Proximate Analysis On Tigernut

CHAPTER ONE

1.1 INTRODUCTION

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.