IODINE CONTENT OF COOKING SALTS USED IN DIFFERENT
HOUSEHOLDS IN NIGERIA (ABEOKUTA AS A CASE STUDY)
BY
NINIOLA DOYINSOLA M.
MATRIC NO 05/0055
A PROJECT REPORT SUBMITTED IN PARTIAL FULFILMENT OF THE
REQUIREMENT FOR THE AWARD OF THE DEGREE OF BACHELOR
OF SCIENCE (B.Sc)
DEPARTMENT OF FOOD SCIENCE AND TECHNOLOGY
COLLEGE OF FOOD SCIENCE AND HUMAN ECOLOGY
UNIVERSITY OF AGRICULTURE, ABEOKUTA
NOVEMBER, 2010
i
ii
DEDICATION
This project is dedicated to ALMIGHTY GOD. Who in his infinite mercy has kept me this far.
What can I ever do without Him? He is my source, strength, inspiration and for His love,
protection, guidance and direction over my life I thank Him.
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ACKNOWLEDGEMENTS
My profound gratitude goes to God Almighty, my hope, my provider, my strength, my all in all
who in his infinite mercy has kept me this far.
My unreserved gratitude goes to my amiable supervisor in person of Dr. T.A Shittu for his
fatherly support, guidance, encouragement, and constructive criticism throughout the period of
my project. Sir, you are indeed a father and ever competent.
My appreciation also goes to all my lecturers in the department of food science and technology.
I’m very grateful for all the knowledge imparted on me.
My deep appreciation also goes to my lovely parent, Mr. and Mrs. Niniola for their support
financially, morally, and spiritually. I pray that God will continue to protect you. May you live
long to eat the fruit of your labour in good health. (Amen).
To my ever supportive siblings Akinola, Damilola, Ajibola, Bukola, Mayowa, and my lovely
sisters, Kemi and Biola. I love you all.
I will also like to appreciate the entire staff of Biotechnology centre UNAAB, God bless you all
My appreciation also goes to Lawal’s family, thank you all for you support.
To my project mate; Deebam, Peju, Tallest, Olayinka, Wunmi, you guys are really wonderful.
Also to my friends, Deola Babatunde, Akegbejo- Samsons Oluwatoyin, Olunlade Tope and to all
my departmental mates. Thank you for been there.
I will also like to appreciate people like; Ganiyat, Daramoye, my roomates (C6), Busayo, Festus
(Clerk), Odunayo, Olaide, Renny, Tolu and Bunmi (T&B), Adeoye, Damola, Abdullahi.You all
are wonderful.
I am greatly indebted to a friend, comforter, my one and only, and my best-half, in person of
Lawal Raman Akinyanju. Thank you so much for the love and sacrifice, am so fulfilled by
meeting you and I pray we will be together forever. I love you and I will always do.
Finally, to all my well wishers. You are the best and God will bless you all.
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TABLE OF CONTENTS
TITLE PAGE
i
CERTIFICATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
TABLES OF CONTENTS
v
LIST OF TABLES
vii
LIST OF FIGURES
viii
ABSTRACT
ix
CHAPTER ONE
1.0 Introduction
1
CHAPTER TWO
2.0 Literature review
4
2.1 Definition of salt
4
2.2 History of salt
4
2.3 Sources of Salt
6
2.4 Properties of salt
9
2.5 Essential composition and quality of salt
9
2.6 Definitions and standards of quality
10
2.7 Salt iodization
12
2.8 Stability of iodine in salt
13
2.9 Effect of packaging material and storage on iodine loss in salt.
14
2.10 Functions of salt
15
2.11 Salt deficiency: the cause of many serious diseases.
17
2.12 Salt storage.
19
2.13 Salt packaging and distribution
20
2.14 The end uses of salt.
21
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CHAPTER THREE
3.0 Materials and methods
23
3.1 Materials
23
3.1.1 Sampling procedure
23
3.2 Methods
24
3.2.1 Determination of moisture content.
24
3.2.2 Determination of iodine content
24
3.2.3 Determination of bulk density
25
3.2.4 Determination of pH
25
3.2.5 Determination of Water Insoluble matter
26
3.3 Statistical analysis
26
CHAPTER FOUR
4.0 Results and discussion
27
4.1 Manufacturing information
27
4.2 Physical and chemical properties
27
4.3 Classification
29
CHAPTER FIVE
5.0 Conclusion and recommendation
34
5.1 Conclusion
34
5.2 Recommendation
34
REFERENCES
35
APPENDIX I
37
APPENDIX II
38
APPENDIX III
39
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LIST OF TABLES
Tables
Pages
Table1: Properties of pure sodium chloride
11
Table 2: Physical and chemical properties of salt samples
30
Table 3: Result of analysis for factory samples
32
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LIST OF FIGURE
Figure
Page
Figure 1: Bi-plot for grouping the salt samples based on iodine
and moisture content.
33
viii
ABSTRACT
Fifty samples of edible salts used in different households in Nigeria (Abeokuta as a case study)
plus three factory samples were studied for their physical characteristics and chemical
constituents. The salt samples were analyzed for moisture content, bulk density pH, iodine
content, and water insoluble matter. Anapunna salt was the most popular brand found in all the
households visited. Based on the Codex standard, most of the salt samples collected had
moisture contents greater than could make them get classified as either table or cooking salt
(moisture content above 4.0%). The pH of the salts was below neutral level indicating the
presence of acidic contaminants and also, the iodine content of the salts reduced with age.
By applying the principal component analysis, moisture content and bulk density varies most
among the samples which makes the parameters different from each other and therefore,
ANOVA (separation of variables) was used to determine the mean of the parameters. Bi-plot was
also used between the iodine content and moisture content which was used to group the salt
samples into three; table salt (0.1-0.6%max.), cooking salt (1.0-4.0%max.), and unclassified
(above 4.0%).
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CHAPTER ONE
1.0
INTRODUCTION
Salt is the crystalline product consisting predominantly sodium chloride (97%) obtained from the
sea like and underground rock salt deposit from natural brine, (Mannar et al., 1995). The grain
size does not exceed 2.0 mm and the maximum moisture is 5.0% (Herrodor et al., 1998). It is a
food item other than water which is universally consumed.
Aside from its seasoning properties, common salt (sodium chloride) historically has been
considered as having value as a food. Salt was the first antimicrobial chemical to be used. It was
its use as preservative rather than as a flavouring agent that gave it its value to early civilizations
(Coultate, 1984). Today, salt levels in the human diet are very important since excessive amounts
of salt have been related to physiological conditions such as high arterial pressure.
The primary sources of salt are either from natural brines, sea, or from underground rock salt
deposits. In which the salt is obtained by solution mining and then concentrated by vacuum
evaporation. Common salt contains essentially sodium chloride and other naturally present
constituents and contaminants such as calcium, potassium, magnesium and sodium sulphates,
carbonates, bromides and of chlorides as well as copper, lead, arsenic, cadmium and mercury,
whose concentrations vary depending on the origin and the method of production of the salt.
Other constituents found in commercial salt samples include nitrate or nitrite (curing salt), iron,
fluoride, iodide or iodate, vitamins and additives which are used to carry or stabilize such
additions.
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In the salt manufacturing industry, vacuum drying is a major unit operation that gives rise to two
types of product; undried salt (2-5% residual moisture) and the pure dried vacuum (≤ 0.5%
residual moisture). The latter is regarded as the edible type of salt found in food market.
Refined edible salt may be categorized as belonging to one of the three principal denominations
including table salt, cooking salt, and special salt. Table salt is a refined salt with a grain size not
exceeding 2.0mm, moisture of 0.5% and sodium chloride content not less than 97% on a dry
basis. Cooking salt is similar to table salt but with a maximum moisture of 5.0%. Special salts
are refined salts containing added substances allowed by the regulatory agency and within this
denomination, dietary salt are of particular relevance. The dendrites salt is a vacuum salt in the
form of fine branched or star-like crystals containing one or more ferrocyanide salts which have
rapid solubility and a high capacity for holding moisture with a moisture level of about 1.5-4%
(Kirk et al., 1991).
Retailers differ in terms of the manner of handling salt at their ends. The salts are commonly
displayed in open air as heaps in plastic or metallic containers. This exposes them to
contaminants and extraneous matter like sand and wood particles, rain, heat, excessive humidity,
foreign metals, sunlight etc. The salts stored under the roof or outside, are not stored with an
impermeable pad or packaging material thereby exposing the salts to moisture which could lead
to caking of the salt. Also, retailers adulterate a branded salt with another. Although, this may not
have a direct economic gain but to balance up product quality of old stock of salt thereby
sustaining patronage and indirectly avoid losses that are attached. Some retailers adopt the
principle of ‘‘first in, first out ’’ to alleviate this problem.
Considering the manner in which salt is traded on the street in the country, it appears food
regulatory actions have not been strictly extended to salt retailing in terms of the common levels
2
of metallic elements that are present in salt. Also, there are about five (5) major salt factories in
Nigeria that concentrate on either refining raw salt from foreign manufacturer or iodize and
package an already refined salt.
In some countries (including Nigeria) iodine is mandatorily added to cooking salt to combat the
problem of Iodine Deficiency Disorders (IDD). The compound used in iodization determines the
stability of iodine after processing. Basically, potassium iodate and potassium iodide are used.
The high solubility of potassium iodide enables dispersion by atomized spray on the dry crystals.
However potassium iodide enables dispersion by atomized spray on the dry crystals. However
potassium iodide in salt is not very stable. It can be easily lost by oxidation to iodine if the
iodised salt is subjected appreciably to any of these conditions: higher moisture in the salt,
humidity or excessively aerated environment, exposure to sunlight, exposure to heat, acid
reaction in the salt, presence of impurities, damped packaging material. Research has shown that
using potassium iodate stabilizes the iodine content of the salt than potassium iodide (Mannar et
al., 1995).
Since various household keeping practices affects the stability of iodine content in salt, there is a
need to analyse salt used in different households to ascertain whether the consumers are still
consuming sufficient quantity of iodine needed for the body. Therefore, the objectives of this
research work are:
i.
To determine various household practices of keeping salts using structured questionnaire.
ii.
To determine some physical and chemical constituents of household salt samples, so
from various household.
iii.
To link the analytical results of physical and chemical constituents to the way salt is kept
in different households and its effect on quality.
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CHAPTER TWO
2.0
LITERATURE REVIEW
2.1
Definition of salt
Sodium chloride or common salt is the chemical compound NaCl composed of the elements
sodium and chloride. Salt occurs naturally in many parts of the world as the mineral halite and as
mixed evaporates in salt lakes. Sea water has lots of salt; it contains an average of 2.6% (by
weight) NaCl, or 26 million metric tonnes per cubic Kilometre. Sea water also contains other
dissolved solids; salt represent about 77% of the Total dissolved solids. Underground salt
deposits are found in both bedded sedimentary layers and domal deposits. Deposits have been
found to have encapsulated ancient microorganisms including bacteria. Some salt is on the
surface, the dried-up residue of ancient seas like the fained Bonneville Salt Flats in Utah. Salt
even arrived on earth from outer space in meteors and its preserve on the planet mars. Scientists
think life may exist there (in fact, scientists speculate that salt-loving bacteria live in
underground water on mars – as they have survived in suspended animation for 250 million
years in Texas). Conversely, surface salt deposits and man-made salt works can be seen from
space. In ocean coastal areas, salt water can intrude on underground fresh water supplies
complicating the lines of those who provide our drinking water supplies (Institute of food and
agricultural science Journal, University of Florida, 1985)
2.2
History of salt
The sodium chloride, the common kitchen salt, and the sodium carbonate are known since
antiquity. The first is probably a vital need and it was probably used in the food since
immemorial times, while the second, besides occurring naturally, constitutes a considerable
4
portion of the ashes of marine algae, being already known and used by the ancient Egyptian.
Metallic sodium was first isolated by Sir Humphrey Davy in 1807 using the electrolysis of solid
sodium hydroxide. At that time, sodium and potassium hydroxides were considered elementary
substances and were called fixed alkalis (Mamantov and Marassi, 1987). The history of salt is
also dated to the existence of religion where there are thirty –two references to salt in the bible,
the most familiar probably being the story of Lot’s wife.
Salt’s preservative ability was a foundation of civilization. It eliminated dependency on the
seasonal availability of food and allowed travel over long distances. By the middle Ages,
caravans consisting of as many as forty thousand camel’s transverse four hundred miles of the
Sahara bearing salt, sometimes trading it for slaves. Until the 1900’s salt was one of the prime
moners of national economics and wars. Salt has played a prominent role in determining the
power and location of the world’s great cities. Timbuktu was once a huge salt market. Liverpool
rose from just a port to Ireland to become the prime producer of the world’s salt in the 1800’s.
Salt created and destroyed empires. The salt mines of Poland led to a vast kingdom in the 1800’s,
only to be destroyed when Germans brought sea salt (often, to most of the world, considered
superior to rock salt). Venice fought and won a war with Genova over salt. Genova, however,
had a last laugh. Genovites Christopher Columbus and Giovanni Caboto destroyed the
Mediterranean trade by introducing the new world to the market.
Salt was once one of the most valuable commodities known to man. Salt was taxed, from as far
back as the 20th century BC in China. In the Roman Empire, salt was sometimes even used as a
currency, given us the term salary. The Roman republic and empire controlled the price of salt,
increasing it to raise money for wars, or lowering it to be sure that the poorest citizens could
5
easily afford this important part of the diet. Throughout much of history, it influenced the
conduct of wars, the fiscal policies of governments and even the inception of revolutions.
In the empire of Mali, merchants in 12th - century Timbuktu- the gateway to the Sahara desert
and the seat of scholar’s valued salt enough to buy it for its weight in gold, this trade led to the
legends of the incredibly wealthy city of Timbuktu, and fuelled inflation in Europe, which was
exporting salt. In later times, for instance during the British colonial period, salt production and
transport were controlled in India as a means of generating enormous tax revenues. This
ultimately led to a march led by Mahatma Gandhi in 1930 in which thousands of Indians went to
the sea to illegally produce their own salt in protest of the British tax on salt. With the British in
control of salt works in the Bahamas and North American cod, there sphere of influence quickly
covered the world. The search for oil in the late 1800’s and early 1900’s used the technology and
methods pioneered by salt miners, even to the degree that they looked where salt domes located
for oil (Anonymous, 2003).
2.3
Sources of Salt
Salt can be obtained most simply by collecting it from natural evaporation pans, such as rock
crevices along dry coastlines, or in salt pans in desert regions. It is short step to constructing
dikes to make larger shallow pans along coasts, and then to heating salt water in pots. It does
take a deal of energy to evaporate salt water to yield salt. Along sunny dry coastlines, solar
energy is free to the patient person. But in wetter, cooler areas, salt water must be heated to
evaporate and the cost of fuel may become the dominant element in the economics of production
(Mannar and Dunn, 1995).
However, in land there are occasional salt springs, and natural outcrops of salt – bearing rocks.
Natural salt springs often yield brines that are more concentrated tan sea water, and yield purer
6
salt (Sodium chloride) than sea water brines. The differences can be crucial because the
magnesium chloride present in small quantities in sea salt can actually slow down the rate at
which meat is salted and therefore prevented from decay. Sea water can be processed to extract
the magnesium as the brine in boiled, but that takes skill, labour and fuel. Natural salt from
springs usually had a competitive edge over sea salt. The relative gravity of salt springs often
provided an important geological resource to an inland community or area. For example Austria
and Germany happen to have many outcrops of salt-bearing rocks, particularly fortunate
circumstances in an inland region with a generally damp climate. Names containing “Salz” and
“halle”, such as Salzburn (salt city”), Salzkammergut, Reichenhall Halle, Hallein and Hallstatt as
well as the old Austria / polish province of Galicia, identify some of the salt-bearing areas.
The Maya made salt at Salinas de los Nnene Cerros, Guatamcia. This site lay where salt springs
flowed into the river, giving easy trading access to downstream customers. This site was the only
large-scale source of salt for the interior lowland Maya. The technology includes solar
evaporation and firing of brine from salt springs in special ceramic bowls that are the largest ever
found in Maya sites. The highly organized salt trade of china was observed by Marco polo, who
recorded that the major item of trade on the Yangtze River was salt, shipped upstream from the
coast (especially from the city of Hangehon) to the interior cities. The Chinese produced salt by
many methods; they evaporated it, boiled seawater and pumped brine from wells drilled into salt
beds. Modern-drilling traces its technological roots back to Chinese methods originally evolved
for salt production (Mannar, 1995).
Salt sources was traced to the medieval and renaissance Europe and inland Europe when central
Europe lacked the access to shipping routes that made an international salt trade possible round
the coasts of northern Europe. Salt could be economically transported only over short distances
7
and local sources of salt became important commercial centre often wielding a good deal of
political power. From about 1000BC onward and possibly since 2500BC, and may be for
unrecorded millennia before that, a brisk salt-mining and salt shipping trade was centred on the
valley of the Salzkammergut, in what is mow Austria. The surface deposits were worked out by
1000BC, and the salt miners drove galleries 400 metres into the mountain side reaching depths
below the entrances of 100 m.
The great salt center of Reichenhall, in Southern Bavaria, operated in Roman times, but was
destroyed later, possibly by Attila the Hun but more likely by German Odoacer a great deal of
power and money from the salt trade. About 1190, however, someone opened a competing salt
works at Berchtes garden nearby, without the Archbishop’s approval and a major quarrel
between churches lost, and in 1198 the Bavarian salt works passed into the control of the duke of
Bavaria. Reichenhall’s production peaked at about this time, and it lost out in competition with
the new salt works. Thwarted in Bavaria, the Archbishop of Salzburg turned to salt springs closer
by and a new industry sprang up at Hallein in 1232. Salt production was always limited in
Austria by fuel shortage and salt played a great part in the politics of the region after 1600. Salt
was produced by three major players, Austria, Bavaria, and the Archbishop of Salzburg.
The great trading ports of the Mediterranean dealt in salt as well as spices and textiles. Not
surprisingly, the greatest of them, Genoa and Venice, not only traded in salt but fought for
supremacy over the trade. Salt can be made in almost any suitable seashore locality in the
Mediterranean. Although it is possible to envisage a trader’s cartel, it is much more difficult to
control the production of salt. It is astonishing how effectively Genoa and especially Venice
managed to take control of production as well as trading (Mannar, 1999).
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2.4
Properties of salt
Sodium chloride is readily soluble in water and insoluble or only slightly soluble in most other
liquids. It forms small, transparent, and colourless to white cubic crystals. Sodium chloride is
odourless but has a characteristic taste. It is an ionic compound, being made up of equal numbers
of positively charged sodium and negatively charged chloride ions. When it is melted or
dissolved in water, the ions can move about freely, so that dissolved or molten sodium chloride is
a conductor of electricity, it can be decomposed into sodium and chlorine by passing an electrical
current through it. Sodium chloride is the salt most responsible for the salinity of the ocean and
of extra cellular fluid of many multi-cellular organisms. Sodium chloride also varies in colour
from colourless, when pure, to white, gray or brownish, typical of rock salt (halite). Chemically,
it is 60.663% elemental chlorine (Cl) and 39.337% sodium (Na). The atomic weight of elemental
chlorine is 35.4527 and that of sodium is 22.989768 (Mamantov and Marassi 1987).
2.5
Essential composition and quality of salt
The content of sodium chloride (NaCl) in salt shall not be less than 97% on a dry matter basis,
exclusive of additives as the major constituents of common salt. The remainder comprises of the
naturally present secondary products, which are present in varying amounts depending on the
origin and the method of production of the salt, and which are composed mainly of calcium,
potassium, Magnesium chlorides as well. Natural contaminants may also be present in amounts
varying with the origin and the method of production of the salt.
Food grade salt may also contain mixture of salt with nitrate and/or nitrate and salt mixed with
small amounts of Fluoride, Iodide or Iodate, Iron, Vitamins etc and additives used to carry or
9
stabilize such additions when the salt is used as a carrier for food additives or nutrients for
technological or public health reasons.
The production of food grade salt shall only be performed by reliable manufacturers having the
knowledge and the equipment requisite for the adequate production of food grade salt, and
especially for the correct proportion of constituents and even intermixing (Codex Standard,
2001).
2.6
Definitions and standards of quality
EDIBLE COMMON SALT: means a crystalline solid, white, pale pink or light grey in colour,
free from visible contamination with clay, grit and other extraneous adulterant and impurities.
IODISED SALT: is a crystalline solid, white or pale, pink or light grey in colour, free from
contamination with clay, grit and other extraneous adulterants and impurities.
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Table 1: The properties of pure sodium chloride
Parameters
Value
Molecular weight NaCl
54.4428
Atomic weight- Na
22.989768 (39.337%)
Atomic weight –Cl
35.4527 (60.663%)
Euctetic composition
23.31% NaCl
Freezing point Euctetic mixture
-21.120C (-6.0160F)
Crystal form
Isometric, cubic
Colour
Clear to white
Index of refraction
1.5442
Density of Specific gravity
2.165 (135lb/ft3)
Bulk density approx. dry
1.154 (7216 lb/ft3)
Angle of repose (dry)
32º
Melting point
800.8ºC (1,473.4ºF)
Boiling point
1,465ºC (2,669ºF)
Hardness (Moh’s scale)
2.5
Critical humidity at 20ºC (68ºF)
75.3%
pH of aqueous solution
Neutral
Source: (Marassi R., 1990), www.saltinstitute.org
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POTASSIUM IODATE SALT: means a crystalline powder, white in colour, free from
impurities.
IRON FORTIFIED COMMON SALT: means crystalline solid, white or pale, pink or light grey
in colour, free from visible contamination with clay and other extraneous adulterants and
impurities.
2.7
SALT IODIZATION
Every healthy man needs iodine, an essential component of thyroid hormones: thyroxin and
triodothyonine which are important in regulating of the basal metabolic rate. Inadequate iodine
leads to insufficient production of the hormones resulting in adverse effect of many parts of the
body especially the muscle, heart, liver, kidney and brain development. This state is known as
Iodine Deficiency Disorders (IDD). The symptoms of IDD include goitre (enlarged thyroid)
mental, physical sluggishness, growth retardation, reproductive failure etc (Mannar et al., 1995
and Kenji et al., 2003).
Since human universally consume salt in small fairly constant amount daily, salt becomes an
ideal vehicle to deliver physiological amount of micronutrients like iodine to the population at
large (Delange et al., 2002 and Diosady et al., 1998). Although iodine is a constituent of sea
water, it is not correct to assume that sea salt contains sufficient iodine for nutritional purpose.
The small quantity of iodine (3 ppm) in sea water is mostly lost in the residual mother liquor
drained during production process (Mannar et al., 1995).
The use of salt as a carrier of iodine began in 1920’s at U.S. A. and Switzerland, and now
successful in these countries (Delange et al., 2002). The awareness of salt iodization is recent in
12
Africa. The programme has been strengthened and initiated also in Nigeria using potassium
iodate (KIO3) with the dosage of 50 mg/kg iodine (i.e. 84.25 mg/kg KIO3) (Mannar et al.1998).
Potassium iodate is more stable under adverse climatic conditions than iodide. It is also less
soluble than iodide and less likely to migrate from the bag. Also, iodate breaks down rapidly in
the human body and effectively delivers iodide to thyroid gland for the synthesis of thyroid
hormones (Mannar et al., 1998).
2.8
Stability of iodine in salt
Several countries are successful in their salt iodization programme while many developing
countries still have a setback. Generally the stability of iodine in edible salt is influence by a lot
of factors:

Variations in amount of iodine added during production.

Uneven distribution within batches or individual bags produced due to poor mixing.

Losses in distribution, retail, in the house (during storage) and meal preparation
(cooking).

Primitive method of salt production leading to poor salt quality (impurities) which
contributes to moisture absorption and leaching of iodine from the salt.

Inadequate packaging.

Exposure to high relative humidity, light, moisture content in impurities.
Diosady et al., 1998 discovered that high humidity resulted in rapid loss of iodine from salt
iodized with potassium iodate with 30% - 98% loss of original iodine content. Although with no
13
clear correlations, the researchers observed most adverse effect on the stability of iodine due to
the presence of reducing agents and hygroscopic compound of magnesium whereas carbonates
had little effect on the stability. They also observed that using low density polyethylene in salt
packaging encourages iodine stability (6 month – a year). However, woven high density
polyethylene bags allowed moist air into the salt thus releasing its iodine as vapour since
moisture played an important role in the iodine stability.
Biber et al.( 2002) concluded that iodine loss was 41.16% by heating at 200ºC for 24hours.
When heated in an oxidized agent, iodine loss rose up to 46% in 24hours long storage (3.5 years)
at room temperature and relative humidity of 30% - 45% in seal paper bag losses 58.5% of initial
iodine content.
From (Kenji et al., 2003) research work it was shown that some manufacturers were fortifying
salt with less or more iodine than claimed and recommended. He suggested that the reduction in
iodine content could be traced to retailers’ handling after iodization, adulteration or
environmental factors.
It was recommended that the addition level of iodine be based on assumption of 50% iodine loss
between iodization and consumption (Mannar et al., 1995).
2.9
Effect of packaging material and storage on iodine loss in salt.
The main objective of salt iodisation program is to ensure that salt contains the recommended
amount of iodine at the time of consumption. The retention of the iodine depends on iodine
compound used, the type of packaging material, exposure to the prevailing climatic condition
and time between iodisation and consumption. The permitted compounds for fortification are
14
sodium and potassium iodides or iodates (FAO/WHO, 2001). Salt has been shown to be
hygroscopic at relative humidity above 76%, hence iodized salt that is improperly packed and
transported over long distance under humid conditions attracts moisture and becomes wet,
carrying the iodate to the bottom of the bah. At humidity lower than 76%, salt can release surface
moisture and this also may, result in some iodine loss. If the bag is porous, the iodine compound
can leak so that little or no iodine is left in the salt by the time it reaches the consumer. To reduce
this loss, iodised salt should be packed in air tight bags of either high density polyethylene
(HDPE) or polypropylene (PP) laminated or non laminated or low density polyethylene – lined
jute bag (Grade 1803 DW ), jute bags lined with 150 gauge polyethylene sheet (FAO/WHO,
2001).
The distribution network should be streamlined so as to reduce the interval between iodisation
and consumption. Iodised salt should not be exposed to rain, excessive humidity or direct
sunlight at any stage of storage, transportation or sale.
Bags of iodised salt should be stored only in covered rooms or “godowns” that have adequate
ventilation. The consumer should be similarly advised to store iodised salt in such a manner as to
protect it from direct exposure to moisture, heat and sunlight.
2.10
Functions of salt
Salt is a vital substance for the survival of all living creatures particularly humans. Water and salt
regulate the water content of the body. Water itself regulates the water content of the interior of
the cell by working its way into the entire cell it reaches. It has to get there to cleanse and extract
the toxic waste of cell metabolisms. Salt forces some water to stay outside the cells. It balances
15
the amount of water that stays outside the cells. There are two oceans of water in the body; one
ocean is held inside the cells of the body and the other ocean is held outside the cells. Good
health depends on a most delicate balance between the volume of these oceans, and this balance
is a achieved by salt.
When water is available to get inside the cells freely, it is filtered from the outside salty ocean
and injected into the cells that are being over worked despite their water shortage. This is the
reason why in severe dehydration we develop an edema and retain water. Naturally, salt intake
should be limited for two or three days because the body is still in an over drive mode to retain it.
Once the edema has cleaned up, salt should not be withheld from the body.
Salt has many other functions than just regulating the water content of the body which are as
follows:

Salt is most effective in stabilizing irregular heartbeats and contrary to the misconception
that it caused high blood pressure, it is actually essential for the regulation of blood
pressure in conjunction with water.

Salt is vital to the extraction of excess acidity from the cells in the body, particularly the
brain cells

Salt is vital for balancing the sugar levels in the blood; a need element in diabetes.

Salt perform the function of generation of hydroelectric energy in cells in the body. It is
used for local power generation at the site of energy needed by the cells

Salt is essential to the nerve cells communication and information processing all the time
that the brain cells work, from the moment of conception death

Salt is essential for absorption of food particles through the intestinal tract

Salt is also essential for the clearance of lungs of mucus plugs and sticky phlegm,
particularly in asthma and cystic fibrosis.
16

Salt also help in the cleaning up catarrh and congestion of the sinuses

Salt is a strong natural anti histamine

Salt is essential for the prevention of muscles cramps

Salt is vital to prevent excess saliva production to the point that it flows out of the mouth
during sleep. Needing to constantly mop excess saliva indicates salt shortage.

Salt is absolutely vital to making the structure of bones form. Osteoporosis, in a major
way, is a result of salt and water shortage in the body.

Salt is vital for sleep regulation. It is a natural hypnotic

Salt on the tongue will stop persistent dry coughs

Salt is vital for the prevention of gout and gout arthritis

Salt is vital for maintaining sexuality and libido

Salt is vital for preventing varicose veins and spider veins on the legs and thighs

Salt is vital for reducing a double chin (Batmenghelidj, 1999).
2.11
Salt deficiency: the cause of many serious diseases.
Both sea salt and rock salt were well known to the ancient Greek who noted that eating salty
food affects basic body functions such as digestion and excretion (Urine and Stools). This led
to salt being used medically. The healing methods of Hippocrates (460 BC) especially made
frequent used of salt. Salt- based remedies were thought to have expectorant powers. A
mixture of water, salt and vinegar was employed as an emetic. Drinking a mixture of twothirds cow’s milk and one-third salt water, in the morning on an empty stomach was
recommended as a cure for disease of the spleen. A mixture of salt and honey was applied
typically to clean bad ulcers and salt water used externally against skin disease and freckles.
Hippocrates also mention inhalation of steam from salt water. We know today that the anti
17
inflammation effects of inhaled salt provide relief from respiratory symptoms. Thus, 2000
years ago, Greek medicine had already discovered typical use of salt for skin lesions,
drinking salty or mineralized water for digestive troubles and inhaled salt for respiratory
diseases (Anonymous, 2010).
The doctor and alchemist Paracelsus (1493-1541AD) introduce an entirely new media
concept. He believed that external factors create disease and conceived a chemical oriented
medical system which contrasted with prevalent herbal medicine. He recommended salt
water for the treatment of wounds and for use against intestinal worms. A hip-bath in salt
water was a superb remedy for skin diseases and itching. The diuretic effect of salt
consumption was also described.
In recent years there has been much publicity about the need to reduce consumption in
societies where salt is added to many processed food (Denton, 1984). It has tended to be
forgotten that some salt intake is absolutely necessary; that people need salt, sodium chloride,
to survive: the chemical requirement of the human body demand that the salt concentration in
the blood be kept constant, if the body does not get enough salt, a hormonal mechanism
compensate by reducing the excretion of salt in the urine and sweat, but it cannot reduce this
output to zero. On a completely salt free diet, the body steadily loses small amount of salt via
the kidneys and sweat glands. It then attempts to adjust this by accelerating its secretion of
water, so that the blood salt concentration can be maintained at the vital level. The result is a
gradual desiccation of the body and final death (Moxham, 1995). An abundance of the
ingredients in unrefined salt are as synonymous with life today as they were a billion years
ago before single cell appeared here. Lack of them is synonymous with birth defect, organ
failure, decay, diseases, premature ageing and death at young age (Marassi, 1990).
18
2.12
Salt storage.
The loss to moisture from the air can be prevented if salt is stored properly. Salt does not
absorb moisture until the humidity reaches 75%. Any absorbed moisture will evaporate when
the humidity falls below 75%. Any resulting thin crust on the surface of the salt is then easily
broken up. Salt however can be lost to precipitation. Salt in piles or bags, whether large or
small, should never be left exposed to rain or snow. A permanent under roof storage facility
which must be economical, availability and convenience is best for protecting salt. Outside
piles can also be built and covered with temporary waterproof materials such as tarpaulins
and polyethylene. Salt storage piles must be covered in order to prevent possible detrimental
effects to the environment. Runoff should be properly controlled. Salt should be stored in a
roofed enclosure in order to prevent formation of lumpy salt, eliminate the possibility of
contaminating streams and wells with salt run off and also eliminate salt loss through
dissolving and run off. Salt should also be prevented from precipitation so that washing off of
anticaking agents meant for salt free flowing from the outer layer of salt. Areas around the
under roof covered storage that is building must be well lighted for safe night time operations
and lights must be placed inside the building as well.
In summary, good storage of salt is extremely important. Protection of the surrounding,
environment and the salt itself, and ease of handling salt, are necessary and can be ensured
through proper storage. Good planning is essential to good storage, and proper storage is the
vital part of sensible salting (Marassi R, 1990).
19
2.13
Salt packaging and distribution
The main objective of salt packaging is to ensure that salt contains the necessary constituent
that it was meant to contain such as NaCl, iodine, anticaking agent, inorganic metals etc at
the time of consumption. The retention of all this constituents and additives in salt depends
on the compound used as in iodine compound, the type of packaging and packaging material,
the exposure of the package to prevailing climatic condition and the period between
production and consumption. Loss of these constituents can be avoided by observing the
following precautions:

The salt should be packed in airtight bags of the appropriate packaging materials.

Bulk packaging unit should not exceed 50 kg (in accordance with international labour
organization) to avoid the use of hooks for lifting the bags.

Bags that have already been used for packaging other articles such as fertilizers,
cements, chemicals etc should not be reused for packaging salt.

The distribution network should be streamlined so as to reduce the interval between
production and consumption of salt.

Salts should be packed in retail pack packaging of 1/10 – 1 kg polyethylene bags with
proper sealing of bags to prevent exposure to the surrounding.

Proper labelling of both bulk and retail bag with adequate information is also
necessary.
Salt in most countries is produced by many small manufactures and few medium or large ones,
and is transported by all available modes, including road, rail, sea and river. The bags must be
protected from moisture, dust, and heat during transportation. The producers or refiners ship salt
20
in bulk bags of 50 kg or in cartons containing a number of packs of a fraction of 1 kg to
wholesalers who in turn distribute the salt to retail outlets (Mannar and Dunn, 1995).
2.14
The end uses of salt.
Besides making food delicious, it is believed that there are more than14, 000 uses of salt, and our
grandmothers were probably familiar with most of them. Many of these uses were for simple
things around the home before the advent of modern chemicals and cleaners. However, many
uses are still valid today and a lot cheaper than using more sophisticated products. The most
familiar use of salt undoubtedly is in the kitchen where it is used to accent the flavour of meat,
brings out individuality of vegetables, put “oomph” into bland starches, deepens the flavour of
delicate desert, develop flavours of melons and other fruits. It is also used in the kitchen to boil
water, peel and poach eggs, test egg freshness, prevents browning, shell pecans, wash spinach,
prevent sugaring, crisping salads, improve boiled potatoes etc.
Salt is also an excellent cleaning agent by itself or in combination with other substances. A
solution of salt and turpentine restores the whiteness to yellowed and enamelled bathtubs and
lavatories. A paste of salt and vinegar cleans tarnished brass or copper. It is also used in cleaning
greasy pans, stained cups, ovens, refrigerators, tarnished silver ware, coffee pots, sink drains,
wicker and grease spot on rugs. It is use to extend broom life, remove wine stains, extinguish
grease fire, improve coffee and poultry, remove pinfeathers, and onion odours from hand,
sweetening containers, to brighten cutting boards, to fix oversalted soups and to prevent food
from sticking, keep milk fresh and setting gelatin (Marassi, 1990).
Salt helps destroy moths and drives away ants, it prevent mould, a dash of salt laundry starch
keeps the iron from sticking and gives linen and fine cottons a glossy -like new finish. A thin
paste of salt and salad oil removes white marks caused by hot dishes or water from wooden
21
tables. It also helps to restore sponges, set suds, brighten colours, remove perspiration stains,
remove blood stains, mildew or rust stains, colour match nylons etc.
Salt is also used in health and beauty where a box of salt is an important item in many
bathrooms. In mild solutions, it makes an excellent mouth wash, throat gargles, and eye wash,
also for cleaning teeth. It is an effective dentifrice, it is an effective antiseptic, and it can be
extremely helpful as a massage element to improve complexion. It also helps to relief bee stings,
tired feet, treat mosquito, chigger bites and poison ivy, it is used to relief fatigue, remove dry
skin and tattoos (Marassi, 1990).
Salt can also be used in aquacultures to clean fish tank, invigorate gold fish and to transport or
handle fish. It can also be used as parasiticides to prevent and treat brown blood disease. Other
uses of salt are to drip proofing candles, removes soot, clean flower vases, keep cut flower fresh,
hold artificial flowers, and to keep patios weed free. Salt is also used in the dicing of sidewalks
and driveways, keep windows frost free and in the deodorizing of shoes (Francis-Floyd, 2000).
22
CHAPTER THREE
3.0
MATERIALS AND METHODS
3.1
MATERIALS
3.1.1 Sampling procedure
Fifty different common salt samples were collected from different households in Abeokuta
(majorly Obantoko, Odeda and Isale-Ake) while three samples were collected from the point of
production from different manufacturers as follows:
a) Obantoko area; Three brands of salt were identified in this area while others are of no
brand. A total of twenty samples were collected of which fourteen samples were branded
while the remaining six were of no brand. Majority of the samples were kept in a plastic
closed container except for one sample which was kept in an opened plastic container and
also, a sample was kept in the packaging material. The samples were then subjected to
analysis.
b) Odeda area: Three brands of salt were also identified and others are of no brand. A total
of fifteen samples were collected of which eight samples are branded while the remaining
seven samples are not branded. Majority of the samples was kept in a closed plastic
container except for one sample which was kept in the packaging material and also, a
sample was kept in a closed glass container. The samples were then subjected to analysis.
c) Isale-Ake area: A total of fifteen samples were collected, three brands were also
identified of which nine were not branded and six samples were branded. Majority of the
samples were also kept in a closed plastic container but five samples were being kept in
the packaging material and also, a sample was been kept in an opened plastic container.
The samples were then subjected to analysis.
23
d) Point of production (Lagos state): Three samples of salt were collected from three
different manufacturers at the point of production for analysis.
3.2
METHODS
3.2.1 Determination of moisture content.
Moisture analysis was carried out using AOAC by weighing 5 g quality of salt into a Petri dish
and was dried in an oven at 105oC for 4 hours. The dried salt was transferred into a desiccator
until it’s cooled, and then it was weighed. The weight loss expressed as a percentage was taken
as percent moisture. The result was obtained as the average of two independent determinations
(AOAC, 2000).
 W - W2
Moisture content (%)  100 *  1
 W1



Where:
W1= weight of sample ± Petri dish before drying
W2=Weight of sample ± Petri dish after drying
W1=Weight of sample
3.2.2 Determination of iodine content
Ten grams (10 g) of salt was dissolved in approximately 100 ml of distilled water. The pH was
adjusted to 2.8 using 0.6% HCl 30 mg of potassium iodide powder was added to convert all of
the iodate present to elemental iodine.
24
KIO3 + 5KI + 3H2O
3I2 + 6KOH
The liberated iodide was titrated with 0.004M freshly prepared sodium thiosulphate solution,
using starch (freshly prepared) as the end point indicator.
I2 + 2S2O3-2 (aq)
2I-(aq) + S4O6-2
Iodine content was calculated using standard conversion table for iodine determination.
3.2.3 Determination of bulk density
Bulk density analysis of the salt samples was carried out according to AOAC (2000) by
weighing 30 grams of salt into a 50 ml measuring cylinder. Making sure the salt is at uniform
level in the cylinder. The measuring cylinder was then gently tapped on the table to about 125
tappings in which at this point no more compactness or reduction in the level of the salt in the
measuring cylinder is observed. The reading of the salt level on the measuring cylinder is
observed. The reading of the salt level on the measuring cylinder was taken and it was expressed
in g/ml or g/cm3. The result was obtained as the average of two independent determinations.
3.2.4 Determination of pH
The pH analysis of the salt samples was determined by weighing 1 gram of the salt into a 10 ml
of distilled water. This was properly mixed to dissolve and then the pH reading was taken using
the mettler delta 340 pH meter after proper calibration of the electrode. The result obtained was
the average of duplicate determination. (AOAC, 2000).
25
3.2.5 Determination of Water Insoluble matter
This was determined by weighing 4.5-10 grams of the salt sample into a 250 ml beaker. Add
about 200-500 ml of freshly boiled water (80-900C), stir to dissolve and allow the solution to
cool to room temperature. Filter the solution through a tarred grade 4 sintered glass filter or filter
paper and wash with cold water until the washings are colourless. Dry the filter and residue at
1350C until a constant weight is obtained. The result was obtained as the mean of duplicate
determinations, was expressed as weight of the residue as a percentage of the weight of sample
taken (Egan et al., 1991).
3.3
Statistical analysis
The data obtained from analysis were subjected to statistical analysis of means, principal
component analysis, Bi-plot concept and ANOVA (separation of variables) using SPSS 16.0
(Statistical Package for Social Scientists, Michigan,USA).
26
CHAPTER FOUR
4.0
RESULTS AND DISCUSSION
4.1
Manufacturing information
From the study, majority of the salt samples collected were bought in the market by the
consumers. It also showed that most of the samples were been kept in a closed plastic container,
two samples were kept in an open container, seven samples in the packaging material while only
one sample was kept in a closed glass container.
The result also showed that majority of the samples collected are not branded, Anapunna was the
commonest branded salt, there were only few samples of Dangote and Master Chef of which
Master Chef was the least among the branded salt.
The manufacturing date of the salt samples (branded) showed that all the samples were produced
this year that is between 03/10 – 09/10 and the expiring date is between 03/12 – 09/12.
Majority of the samples collected w3ere being consumed within one to four weeks by the
consumers, seven samples were consumed within five to twenty weeks; four samples were
consumed for less than one week while only one sample was consumed for more than twenty
weeks.
4.2 Physical and chemical properties
Analysis of variance of the data shows that the samples are significantly different from each
other (p<0.05). This resulted in the determination of mean for each parameter carried out on the
salt samples shown in Table 2.
27
The only physical parameter investigated in the salt samples is bulk density while the chemical
parameters include moisture content, pH, iodine content, and water insoluble matter. Most of the
salt samples were unclassified based on their percent moisture; fourteen samples fall within the
category of cooking salts while thirteen were typical of table salts. Bulk densities of the samples
were analyzed to know the compactness of the free flowing nature of the salts. It was observed
that majority of the salt samples have the same value for bulk density but relatively higher than
the factory samples.
The results of the pH determination of most of the samples tend towards acidic value compare to
the codex standard of neutral. The pH value of most salt samples collected from the households
tends to decrease from that of the point of production with time and this may be primarily due to
contamination during handling (Diosady et al., 1998) at the retail end and also, different keeping
conditions in different households.
Data analysis showed that majority of the salt collected in different households contained iodine
level above the minimum level of 30 ppm recommended at retail sale. The iodine level in the salt
samples ranged between 26.6 ppm and 89.9 ppm. Two samples were found to be below the
minimum level while twenty one samples were above 60 ppm.
The results of the water insoluble matter which was between 0.12 – 2.82 in the salt samples is an
indication of the level of impurities and some natural contaminants that are present in the salts as
a result of production and handling practices at the retail end and also, keeping conditions in
different households.
28
4.3 Classification
Using the principal component analysis, bulk density and moisture content varies most among
the samples which makes the parameters different from each other.
The Bi-plot of bulk density and moisture content was used between the iodine content and
moisture content which classified the salt samples into three groups that is table salt, cooking
salt and unclassified shown in Figure 1. For table salt, we have eighteen samples in a cluster
which are qualified as cooking salt, twenty four samples as table salt while we have eight
samples for unclassified salt which are together.
29
Table 2: Physical and chemical properties of salt samples
Serial
number
Brand
Moisture
content
(%)
Bulk
density
(g/ml)
pH
Iodine
content
(ppm)
1
D
2.21f-h
1.46o
5.61fg
69.55q-s
Water
insoluble
matter
(%)
0.38a-e
2
A
0.48ab
1.29i-k
5.84m
78.95u
0.61a-g
3
NB
6.09q-s
1.27h-j
5.95n
65.45n-q
0.79e-j
4
A
1.43a-g
1.22f-h
6.05o
84.25v
0.23ab
5
A
1.05a-e
1.15b-d
8.04w
58.65j-m
0.21a
6
A
0.91a-d
1.21e-g
6.16p
43.40c
0.49a-g
7
A
5.90p-s
1.30j-l
6.21q
71.65r-t
1.16i-l
8
NB
6.37rs
1.17c-f
5.23b
64.45m-q
1.77o-q
9
MC
0.65a-c
1.25g-j
5.13a
50.80d-i
0.40a-e
10
A
0.30a
1.17c-f
6.54r
56.20i-l
1.35l-n
11
A
0.88a-d
1.25g-j
5.34c
74.20s-u
0.65b-g
12
A
7.87v
1.17c-f
5.57ef
62.45m-p
0.87f-k
13
MC
0.60ab
1.27h-j
5.20b
44.95cd
0.23ab
14
D
2.20f-h
1.25g-j
5.51e
47.40c-f
0.80e-j
15
NB
1.05a-e
1.20d-g
5.67hi
73.85s-u
1.84pq
16
D
7.10t-v
1.15b-e
5.66g-i
27.00a
1.21j-m
17
A
5.50o-r
1.17c-f
5.69hi
32.50ab
0.41a-e
18
NB
5.10l-p
1.25g-j
8.08w
54.50h-k
0.70c-g
19
NB
4.81j-o
1.17c-f
7.78v
43.40c
1.23k-n
20
NB
0.59ab
1.25g-j
5.67hi
63.60m-q
1.33l-n
21
MC
1.28a-g
1.25g-j
5.68hi
59.35k-n
0.88f-k
22
D
7.33uv
1.25f-h
5.69hi
64.30m-q
0.65b-g
23
NB
5.64o-r
1.20d-g
5.71ij
48.60c-h
1.22k-n
24
NB
5.31n-q
1.17c-f
8.10w
55.50i-k
0.38a-e
25
NB
5.05l-p
1.30i-k
7.79v
68.20p-s
0.78d-i
26
NB
0.66a-c
1.27h-j
5.55e
52.50e-i
0.53a-g
27
A
0.33a
1.24g-i
6.12b
90.05w
0.43a-e
A= Anapunna, D= Dangote, MC= Master Chef, NB= Not Branded
Table 2: Physical and chemical properties of salt samples (continued)
30
Serial
number
Brand
Bulk
density
(g/ml)
1.25g-j
pH
D
Moisture
content
(%)
5.28n-q
5.11a
Iodine
content
(ppm)
61.40l-o
Water insoluble
matter
(%)
0.76d-i
28
29
NB
8.02v
1.29i-j
5.41d
29.40a
0.79e-j
30
NB
4.12i-l
1.35l-n
5.33c
63.80m-q
2.03q
31
NB
4.35i-n
1.25g-j
6.67s
46.60c-e
0.29ab
32
NB
3.86ij
1.25g-j
6.12b
48.30c-g
0.53a-g
33
A
0.54ab
1.15b-e
5.82l-m
77.45tu
0.61a-g
34
A
6.80s-u
1.17c-f
5.64gh
85.30bw
1.23k-n
35
A
1.42b-h
1.20d-g
5.24b
65.20n-q
0.91g-k
36
MC
7.73v
1.21e-g
5.70h-j
53.05f-j
0.65b-g
37
NB
2.24gh
1.25g-j
4.42d
53.60g-h
0.73d-h
38
NB
4.27i-m
1.25g-j
5.54e
66.10o-r
0.35a-d
39
NB
1.00a-e
1.17c-f
6.06o
63.85m-q
1.18i-l
40
NB
3.56i
1.22f-h
5.37cd
72.25st
0.46a-f
41
NB
4.03i-k
1.11b
5.93n
65.60o-q
2.50r
42
A
4.87k-o
0.90a
5.33c
86.70vw
1.60m-p
43
D
1.63c-h
1.27h-j
5.75jk
44.85cd
2.47r
44
A
1.93e-h
1.14bc
6.82u
54.65h-k
0.88f-k
45
NB
0.88a-d
1.23f-h
5.78kl
51.30e-l
0.88f-k
46
NB
5.25m-q
1.39n
5.96n
42.90c
0.79e-j
47
NB
1.77d-h
1.36mn
6.75t
35.85b
1.14h-k
48
D
1.23a-f
1.25g-j
6.82u
36.65b
1.63n-p
49
A
2.34h
1.33k-m
5.10a
52.95f-j
0.81e-k
50
NB
4.95k-p
1.25g-j
5.22b
74.15s-u
1.42l-o
A= Anapunna, D= Dangote, MC= Master Chef, NB= Not Branded
31
Table 3: Showing the result of analysis for factory samples
Analysis
Moisture
content
Bulk
density
pH
Replicate
1
2
1
2
1
2
1
2
1
2
Anapunna
0.72
0.72
1.03
1.03
8.23
8.22
0.71
0.73
34.9
37.2
Dangote
0.65
0.66
1.05
1.04
8.11
7.71
1.00
1.05
32.8
34.7
Master
0.59
0.60
1.02
1.03
8.25
8.26
0.82
0.89
42.4
43.8
Chef
32
Water
insoluble
matter
Iodine
content
Figure 1: Bi-plot for grouping the salts samples based on iodine and moisture content
33
CHAPTER FIVE
5.0
CONCLUSION AND RECOMMENDATION
5.1
CONCLUSIONS
The study has shown that most commonly consumed in the household visited, the salt samples
collected had moisture contents greater than could make them get classified as either table or
cooking salt. The pH tends towards acidic value from neutral as a result of different keeping
conditions in the households which may lead to inability of important components like iodine
content.
5.2 RECOMMENDATION
It could be recommended that consumers should be informed or enlightened on the basic
constituents of edible salt and their sources for public health reasons.
Further studies should also be carried out to include batch monitoring from the factory to the
retailing sale and effect of different household keeping practices on the stability of iodine content
in salt.
34
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Batmanghelidj, D. (1999). Salt intake is vital. 3rd (ed). Bragt, India. 155pp
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International Council for Control of IDD (ICCIDD, 1995)
Mannar, R; and Dunn J. T. (1997). The Real-unrefined – unheated- untreated- natural sea-salt
Institute of Food and Agricultural Science, (IFAS), Florida.
Marassi, R. (1990). Uses and benefits of salt. Website visited on 9th october, 2010.
www.saltinstitute.org.
Moxham R. (2000): Salt deficiency the of many serious diseases. Balt. Int. Lab. Sys.
Vol 8, 105-125.
The American Heritage Stedman’s medical dictionary 2002. By Houghton Mifflin company.
36
APPENDIX I
Table Showing the codex standard of edible salt.
Parameter

Standard
Physical
(a) Moisture content
(i)Table
0.1-0.6% max
(ii)Cooking
1.0-4.0% max
(b) Particle size
0.2-0.5mm

Chemical
(c) pH
7.0- 7.9 (neutral)
(d) Colour
Pure white
(e) Purity
not < 97% on a dry basis
(f) Alkalinity(Total)
300ppm
(g) Sulphate
3000ppm
(h) Water insoluble
300ppm
(i) Potassium (K)
100ppm
(j) Calcium (Ca)
100ppm
(k) Magnesium (mg)
50pm
(l) Zinc (Zn)
25ppm
(m) Manganese (Mn)
10ppm (Mediterranean = 0-1.4ppm and Atlantic ->
2ppm).
2ppm
(n) Lead (Pb)
Source: Codex Standard, (2001)
37
APPENDIX II
QUESTIONAIRE ON EDIBLE SALTS USED IN DIFFERENT HOUSEHOLDS IN
NIGERIA (ABEOKUTA AS A CASE STUDY)
Date collected
Location
Brand name
HABIT OF SALT USAGE/PURCHASED
1.
Where do you buy your salt?
2. What do you look for when purchasing your salt?
Whiteness
brand
price
grain size
Manufacturing/Expiring date
label
3. How do you keep your salt?
Closed container
Plastic container
opened container
packaging material
metal container
4. How long does it take you to use your salt?
INFORMATION ON SAMPLE COLLECTED
5. Date of purchasing
6. What is it condition when purchased
7. Manufacturing date
8. Expiring date
9. Condition/state of packaging material during sampling
38
APPENDIX III
Table Showing the manufacturing information of the samples collected`
S/N
Location
Date of
purchase
Date of
samplings
Duration
Manufacturing
date
1
Obantoko
25/07/10
11/08/10
17days
07/10
2
Obantoko
12/07/10
11/08/10
30days
05/10
3
Obantoko
09/08/10
11/08/10
2days
NB
4
Obantoko
2 months ago
11/08/10
2months
04/10
5
Obantoko
2 1/2months ago
11/08/10
2 1/2months
09/10
6
Obantoko
14/07/10
11/08/10
28days
03/10
7
Obantoko
17/07/10
11/08/10
25days
06/10
8
Obantoko
4 weeks ago
11/08/10
4weeks
NB
9
Obantoko
21/05/10
11/08/10
2months and
21days
07/10
10
Obantoko
11/08/10
11/08/10
1day
06/10
11
Obantoko
01/08/10
11/08/10
10days
03/10
12
Obantoko
25/07/10
12/08/10
18days
06/10
13
Obantoko
10/10/10
13/08/10
3days
07/10
14
Obantoko
02/10/10
13/08/10
11days
07/10
15
Obantoko
11/10/10
13/08/10
2days
NB
16
Obantoko
04/10/10
13/08/10
9days
06/10
17
Obantoko
05/10/10
13/08/10
8days
05/10
18
Obantoko
04/10/10
13/08/10
9days
NB
19
Obantoko
12/10/10
13/08/10
1day
NB
20
Obantoko
08/10/10
13/08/10
3days
NB
21
Odeda
12/08/10
18/08/10
6days
07/10
22
Odeda
12/08/10
18/08/10
6days
06/10
23
Odeda
12/08/10
18/08/10
6days
NB
24
Odeda
15/08/10
18/08/10
3days
NB
25
Odeda
20/07/10
18/08/10
29days
NB
39
Table Showing the manufacturing information of the samples collected`(continued)
S/N Location Date of purchase Date of samplings
Duration
Manufacturing
Date
26
Odeda
14/08/10
18/08/10
4days
NB
27
Odeda
27/07/10
18/08/10
22days
03/10
28
Odeda
15/08/10
18/08/10
3days
07/10
29
Odeda
12/08/10
18/08/10
6days
NB
30
Odeda
12/08/10
18/08/10
6days
NB
31
Odeda
17/08/10
18/08/10
1day
NB
32
Odeda
08/08/10
18/08/10
10days
NB
33
Odeda
10/08/10
23/08/10
13days
05/10
34
Odeda
15/08/10
23/08/10
8days
06/10
35
Odeda
04/05/10
23/08/10
3months and 19days
06/10
36
Isale- Ake
30/08/10
01/09/10
2days
08/10
37
Isale- Ake
31/08/10
01/09/10
1day
NB
38
Isale- Ake
31/08/10
01/09/10
1day
NB
39
Isale- Ake
01/09/10
01/09/10
1day
NB
40
Isale- Ake
29/08/10
01/09/10
3days
NB
41
Isale- Ake
30/08/10
01/09/10
2days
NB
42
Isale- Ake
31/08/10
08/09/10
8days
05/10
43
Isale- Ake
14/08/10
08/09/10
25days
06/10
44
Isale- Ake
24/08/10
08/09/10
15days
03/10
45
Isale- Ake
02/09/10
08/09/10
6days
NB
46
Isale- Ake
02/09/10
08/09/10
6days
NB
47
Isale- Ake
06/09/10
08/09/10
2days
NB
48
Isale- Ake
05/04/10
15/10/10
6months and 10days
05/10
49
Isale- Ake
02/10/10
15/10/10
13days
07/10
50
Isale- Ake
05/10/10
15/10/10
10days
NB
40
41