birth defects, and
other health concerns
• Improve the national economy by increasing productivity
and decreasing healthcare expenditures
FFI photo
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Why Fortify?
Leverage Existing Infrastructure to Reach Population
Grain milling is a
centralized business
with broad distribution
of products
Foods made with
wheat and maize are
widely consumed
Consequently,
fortification has the
potential to reach
millions of people.
Siemer flour mill
http://www.siemermilling.com/Locations/125/a/159
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Overview: Wheat’s Natural Iron
• Bran contains 55% of wheat’s
natural iron
Bran
• Germ contains 5% of wheat’s
natural iron
Endosperm
The bran and germ are primarily
used for animal feed.
Germ
Percentages calculated from USDA Nutritional Database
Image courtesy of the Wheat Foods Council
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Wheat’s Mineral Loss in Milling
Mineral loss at 75-80% extraction
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
►Marketing
Overview: Wheat’s Natural Vitamins
Found in
Bran (%)
Found in
Germ (%)
Folic Acid (B9)
33
12
Niacin (B3)
86
2
Thiamine (B1)
33
64
Riboflavin (B2)
42
26
Pyridoxine (B6)
73
21
Pantothenic Acid (B5)
50
7
Vitamin
Bran
Endosperm
Germ
Percentages calculated from USDA Nutritional Database
Image courtesy of the Wheat Foods Council
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Wheat’s Vitamin Loss in Milling
Vitamin loss at 75-80% extraction
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
►Marketing
Overview: Fortification Process
Powdered vitamins and minerals are added to flour during
the milling process using equipment called feeders.
A large mill may use a “feeder bank”
such as this set of four. One feeder is
for fortification and three are for other
flour improvers.
Photo copyright: David Snyder / CDC
Foundation
Photo courtesy of Research Products Company
►Introduction
►Premix
Smaller mills may use a
single feeder for
fortification.
► Mill Set-Up
►Operations
►Quality
► Advocacy
Impact on Health: Iron
Burden of Deficiency
• Reduced productivity
• Iron deficiency anemia
• Undeveloped mental
capacity
• Maternal mortality
• Pre-term births
Health Benefits
• Increased productivity
• Fully developed mental
skills
• Improved maternal and
child health
“Iron deficiency affects more people than any other condition, constituting a
public health condition of epidemic proportions.”
-World Health Organization
http://www.who.int/nutrition/topics/ida/en/
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Success of Fortifying with Iron
Four studies of the effectiveness of fortifying with
iron all showed improvement in iron status:
Country
Population studied
China
Women
Iran
Women and men
Venezuela
School-age children
Fiji
Women
FFI review December 2012. Photo from istockphoto.com
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Results of Insufficient Folic Acid
(vitamin B9)
• Children born with neural
tube birth defects (NTDs)
such as spina bifida
• Permanently disabling or
fatal
Photo of child with spina bifida from Google images
• More than 300,000 NTDs
occur every year globally*
* Global Report on Birth Defects, March of Dimes Birth Defects Foundation, 2006
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Impact of Fortifying with Folic Acid
• Reduce risk of NTDs 31% to 78%
• Healthcare savings from averted
surgeries and therapy
• Cost: benefit ratios reported:
o 1:12 in Chile
o 1:30 in South Africa
o 1:48 in the United States
Photo from istockphoto
Risk reduction from Blencowe, H: Folic acid to reduce neonatal mortality form neural tube disorders. International Journal of Epidemiology. April
2010 (suppl_1):i110-i121
Cost benefit data from:
Llanos, A., et. al., Cost-effectiveness of a Folic Acid Fortification Program in Chile. Health Policy 83 2007:295-303.
Sayed, A., et.al., Decline in the Prevalence of Neural Tube Defects Following Folic Acid Fortifcation and Its Cost-Benefit in South Africa. Birth
Defects Research 82 2008:211-216.
Grosse, Scott, et. al., Reevaluating the Benefits of Folic Acid Fortification in the United States: Economic Analysis, Regulation, and Public Health.
American Journal of Public Health 95 2005:1917-1922.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Minerals and Vitamins
Used in Flour Fortification
Minerals
• Iron
• Zinc
►Introduction
►Premix
Vitamins
• Folic Acid (B9)
• Thiamine (B1)
• Riboflavin (B2)
• Niacin (B3)
• B12
• Vitamin A
• Vitamin D
► Mill Set-Up
►Operations
►Quality
► Advocacy
Types of Iron Used In Fortification
Elemental Iron
(reduced iron or electrolytic iron)
Ferrous Fumarate
►Introduction
►Premix
Ferrous Sulfate
Sodium Iron EDTA (NaFeEDTA)
► Mill Set-Up
►Operations
►Quality
►Marketing
Factors for Choosing Iron Compound
• Bioavailability (absorption)
– Water soluble compounds have the highest relative bioavailability
because they are very soluble in gastric juices.
– The size, shape and surface area of the iron particle affects
bioavailability, as does composition of food made with fortified
flour.
• Sensory changes
– High levels of some iron compounds could cause coloration or
rancidity of the flour.
• Cost:
– Highly bioavailable forms of iron are more expensive, but less is
needed per metric ton of flour for fortification to have a health
impact.
• Magnets:
– Iron salts (ferrous sulfate, ferrous fumarate and iron EDTA) will not
be attracted to magnets that may be used in milling process
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Other Minerals in Flour Fortification
Zinc
• Zinc oxide is most
commonly used
• Inexpensive
• No sensory concerns
• Use higher levels in highextraction flours due to
higher phytic acid content
►Introduction
►Premix
► Mill Set-Up
Calcium
• Calcium sulfate and
calcium carbonate are
both used
• No sensory concerns
• Not included in premix
with other nutrients
because levels are far
higher than other nutrient
additions
• Not usually included in
fortification standards
►Operations
►Quality
► Advocacy
B Vitamins in Flour Fortification
Folic Acid (B9)
• Folic acid is preferred
source
• No sensory concerns
• Relatively stable with
some loss from exposure
to light and food
preparation
• More bioavailable than
B9 in natural food
sources
►Introduction
►Premix
► Mill Set-Up
Thiamine (B1)
• Thiamine mononitrate is
preferred source
• No sensory concerns
• Susceptible to losses
from exposure to light
and heat and alkaline
conditions (pH over 7)
►Operations
►Quality
► Advocacy
B Vitamins in Flour Fortification
Riboflavin (B2)
• Orange crystalline
powder
• Use only food grade
material exceeding 97%
purity
• Unstable in light
►Introduction
►Premix
► Mill Set-Up
Niacin (B3)
• Commonly used source:
nicotinic acid (commonly
just called niacin) and
nicotinamide.
• No sensory concerns
• Nicotinic acid can cause
reddening in the skin on
exposure
• Both niacin compounds
are very stable in heat
and light
►Operations
►Quality
► Advocacy
B Vitamins in Flour Fortification
Pyrodoxine (B6)
Cobalamin (B12)
• Pyrodoxine
hydrochloride is
preferred source
• No sensory
concerns
• Stable to heat, but
sensitive to UV
light.
• Cyanocobalamin is common
source
• No sensory concerns
• Relatively stable in heat, but
unstable in alkali and strong
acidic environments
• Difficult and expensive to test
for the small amounts used in
fortification
• More bioavailable than B12 in
natural food sources
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Other Vitamins in Flour Fortification
Vitamin A
• Retinyl acetate and retinyl palmitate are recommended.
• Beta-carotene’s yellow color makes it undesirable for
flour.
• Available in encapsulated forms that do not cause
sensory concerns
• Significant losses can occur on storage if the
encapsulation and antioxidant protection system is poor.
A standard stability test at 45°C on the raw material
should show losses no greater than 20% after 21 days.
• Countries often fortify edible oil or sugar rather than flour
with vitamin A.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Other Vitamins in Flour Fortification
Vitamin D
• Form used in fortification: D3 Cholecalciferol
• Countries often fortify dairy products with vitamin D in
combination with vitamin A
• Currently only a few countries fortify flour with vitamin D
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
More Information
• Health, productivity and economic benefits of flour fortification:
http://www.ffinetwork.org/why_fortify/index.html
• World Health Organization recommendations for wheat and maize
flour fortification:
http://www.who.int/nutrition/publications/micronutrients/wheat_maize
_fortification/en/
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 2
Premix
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Premix Components
Individual Nutrients or Premix?
Premix Formulation
How to Procure Premix
Costs for Premix Through the Supply Chain
Premix Shelf Life and Storage
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Components
The most common flour fortification practice is to add
multiple vitamins and minerals using a single ingredient
called a premix.
Premix includes:
• Fortificants (powdered vitamins and minerals)
• Excipients (carriers, fillers)
• Free-flow agent
Premix may have a yellow or green color. This
does not affect the color of flour because premix
is added in such small amounts.
Photo courtesy of Hexagon Nutrition
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Non-Fortificant Premix Components
Excipient
Free-flow agent
• Lowers premix bulk
density to match flour
• Keeps the premix from
clumping and bridging in
the hopper
• Improves feeding and
blending
• Also referred to as carrier
or filler
• Examples include starch
or maltodextrin
►Introduction
►Premix
► Mill Set-Up
• Examples include tricalcium phosphate or
precipitated silica (silicon
dioxide)
►Operations
►Quality
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Limitations of Fortifying with
Individual Nutrients
• Used in very small amounts
• Tend to be excessively light or dense
compared to flour
• Tend to clump
• Difficult to feed individually
• Requires multiple feeders, checks and
adjustments
Folic acid, pictured here, is hard to add to flour individually due to the small
amounts needed. Recommended addition rates are 1 to 5 parts per million
based on the country’s consumption patterns. It is easier to add nutrients in a
premix with other vitamins and minerals. Photo by Jeff Gwirtz
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Benefits
• Easier to test
• Single feeder, check and adjustment
• Easier to feed
• Provides uniform nutrient distribution
• Single ingredient tracer possible
• Less expensive than buying individual nutrients
Individual nutrients, such as these pictured,
are more difficult to add to flour than a single
premix with a blend of the required nutrients.
Photo courtesy of WIN, World Initiative for Nutrition, a business unit of Fortitech
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Formulation
Manufacturers select ingredients and formulations based on:
• Compound composition
• Additive characteristics
– Bioavailability
– Storage stability
– Cost
• Targeted premix addition rate
Premix manufacturers create premix based on a
variety of factors.
Photo courtesy of Muehlenchemie GmbH & Co
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Manufacturer Overages
Premix manufacturers usually
include nutrients at levels
approximately 2% to 5%
higher than listed on the label.
Premix photo courtesy of Muehlenchemie GmbH & Co
►Introduction
►Premix
This accounts for potential
nutrient loss and ensures that
the premix meets the label
claims.
► Mill Set-Up
►Operations
►Quality
► Advocacy
Flour Improvers
Flour improvers used in mills may include:
Enzymes
Oxidants
• Alpha Amylase
• Azodicarbonamide
• Proteas
• Benzoyl peroxide
• Potassium bromate
• Ascorbic acid
Do not add these materials to the fortification
premix in a single feeder.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Risks of adding improvers to
fortification premix:
• Quality is compromised as addition of fortificant should
be constant but improver addition rates are adjusted to
meet specifications.
• Shelf life of vitamins may be altered if combined with
improvers in a highly concentrated mix in the feeder.
• Some fortificants can react with benzoyl peroxide and
degrade the nutritional value of the premix.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
How to Procure Premix
• Establish premix
specifications
• Develop list of alternate
suppliers
• Establish an economic
order quantity
• Conduct annual review
of:
• Establish internal re-order
point considering:
- Certificate of Analysis
- Pre-mix performance
-
Lead time
- Delivery Time
-
Inventory
- Quality
-
Production schedule
- Price
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Specifications
1. Definition
– Describe the product, source, intended purpose, processing aids
2. Chemical Analysis
– Moisture, vitamin activity, mineral content
3. Organoleptic qualities
– Aroma, taste
4. Physical
– Particle size, density, color, appearance
5. Bacteriological
– Total plate count, salmonella, staph, aureus, e. coli, yeast, molds
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
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Specifications (continued)
• 6. Mycotoxin Status: none should be present
• 7. Enzyme Activity: alpha-amylase if applicable
• 8. Functional/Characterization: nutritional improver
9. Packaging and Storage Conditions
• Package net weight, type and size, label declaration, storage conditions
(temperature and RH), shelf stability, length of time in storage
• 10. Dietary Law Status
Target, minimum, and maximum levels and test methods should be
identified for each specification as appropriate.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
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Purchasing Department
The Mill Purchasing Department keeps the following
information about the supplier on file:
• Name and address of the supplier’s company or
organization
• Name and phone number of the principal contact to
whom the order should be directed.
• Name or type of the premix to order (specification)
• Standard amount of the premix ordered
• Premix price history
• Method and time of delivery
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
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Premix Supplier Provides:
A Product Information Sheet or Fact Sheet including:
• Name and intended use of premix
• Name and contact information of manufacturer
• Ingredient composition of premix – usually in descending order
• Food grade status of ingredients (i.e. Food Chemicals Codex (FCC)
grade)
• Recommended addition rate of premix to flour and levels of
micronutrients added at that rate
• Certificate of analysis for each lot with:
• Minimum assay standards for the premix
• Maximum assay standards if any exist
• Storage and handling instructions
• Allowable storage periods or shelf life of premix
Keep this document on file at the mill.
Make it available to key operating and quality control personnel.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Procurement Options
• Order domestically if possible to avoid importing fees
• Look for regional or global producers if needed
• Purchase from direct private enterprise, representative,
or broker
• Centralized, cooperative purchasing group such as a
local millers association may purchase in bulk for
members
• Some governments provide premix to all millers in
country
• Non-governmental agencies may provide premix for a
limited time
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Procurement Alternatives
• GAIN Premix Facility: Competitive bids from approved
suppliers for a specified premix through an internet
bidding system. GAIN is the Global Alliance for Improved
Nutrition. See http://gpf.gainhealth.org/
• Some countries, such as South Africa, have created
approved premix supplier lists that must be used. See
http://www.grainmilling.org.za/ - click Vitamin Suppliers.
Please Note: No supplier is endorsed by this toolkit.
Potential suppliers should be thoroughly
investigated prior to purchasing premix.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Estimated Premix Costs
Premix
US $ per metric ton
of flour
Iron + folic acid
$0.85 - $3.00
Iron, folic acid, other B
vitamins
$1.60 - $3.90
Iron, folic acid, other B
vitamins, vitamin A
$2.85 - $9.90
Note: Estimates do not including shipping, import duties and value added tax.
Actual costs may vary by as much as 30% and is dependent on manufacturer,
location, amount ordered and should NOT be used as official market prices.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Cost Reduction Approaches
•
Pursue government reduction and/or elimination of
premix taxes and import fees
•
Seek price quotes from two or more suppliers to ensure
competitive bids.
•
Follow Economic Order Quantity principles:
-
Order large quantities as determined by premix shelf life
-
Commit to purchase premix from a single supplier for a
longer contract period
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Cost in the Supply Chain
Fortification costs are minimal throughout the supply chain.
Flour millers:
•
US$1.00 - $4.00 metric ton
Bakers and re-processors:
•
US $0.05 - $0.20 per 50 kilogram of flour
Consumers:
•
< US $0.02 per 5 kilogram bag of four
•
< US $0.003 per 1.5 kilogram loaf of bread,
•
< US$0.001 for 250 grams pasta.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Shelf Life
•
Minerals are particularly stable
•
Vitamin effectiveness reduced over time
•
Premixes without vitamin A may keep their nutritional
value up to two years
•
Premixes with vitamin A may only keep their nutritional
value for 6 months
Special Notes: Premix manufacturers or distributors do not
accept return of premix that has exceeded its shelf life.
Shelf life may be further reduced if premix is stored
incorrectly at the mill.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Storage
In the Warehouse:
• Readily accessible
• Not Exposed to:
- Sunlight
- Excessive Heat
Above: http://www.flourarranging.com/2010/10/14/wright-out-ofnowhere
Below:
http://www.dnpint.com/email_newsletter/Ingredient_Times_No82.htm
- Moisture
- Damage or Theft
• First-In-First-Out (FIFO)
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
On the Production Floor
Segregate premix and improvers by color coding or labeling.
Keep one or two working
boxes of premix near the
feeders for easy access.
Multiple feeders installed in a
row are known as a feeder bank.
Identify each feeder clearly to
prevent accidently mixing
improvers and premix.
Photo courtesy of Research Products
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
More information on Premix
• Recommended practices for premix manufacturers:
http://www.ffinetwork.org/implement/documents/Premix_Best_Practi
ce270408.pdf
• Answers to frequently asked questions about wheat flour milling:
http://www.ffinetwork.org/about/faq/faq_wheat_industry.html
• Code of Practice for Food Premix Operations
• Pan American Health Organization of the World Health Organization
http://www.who.int/nutrition/publications/micronutrients/92_75_1258
9_9/en/index.html
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 3
Setting Up the Mill for Fortification
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Required Equipment
Premix Addition Options
Types of Premix Feeders
Mechanical Principle and Size
Delivery Mechanisms
Equipment Suppliers
Photo courtesy of Research Products
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Required Equipment
Premix Feeder
• Measures correct
amount of premix
• Position at
appropriate place
in production line
►Introduction
►Premix
► Mill Set-Up
Mixing Mechanism
• Can be done
during normal flour
transport or with
special equipment
• Assures that
premix is uniformly
added to flour
►Operations
►Quality
► Advocacy
Premix Addition
Premix is usually added to
flour using one of two
procedures:
• Continuous
• Batch
The gravity-based system such as the one
pictured here is an example of premix being added
to flour continuously as it is produced at the mill.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Addition: Continuous
• Premix is continuously
added to the flour
stream using a feeder
feeder
• Premix addition is
proportional to the rate
of flour production
• Validation of mixing
uniformity is required
conveyor
Premix can be continuously added into a collection
conveyor such as the one shown here.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Addition: Batch
• Premix is generally added
to a batch of flour via a
gravity spout and blended
in a mixer
• Premix addition is based
on flour batch size
• Operation can be manual
or automatic
• Validation of mixing
uniformity is required
Batch mixer photo courtesy of Buhler
Company
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
All Feeders Require Anti-bridging
With continuous or batch, use feeders with anti-bridging
devices to provide consistent premix flow.
Two product flow issues resulting in flow stoppage include:
• Bridging occurs when product discharges above the outlet but no
premix flows in to fill the void. Looking into the top of the feeder
hopper, it appears to contain premix across the entire hopper.
• Tunneling is a form of bridging where the product falls directly
through the outlet but premix remains on the sides of the hopper.
Looking into the feeder hopper, the discharge point is visible but the
sides of the hopper remain covered with a wall of premix.
See the troubleshooting pages of section 4, Operations,
for more information.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Outlet Requirements
• Cover the feeder’s
outlet spout for
sanitation purposes
• The cover can be part
of the feeder design or
it can be addressed in
installation
• Locate the outlet spout
for easy opening for
inspection and check
weighing
►Introduction
►Premix
► Mill Set-Up
At left, a screw feeder discharge spout is
covered. At right, the cover opens to
allow for easy inspection and check
weighing.
Photo by Jeff Gwirtz
►Operations
►Quality
► Advocacy
Control Systems for Premix Addition
• Control systems selected should match the
technical capability of the plant operation and
maintenance program.
• Systems range from manual systems, to those with
basic and advanced interlocking to fully automated
systems.
• All systems presented achieve the basic needs of a
fortification program.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Controlling the Feeder Manually
• In a manual system,
the feeder is started
and stopped manually
by the mill operator.
• Feeder settings are
controlled and
monitored by the mill
operator.
Flour
Streams
Premix
Feeder
In manual
operation, the
feeder control is
near the premix
feeder. This
control model can
be operated
manually or
automatically.
Photo by Jeff Gwirtz
• This is the least
expensive approach to
install requiring no
sensors or electronic
controls.
►Introduction
►Premix
Flour
Out
► Mill Set-Up
►Operations
►Quality
► Advocacy
Controlling the Feeder Using Basic
Sensors and Interlocking
Sensors:
• Monitor for incoming flour
• Switch the premix feeder
on and off as needed
Flour
Streams
Flow
Sensor
Premix
Feeder
Mill/Control
Room Warning
Flow or Level
Sensor
• Monitor premix level and
flow
• Warn operator of
problems
Flour
Out
• Reduce mill operator
workload
• Are inexpensive
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Controlling the Feeder Using
Advanced Sensors and Interlocking
• Loss in weight feeder
makes feeder setting
and monitoring easier
for the operator
• An online flour scale
more accurately starts
and stops the feeder
using a baseline flow
rate
Flour
Streams
Premix
Feeder
Loss-In-Weight
Flow
Sensor
Mill/Control
Room Warning
Flow or Level
Sensor
Flour
Out
• These system
improvements are
needed to develop an
automated system
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Controlling Feeder with Automation
• Programmable logic
controller continuously
matches the addition rate
of premix to the
measured flow rate of
flour
Flour
Streams
Flow
Sensor
Premix
Feeder
Loss-In-Weight
Mill/Control Room Warning
Programmable Logic Controller
Flow or Level
Sensor
• Requires appropriate
human machine interface
• Most accurate method of
flour fortification and
exceeds minimal
requirements
Flour
Scale
• Easily retrofitted into mills
using existing automation
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Controlling the Feeder-Summary
Control Point
Control System
Level
Manual
Basic
Advanced
Automation
1
Manual
Feeder
On/Off
X
X
X
X
X
X
X
►Introduction
2
Automatic
Feeder
On/Off
3
Premix
Hopper
Level
X
X
X
X
X
X
X
X
►Premix
4
Premix
Flow
Sensor
X
X
X
X
X
5
Premix
Rate Set
Manual
X
X
X
X
► Mill Set-Up
6
Premix
Loss-InWeight
X
X
X
X
X
X
X
7
Warning
System
X
X
X
X
X
X
►Operations
8
Flour
Flow
Sensor
9
Flour
Production
Scale
10
Programable
Controler or
Computer
X
X
X
X
X
X
X
X
X
►Quality
► Advocacy
Mechanical Principles
Two ways feeders control amount of premix added to flour:
Gravimetric
Volumetric
• Also known as “loss in
weight”
• Most commonly used by
screw feeders
• Continuously weighs
premix
• Similar to using a
measuring cup
• Requires greater volume
of premix than generally
used
• Minimum error of
measurement is +2%
• More complex and
expensive than required
in most cereal milling
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Mechanical Information
Electrical interlock system
prevents flow of premix
when flour flow stops.
• The on/off switch, speed
controller, and low- level
indicator light can be
located near the feeder or
at a remote location.
Controller
Feeder
• Some installations may
need a voltage regulator
to ensure proper
performance of the feeder
and controller.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Mechanical Information
• The electrical interlock system be installed between the
feeder motor and the motor driving the flour collection
conveyor.
• In pneumatic delivery systems, an interlock should be
made between the feeder and the blower to ensure that
the feeder cannot be turned on without the blower
operating. This prevents buildup of premix in pneumatic
lines followed by over-treatment of flour once the blower
is turned on.
• An alternative is an automatic shut-off switch on the
feeder that is hooked up to a flour flow indicator or a
pressure indicator in a pneumatic system.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Feeders
Feeders are required for automated batch and continuous
addition. Three main types of premix feeders are used to
fortify flour.
1.Screw Feeder
►Introduction
►Premix
2. Revolving Disk
► Mill Set-Up
►Operations
3. Drum / Roller
►Quality
► Advocacy
Premix Feeders: Screw Feeders
• Dispense fixed volume of
premix per revolution
• Size of feed screw
determines the feed rate
volume of premix
dispensed per revolution
• Variable speed controls the
number of revolutions per
unit of time
• Weight of premix
dispensed is determined by
product density
►Introduction
►Premix
► Mill Set-Up
Size of the feed screw vary such
as the small ones above and the
larger one below.
►Operations
►Quality
► Advocacy
Premix Feeder: Revolving Disk
•
•
•
•
Slide mechanism controls rate of premix addition
Powered by either an AC or DC motor
Small hopper must be refilled frequently
More mechanical components than the screw feeder
Hopper
Gate Adjustment
Rotating Spring
Rotating Disc
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Feeder: Drum or Roll Type
Premix passes between two closely set revolving cylinders.
Floating Fill Container
Flexible Hopper
with Agitation
Guide Veins
Feed Rate Slide
Bar Adjustment
Motor
Roll Scraper
Feed Rolls
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Feeder: Drum or Roll Type
• Used for decades and many are still in use
• Can be volumetric, gravimetric or loss of weight feeders
• Either a DC or AC motor for power
• Pulley system controls the rotation speed
• Pulleys and wheels of differing diameters make gross adjustments in
the feed rate. An adjustable gate is used to make fine adjustments
• Require more parts and more maintenance
• Shear pins in the drive mechanism break if large objects (bolts,
plastic) get stuck between the rolls
• In some newer models, a variable speed DC drive motor allows
addition rate to be adjusted electronically rather than mechanically
• Variable speed AC drive motors are also available
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Hopper Size
• Choose a feeder with a large enough hopper that it does not have to
be filled frequently
• Regardless of type of feeder used, the size and number of feeders
needed will depend on:
– Number of production lines
– Hourly production of respective production line
This feeder bank has feeders with different size hoppers for different additives.
Photo courtesy of Research Products Company
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Premix Discharge Rates
All types of premix
feeders are available with
different discharge rates
• A small feeder may
discharge premix at
levels as low as 25
g per hour (0.4
g/min)
• The largest can
discharge up to 32
kg per hour (533
g/min)
►Introduction
►Premix
► Mill Set-Up
Estimated premix discharge rate
Mill
Capacity
(MT/day)
Flour flow
rate*
(kg/min)
Premix**
Discharge rate
(g/min)
5
2.5
0.4
20
10
1.5
50
25
3.8
100
50
7.5
200
100
15
400
200
30
* At 72% extraction rate
** At 150 grams premix per metric ton of flour
►Operations
►Quality
► Advocacy
Continuous Premix Delivery Systems
With continuous feeding, two types of premix delivery are
possible. Location of the feeder depends on the type used.
Gravity
Pneumatic
• Feeder is placed above
the flour collection
conveyor
• Can be located at several
places in the mill
• Premix drops directly into
flour as it flows through
the conveyor
►Introduction
►Premix
► Mill Set-Up
• Premix drops into a
venturi tube
• Premix is blown into the
flour collection conveyor
►Operations
►Quality
► Advocacy
Premix Delivery System: Gravity Feed
Things to consider:
– Feeder is installed
above the flour
collection conveyor
Gravity Method of Premix Delivery
Premix Feeder
Flour In
– Premix is delivered via
a nearly vertical gravity
spout
Mixing Conveyor
– Install spout away from
general suction system
►Introduction
►Premix
► Mill Set-Up
Flour Out
►Operations
►Quality
► Advocacy
Premix Delivery System: Pneumatic
Things to Consider:
• Requires equipment
such as blowers,
valves and piping
Pneumatic Method of Premix Delivery
• Conveying lines
should have minimal
length and directional
changes
Feeder
Air
Blower
Venturi
Tube
• Make the venturi tube
accessible for
Flour
monitoring
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Delivery System: Pneumatic
1
2
1. Venturi tube with air
flow restriction and
product inlet
2. Attaching venturi tube
to premix hopper
transition
3. Completed assembly
►Introduction
►Premix
► Mill Set-Up
3
►Operations
►Quality
► Advocacy
Ensuring Adequate Mixing in the Mill
Proper addition point for premix on the flour collection
conveyor is essential for effective flour fortification.
•
Locate the feeder at the front half of collection conveyor, above the
blades of the mixing screw
•
At least 3 meters of conveyor length is normally needed to ensure
adequate blending
•
Introduce premix away from general suction system
Poor
To Little Flour
Good
Mixing
Poor
To Little Mixing
Flour
Level
Flour Flow
Flour
Outlet
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Ensure Adequate Mixing In Packaging
If premix addition cannot be accomplished in mill,
consider this option:
• Install mixing conveyor between holding bin and
packout bin
• The premix is discharged into the start of this special
conveyor
• At least 3 meters of conveyor length is normally
needed to ensure adequate blending
• Introduce premix away from general suction system
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Equipment Recommendations
When considering equipment, look for these specifications:
• Directions for installation and maintenance available in desired
language or can be translated
• All surfaces in contact with premix are food-grade and non-corrosive
• Adjustable delivery control, calibrated from 0 to 100% of feeder
capacity
• 220 volt ± 10% 50/60 Hz single phase power
• Anti-bridging design to prevent bridging or tunneling of premix in
hopper
• Capable of delivering from 0.04 to 8 L/hr with ± 5% accuracy over
full range
• Hopper capacity of 8 liter minimum
• Easy accessibility for operator to check hopper and flow rate
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
System Recommendations
When considering equipment, look for these specifications:
• Directions for installation, maintenance, and system operation
available in desired language or can be translated
• Automatic shut off / warning capability
-
Feeder shuts off when flour flow stops
-
Warning if feeder is empty or premix fails to discharge
• Place feeder on load cells to aid in monitoring premix usage or use
loss-in-weight feeder
• If possible, use electronic control loop to balance feeder discharge to
flour production scales
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Vendor Expectations
Millers should expect the following from equipment and system
vendors:
• At least two references from mills where equipment and
systems have been in operation for at least one year
• Installation and operating instruction manual that explains in
words and diagrams the installation, calibration and
maintenance of the equipment and system
• Technical support for installation, training, calibration, and
maintenance
• Recommended spare parts inventory for items with life span of
less than three years
• Identified lead time for parts delivery and commitment to
maintain parts inventory support
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Equipment Costs
• Cost of feeders
varies with the
capacity of the
production line and
optional equipment.
• Cost of blending
equipment, if needed,
varies with capacity
of production line.
• Costs shown do not
include shipping,
import duties, value
added tax or
installation.
►Introduction
►Premix
Equipment
Cost Range (USD)
Feeders
Volumetric Feeder
$1,000 - $8,000
Gravimetric Feeder
$5,000 - $20,000
Loss-of-weight Feeder
$10,000 - $21,000
Powder Feeder
$1,000 - $25,000
Scales
Electronic
$100 - $2,000
Blenders / Mixers
Screw-Ribbon
/Paddle/Cut Flight
$10,000 - $25,000
Rotary Batch Blender
$35,000 - $170,000
Vertical Batch Mixer
$15,000 - $200,000
► Mill Set-Up
►Operations
►Quality
►Marketing
More Information About Mill Set-up
Contact FFI at info@ffinetwork.org
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 4
Milling Operations for Fortification
►
►
►
►
►
►
►
Operation Guidelines
Examples of Record Keeping
Premix Receiving and Safety
Maintaining Premix Supply
Feeder Calibration and Premix Feed Rate
Check-weighing Procedure
Equipment Maintenance and Troubleshooting
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Fortification Operation Guidelines
1.
2.
3.
4.
Know actual production rate of mill
Calibrate feeders to production rate of mill
Ensure feeder hopper contains premix
Start mill and run for at least 15 minutes to reach normal
production rate
5. Start feeder at required setting as determined by the
feeder calibration process
6. Conduct check weighing at start of mill production run
and every 2 hours to verify correct addition rate. Adjust if
addition rate is greater than 10% above or below target,
and recheck addition rate.
7. Check weights at the start of every shift or every 2 hours
of operation
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Fortification Operation Guidelines
8. Maintain check weight within 5% of target
9. Ensure that the feeder does not run out of premix. This
is the most important check on the production line. To
do this:
• Check the low-level signal
• Check each premix feeder routinely and fill hopper
• Record weight of material left in premix supply
container
• Compare actual premix use with the expected premix
use based on flour production
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Fortification Operation Guidelines
10. At the end of a production run, turn off the premix
feeder before shutting down the mill.
11. Production records need to record the following:
• The lot number of the premix used
• Check weights
• Feeder adjustments if made
• Times of check weighing
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Flour Ingredient Usage Report
First Shift
Production
Report
Example
Date:
Mill:
Beginning Lot #
701 CCN
Flour Production
Time
052 AGU
Enrichment
Grade
MT Flour
%
700 CCN
Malt
KG
%
Bleach
KG
%
KG
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
Shift Total
0.00
0.00
0
0
Shift Total
MT Flour
KG
0
KG
0.00
KG
0
0
Begin Inventory
Transfer to Mill Floor
0
Total to account for
0
0
0
0
0
0
Closing Inventory
Disappearance
INGREDIENT
Enrichment
Malt
Bleach
NEW LOT #
START TIME
STOP TIME
SUPERVISOR (name):
OPERATOR (name):
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Check Report Example
Flour Fortification Feeder Check
First Shift
Date:
5/31/2012
Mill:
B Mill
Fortification - Feeder Test
Enrichment
Lot #
701 CCN
Time
Flour Grade
Flour Rate
(Mt/hr)
Target
(g/min)
Test #1
(g/min)
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
MXE
MXE
MXE
MXE
MXE
MXE
MXE
MXE
9.4
9.4
9.4
9.4
9.4
9.4
9.4
9.4
24.6
24.6
24.6
24.6
24.6
24.6
24.6
24.6
24.2
24.5
24.8
24.1
24.6
24.8
24.9
24.7
Test #2*
Adjusted
(g/min)
Test #3*
Re-check
(g/min)
* Required only if Test #1 is out of specification
SUPERVISOR (name):
OPERATOR (name):
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Receiving Procedures
1) Assess package
condition
►Introduction
2) Ensure that you
received what you
ordered
►Premix
► Mill Set-Up
3) Record Lot #
and type of premix
►Operations
4) Remove and file
certificate of
analysis
►Quality
► Advocacy
Premix Safety
Premixes are concentrated sources of vitamins and minerals
and are too concentrated for direct consumption.
Mill workers must follow these safety instructions:
1. Label premix boxes with
warning labels and handling
precautions
2. Inform all workers handling
the premix of the material
safety data sheet (MSDS) or
product information sheet
with safety instructions
►Introduction
►Premix
WARNING. COMBUSTIBLE DUST.
Avoid generation of dust to prevent
dust explosions. Keep away form
sources of heat and ignition.
Prolonged and/or repeated contact
may cause skin irritation. Gloves, dust
mask, and protective clothing should
be worn when handling. Wash
thoroughly after using.
► Mill Set-Up
►Operations
►Quality
► Advocacy
Premix Safety
3.
Wear long sleeves, gloves and dusk mask when filling the feeder
hopper, even if it just takes a minute. The operator may also wear
safety goggles, a hair net, safety helmet or other protective
devices depending on mill policy.
4.
Wash hands and any skin exposed to the premix after filling
hoppers.
5.
Clean any premix spill immediately by putting meal on the spill
prior to sweeping.
Some people have allergic skin reactions
to flour fortificants, in particular niacin.
This can be avoided by following the precautions outlined.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Maintaining Premix Supply
1. Keep Small Quantities on Mill Floor
• Estimate amount of premix needed and have sufficient quantities
in the mill for production
2. Stock Rotation
• Record the production lot number(s) upon receipt
• Develop a rotating first-in, first-out (FIFO) system
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Maintaining Premix Supply
3. Use of Active Containers
•
•
•
•
•
Place a scoop inside the container for convenient use
Keep paper, plastic, and other contaminates out of the
container as they may get in the feeder cause its malfunction
After the hopper is filled, put the scoop back in the container or
another designated location
Seal container and close outer container if applicable
Keep operating container away from damaging conditions
including heat, light, and moisture
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Maintaining Premix Supply
4. Assign specific mill staff these responsibilities:
•
Stock control
- Order new premix at intervals that take into account
usage rates, time for processing the order and receiving
a shipment.
•
Premix handling in the mill
- Including storage, movement to the production line and
addition to the feeder(s)
•
Premix quality control
- Inspect the premix when a shipment arrives, periodically
check the storage conditions of unopened premix, and
check the production line process
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Calibration Instructions
Confirm the flour flow rate (kilograms per hour) for the production line.
This is typically done at one of two points in a continuous system:
1. If fortifying in the mill, check the flour production scales and
confirm with a weigh-off if possible
2. If fortifying in packaging and load-out, check the scales of the
flour transfer system in which the flour will be fortified and
confirm with a weigh-off if possible
In a batch system, check the weight of material delivered to the batch
mixer by confirming scale reading accuracy.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Calibration Instructions
Next, determine the premix feed (discharge) rate at different speed
settings on your feeder.
1. Fill hopper half full with premix
2. Set feeder to maximum discharge
3. Run feeder for 2 minutes
4. Weigh the premix that has been discharged
Operator at a feeder control panel.
5. Calculate maximum discharge per minute by dividing total weight by 2
6. Repeat multiple times at different speeds or percent settings
7. Make a chart that shows the premix discharge rate per minute at
different speed settings from 0 to 100% of maximum discharge
8. Display the chart near the feeder. See example on next slide.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Feeder Calibration Chart Example
20.0
17.5
Premix (g/min)
15.0
y = 0.2024x - 1
R² = 0.996
12.5
10.0
7.5
5.0
2.5
0.0
0
10
20
30
40
50
60
70
80
90
100
110
Feeder Setting (%)
Actual results from commercial premix feeder
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Determining Premix Feed Rate
1. Identify the premix addition rate recommended by the premix
supplier
2. Multiply by the flour production line flow rate to calculate the
premix delivery required in grams per minute
Premix Addition
(grams / MT flour)
X Flour Flow Rate
(MT/minute)
= Premix Required
(grams/minute)
3. Adjust feeder control to calculate delivery rate (consult your mill’s
calibration chart)
4. Check the weigh-off and adjust accordingly
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Check-Weighing Procedure
1. Zero the scale
or weigh the
sample container
►Introduction
2. Position the
container at
feeder discharge
►Premix
► Mill Set-Up
3. Collect premix
for 2 minutes
►Operations
4. If you zeroed the
scale in step one,
the weight shown is
that of the premix.
Otherwise, subtract
the container weight
from the total to
determine premix
weight
►Quality
► Advocacy
Equipment Maintenance
• Follow the recommended maintenance schedule from
the equipment supplier (request supplier to provide this
information in local language)
• Lubricate moving parts as required (use approved foodgrade lubricants)
• Inspect for wear; adjust and/or replace parts as needed
• Maintain inventory of spare parts that may need
replacement
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Troubleshooting: Premix Flow
Compact and sticky premix may ball, bridge or tunnel in the feeder.
This results in feed rate variability.
ACTIONS:
1. Frequently inspect the premix feeder, especially after it is
newly installed
2. Specify and use premix feeders with mechanical agitation
(see next two slides)
3. Empty feeders that will be unused for any length of time
4. Have premix supplier change the levels of excipients and
free-flow agents
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Hopper Agitators Improve Flow
A mechanical agitator in the hopper prevents the premix from bridging,
clumping and compacting. Some models come with an agitator device.
Photo by Jeff Gwirtz
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
►Marketing
Hopper Design Improves Flow
The hopper of the premix feeder at left is made of flexible
material. A mechanical device such as the motor and paddle
pictured at right causes the flexible wall to pulsate and prevents
the premix from bridging.
Photos by Jeff Gwirtz
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Troubleshooting: Flour Flow
If the flour or premix flow is intermittent, fortification level will
not be correct.
ACTIONS:
1. Frequently inspect the feeder and flour flow
2. Install low-level alarm or indicator light on hopper
3. Install electrical interlock system between the mill and feeder
controls (described in section three on the mill set-up)
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Troubleshooting: Magnets
If using elemental iron, the surface of rare earth magnets in the
production process may collect iron powder.
ACTIONS:
1. No change required. This will not affect the iron fortification level or
the magnet’s performance regarding tramp metal.
2. Install magnets in a location so that the flour stream acts as a
continuous cleaning mechanism as it passes over the magnet.
3. If the iron powder bridges between the
magnet tubes, use a magnet system with a
larger distance separating the tubes.
4. Use a non-magnetic iron source, such as iron
salts.
5. Continue to inspect and clean magnets
following good manufacturing practices (see
photo)
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Troubleshooting: Power Supply
Variations in voltage can alter flour production and premix feed
rates, which will cause the flour to be fortified incorrectly.
ACTIONS:
1. Install voltage regulators when working with single-phase
voltage feeder motors
2. Use three-phase motors
3. Work with electric supplier to provide uniform, high-quality
power into the plant
4. Negotiate with energy company to provide alerts before
power outages
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Troubleshooting: Nutrient Loss
Quantitative testing may show that vitamins and mineral content is
consistently lower than the expected value. Vitamin A and riboflavin
are particularly vulnerable due to exposure to light.
ACTIONS:
1. Confirm that premix is appropriate for type of flour
2. Confirm that the correct addition rate is used
3. Put sample bags in opaque containers
4. Analyze flour sample as soon as possible
5. Make sure both the premix and fortified flour is not exposed to
high heat (>40°C) or light during storage
6. If the dust collection stock is yellow, the collection system may be
removing riboflavin near the premix addition point. In this case,
• Confirm and set suction to proper pick-up velocity
• Position suction system away from premix addition point
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
More Information on Operations
• Contact the Food Fortification Initiative at
info@ffinetwork.org
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 5
Quality Control / Assurance
► Quality Control / Assurance
► Internal Quality Overview
► Qualitative Testing, including iron spot test procedures
► Record Keeping and Quality Control Schedule
► Quantitative Testing and Composite Samples
► Government’s Role In Monitoring
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Quality Control / Assurance
Ramadan Deliu, Head of Laboratory at M &
Sillosi Milling Company, prepares flour for an
iron spot test. Photo by Kate Wheeler.
►Introduction
►Premix
An effective quality assurance and
quality control program throughout
a country’s flour fortification
program:
• Ensures adequate levels of
vitamins and minerals to improve
nutrition among the population
• Prevents the cost of over-using
premix
• Gains customer satisfaction
• Adheres to government
regulations
► Mill Set-Up
►Operations
►Quality
► Advocacy
Quality Control / Assurance
Five parts of the program
Internal
External
Commercial
Intake
Impact
Flour millers conduct process control and quality
checks
Food control authorities inspect flour mills and
analyze flour samples
Inspectors check fortified products at retail stores
Household surveys confirm consumption
Biological impact is verified
Source: Chapter eight of the Guidelines on Food Fortification with Micronutrients published by the World
Health Organization and the Food and Agricultural Organization of the United Nations
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Quality Control / Assurance
Five parts of the program
Internal
External
Flour millers conduct process control and quality
checks
Food control authorities inspect flour mills and
analyze flour samples
This tool kit focuses on the internal quality control with the
assumption that the millers purchased high-quality wheat to meet the
customers’ expectations.
The tool kit also highlights the quality assurance process at external
laboratories.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Internal Quality: Overview
Use these five quality control methods in every mill:
1. Monitor the fortification system regularly
2. Conduct qualitative testing regularly
3. Monitor premix feed rate and flour flow rate
4. Keep records of premix usage and fortified flour
production
5. Submit samples for quantitative testing
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Qualitative Flour Testing
Used to:
• Determine if flour sample has
been fortified
• Provide visual estimate of
fortification level
A common qualitative test is the
iron spot test. If iron is
detected by this method, it is
assumed that other nutrients
in the premix are present.
►Introduction
►Premix
► Mill Set-Up
The iron spot test is
formally Method 40-40.01:
Iron Qualitative Method as
approved by the American
Association of Cereal
Chemists (AACC).
Photo by Kate Wheeler.
►Operations
►Quality
► Advocacy
Iron Spot Test Procedure
1. Take a sample of fortified flour.
Make an impression in the sample.
2. Add the reagents with a plastic,
disposable dropper.
3. Wait for red spots to appear to
indicate presence of iron.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Iron Spot Test Procedure
4. Compare test with prepared samples or images
such as the one below to estimate premix addition
level
22 ppm
½ treatment
44 ppm
Target Treatment
88 ppm
Double Treatment
ppm = parts per million
5. Discard sample
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Test Responses
• Variability is expected (quantitative test show below)
Feeder Test Results- May 31, 2012
Running Average (N=3)
26.0
Upper
Control
Limit
25.5
g/min
25.0
Target
24.5
24.0
23.5
1
3
5
7
9
11
13
15
17
19
21
23
Lower
Control
Limit
Hour of Day
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Iron Spot Test Response
• Make adjustments based on systematic trends over time
established by multiple observations.
• Adjusting a premix addition system based on one or two
spot test results could widen the system variability and
complicate future measurements.
• If 2 out of 5 consecutive samples do not meet
expectations, increase the sampling frequency as
outlined on the next page.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Iron Spot Test Sample Frequency
• If 2 of 5 consecutive samples do not meet the requirements,
increase sampling frequency.
• If the next 2 of 5 samples fail to meet requirements, implement
corrective actions. Verify that the feeder is operating properly then
consider adjusting the:
• premix feeder control
• flour transport scales
• mixing machinery
• If the next 2 out of 5 consecutive sample fail to meet requirements,
stop production until the error is found and corrected.
• Once production restarts, continue frequent sampling.
• Return to normal sampling schedule after 3 consecutive samples
are correct.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Iron Spot Test
Advantages
Limitations
• Simple, fast, inexpensive
• Not quantitative: does not
determine amount of iron in
sample.
• Requires no sample pretreatment.
• Requires only two reagents:
potassium thiocyanate (KSCN)
or sodium thiocyanate (NaSCN)
and hydrochloric acid (HCI)
• Iron spot test is not currently
applicable for sodium iron
EDTA.
• Food grade NaSCN is
available if desired
• Easy: personnel with minimum
training can perform this
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Iron Spot Test Alternatives
• If using sodium iron EDTA, include elemental iron in
premix
– The simplest solution is to order premix with a minimal amount
of elemental iron (10 ppm) to respond to the iron spot test. This
slightly increases the total iron content in quantitative
measures.
• Ask premix provider for alternatives
• If the premix has riboflavin, use a black light test
– Riboflavin (vitamin B2) will fluoresce under ultraviolet light.
Perform this test in a dark room or box using a wet Pekar slick
to compare fortified with unfortified flour.
• If the premix has vitamin A, use a color test
– Must be done in a laboratory to compare the intensity of color
when vitamin A mixes with copper sulfate.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Record Keeping
Maintaining accurate records is an essential part
of internal monitoring. Develop a system to track:
Flour Ingredient Usage Report
First Shift
Date:
Mill:
Grade
Time
MT Flour
%
KG
%
Premix delivery and usage
•
Flour production
•
Comparison of premix usage with target
needs based on flour production
•
Results of check weighing tests
•
Internal and external quality control testing
results.
Bleach
Malt
Enrichment
Flour Production
•
700 CCN
052 AGU
701 CCN
Beginning Lot #
%
KG
KG
7:00
8:00
9:00
10:00
11:00
12:00
13:00
14:00
Shift Total
0
0
0.00
0.00
Shift Total
MT Flour
KG
KG
KG
0
0.00
0
0
Begin Inventory
Transfer to Mill Floor
0
Total to account for
0
0
0
0
0
0
Closing Inventory
Disappearance
INGREDIENT
Enrichment
Malt
Bleach
NEW LOT #
START TIME
STOP TIME
These records help the mill assure quality and
may be required during an external inspection.
SUPERVISOR (name):
OPERATOR (name):
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Internal Quality Control Schedule
1. Check premix feeder hourly. Make sure the speed
detector shows that it is running. Fill hopper if it is low.
2. Run feeder check weights at least every 8 hour shift.
3. Run iron spot tests at least every 8 hour shift.
4. Conduct inventory control of premix usage and fortified
flour production at least quarterly.
Detail the quality control responsibility, frequency, protocol,
and reporting activities in the mill’s quality assurance
manual. Instruct all mill personnel in the procedures.
Assign reporting to someone with authority to act on the
information.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Internal and External Testing
Types of laboratories testing fortified flour
- Quantitative tests.
- Quantitative tests of all added nutrients
- Checks results and procedures of other labs
- Runs or manages biological testing.
- Audits mills.
Government
Laboratory
Reference
Laboratory
Premix
Suppliers
-Certificate of analysis on premix
- Quantitative tests of all added nutrients
Central Milling
Laboratory
-Runs quantitative tests on
indicator nutrient and other tests
-Audits mills within the company
Mills
Laboratory/Production Activities
- Fortificant inventory control
- Feeder checks
- Iron spot tests (if applicable)
- Flour sampling
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Quantitative Testing
• Send samples to laboratory using internationally recognized
methods (AACC or ICC and AOAC)
• Requires sophisticated equipment and careful adherence to
protocols due to the small concentration of vitamins and minerals in
a flour mixture.
• If results are suspect, the sample can be submitted to a certified,
reference laboratory for further analysis.
Laboratories running quantitative tests should:
• Make a sample of standardized flour fortified with a certified level of
nutrients as a reference
• Routinely conduct a blind analysis of the reference sample to verify
laboratory procedures
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Indicator Nutrient Testing
• One premix ingredient (usually iron) is typically tested
as “indicator” of others. This is valid for premix that has
been properly designed, manufactured and mixed
• Because the ratio is constant, measuring one nutrients
can verify the delivery of the others.
• Assumes no destruction
or separation of the
indicator nutrient after
the premix was added.
Spectrophotometric test for iron
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Creating Composite Samples
A composite sample may be used to estimate the weighted
average nutrient value in a production run. For a composite
sample:
– Take 5 to 10 spot samples representative of a
production lot, such as an 8-hour run
– Collect the same sample size
– Distribute sample collection evenly over the
production time period
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Capability Study Guideline
Mills may seek external quantitative testing to determine their ability to
produce a uniformly fortified flour, meeting specifications.
• Collect individual, not composite, flour samples
• Take 7 or more samples over an 8-hour run.
• Calculate the coefficient of variation (CV). The CV is the standard
deviation divided by the mean, expressed as a percent.
• Identify the analytical error for that lab assay
Assay Error
Acceptable CV
4.9% or less
20%
5 - 9.9%
35%
10 - 15%
45%
Guidelines developed from FFI references
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Control Chart
Feeder Test Results- May 31, 2012
Running Average (N=3)
26.0
Upper
Control
Limit
25.5
g/min
25.0
Target
24.5
24.0
23.5
1
3
5
7
9
11
13
15
17
19
21
23
Lower
Control
Limit
Hour of Day
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Government’s Role in Mill Monitoring
Government authorities conduct various roles in flour fortification
monitoring, often including:
• Confirming that technical specifications, process control and quality
procedures and performance records are maintained at the mill,
packaging sites, and points of entry into the country
• Inspecting and verifying legal compliance with the country standard,
based on a quantitative assay
– Samples should contain the fortificant, and at least 80% of
samples should present the legal minimum.
– Less then 20% of the samples should have a nutrient content
above the maximum level, if one has been established.
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Plant Audits
• Off-site audit with government official reviewing
information supplied by mills
• On-site audit with government official visiting the mill to
determine if the mill is properly fortifying flour and to
validate data supplied in off-site audits
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
More Information on Quality
Control / Assurance
•
Chapter eight of the Guidelines on Food Fortification with
Micronutrients published by the World Health Organization and
the Food and Agricultural Organization of the United Nations
•
The Food Fortification Initiative at info@ffinetwork.org
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Section 6
Advocacy and Marketing
►
►
►
►
►
Fortification Regulations
Marketing Mandatory Fortification
Identify Audiences and Ensure Satisfaction
Marketing Ideas
Marketing, Logo, and Packaging Examples
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
►Marketing
Fortification Regulations
Ideally national leaders from public, private, and civic
sectors work together to establish country standards for
fortification. Among factors to consider are:
• Existing regulations
• Global and regional recommendations
• Dietary needs in the population
• Per capita flour consumption
• Extraction rate of commonly consumed flour
• Cost of premix combinations
• Effect on sensory properties
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Fortification Regulations:
Industry’s Role
• Understand and follow existing country regulations for
food fortification
• Follow best practices for quality control and quality
assurance
• Participate in national process to develop standards that
reflect industry capability
• Advocate for mandatory legislation
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Fortification Regulations:
Benefits of Mandatory Legislation
• Population has equal access to health benefits from
fortified flour, regardless of economic status
• All millers in country have the same cost expectations
• Quality assurance is easier to accomplish
More than 70 countries have
legislation for mandatory wheat
flour fortification. See the current
map and country list at:
http://www.ffinetwork.org/global_
progress/index.php
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Marketing Mandatory Fortification
The role of marketing is to ensure acceptance of
fortification.
Marketing is a joint effort of public, private and civic sector
partners.
Civic
Sector
Private
Sector
►Introduction
►Premix
► Mill Set-Up
Public
Sector
►Operations
►Quality
► Advocacy
Marketing Audience
Potential audiences for fortification messages are:
• Consumers, especially women and children who are most likely to
benefit from fortification
• Customers who purchase food for women and children
• Government leaders who influence healthcare and economic
policies
• Health advocates who provide research, education, and outreach
• Millers, bakers, and others involved in the supply chain
• Media who influence consumer decisions
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Potential Concerns
Highlight fortification’s health benefits, but be prepared to
address concerns such as:
• Product uniformity
• Market competition
• Price increase
• Change in flour’s taste, appearance, or smell
• Change in flour’s baking qualities
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Meeting Customer Expectations
Properly fortified flour will not change:
• Color and appearance
• Shelf life
• Sensory testing
• Functional qualities
Photo by Karen Codling
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Ensuring Customer Satisfaction
– World Health Organization
recommendations reflect
organoleptic properties
– Fortified foods accepted by
consumers globally
Workshop participants in Kenya conducted taste tests of
bread made with different iron compounds.
Photo by Sarah Zimmerman
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Marketing Ideas
•
•
•
•
•
•
•
•
•
Billboards
Brochures
In-store banners
Community skits
T-shirts
Calendars
Cartoons
Coupons
Rebates
►Introduction
►Premix
• Text and phone messages
• Radio and television
advertisements or interviews
• Messages on Facebook or other
social media
• Posters on trucks and buses
• Coloring contests for children
• Interactive packaging
• Give-away items
• Sponsorships of special events
► Mill Set-Up
►Operations
►Quality
► Advocacy
Marketing Examples
Billboards
►Introduction
Signs on Trucks
►Premix
► Mill Set-Up
Posters
►Operations
►Quality
► Advocacy
Fortification Logo Examples
Logos can be used to enhance awareness
Kosovo
Uganda
Regional logo used for
fortified foods in West Africa
Azerbaijan
South Africa
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Labeling Examples
Label fortified products with the additional vitamin and mineral content
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
More Advocacy Information
• Contact FFI for a advocacy toolkit: info@ffinetwork.org
• Topics to consider when setting fortification standards and writing
legislation: http://www.ffinetwork.org/plan/index.html
• Sensory tests in Asia:
http://www.ffinetwork.org/plan/documents/AsiaFoodImpact.pdf
• Sensory tests in Africa:
http://www.ingentaconnect.com/content/nsinf/fnb/2012/00000033/A0
0304s3/art00011
• More marketing examples:
http://www.ffinetwork.org/implement/documents/MarketingFlourFortif
ication.pdf
• West Africa marketing experiences at:
http://www.ffinetwork.org/implement/documents/SocialMarketing_HK
I_Experience.pdf
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy
Thank You
For more information:
www.FFInetwork.org
Contact FFI at info@ffinetwork.org
►Introduction
►Premix
► Mill Set-Up
►Operations
►Quality
► Advocacy