PROXIMATE ANALYSIS ON TIGERNUT
TABLE OF CONTENT
Title page i
Table of content vi
1.1 Literature Review 5
1.2 Tiger-Nut as a Plant 11
1.2.1. Fresh Tiger-Nut 17
1.2.2. Tiger-Nut Milk 19
1.2.3. Tiger-Nut Flower 21
1.3 Economic and Nutritional Benefit of 26
1.4 Uses of Oil 32
1.4.1 Use in Medicine and Cosmetic Industry 33
1.5 Storage 34
1.6 Side effect of Eating Tiger-Nut 35
2.0 Materials and Method 36
2.1 Yellow Variety of Tiger-Nut 36
2.2 Proximate Analysis on Tiger-Nut 37
2.2.1Determination of Moisture content37
2.2.2 Determination of Ash Content 38
2.2.3 Determination of Protein Content 39
2.2.4 Determination of Fat Content 41
2.2.5 Determination of Fiber Content 43
2.2.6 Determination of Crude Fat 44
3.0 Result 47
3.1 Proximate Composition of Tiger Nut 47
3.1.1 Moisture content (Percentage 47
3.1.2 Ash content (Percentage) 48
3.1.3 Protein content (Percentage) 49
3.1.4 Fat content (Percentage) 49
3.1.5 Fibre content (Percentage) 49
3.2 Analysis on Fat Extraction 49
3.3. Sterols Composition 51
3.4 Calculation for Crude Fat 51
4.0 Discussion and Recommendation 52
4.1 Conclusion 52
4.2 Reference 54
Tiger nut is a tuber that is grown in the soil. It has a dimension ranging from 6-10 mm and occurs in different varieties. The colour is brown and has a sweet flavor when eaten. Tiger nut has been used extensively mainly for human consumption in Spain (Mason, 2008; Tiger nuts Traders, 2009). Tiger nuts are prepared and eaten cold as snacks. The milk can be extracted, treated and bottled. The flour is used to make cakes and biscuits and the oil is used for cooking (Wise, 2009). In United Kingdom, tiger nut is superb bait for carp fishing (Wise, 2009).
In Nigeria, the utilization of tiger nut is highly limited in spite of the fact that tiger nut is cultivated widely in the Northern part of the country. Tiger nuts are eaten raw mainly as snacks or fried and eaten mixed with roasted groundnuts (Abaejoh et al., 2006).
Kofi (1990) reported that sweetened tiger nut extract are bottled and sold in Ghana.
Recently, there is awareness for increased utilization of tiger nut (Belewu and Abodunrin, 2006; Belewu andBelewu, 2007; Ade-Omowaye et al., 2008; Ukwuru et al., 2008). Tiger nuts are valued for their highly nutritious starch content, dietary fibre and carbohydrate (Umeneand Enebeli, 1997) and are rich in sucrose (17.4-20.0%), fat (25.5%), protein (8.0%) (Kordyias, 1990; Temple et al., 1990). Tiger nut is also rich in mineral content such as sodium, calcium, potassium, magnesium, zinc and traces of copper (Omode et al.,995; Oladele and Aina, 2007). The dietary fibre content of tiger nut is effective in the treatment and prevention of diseases such colon cancer, coronary heart diseases, obesity, diabetes and gastro-intestinal disorders (Anderson et al., 1994).
Tiger nut tubers are diuretic and can be used as stimulant and tonic (Chopral et al.1986) and in the treatment of flatulence, indigestion, diarrhea, dysentery and excessive thirst (Chevalier, 1996). In addition, tiger nut has been demonstrated to contain higher essential amino acids than those proposed in the protein standard by FAO/WHO (1995) for satisfying adult needs for protein (Bosch and Alegna, 2005). Researchers have developed phyto milk of acceptable quality from tiger nut tubers (Abaejo et al., 2006; Ukwuru et al., 2008). Possible industrial application of tiger nut tubers has also been investigated (Oderinde and Tahir, 1988).
Tiger nut tubers can be processed in different ways to obtain different products. Pak. J. Nutr., 10 (2): 101-105, 2011-102. These products are of high nutritional values and Collins and Lyne (1979). The samples were serial economic potentials, hence deserve a greater attention diluted and an aliquot was plated in duplicate plates offhand it is currently given. As a crop that is grown widely in plate count agar for bacteria and potato dextrose agar for Nigeria, its availability is guaranteed. What are currently moulds. The plates were incubated at 37 C, 24 h and militating against the utilization of tiger nut is the little 25 C, 3 days for bacteria and moulds respectively. Awareness of the importance of this plant. The following Counts were carried out on plates containing 30-300are possible derivatives of tiger nut: flour, milk, oil, cake, colonies using a colony counter and expressed as cream cheese, chocolate, biscuits, cookies, etc. The colony forming unit (cfu).objective of this research was to develop new products from tigernut tubers in other to increase the utilization of tigernut.
1.1 LITERATURE REVIEW
Tiger nut (Cyperus esculentus var. sativa) as a plant, its derivatives/uses and benefits are mainly discussed. The hunt for lesser known and un-exploited crops, many of which are potentially valuable as human and animal foods has been on the high side now to retain the equilibrium between population growth and agricultural productivity, particularly in the tropical and sub-tropical areas of the world. Tiger nut is an underutilized crop of the family Cyperaceae, which produces rhizomes from the base and tubers that are somewhat spherical.
Pollination is by wind. Young tubers are white, while older tubers are covered by a yellow outer membrane; they are usually found within six inches of the ground surface. Vegetative colonies of its plants are often produced from the tubers and their rhizomes. They are usually preserved by sun drying for about three months before storage. It can be eaten raw, dried, roasted, or grated and can be subjected to further processing. Its uses in cooking and as fuel, baking flour, fish baits; milk in lieu of cow’s milk is outlined. Regarding the plant high percentage of carbohydrates (mono- and di-), fibre, and oil (especially oleic acid) and its moderately high level of protein, minerals (calcium, magnesium, iron and phosphorous), and vitamins C and E makes it a good source of food for humans and animals. It is a cheap source of nutrition for both the rich and the poor. The health benefits reflect reduction of low density lipoprotein-cholesterol, which is good for sports’ men and women and those intending to lose weight; it is also said to serve as a cure for flatulence and diarrhea, and as control against heart attacks, thrombosis and colon cancer, among others. The presence of anti-nutrients like polyphones and tannins can be eliminated by boiling in water. The tiger nut, though under-utilized, is still a good food snack for all. There is a need for awareness creation on tiger nut’s inherent nutritional properties.
The effects of Cyperus esculentus tuber oil based meal on the growth performance and its absorption in some selected organs (hearts, kidney, brain and liver) of rats were investigated.
Twenty five weaning albino rats (Rattus norvegicus) with an average weight of 24.0 ± 3.4g were maintained on diets composed of Cyperus esculentus tuber oil meal (Tg meal) and soybean oil based meal (control) for six weeks. The weights of the rats were monitored on weekly basis, at the same period of the day and before being served the (weighing) day’s feed. The organs and carcasses of the rats were weighed after they were sacrificed and disemboweled, and the chemical compositions of the carcasses were also determined. There was a significant increase(p<0.05)in the body weights of rats fed on Tiger nut oil while the organ to body weight ratio of the rats maintained on of Cyperus esculentus tuber oil meal compared significantly with the weights of the control animal (p>0.05). The organs showed the presence of Lauric, Myristic,Palmitic, Stearic, Oleic and linoleic acid using HPLC. It can be deduced that the oil of Cyperus esculentus tuber oil meal could competitively compare with that of soybean oil by increasing thegrowth rate of rats and in reducing accumulation of lipids in vital organs that can cause Inflammation or constriction of the cell.
This work analyzed proximate composition, mineral elements and anti-nutrients in Citrullus vulgaris (guna) seed. Proximate composition of guna showed by percent dry matter of moisture, fat/lipid, crude protein, ash, crude fibre, carbohydrate, forum defatted, defatted and protein concentrates. The mineral elements in mg/100g include; sodium, calcium, zinc, iron, copper, manganese and chromium, but chromium was not detected in any of the three samples.
The anti-nutrients determined were phytate, oxalate and tannin, in undefeated, defatted and protein concentrate. Tannin was not detected in any of the flours samples. Thus, ‘guna’ compares with other protein rich foods like soybean, pumpkin, cowpea and pigeon pea.
Tiger nut (Cyperus esculentus var. sativus), an emergent grass- like plant belonging to the sedge family, is also found to be a cosmopolitan perennial crop of the same genus as the papyrus plant that is common in seasonally flooded wetlands . It is widely distributed in the temperature zones within South Europe as its probable origin, and has become naturalized in Ghana, Nigeria and Sierra Leone. Tiger nut is one of the earliest domesticated crops and in fact, was found in vases and was used to embalm bodies of the Egyptian Pharaohs.
In Nigeria, tiger nut is available in fresh, semi-dried and dried form in the markets where it is sold locally and consumed even uncooked. Tiger nuts are under-utilized due to lack of information on their nutritional potential. A lot of people eat the tiger nut without knowing the nutritional benefits and products that can be obtained from it like tiger nut oil and milk. The purpose of this review was to bring together some of the data on the uses, health and economic benefits of the tuber of the tiger nut that is completely unexploited in Nigeria.
1.2 TIGER NUT AS A PLANT
Tiger nut is a tough erect fibrous-rooted perennial plant, 1 to 3 ft high, reproducing by seeds and by many deep, slender rhizomes, which form weak runners above the ground, and small tubers or nut lets at the tips of underground stems. This native perennial sedge is ½–2 inches tall and unbranched. The central stem is erect, 3-angled, and mostly covered by the sheaths of the leaves. The leaves tend to congregate toward the base of the plant. The leaf blades are up to 1½ inches long and 1/3 inches across; they are light green and glabrous, spreading outward from the stem. There is a conspicuous channel along the central vein of each leaf blade, especially the larger ones. The leaf sheaths are whitish green, closed, and hairless; sometimes they become pale red towards the base of the plant The central stem terminates in an umbel or compound umbel of floral spikes; the size and shape of the umbel is rather variable (on larger plants, it is usually several inches across). Each umbel has 1-3 sessile spikes and 6-10 non-sessile spikes on straight branches of varying length. At the base of each umbel or compound umbel of spikelets, there are several leafy bracts of varying length; the largest bract is usually longer than the inflorescence. Each floral spike is about 2-3 inches long, consisting of 4 ranks of spikelets along its central stalk (or rachis). The central stalk is flattened and narrowly winged. The spikelets are perpendicular to this stalk and about ½–¾ inches long. The spikelets are yellow to golden brown, narrowly linear, and flattened in shape; they consist of 10-30 florets and their scales.
The overlapping scales are slightly spreading along the length of each spikelet; each scale is 2.0–3.0 mm. in length. Each floret has a white tripartite style and yellowish brown anthers; the tips of the styles are curly. The blooming period occurs from mid-summer to early fall.
Pollination of the tiger nut plant is by wind. The florets are replaced by small achenes that are 1.0–1.5 mm. long, oblongoid or oblongoid-obovoid, and flattened. The shallow root system is fibrous, rhizomatous, and tuberous.
The white rhizomes have a slightly segmented appearance from the brown margins of their outer membranes; the rhizomes are connected to small globoid tubers up to ½ inch across. Young tubers are white, while older tubers are covered by a yellow outer membrane they are usually found within 6 inches of the ground surface. Vegetative colonies of plants are often produced from the tubers and their rhizomes.
The nutlets are almost smooth at maturity and unevenly globe shaped . High temperatures and low nitrogen levels increase tuber production and an increased day length (by lighting) will reduce tuber formation. The tuber epidermis (skin) contains substances, which inhibit sprouting of tubers; the plant grows best in moist sandy-loam soils but will grow in the hardest clay, tolerates high soil moisture and is intolerant to shade [8, 9]. The plant produces small, oblong tubers in abundance, which are sweet and rich in fat.
It has many other names like Zulu nut, yellow nut grass, ground almond, and chufa, edible rush and rush nut. In Nigeria, the Hausas call it “Aya”, Yorubas “imumu”, the igbos “ofio”, “aki Hausa” in southern Nigeria . Tiger nuts which are incorrectly called “nuts” or “nutlets,” thus the origin of their common name, are small about the size of a peanut growing at the rhizome of the plant. Like other sedges, the plant is most frequently found inhabiting wet marshes and edges of streams and ponds where it grows in coarse tufts . Tiger nut tubers are daily ingredients of the diet of many people in North Africa and Spain. In North Africa, the tubers are consumed in their natural form or after being soaked in water for some hours. In Spain, the tubers are consumed mainly as a drink called locally “horchata de chufa” (chufa milk).
This plant was originally native to the Mediterranean region but its cultivation has now spread to many warm countries. It is usually sown in April and picked in November. There are mainly three varieties namely: black, brown and yellow, and only yellow and brown are readily available in the Nigerian markets. The yellow variety is preferred to all other varieties because of its inherent properties like its bigger size, attractive colour and fleshier body. The yellow variety also yields more milk, contains lower fat and higher protein and less anti-nutritional factors especially polyphones
1.2.1 FRESH TIGER NUT
In Northern Nigeria, the nut can be bought in the market all year round. The weight of fresh tuber ranges from 70mg to about 900mg while the weight of dried tuber ranges from 30mg to 350mg. A dried tuber nut can absorb up to three times its own weight of water. A single tuber can produce nearly 2000 plants and 7000 tubers in one growing season. It was observed that tiger nut production is predominantly the work of women farmers as high as 70% and 30% men . The nuts are valued for their highly nutritious starch content, dietary fibre, digestible carbohydrate (mono, di and polysaccharides) [14, 19]. The nut was reported to be rich in sucrose (17.4 to 20.0%) and fat (25.50%) which are resistant to per oxidation, and protein (7-8%) [9, 20, 21] as indicated in Table 1. The nut is also fairly rich in mineral content (Sodium, Calcium, Potassium Magnesium, Zinc and traces of Copper) . Tiger nut has been cultivated as a livestock food and for human consumption; it can be eaten raw, roasted, grated, baked or used for ice cream and beverage making for its many useful benefits [22, 23]. They taste best when dried. They are generally dried out (mostly in the sun), a process that takes one or more months with occasional turning over to ensure uniform drying to preserve them and to eliminate prevailing rot or any microbial infection.
This secures their nutritional quality although, unfortunately, as they dry, they become wrinkled. As they dry, temperature and relative humidity are monitored. Once dry, they can be kept for several years, to be reconstituted by soaking overnight or by boiling when ready to serve those. The nutritional value of tiger nut derivatives, like oil and milk, arises from the very composition of the tiger nut. The level of anti-nutrients such as tannins, alkaloids and polyphones is drastically reduced by soaking in water for 6 hours, thereby making it free of unwanted elements especially in making the milk.
1.2.2 TIGER NUT MILK
The origin of the use of this tuber for making milk is exclusive to the Spaniards to which it may have been introduced by the Arabs. Tiger nut milk/beverage/drink commonly called ‘kunnu aya’ in northern Nigeria is a healthy drink with many nutrients. It is a nourishing and energetic product recommended by experts to be taken during any season of the year, especially in dry season when the sun is hot. In Spain, it is called chufa de horchata. It is a rich source of nutrients such as vitamins C and E, and minerals such as phosphorus, magnesium, potassium, calcium, iron, and also carbohydrates, unsaturated fats, proteins and some enzymes which help in digestion.
In fact this drink contains more iron, magnesium and carbohydrates than the cow’s milk. It has also the advantage of not containing lactose, casein, sugar or proteins of the milk, or cholesterol and is therefore an ideal drink for people who do not tolerate gluten or cow’s milk. The nutritional value of tiger nut beverage is, however, insufficient given that its protein content is low (6.05%)
1.2.3 TIGER NUT FLOUR
Tiger nut flour has a unique sweet taste, which is ideal for different uses. It is a good alternative to many other flours like wheat flour, as it is gluten free and good for people who cannot take gluten in their diets. It is also used in the confectionery industry it is considered good flour or additive for the bakery industry, as its natural sugar content is fairly high, avoiding the necessity of adding too much extra sugar. Also, it can be used as a flavoring agent for ice cream and biscuits.
In the Keta area of Ghana, the sun-dried tubers are ground to a fine powder to which sugar can be added to be stored till required. Roasted tubers may be similarly ground to a powder known in Vhe (Awlan) as fie-dzowe. These meals may be eaten alone or with water added to make a beverage.
In addition, tiger nut has been demonstrated to contain higher essential amino acids than those proposed in the protein standard by the FAO/WHO  for satisfying adult needs. Therefore, tiger nut, with its inherent nutritional and therapeutic advantage, could serve as good alternative to cassava in the baking industry.
Furthermore, tiger nut flour does not lose any of its nutritious properties in the milling process. The fine ground tiger nut flour gives baits a smooth, creamy texture with a distinctive taste fish love, and can be incorporated into any mix as base ingredient, allowing baits to retain moisture.
Incidentally, cutting part or all of the skins off tiger nut hook baits makes them more effective. Part of tiger nuts’ attraction is that they are rich in lysine, a major fish feeding stimulant though tiger nuts also contain many other extremely important and stimulatory dietary essential amino acids for fish, including methionine, cystine, arginine and histidine.
The edible and stable oil obtained from the tuber is said to be superior oil that compares favorably with olive oil. The oil is golden brown in colour and has a rich, nutty taste. The oil remains in a uniform liquid form at refrigeration temperature. This makes the oil suitable for salad making. It has a high oleic acid and low polyunsaturated fatty acid (linoleic acid and linolenic acid) [36, 37], enough to cover daily minimum needs for an adult (around 10 g) and low acidity, and so is excellent for the skin. It also has higher oxidative stability than other oils, due to the presence of polyunsaturated fatty acids and gamma-tocoferol .
It is regarded as high quality oil due to its extraction without adding any external heat (cold pressed oil), and is highly recommended for cooking over other oils because it is more resistant to chemical decomposition at high temperatures . Furthermore, less fat is absorbed into the food as it creates a crust on the surface during cooking, preventing the oil itself being absorbed into the product. In the textile industry, the oil is used to waterproof textile fibres. The oil compares well with corn, soybean, olive and cotton seed oil and can thus serve as a substitute for these oils especially in times of scarcity . The oil is a potential source of biodiesel and much research has been conducted.
The edible and stable oil obtained from the tuber is said to be superior oil that compares favorably with olive oil. The oil is golden brown in color and has a rich, nutty taste . The oil remains in a uniform liquid form at refrigeration temperature. This makes the oil suitable for salad making. It has a high oleic acid and low polyunsaturated fatty acid (linoleic acid and linolenic acid) [36, 37], enough to cover daily minimum needs for an adult (around 10 g) and low acidity, and so is excellent for the skin. It also has higher oxidative stability than other oils, due to the presence of polyunsaturated fatty acids and gamma-tocoferol It is regarded as high quality oil due to its extraction without adding any external heat (cold pressed oil), and is highly recommended for cooking over other oils because it is more resistant to chemical decomposition at high temperatures .
Furthermore, less fat is absorbed into the food as it creates a crust on the surface during cooking, preventing the oil itself being absorbed into the product. In the textile industry, the oil is used to waterproof textile fibres. The oil compares well with corn, soybean, olive and cotton seed oil and can thus serve as a substitute for these oils especially in times of scarcity . The oil is a potential source of biodiesel and much research has been conducted..