Determination Of Glycemic Indices Of Composite Gari And Fufu From Cassava And Maize

ABSTRACT

This study investigated the glycemic indices of two different cassava and maize (corn) food products. Four groups of volunteers were each fed with 167g of garri and 162g of fufu form corn, 169g of garri and 205g of fufu form cassava diets and control volunteers were fed with 50g anhydrous glucose. The venous blood samples were drawn at 30mins intervals for 2 hours after fasting blood glucose test, which was determined, using glucose oxidase method. The blood levels after were determined and the areas under curve were calculated by trapezoid method. The glycemic indices for fufu and garri from cassava, garri and fufu from corn were found to be 84, 92, 84 and78 respectively. The analysis of variance (F= 0.05) carried out showed that the method of preparation of the diets did not affect the glycemic indices of the food, there is also no significant differences (p< 0.05) in the glycemic indices of fufu and garri from cassava, and fufu and garri from corn. The diets were within the high glycemic index range of above 70. From these results, it can be concluded that cassava food products are of high glycemic index than corn.

 TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• Background of the study
• Problem statement
• Purpose of the study
• ResearchHypothesis
• SignificanceoftheStudy
• Scope of the study
• Delimitations
• Limitations
• Research Question
• OrganisationoftheStudy

CHAPTER TWO

LITERATURE REVIEW

• Introduction
• Fufu
• Differentprocessingformsoffufu
• Differentprocessingformsoffufu
• Cassava
• Carbohydrate
• Dietarycarbohydrate
• Totalcarbohydrate
• Sugars
• Starch
• Available carbohydrate
• Carbohydrate digestion
• Dietary fibre
• Glycaemic index concept
• Glycaemic load concept
• Portion size and glycaemic control
• Determination of glycaemic index
• Glycaemic Load and Health
• Glycaemic load and diabetes
• Glycaemic load and coronary heart diseases
• Glycaemic load and obesity
• Factors Affecting Preference and Food Choice

CHAPTER THREE

• MATERIALANDMETHODS
• Sample collection
• SamplePreparation
• ProximateAnalysis
• Determination of Fat Content
• Determination of Ash Content
• Determination of Crude Fiber Content
• DeterminationofProteinContent
• DeterminationofCarbohydrate
• MethodologyForBloodGlocoseDetermination
• DeterminationofBloodGlucoseResponse
• CalibrationofOneTouchGlucometer
• Determination of Area Under Curve (Auc)
• DeterminationofGlycemicIndex
• StatisticalAnalysis

CHAPTER FOUR

4.0      RESULT AND DISCUSSION

CHAPTER FIVE

• Conclusion
• References

CHAPTER ONE

1.0                                                                                  INTRODUCTION

1.1                                                                    BACKGROUND OF THE STUDY

Cassava (Manihot esculenta Crantz) and maize (zea mays) are major staple food in tropical countries. Nigeria is the world’s largest producer of cassava and maize with the potential for higher production. Cassava and maize containanti-nutritionalfactorsandtoxins,itmustbeproperlyprepared before consumption, and improper preparation of cassava can leave enough residualcyanide to cause acute cyanide intoxication and goiters and may even cause a toxic or partialparalysis(Taiwo,2006).Cassavaisanimportantfoodcropinthetropicsandamajorcarbohydrate staple consumed in various forms by humans.It contributes significantly to thenutrition and livelihood of about 800 million people and thousands of processors and tradersaround the world and forms a base for a wide variety of fermented foods in Africa, Asia,Brazil, India and America.In addition it serves as raw material in the manufacture ofprocessed foods, animal feed and industrial products (Balagpalan, 2002, Aloys and Mings2006, Taiwo 2006).

In Nigeria the main food product of considerable domestic importance are garri (eba), and fufu (Taiwo, 2006). Garri is the most common food product processed from cassava in West Africa; production involves peeling, washing and grinding of the roots. The grated mash is put in jute sacks which are pressed using screw press and the dewatered mash is then sieved and fried. The average moisture content of garri ranged from 8 to 14% which makes it suitable for long term storage. It is usually eaten in the form of snacks by soaking in water or in the meal form where it is reconstituted by stirring in hot water to form a dough (eba) which is eaten with soup (Udoro, 2012). Fufu is fermented cassava and is popular in Nigeria; it is prepared by soaking the tuber in water either with the peel or after peeling for 3 to 4 days. The tubers are then manually disintegrated by crushing, decanted and the mash spread on a flat surface. The   mash is dried and milled to obtain the fermented flour.   The flour is prepared by stirring in hot water to make smooth elastic dough which is eaten with vegetable soup (Taiwo, 2006). Fufu is a meal from soaked fermented cassava in Eastern Nigeria. The tubers are peeled, washed, cut into thick chunks and soaked in water for 4 to 5 days. During this period, the cassava tubers ferment and soften in water. A characteristic flavour of retted cassava meal is also produced. The retted tubers are disintegrated then passed through the sieve and allowed to settle for about 3 to 4 hours. The water is decanted while the sediment is packed into a cloth bag, tied, squeezed and subjected to a heavy pressure to expel excess water. The resulting meal is rolled into balls and cooked in boiling water for about 30 to 40 minutes. The cooked mass is pounded with a mortar and pestle to produce a paste (fufu) that can be eaten with soup, (Balagopalan, 2012).

Certain carbohydrate foods such as garri and fufu are digested rapidly releasing glucose into the blood stream whereas some carbohydrate foods are digested slowly releasing glucose slowly into the bloodstream (Jenkins et al., 2014).

Carbohydrates are the main energy source in most human diets, making up about 40–80% of our calorie intake play an enormous role in human physiology (Mann et al. 2017). Most Nigerian diets are carbohydrate based and most families plan their meals around it. Despite the energy value of carbohydrates, its physiological effects on human health cannot be overemphasized. The energy contents and digestibility of different carbohydrates, however, differ (Mann et al. 2017). Some carbohydrate foods elicit a quicker response from insulin than others (Lin et al. 2010). This is due to differences in the rate at which they release glucose into the blood. The relative ranking of how fast or slow a carbohydrate food is converted to glucose after ingestion is a measure of its glycemic index (Lavigne et al. 2010).

Health problems associated with high blood glucose such as obesity, metabolic syndrome, diabetes mellitus are due to high glycemic index foods. Therefore clinical trials have shown that low glycemic diets improve glycemic control in diabetes, increase insulin sensitivity; reduce food intake and body weight (Juntmen et al., 2013). Prospective studies suggest that low glycemic index diets may reduce the risk of diabetes, metabolic syndrome cardrovascular disease and possibly some type of cancer (Liu et al., 2000, Sulmeron et al; 2017).

Glycemic index (GI), though a simple numerical index which measures the blood glucose raising ability of carbohydrates, has become an established concept for classifying carbohydrates (FAO/WHO, 2018). In determining the glycemic index of a carbohydrate food, the postprandial glycemic response of the food is measured against a reference food (FAO/WHO, 2018). A number of factors influence the postprandial glycemic response of a carbohydrate when ingested. These factors range from extrinsic components such as composition of the whole meal and variations in the overall diet, to intrinsic properties, such as the amylose to amylopectin ratio, presence or absence of viscous fiber, and the length of the monosaccharide units (Bjorck et al. 2014).

Garri and Fufu are the most Nigerian carbohydrates, are subjected to quite a number of processing techniques during preparation for consumption. The processing of a particular carbohydrate food plays an important role in determining its overall properties (Englyst et al. 2007), which also has a significant influence on physiological function in the human body. Glycemic index value is also directly influenced when the physiological effect of a carbohydrate is altered (Bahado‐Singh et al. 2011). Such factors as particle size, processing methods, nature of starch, and antinutrients present which are not commonly available in food tables, and yet have very significant effects on physiological properties of food, which further highlight the importance of determining the GI of foods individually and not by extrapolation from international GI values of foods of similar qualities (Aston et al. 2018).

The study aim was to determine the GI of some carbohydrate‐rich Nigerian staples (garri and fufu).

1.2       Statement of the Problem

Willet et al. (2012) report that the consumption of high glycaemic indices and high glycaemic load diets for several years might result in increased postprandial blood glucose spikes and excessive insulin secretion. This could lead to the loss of insulin-secreting function of the pancreatic β- cells, resulting in irreversible Type 2 Diabetes mellitus. In addition to this assertion, Ludwig and Daniel (2012) in a study state that, sustained spikes in blood sugar and insulin levels may lead to increased diabetes risk. Diabetes mellitus Type 2 is currently one of the most prevailing chronic diseases in the world and the number of people with the disease is stated to be increasing in every country. International Diabetes Federation (IDF) has estimated that 415 million adults globally, are presently living with the condition. Nonetheless, this is predicted that people having this condition would rise to 642 million by 2040. An estimated 14.2 million adults (aged 20-79) have diabetes in Africa, representing 6.7% (IDF, 2016). This prevalence can be minimized to a lower rate when people are made aware of the glycaemic indices and glycaemic loads of the foods they consume, as these play major roles in the development of this condition. When consumers are well informed on the rate at which the glucose in our local foods is released into the bloodstream, they will be very cautious about their choice of food and even the time they eat these foods as well as the amount they consume.

A study by Wormenor (2015) revealed that the fufu made from cassava  and corn has a low glycaemic index of 55, hence it has little impact on blood glucose level when ingested and digested. However, people do not only consume cassava-corn variety of ‘fufu’ in Nigeria. Some take the cassava and yam and the cassava and cocoyam combinations.

1.3       Purpose of the Study

The purpose of this study was to determine the glycaemic load of the      differentvarietiesof garri and fufu. Toachievethis, thestudy soughtto;

1. examine participants’ glycaemic response to ingested
2. determine the glycaemic load of garri and fufu produce from cassava and corn.
3. perform proximate analysis on all varieties of
4. sensorily analyze the garri and fufu varieties.

1.4       Research Hypothesis

H0 = There is no significant difference in the glycaemic load of the different varieties of garri fufu.

H1= There is a significant difference in the glycaemic load of the different  varieties of garri and fufu.

1.5       Significance of the Study

Essentially, the glycaemic load, which is the product of the glycaemic index and the carbohydrate content of a given food, may be more useful than only the glycaemic index. This is because the glycaemic load takes into account the portion size of the food as well as the carbohydrate content. Glycaemic load is a significant factor in dietary programmes aiming at the metabolic syndrome, insulin resistance, and weight loss.

When mixed meals containing carbohydrate foods of different glycaemic index are consumed, it is known that the difference in postprandial blood glucose response is maintained (Chew, Brand, Thorburn & Truswell, 1988). However, the extent of this differential blood glucose response may be dependent on the size of the meal consumed. It is hoped that this study will come up with the optimal size of fufu which when consumed will have no effect on the blood glucose level. Knowledge of the glycaemic load of the various fufu variety could serve as a guide to diabetics to choose the fufu variety with the best glycaemic load.

It may also inform nutritionists, dieticians and diet therapists on the optimal garri and fufu variety to recommend to prediabetics and diabetics when they counsel their clients. Since fufu is widely eaten across Nigeria, providing information on the nutritional value on garri and fufu would be worthwhile and helpful to consumers. It is anticipated that the findings from the study will provide literature on fufu and its nutritional value.

This study will solve the problem of high intake of food containing large amount of carbohydrates. Example such  as cassava and maize. The study also makes important contribution to future research  by contributing to the existing literature particularly on nutrition.

1.6        Scope of the study

The research focused on garri and fufu varieties and their impact on the blood glucose. This study investigated all the possible varieties of fufu and garri that are consumed in the country and to analyze the extent to which each of variety affects the blood glucose level. The cassava and maize obtain will be used to produced flour, garri and fufu which can be consumed. The glycemic indices composition, functional,sensory and anti nutritional properties of the product from the composite flour will be analysed using glucose oxidase method.

 1.7       Delimitations

The study determined the glycaemic load of varieties of garri and fufu. All the different fufu mixtures; cassava-garri and cassava-fufu were analyzed. Findings cannot be easily generalized for other carbohydrate foods. The study focused on the effect garri and fufu has on blood glucose level after it has been digested and so healthy individuals were used for the study. Diabetics already have elevated blood glucose levels and using them for the study may not be appropriate. The study was carried out in Wenchi in the Brong Ahafo region. However, those who were not fit or had any respiratory infection like cold were excluded.

1.8       Limitations

Even though the nature of the sensory analysis test used demands more panel members, the number of panel members used in the study had to be limited. This was because panelists were not given prior notice but were told instantly to participate in the sensory evaluation and since it was carried out on a weekday, it was difficult persuading them to spend few minutes of their time to undertake the test. Since sensory perception of a food is subjective, the texture of the food presented to  them may not have been liked by some participants and hence affect their ranking choice.

1.9      Research Question

1. Is garri high glycemic index?
2. What is the glycemic index of cassava fufu?

• Does cassava have high glycemic index than maize?

1. What is the glycemic index of maize?

1.10           Organisation of the Study

Chapter one of the study dealt with the background to the study. It gave a vivid explanation of the concept of glycaemic load and the important role it plays in minimizing the increasing rate of diabetes and other related diseases. It further explained the fact that most people choose to eat foods not necessarily thinking about its effect on their health. The chapter also includes the problems statement, objectives of the study, research questions and significance of the study.

In chapter two, an extensive review of relevant related literature was carried out. The researchers further explained the concept of glycaemic index and load as well as issues relating to them. It draws extensively from the work of other researchers which are published in journals and scholarly articles.

The third chapter dealt with Methodology which included the study design. The study design is purely experimental. It also dealt with the study area, sources and type of data, sampling technique, data collection procedure, data processing and analysis and limitations of the study.

In chapter four, data analysis and discussion of major findings were done. Quantitative content analysis was done and findings were presented in graphs and tables. The chapter five of the study which is the final chapter dealt with the summary of the major findings, conclusion, and recommendations of the study.