ABSTRACT
The quality of crude palm oil sold in major markets in Enugu state was assessed. The objectives were to collect information on production, processing and storage of crude palm oil from sellers in the selected major markets, to determine the peroxide value, free fatty acid value, beta-carotene level and Deterioration of Bleachability index (DOBI) of crude palm oil. The study design employed cross sectional survey and experimental studies. A three-stage sampling technique was used in selection of the subjects (palm oil sellers). In the first stage, three local government areas were selected. In the second stage, one major market was selected from each of the local government areas and they include; Ogbete, Eke Agbani and Garki markets. In the third stage, nine (three from each market) oil sellers were identified and interviewed. Subsequently, nine oil samples were randomly selected (three from each market). The nine oil samples were subjected to the following analyses; peroxide value, Free Fatty Acid (FFA), Deterioration of Bleachability Index (DOBI) and Beta-carotene determination using standard methods. It was deduced that, majority (55.6%) of the oil sellers do not produce the oil themselves and 44.4% who produce the oil on their own, process their palm fruits traditionally within 2 to 5 days after harvest. In addition, 66.67% of the respondents do not add additives to the palm oil and all (100%) the respondents store their oil in plastic containers. The analytical result revealed that, the FFA and beta-carotene mean values ranged from 10.95 to 15.86mgKOH/g and 4086.56 to 4163.88mg/kg respectively. The free fatty acid (FFA) and beta-carotene levels were of real concern, as the oil samples from Ogbete, Eke Agbani and Garki markets did not comply with recommended levels of 3.5mgKOH/g and 500 –2000mg/kg respectively. The peroxide values and the Deterioration of Bleachability Index mean values range from 4.73 to 10.07Meq/kg and 2.52 to 3.72 respectively. All the samples investigated were in compliance with recommended levels regarding Peroxide Value and Deterioration of Bleachability Index, thus confirming the good oxidative stability and good bleaching property of the crude palm oil samples. The high FFA and beta-carotene values of the nine crude oil samples could be due to poor hygienic and storage practices hence, there is need to raise public awareness on the palm oil processing practices and hygiene.
TABLE OF CONTENT
Title page i
Certification ii
Dedication iii
Acknowledgement iv
Table of content v
Abstract vi
CHAPTER 1
INTRODUCTION
1.1 Background of
the study 1
1.2 Statement of
the problem 5
1.3 Objective of
the study 6
1.3.1 General
objective of the study 6
1.3.2 Specific
objectives of the study 7
1.4 Significance
of the study 7
CHAPTER 2
LITERATURE REVIEW
2.1
Palm oil 9
2.1.1
Botanical Information on Palm Oil 10
2.1.2
Production and Utilization of Palm Oil in Nigeria 12
2.3
Nutrient content of palm oil 14
2.3.1
Contaminants in Palm Oil and the implication for human health 15
2.3.2
Presence of Sudan IV chemical Dry in Crude Palm Oil 17
2.4
Quality Characteristics of palm oil 17
2.5
Health benefits of palm oil 18
2.5.1
Nutritional benefits of palm oil 22
2.5.2
Free fatty acids content (FFA) 23
2.5.3
Determination of peroxide value 23
2.5.4
Deterioration of bleachability index of palm oils 24
2.5.5
Determination of carotene value 25
2.6
Effects of carotenoids on human health 25
2.6.1
Effects of tocopherols and tocotrienols on human health 26
2.6.2
Free Fatty Acids and Human Health 27
2.6.3
Peroxide value 29
2.6.4
Determination of peroxide value 29
CHAPTER 3
MATERIALS AND METHODS
3.1
Study design 30
3.2
Area of study 30
3.3
Sampling techniques 31
3.4
Method of data collection 31
3.4.1
Collection and preparation of samples for laboratory analysis 32
3.5
Laboratory analysis 32
3.5.1
Determination of free fatty acid
(FFA) 32
3.5.2
Determination of peroxide value 33
3.5.3
Determination of Carotene value (pro-vitamin A) 34
3.5.4
Determination of Deterioration of Bleachability Index 34
3.6
Statistical analysis 35
CHAPTER 4
RESULTS AND DISCUSSION
4.1
Production, Processing and storage of Palm Oil by the sellers 36
4.2
Peroxide values of the palm oil samples 38
4.3
Free Fatty Acid (FFA) values of the oil samples 40
4.4
Deterioration of Bleachability Index (DOBI) of the oil samples 42
4.5
Beta-Carotene Content of the crude palm oil samples 44
CHAPTER 5
CONCLUSION AND RECOMMENDATIONS
5.1
Conclusion 46
5.2
Recommendations 46
REFERENCES
APPENDIX
LIST
OF TABLES
Table
2.1: Food and Non Food Uses of Palm Oil……………………………………..14
Table
4.1: Frequency Distribution of Crude Palm Oil Sellers………………………...37
Table
4.2: Peroxide values (MeqO2/kg) of Palm Oil Samples…………………….......39
Table
4.3: Free Fatty acids (FFA) values (%) of Palm Oil Samples………………….41
Table
4.4: Deterioration of Bleachability Index of Palm Oil Samples………………..43
Table
4.5: Beta-Carotene values (mg/kg) of Palm Oil Samples………………………45
CHAPTER 1
INTRODUCTION
1.1
BACKGROUND
OF THE STUDY
Palm oil is one of the most consumed edible oils
within the tropics. In Nigeria, it forms the basic food ingredient of every
household. It is a product of oil palm tree (Elaeis guineensis), an
ancestral cash crop tree of African origin. It is believed to have spread to
various countries by farmers who practiced shifting cultivation. History has
shown that human use of palm oil may be dated as far back as 5000 years in
West Africa (Kiple and Conee,2000). All over the globe,
palm oil has become one of the leading sources of income especially in Africa
and Asia, with a special reference to Malaysia where it has become the most
relied on source of revenue for the government. In tropical Africa, South-East
Asia and parts of Brazil, palm oil is a common cooking ingredient, while in
commercial industries, it is used for manufacturing soaps, washing powder, and
other products (Bellis,2005).The oil is extracted
from the mesocarp of the fruit.
Since 2006, palm oil has become the world’s most
important edible oil (Udensi et al.,
2007). It is also a source of energy and fat deposits which insulate the body
against loss of heat and also protects the vital organs against mechanical
injury (Baku et al.,2012). Palm oil is an
important food source to humans because it supplies essential fatty acids such
as linoleic and arachidonic acid and also contains large amounts of tocotrienol
which is a part of the vitamin E family (Bonnie and Choo,2000).
In Nigeria, the demand for palm oil has been on
the rise due to the rising population and the need to meet international market
demand. This has necessitated an increase in the manual and traditional process
of production which is predominantly carried out by villagers with little or no
knowledge of aseptic techniques. There has been speculation that the potential
harmful effects of unrefined traditionally processed palm oil could outweigh
its nutritional benefits since these oils could be containing some components
that enhance numerous reactions involved in the degradation of the product (Tagoe
et al.,2012).
Palm oils is an essential nutrient in both human and animal
diets and provide the most concentrated source of energy of any foodstuff. The
principle function of oils in food is that it enhances stability and taste of
food (Pachecoet al., 2017). The fruit
produces two unique types of oils orange-red crude palm oil which is extracted
from the mesocarp and brownish yellow crude palm kernel oil extracted from the
seeds (kernel). Both oils are important
in the world trade. Palm oil is an important vegetable oil which has an
increasing consumer interest in West Africa. It contains approximately 50%
saturated fats and 40% unsaturated fats. The light orange-red colour of palm
oil is due to the fat soluble caretenoids, which are responsible for the high
vitamin A content (Ugwu et al., 2002). These essential fatty acids help to lower blood
cholesterol levels in the body. It is the richest vegetable oil source of
tocotrienols – which are potent forms of vitamin E. Vitamin E strengthens the
immune system, and protects skin cells from toxins and ultraviolet radiation
(Ugwu et al., 2002). From its
reddish-orange colour, palm oil is also a good source of β-carotene, a nutrient
found in sweet potatoes, carrots, and other orange coloured foods. β-Carotene
is useful as a precursor to vitamin A (retinol) in the body, it is a powerful
antioxidant and act to reduce the risk of certain cancers and heart diseases
(Tanumiharjo, 2002).The high nutritional value especially, its high oil content
greatly predisposes it to deterioration.The carotenoids (500–700ppm) are
responsible for the characteristic deep orange-red color. Vegetable oils in
food technology composition properties and uses (Gunstone, 2011), while its
semi-solid consistency at tropical room temperature is mainly due to the
presence of triacylglycerols of palmitic and oleic acids (Gee, 2010a). Fats and
oils store the majority of the energy in most animals and plants. Fats and oil
are found in both plants and animals and are components of one of the major
food groups in our diet. Sources of oil include coconut oil, corn oil, olive
oil, palm oil, peanut and safflower oil (Gordon, 2012).
In
recent years there has been rising production (supply) and consumption (demand)
of palm oil in Nigeria, with demand growing faster than the supply. As a
result, the trend has been that of increasing domestic consumption unequally
matched by a rather slow growth in production. This widening gap between demand
and production has also been accompanied by increasing reports (from the media)
of adulteration (Aparicio and Aparicio-Ruiz, 2000).
The
quality of palm oil could be affected by improper post-harvest handling,
processing and storage techniques. Again there is a wide spread speculation
that palm oil is adulterated for the sole purpose of profit maximization. The
adulteration ranges from the use of colours, dyes, water and other illegal food
additives which could affect the quality of palm oil in terms of nutritive
value, wholesomeness, utilization, safety and shelf-life.
Adulteration
is the process in which the quality of food is reduced by addition of inferior
quality material. It includes the intentional addition of the inferior material
during the period of growth, storage, processing, transport and distribution of
the food products. It is also responsible for the lowering of the quality of
food products. The expert put to use in the production of this oil has made it
practically impossible to physically differentiate between a good palm oil and
the fake. Many consumers look for redness before buying their palm oil. Of
course, that is one major attribute of the oil. Often times, these improperly
made bottles of oil are more expensive than the properly made ones as consumers
tends to rush them (CSPI, 2006). Adulterants are those substances which are
used for making the food products unsafe for human consumption.
Technical
palm oil (TPO) account for 25%, on average of total fat supply in Nigeria
between 1990 and 2009. Despite all the good nutritional health benefits
Nigerians get from palm oil (technical palm oil), not much attention has been
given to assess the quality of palm oil sold in the market and consumed by
households. Some nutritional quality parameters have been associated with oils.
These include peroxide value, free fatty acid, and deterioration of
Bleachability Index, carotene and contaminant level. They are associated with
all levels of production, storage and preservation of palm oil (Udensi and Iroegbe, 2007).
The
adulteration is believed to be practiced by producers in order to increase the
quantity of crude palm oil (CPO), for the sole purpose of profit maximization.
Unfortunately, the adulteration practice is normally done without considering
its possible effect on the quality of palm oil and the health of consumers.
This study
is hence aimed at determining the level of the above mentioned quality
parameters from palm oil samples collected from major markets in Enugu State,
Nigerian in order to ascertain their safety level.
1.2 STATEMENT OF PROBLEM
The
quality of palm oil could be affected by improper post-harvest handling,
processing and storage technique. Again there is a wide spread speculation that
palm oil is adulterated for the sole purpose of profit maximization.
High free
fatty acid values and peroxide values are useful indicators of quality of oils
and predispose one to cardiovascular diseases (CVD) with habitual intake (
Reddy et al 2001). Other indicators include Deterioration of bleachability
Index and beta-carotene levels. This has led to increasing rate of mortality
and morbidity (Beaglehole and Yach, 2013). Cardiovascular diseases develop at
different rates in different individuals based on a variety of factors. High
blood pressure, abnormal blood cholesterol levels (high LDL “bad” cholesterol
and or low HDL “good” cholesterol), smoking, diabetes, male gender, and
hereditary factors all independently increase the risk of CVD developing
earlier in life. Other risk factors include levels of saturated fat and
cholesterol intake (whether the blood cholesterol levels are abnormal or not),
being overweight, being sedentary, the use of cocaine, and high levels of other
chemicals in the blood, like homocysteine. Each of these factors causes damage
to the arterial lining (WHO, 2002).
The
cardiovascular disease (CVD) in the world is enormous and growing, and the
majority of those affected are in developing countries (Beaglehole and Yach,
2013). In 2002, it was estimated that 29
percent of deaths worldwide (12.7 million deaths) were due to cardiovascular
disease (CVD) and that 42 percent of global morbidity and mortality, measured in disability
adjusted life years (DALYs), was caused by CVD (WHO, 2002). Furthermore, 72% percent of global mortality
and 86 percent of mortality and morbidity from CVD occurs in developing
countries. Free fatty acid content of palm oil is the most used index for
determining the quality of palm oil and must not exceed 5% (expressed as
palmitic acid) according to Codex Alimentarius/FAO/WHO (2005). Different
extraction methods and major processing activities like transportation,
fermentation prior to threshing, clarification and storage can equally increase
the free fatty acid value of crude palm oil (Ohimain, 2012).
The major
source of obtaining crude palm oil is through the traditional markets which is
three times higher than the industrial demand (Basiron, 2007).Despite the good nutritional and health
benefits Nigerians get from crude palm oil, not much attention has been given
to assessment of the nutritional quality parameters of palm oil sold especially
in major markets of Enugu state hence, the need to evaluate some quality
parameters like free fatty acid, peroxide value, beta-carotene level and
deterioration of bleachability index in palm oil samples collected from major
markets in Enugu State.
1.3 OBJECTIVES OF THE STUDY
1.3.1 General Objectives of the Study
The
general objective of the study was to assess the quality of crude palm oil
samples sold in major markets in Enugu state.
1.3.2 SPECIFIC OBJECTIVES OF THE STUDY
The Specific Objectives are to:
1.
Collect information on production, processing and storage of crude
palm oil from palm oil sellers in
major markets in Enugu State.
2.
Assess the peroxide value of crude palm oil samples collected from
major markets in the study area.
3.
Determine the carotene value of crude palm oil samples collected from
major markets in the study area.
4.
Determine the free fatty acid value of crude palm oil samples
collected from major markets in
the study area.
5.
Determine the deterioration of bleachability index of crude palm oil
samples collected from major markets
in the study area.
1.4 SIGNIFICANCE OF THE STUDY
1.
This study will provide information to researchers on quality
characteristics of palm oil marketed and consumed in Enugu state.
2.
This study will help marketers in knowing the best palm oil samples
based on deterioration of bleach
ability index values.
3.
This study will help nutritionists and dietitians in counseling
patients on quality of palm oil sold in
the markets and their health implications.
4.
This study will help government, non-governmental organizations and
health enforcement bodies to do
more extensive researches that could provide further evidence to enforce standard safety rules
concerning palm oil production, storage and preservation among palm oil producers.
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