EFFECT OF PROCESSING ON FUNCTIONAL PROPERTIES, NUTRIENTS COMPOSITION, GLYCEMIC INDEX AND SENSORY ATTRIBUTES OF FINGER MILLET (ELEUSINE CORACANA) FOOD PRODUCTS
The effect of various processing methods (roasting, germination and fermentation) on functional properties, nutrient composition, glycemic index and sensory attributes of finger millet (Eleusine coracana) food products (Pap and Tuwo) were evaluated in context of management of type II diabetes. The cereal grain was purchased from a local market in Kaduna metropolis and the analytical method used followed standard procedures. Result obtained indicate that, functional properties of unprocessed and processed flour showed no significant difference (P>0.05) in bulk density. The fermented sample had higher water absorption and swelling capacity (1.67 ±0.06 g/ml and 939.00±3.00%) than unprocessed flour (1.40±0.10g/ml)while germinated hadthe highest (39.10±1.30 g/100ml) solubility and lowest (263.67±12%) swelling capacity.The flour from germinated seeds showedthe lowest (2.0%)gelation capacity and higher (84oC) gelatinization temperature.Proximate composition showed no significant difference (P>0.05)in the carbohydrate content of flour from unprocessed (86.32±2.11%), roasted(86.43±0.31%), and fermented (85.64±0.54%) seeds, except for flour fromgerminated seeds that had the lowest value of 80.99±2.10%. Likewise, food products (pap and tuwo) from unprocessed(86.89±1.21and 86.6±0.31%), roasted (85.71±0.32 and 86.99±1.41%), germinated (87.24±0.54 and 85.64±1.45%), and fermen ted(86.05±1.10 and 86.22±1.32%) seeds. Higher fiber content was observed in flour (4.90±0.12%)and tuwo (3.57±0.06%) from germinated seeds compared to value shown in flour, Pap and tuwo (3.54±0.06,1.74±0.06 and 2.90±0.05%) from fermentedseeds. There was no significant (P > 0.05) difference in the moisture content of flour samples from unprocessed and processed seeds. Likewise the food products, although higher values were observed in flour and pap (8.26±0.17 and 91.25±0.12%) from fermented seeds compared to the lowest value in flour and pap (6.80±0.19 and 84.99±0.02%) from roasted seeds. Significant differences (P<0.05) were observed between unprocessed and processed finger millet seeds in the antinutrient composition. Flour from unprocessed sample had significantly higher content of phytate (483.72±0.29mg/100g), cynogenic glycosides (2.66±0.07 mg/100g), alkaloids (1.75±0.05%), oxalate (36.14±0.39mg/100g, and tannins (851.12±0.04 mg/100g) compared to theprocessed samples. Flour (501.33±1.53µ/g) and food products (Pap and Tuwo) from germinated seeds had highest (82.60±1.00 and 63.63±1.89µ/g) phenol content respectively.Micronutrient conc entration showed significant difference (P<0.05)between unprocessed and processed finger millet flour and food products (Pap andtuwo). Higher content of phosphorus (16.10±1.20mg/100g), iron (24.00±4.60mg/100g), magnesium (12.00±1.20mg/100g) and calcium (16.00±2.10mg/100g) was recorded in flour from unprocessed seeds compared to processed samples.Pap from germinated seeds had higher content of iron(14.00±2.60mg/100g) and calcium (13.00±1.20mg/100g)compared to samples from roasted (11.00±1.80 and 12.00±1.20mg/100g) and fermented(11.00±1.60 and 10.00±1.10 mg/100g respectively) of the sample. Likewise phosphorous content is higher (9.00±1.60mg/100g) in tuwo from germinated seeds than sample from unprocessed (6.00±1.60g/100g). Flour and food products(pap and tuwo) from unprocessed seeds had higher total dietary fiber (19.80±0.50, 16.50±0.50 and 18.70±0.50g/100g) compared to the values shown in Flour, Pap and Tuwo (11.40±0.50, 10.40±0.05 and 11.21±0.50g/100g) from fermented seeds. The amino acids profile shows that, Tuwo from germinated had higher Leucine (10.39g/100g), phenylalanine(5.58 g/100g), methionine (2.40g/100g) content, than the fermented,unprocessed and the lowest was observed in tuwo from roasted seeds. Processing significantly (P < 0.05) affected the glycemic index of the food products as pap (28.51±10.11%) and tuwo (28.59± 14.21%) from unprocessed seeds showed lower glycemic index compared to processed samples( pap and tuwo): roasted (32.44±14.05 and 32.74± 8.10 %), germinated(40.56±12.10 and 51.04± 11.2 %), and fermented(35.71±14.10 and 40.24± 13.12 %).Lowest blood glucose response to pap and tuwo (9.31± 1.53 and 8.21± 2.04mmol/L), from unprocessed seeds in the diabetic subjects was observed compared to product from germinated seeds having the highest value (13.28± 1.21 and 14.31± 1.22mmol/L). The same trend was observed in normal subject as lowest blood glucose response to pap and tuwo (4.22± 0.3 and 4.22± 1.1mmol/L) from unprocessed seeds was also shown compared to products from germinated seeds (7.02± 0.9 and 6.53± 1.5mmol/L) showing higher values. Sensory analysis revealed that Pap and Tuwo from roasted and germinated seedswere the most prefered compared to food products from the unprocessed and fermented. The results suggest that, processing methods (roasting, germination and fermentation) decreased the anti-nutrient content, improved amino acids content, and improves the sensory attributes and general acceptability of food products from finger millet.Ithowever, significantly (P05) increased the glycemic index and glycemic response of the food, making it not to be verysuitable for the management of type II diabetes.
Background of the Study
Diabetes Mellitus is a metabolic disorder and has been defined as a condition in which the pancreas no longer produces sufficient insulin or cells stop responding to the insulin produced, therefore, the glucose in the blood cannot be taken up by the cells of the body (Goldhaber et al., 2011). Diabetes mellitus is the most common endocrine disorder that presently affects 415 million people of the world population and the majority are aged between 40 and 59 and 80% live in low and middle income countries (IDF,2015). Current figures indicate that people living with diabetes is expected to rise from 382 million in 2013 to 642 million by 2040, if no urgent action is taken (IDF, 2015).
The World Health Organization described diabetes as a chronic disease that causes serious complications such as; cardiovascular disease, chronic renal failure, retinal damage (which can lead to blindness), nerve damage (of several kind) and micro vascular damage, which may cause impotence and poor healing of wounds, particularly of the feet, which can lead to gangrene and may require amputation (WHO, 2015).
Diabetes is a global problem with devastating human, social and economic impact leading to disabilities such as; reduction in quality of life and massive rise in direct and indirect medical cost. International Diabetes Federation (IDF,2015) recommended adequate treatment of diabetes with increased emphasis on blood glucose control, lifestyle factors such as smoking, consumption of alcohol, keeping a healthy body weight by increasing physical activity and a healthy eating habit which include the consumption of whole grains.
According to Global Report on Diabetes (WHO, 2016), 499 billion US dollars were spent on health care for diabetes in 2011, 548 billion in 2013 and 673 billion in 2016, but the disease is still ravaging many parts of the world especially Africa where more than three quarters of deaths from diabetes in 2013 occurred in people under 60 years which is a prime productive years(WHO,2016).
People with diabetes cut between the ages of 20 – 79 years (IDF, 2013). There is no country in the world that is an exception in diabetes epidemic and in states and territories worldwide; it is the poor and disadvantaged that are suffering the most.A study estimated that, losses in GDP worldwide from 2011 to 2030 for direct and indirect cost of diabetes management will total 1.7 trillion US dollars, out of which 900 billion for high income countries and 800 billion for low and middle income countries (WHO,2016).
International Diabetes Federation (IDF) in 2011 revealed that Nigeria with less than 5% health insurance coverage has the highest rate of diabetes in Africa with over 5 million people living with the disease (IDF,2016) compared to the previous figure of 1 million affected people reported in 2000. South Africa ranked second with 1.9 million followed by Kenya with 769, 000.
A study conducted in Nigeria estimated the morbidity to be about 4 million people, even though there are no accurate data on the prevalence of the disease, which indicated that 4 million Nigerians may be suffering from diabetes, but hospital records show a yearly increase in the number of newly diagnosed cases (Osibogun et al., 2015).
African finger millet (Eleusinecoracana) belongs to the family Poaceae (Gramineae) which is an annual plant widely grown as a cereal in the arid areas of Africa and Asia. It is called Tamba in Hausa, Oka in Yoruba and in Igbo. The millet seed coat reserves several phenolic compounds like flavonoids, polymeric tannins and anthocyanins, some of which are effective inhibitors of pancreatic amylase and intestinal – glucosidase (Adekule,2012). It is also a rich source of phytates and minerals (Shobanaet al.,2006). Traditionally, finger millet food preparations are known for their higher sustaining power, lower glycemic response and higher satiety scores compared with other cereal foods which are usually recommended for diabetic patients (Singh and Raghuvanshi, 2012).
Finger millet has significant potential as food and feed in addition to its current usage as forage. It is a drought – tolerant crop and can be grown under difficult ecological conditions. For this reasons it is widely grown in tropical regions of world including Africa and Asia. It is comparable and even superior in some of the nutritional characteristics to major cereals, with respect to its energy value, protein, fat and mineral content (Shobanaet al.,2007). The use of finger millet for human consumption is limited to non – availability in convenient form. The millet is mostly used as whole flour for traditional food preparation and hence confined to traditional consumers and to people of lower economic status. Finger millet can be consumed raw after soaking and sprouting in form of salads but most of them require cooking to improve digestibility and palatability.
Dietary polyphenols and phytates are known for their ability to reduce carbohydrate digestibility and thereby regulate postprandial glycaemic response (Thompson et al.,1987). Moreover, polyphenols are known to inhibit glucose absorption and prevent Advanced Glycation End (AGE) product formation (Salehet al.,2013).
Though, considerable progress in the research for the treatment and management of diabetes has been made, a lot still needs to be done to improve the lives of the people, for instance, in the attainment of the Millennium Development Goals (MDGs) 1 (reduction of poverty and extreme hunger), 4(reduction of infant and under five mortality), 5 (reduction of maternal mortality), and 6(eradication of infectious diseases), which is currently called Sustainable Development Goals(SDGs), no mention was made of diabetes or related non – communicable diseases (NCOs). This reflects the misconception that these are diseases of affluence, but it is no longer true, because studies have shown an increasing prevalence of the disease even among poor urban dwellers in developing countries (WHO, 2013).
A good nutrition plan serves as the cornerstone of any diabetes management, therefore, eating healthy and increased physical activity helps prevent and effectively manage diabetes and related diseases. Consumption of whole grains, cereals and products provides the primary sources of nutrition and health benefits for diabetes and non-diabetes. These benefits include; keeping the blood glucose level within the acceptable range, reduction of cholesterol level, prevention of constipation (Chandrasekara and Shahidi,2012).
Finger millets meals are normally prepared from whole grain which is high in fiber and minerals. It is a good source of magnesium, manganese and phosphorus. Research (Shobana et al.,2013) has shown that magnesium is associated with reduced risk of heart attack, phosphorus is important for the development of the body tissues and energy metabolism(Bauman et al.,2000). It is also rich in phytochemicals including phytic acid which is believed to lower cholesterol level and reduce the risk of cancer (Shobana et al.,2009). The grain contains essential amino acids e.g. isoleucine (4.4g/100g), leucine (0.5g/100g), methionine (3.1g/100g) and phenylalanine (5.2g/100g) which are deficient in other cereals. It contains B vitamins especially niacin, B6, folic acid, and other mineral elements such as calcium, iron, potassium and zinc (Yanget al., 2012).
The term local diet or foods means indigenous foods that can be found in a rural setting or community, most of which are minimally processed, in season, locally grown, available and affordable. It differs greatly from region to region and most often specific to a location (Knowleret al., 2002). Although a healthy and adequate diet is recommended, but the specific details may vary depending upon individuals personal needs and goals, (individuals at risk for diabetes, heart disease, obesity etc). A healthy dietary plan that emphasizes weight management and healthy health is important. Personal preferences and life style are also valuable considerations, such as whether individual is a vegetarian, vegan or eats in a particular way either for religious or cultural reasons. Both in health and diseases, people require different amount of nutrients and calories depending on age, activity level, body size, and physiological status.
The main dietary requirements of a diabetic patient are the same as those without diabetes (WHO, 2013), but is the regimentation of food intake that constitutes the corner stone of diabetic therapy such as timing of food intake, the caloric value of the food and the proportions and quantity of carbohydrates, fats and proteins.Therefore, education, communication and knowledge of vital locally grown, available and affordable foods that can be used to build strong immunity, helps prevents diseases and specifically manage diabetes mellitus is important.
EFFECT OF PROCESSING ON FUNCTIONAL PROPERTIES, NUTRIENTS COMPOSITION, GLYCEMIC INDEX AND SENSORY ATTRIBUTES OF FINGER MILLET (ELEUSINE CORACANA) FOOD PRODUCTS
1.2 Statement of the Problem
People are increasingly dying in large numbers everyday due to chronic diseases such as diabetes, obesity, hypertension, coronary heart disease, atherosclerosis and certain cancer including colon and breast cancer (WHO, 2015).
The traditional African diets, that are locally available, accessible and affordable which was low in animal foodstuffs, fats, cholesterol, but high in carbohydrate, antioxidants and fibre was associated with low occurrence of atherosclerosis, appendicitis, obesity, hypertension, coronary heart disease, diabetes, gallstones, and certain cancers, according to Walker(2000).This scenario has changed rapidly with urbanization of African populations to a westernized diet(change of lifestyle, from traditional to modern), lack of physical activity, obesity, obstruction of beta cells function (e.g. pancreatitis), peripheral resistance to insulin, severe malnutrition in childhood which is referred to as malnutrition – induced diabetes (IDF, 2014). In addition, there is a lot of consumption of refined foods like rice, spaghetti, noodles, refined maize flour, semovita, semolina etc.
Dietary polyphenols and phytates are known to have the ability to reduce carbohydrate digestibility and thereby regulate postprandial glycaemic response.
In spite of all its nutritional and medical importance, finger millet has not been exploited to its full potential and it is grossly neglected both scientifically and internationally. It receives less research compared to that lavished on other cereals such as wheat, rice, and maize. Globally, many countries have never heard of the crop,incuding many parts of Nigeria especially South South, South West, South East,some parts of North Central region even in the North West where it is cultivated. Untill recentlyfinger millet is an under utilized cereal and those that grow it have allowed it to waste away in the perspective of a “poor person’s crop,” a “famine food,” or, even worse, a “birdseed. (Adekule,2012). This has resulted in increased marginalization and accelerated loss of its genetic diversity. It is believed that in a few years it will be hard to find finger millet even in places where it is the predominant cereal.
The lack of modern technologies for their effective processing and utilization has made the grain entirely a subsistence crop which is used primarily for the production of traditional foods, almost none of which are commercialized. Food uses of finger millet have been confined to traditional consumers (Anderson, 2004). In Africaproduction and processing of finger millet is still limited to areas where they are cultivated thereby hampering the development of processing industries based on this grain. For instance, the utilization of sorghum a less common cereal, is being increased by using it to produce novel commercial products, the same is very limited with finger millet (Shobana and Malleshi, 2007).
The presence of antinutritional factors is another major constraint which adversely affects the utilization of plant proteins in animal and human diet. The finger millet seed coat reserves several compounds like phytates (Shobana et al.,2013), phenolics, flavonoids, condensed tannins and anthocynanins some of which are effective inhibitors of pancreatic amylase and intestinal α-glycosidase (Chethan and Malleshi, 2007).
The seeds are difficult to convert into flour because of its tiny size according to East African Standard (EAS, 2010). Its consumption and utilisation for diabetic management would have been complete if its usefulness and best processing methods are known. Improvement on the processing methods would enhance production of sufficient good-quality flour which would be available to meet the demand of food shortage in some developing countries. In order to improve the potential of finger millet, maximise its utilisation, enhance its acceptability and produce good- quality flour, there is need to evaluate the nutritional quality of finger millet flour and foods produced using various processing techniques like roasting (dry heat treatment), fermentation and germination.
Diabetes mellitus is a global problem with devastating human, social and economic impact leading to disabilities such as; reduced quality of life and massive rise in direct and indirect medical cost (IDF, 2016). Nigeria with less than 5% health insurance coverage has the highest rate of diabetes in Africa (Osibogun, 2015). While global incidence of diabetes is increasing in an exponential manner, not much has been done to explore the anti-diabetic potentials of local food products. The traditional African diet that are locally available, affordable have been abandoned to westernized diet that include high energy, refined foods and fat.
The global incidence of diabetes is increasing in an exponential manner. It has been shown that the consumption of foodstuffs containing complex carbohydrates with high level of dietary fibre and health benefiting phytochemicals like polyphenols and phytates (Bouchenak and Lamri, 2013); Pulse Canada, 2013), could improve the condition (Shobanaet al.,2013). At present, diabetic individuals are advised to avoid the consumption of mixed diets (different components of food groups) which leads to complication faster and most Nigerian diets have not been evaluated for suitability in diabetic management.
Recommended: EFFECT OF PROCESSING ON FUNCTIONAL PROPERTIES, NUTRIENTS COMPOSITION, GLYCEMIC INDEX AND SENSORY ATTRIBUTES OF FINGER MILLET (ELEUSINE CORACANA) FOOD PRODUCTS
1.4 Aim and Objectives
|The aim of||this work||is to||determine the||effect ofprocessing (roasting,|
|fermentation||and germination) on some functional properties, nutrient|
|composition, glycemic||index||and sensory||attributes||of finger millet|
|(Eleusinecoracana) food products (pap and tuwo).|
The objectives are:
- To determine the effect of processing (roasting, fermentation and germination) on some functional properties (bulk density, water and oil holding capacity, swelling power and solubility) of finger millet flour.
- To determine the effect of processing (roasting, fermentation and germination) on nutrients composition (proximate, minerals, amino acids, dietary fibre) and anti-nutrient composition of finger millet flour and food products.
- To determine the effect of processing (roasting, fermentation and germination) on the glycemic index of food products (Pap and tuwo) developed from processed finger millet food ptoducts (Pap and tuwo)
- To determine the effect of processing method on sensory attributes of common food products made from processed finger millet.
1.5 Null Hypothesis
Processing has no effect on functional properties, nutrient composition of flour, glycaemic index and sensory attributes of finger millet food products.