NUTRIENT COMPOSITION, FUNCTIONAL AND ORGANOLEPTIC PROPERTIES OF COMPLEMENTARY FOODS FROM SORGHUM, ROASTED AFRICAN YAM BEAN AND CRAYFISH

ABSTRACT

Complementary foods were formulated using sorghum, African yam bean and crayfish. The nutrient composition, functional properties and organoleptic attributes of the formulated complementary foods were investigated. The different flours were combined in the ratios of; 70:20:5, 80:15:5, 75:20:5, of sorghum, African yam bean and crayfish respectively. Cerelac, a commercial sample served as control. Porridges were prepared from the composite blends for organoleptic evaluation. Standard methods were used to analyze the composite flours. The protein content of African yam bean and crayfish flours complemented the sorghum protein and improved the nutritional quality of the formulated food. The result of the functional properties showed no significant difference (P > 0.05) in both bulk density and viscosity. Sensory evaluation revealed that the porridge from the control was preferred over the others. Among the blends, the porridge made from 70:20:5 sorghum / African yam bean / crayfish was preferred over the others. The study showed that composite blends from sorghum, African yam bean and crayfish are nutritionally adequate and possess good functional properties which are required for the preparation of complementary foods for infants.

CHAPTER ONE

INTRODUCTION

In developing countries like Nigeria, complementary foods are mainly based on starch tubers like cocoyam, sweet potato or on cereals like maize, millet and sorghum. Children are normally given these staples in the form of gruels that is either mixed with boiled water (Igyor et al., 2011).

Sorghum is an important food crop grown on a subsistence level by farmers in the semi arid tropics of Africa and Asia. It is the principal food crop grown in Northern Nigeria (Zakari and Inyang, 2008). Sorghum like other cereals is predominantly starchy and remains a principal source of energy, protein, vitamins and minerals. Sorghum grows in harsh environments where other crops do not grow well, just like other staple foods, such as cassava, that are common in impoverished regions of the world. It is usually grown without application of any fertilizers or other inputs by a multitude of small _holder farmers in many countries FAO (1999).

African yam bean (Sphenostylis stenocarpa) is an underutilized legume crop that is predominantly cultivated in Western Africa. It produces nutritious pods, highly portentous seeds and capable of growth in marginal areas where other pulses fail to thrive (Enwere, 1998). It has the potential to meet the ever increasing protein demands of the people in this region.

Crayfish, also known as crawfish, freshwater lobsters, to which they are related; taxonomically, they are members of the super families Astacoidea and parastacoidea (Hart 1994). The greatest diversity of crayfish species is found in Southeastern North America, with over 330 species in nine genera, all in the family Cambraridae (Tennessee Aquatic Nuisance 2007). A further genus of astacid crayfish is found in the Pacific Northwest and the headwaters of some rivers east of the continental Divide. Many crayfish are found in lowland areas where the water is abundant in calcium, and oxygen rises from underground springs (Thompson et al., 2007).

Since many African mothers use gruels made from sorghum as complementary foods, for their infants, due to their inability to afford the cost of nutritional superior commercial meaning foods, this work was conducted to evaluate the nutrient composition, functional and organoleptic properties of complementary foods from sorghum, roasted African yam bean and crayfish locally formulated into flour blends.

AIM AND OBJECTIVE

To determine the nutrient composition, functional and organoleptic properties of complementary foods from sorghum, roasted African yam bean and crayfish.

CHAPTER TWO

LITERATURE REVIEW

COMPLEMENTARY FOODS

Complementary foods are foods other than breast milk or infant formula (liquids, semisolids, and solids) introduced to an infant to provide nutrients. Recommendations on the introduction of complementary foods provided to caregivers of infants should take into account:

• The infant’s developmental stage and nutritional status;
• Coexisting medical conditions;
• Social factors;
• Cultural, ethic, and religious food preferences of the family;
• Financial considerations; and
• Other pertinent factors discovered through the nutrition assessment process.

The ideal time to introduce complementary foods in the diets of infants is difficult to pinpoint. Complementary foods introduced too early are of little benefit to the infant and may even be harmful due to the possibility of breast milk or infant formula. Introducing complementary foods too late may cause an infant to develop nutritional readiness. Consequently, the infant may have difficulties learning to eat complementary foods when they are introduced later. When complementary foods are introduced appropriate to the developmental stage of the infant, nutritional requirements can be met and eating and self_ feeding skills can develop properly. Pediatric nutrition authorities agree that complementary foods should not be introduced to infants before they are developmentally ready for them; this readiness occurs in most infants between 4 and 6 months of age.

‘There is no evidence for harm when safe nutritious complementary foods are introduced after 4 months when the infant is developmentally ready. Similarly, very few studies show significant benefit for delaying complementary foods until 6 months’ (Complementary Feeding 2004). The timing of introduction of complementary foods for an individual infant may differ from this recommendation. There is some disagreement among authorities on the need for additional sources of nutrients of nutrients besides breast milk in the first 6 months. However, there is agreement that infants need a good dietary source of iron and zinc by about 6 months of age, which cannot be met by breast milk alone.

Older babies and young children need foods other than breast milk for two reasons: firstly for nutrition to grow and develop healthy; secondly to accustom them to the eating habits of the family and community. These two goals do not always harmonize. However, in some societies, the shamed family meal may not deliver appropriate nutrients to the young child and she may miss out nutritionally if parents and caregivers are unaware of the importance at active feeding and do not know which foods are the most appropriate.

The use of an age based cut-off for the introduction of complementary foods is unphysiological and is a clumsy (though necessary) public health tool. As Gill Raphey has pointed out so cogently, children do not crawl, walk, cut their teeth or talk at an exact age so why are they all expected to need complementary feeding at the same age (Raphey G, 2006).

Contaminated complementary foods are the major route of transmission of diarrhea among infants (Black et al., 1999). For this reason, the higher incidence of diarrhea in the second semester of life coincides with the increase in the intake of these foods (Martinez et al., 1992). Proper material practices regarding the management, preparation, administration and storage of complementary foods may reduce their contamination (Feachem et al., 1993).

Safe food hygiene practices include the following : those who handle the food, during preparation or feeding should wash their hands properly with soap and water, after using the toilet and before meals, and the infant’s hands should be washed likewise; kitchen utensils and cooking surfaces should be kept clean; only healthy- looking foods should be kept in a safe place; an amount of food that suffices one meal only should be prepared and it should be served immediately after preparation; the infants should be fed from a glass or cup, spoon and plate, avoiding the use of baby bottles; infants should not be given leftovers from the previous meal; and if using a fridge, it should be cleaned regularly and any spoilt foods should be thrown away (WHO 2001). Baby bottles are difficult to clean and are a major source of contamination. In Peru, an inspection revealed that 35% of bottles nipples were contaminated with E. coli. This bacterium was detected in 31% of teas offered in bottles, but in only 2% of teas served in glasses (Black et al., 1999).

SORGHUM

Sorghum in general is a very competitive crop, and does well in competition with weeds in narrow rows. Sorghum produces a chemical compound called soroleone, which the plant uses to combat weeds. The chemical is so effective in preventing the growth of other crops harvested on the same field. To address this problem, Researchers at the Agricultural Research Service found two gene sequences believed to be responsible for the enzymes that secrete the chemical compound soroleone. The discovery of these gene sequences will help researcher one day in developing sorghum varieties that cause less soil toxicity and potentially target gene sequences in other crops to increase their natural pesticide capabilities as well (USDA 2010). Sorghum’s nutritional profile includes several minerals such as phosphorus, iron, zinc and copper decreased with lower extraction rates.

Similarly, pearling the grain to remove the fibrous seed coat resulted in considerable reductions in the mineral contents of sorghum. The presence of antinutrition factors such as tannins in sorghum reduces its mineral availability as food. It is important to process and prepare sorghum properly to improve its nutrition value.

Sorghum is a good source of B-complex vitamins. Some varieties of sorghum contain B-carotene which can be converted to vitamin A by the human body; given the photosensitive nature of carotenes and variability due to environmental factors, scientists claim sorghum is likely to be of little importance as a dietary source of vitamin A precursor. Some fat-soluble vitamins, namely D, E and K, have also been found in sorghum grain in detectable, but insufficient, quantities.

HEALTH BENEFITS SORGHUM (United States Grain Council 2010)

• Sorghum may inhibit cancer tumor growth.
• Sorghum may protect against diabetes and insulin resistance.
• Sorghum may help manage cholesterol.
• Sorghum is safe for people with celiac disease.
• Sorghum may help treat human melanoma.

Sorghum’s yields are not affected by short periods of drought as severally as other crops such as maize, because it develops its seed heads over longer periods of time, and short periods of water stress do not usually have the ability to prevent kernel development. Even in a long drought severe enough to hamper sorghum production, it will still usually produce some seed on smaller and fewer seed heads. Rarely will one find a kernelless season for sorghum, even under the most adverse water conditions. Sorghum’s ability to thrive with less water in its foliage better than maize. Sorghum has a waxy coating on its leaves and streams which helps to keep water in the plant, even in intense heat.

Sorghum’s growth habitat is similar to that of maize, but with more side shoots and a more extensively branched root system is very fibrous, and can extend to a depth of up to 1.2m. The plant finds 75% of its water in the top meter of soil, and because of this, in dry areas; the plant’s production can be severely affected by the water holding capacity of the soil. The plant’s require up to 70 100mm of moisture every 10days in early stages of growth stages and the roots penetrate more deeply into the soil to tap into hidden water reserves, the plant needs progressively less water. By the time the seed heads are filling, optimum water conditions are down to about 50mm every 10days. Compacted soil or shallow top soil can limit the plant’s ability to deal with drought by limiting its root system. Since these plants have evolved to grow in hot, dry areas, it is essential to keep the soil from compacting to grow on land with ample cultivated top soil.

Insect and diseases are not prevalent in sorghum crops. Birds, however, are a major source of yield loss. Hybrids with higher tannin content and growing the crop in large field blocks are solutions used to combat the birds. The crop may also be attacked by corn ear worms, aphids, and some Lepidoptera larvae, including turnip moths (Agricultural Production, Worldwide 2009 and FAOSTAT 2010).

AFRICAN YAM BEAN (AYB)

African yam bean (Sphenostylis stenocarpa), is the most economically important among the seven species of sphenostylis (Potter 1992) and it is one of the most important tuberous legumes. The domestic action, cultivation, and distribution of the crop are very evident in the tropics of Africa (Okigbo 1973, Potter 1992, Anochili 1984, and Okpara and Omalico1997) where it had been reported to exhibit very high diversity. There is no record of any other center of diversity for the crop beyond tropical Africa. It should not be confused with the Pachyrhizus spp. is a more popular tuberous legume that is common in the tropics of Asia and Southern America.

DOMESTICATION, CULTIVATION, AND THE CULTURAL PLACE OF AYB.

AYB is rarely planted as a sole crop in Ghana and Nigeria; it is mostly interplant with yam (Okigbo 1973 and Klu et al., 2001). The seeds and tubers (plates 1 and 2) are the two organs of humans and livestock. However, there is a cultural and regional preference for each; West Africans, especially among the Bandudus, the Shabas, and the tribe at Kinshasha in Democratic Republic of Congo (Potter 1992 and Nwokolo 1987). This exceptionally nutritious pulse (Rachie 1973) has a very significant link with African sociocultural life. For instance, the Avatimes in Ghana prepare a special rite of adolescent girls (Klu 2001). Likewise a special meal from it features during the marriage ceremony among the Ekiti’s in Nigeria (Potter 1992). Different forms of local recipes are prepared from the crop to meet the dietary meal of the people.

POTENCIALS OF AFRICAN YAM BEAN

The economic potentials of AYB are immense. Apart from the production of two major food substances, the value of the protein in both tubers and seeds is comparatively higher than what could be obtained from most tuberous and leguminous crops (Okigbo 1973 and Nwokolo 1987). The protein in the tuber of AYB is more than twice the protein in sweet potato (Ipomea batatas) or Irish potato (solanum tuberose) (National Research Council 1979) and higher than those in yam and cassava (Amoatey et al., 2000).

Moreover, the amino acid values in AYB seeds are higher than those in pigeon pea, cowpea, and bambara groundnut (Uguru and Madukaife 2001). Protein content is up to 19% in the tuber and 29% in seed grain. The content protein in AYB seeds is lower than that the level of most of the essential amino acids especially lysine, methionine, histidine, and iso-luceine in AYB is higher than those in other legumes including soybean (Abbey and Berezi 1988, National Research Council 2007, Evang and Haismer 1977 and Ihekoronye and Ngoddy 1985). AYB is rich in minerals such as K, P, Mg, Ca, Fe, and Zn but low in Na and Cu (Nwokolo 1987, and Edem et al., 1990)

• Insecticidal and medical usefulness

AYB as a crop is less susceptible to pests and diseases (Duke 1981) compared with most legumes; this quality may undoubtedly be due to the inherent lectin in the seed of the crop (Omitogum et al., 1999) advanced the prospect that the lectin in the seed of the crop is a promising source of a biologically potent insecticide against field and storage pest of legumes. Therefore, the inclusion of the lectin extract from AYB in the meal for three cowpea insect pests, namely, maruca vitrata, callosobruchus maculatus, and clavigralla tomentosiocollis gave a mortality rate greater than 80% after 10days. The physiological system of C. tomentosicallis was found to be very vulnerable to the lectin in AYB (Okeola and Machuka 2001). In Togo, Ghana, and Nigeria, paste made from the seeds of AYB is used as a cure for stomach aches, and when the paste is mixed with water it is traditionally used for the treatment of acute drunkness (Gaisser 1912 and Asuzu 1986). Asuzu 1986 reported that there might be pharmacological evidence for the use of AYB in treating such conditions.

• Stable yield across wide environments

The seed yield of AYB can be as high as 300kg/ha (Okigbo 1973 and Dukes 1981). The average seed/plant is between 100 and 200g and the tuber yield per plant is 0.5kg (Anochili 1984 and National Research Council 2007). In different yield trials in Nigeria (IITA, Ibadan and Nsuka), the most production accession in each case gave 1860kg and 2000kg of seeds/ha (National Research Council 2007). Coupled with high yield is vast adaptability to adverse edaphic conditions (Schippers 2000 and Betsche 2005). AYB produces an appropriate yield more than most other pulses on poor soil and in a hot climate (Nwokolo 1996). AYB has very high ability to fix nitrogen (Assefa and Kleiner 1997); it is therefore an important crop which merits significant consideration for land reclamation.

LIMITATIONS IN AYB

Overtime, some conditions have negatively influenced the productibility and acceptability of the crop among cultivators, consumers, and research scientists. Nationable among the list are;

• The characteristics hardness of the seed coat (Oshodi et al., 1995 and Ene-Obong and Okoye 1993) which makes a high demand on the cost and time of cooking.
• The agronomic demand for states, the long maturation period (Okpara and Omaliko 1997 and National Research Council 2007), and
• The presence of antinutritional factors (ANF) or secondary metabolites (Machuka and Okeola 2000). The photoperiodic sensitivity of AYB (Anochili 1984) seems to compound the above disadvantages as it confines the cultivation and production of the crop to one season in the year. However, a concerted crop breeding research programme may overcome these problems.

CRAYFISH

Crayfish are the small lobster-like crustaceans that are found in freshwater bodies. Also known as crawfish and crawlands, these creatures are close relatives of the larger marine lobsters. Indeed, there is considerable physical resemblance between lobsters and crayfish, with the latter being much smaller in size than the former. Although most crayfish are found in fresh water, sometimes they are found in brackish water bodies and creeks (from where they might migrate further into salt water). Crayfish belong to the biological order Decapoda, and are also related to crabs, hermit crabs, hermit crabs, and shrimp, besides lobsters (Harold 1995).

GEOGRAPHICAL DISTRIBUTION AND CLASSIFICATION OF CRAYFISH

There are three families of crayfish, two in Northern Hemisphere (Gondwana-distributed) family parastacidae lives in South America, Madagascar and Australia, and is distinguished by the lack of the first pair of pleopods (Horton 1994). Of the other two families, members of the Astacidae live in Western Eurasia and Western North America and members of the family cambaridae live in eastern Asia and Eastern North America.

USES OF CRAYFISH

Crayfish are eaten worldwide. Like other edible crustaceans, only a small portion of the body of a crayfish is eaten. In most prepared dishes, such as soups, bisques and etuoffees, only the tail portion is served. At crawfish boils or other meals where the entire body of the crayfish is presented, other portions, such as the claw meat, may be eaten. Like all crustaceans, crayfish are not kosher because they are aquatic animals that do not have both fins and scales (Kosher 2010). They are therefore not eaten by observant Jews. As of 2005, Louisiana produced 90% of the crayfish harvested in the world, 70% of which were consumed locally (Larry and Robert 1990). In 2007, the Louisiana crawfish harvest was about 54.800 tons, almost all of it from aquaculture (The Louisiana 2007). About 70%_80% of crayfish produced in Louisiana are procambarus clarkia (red swamp crawfish), with the remaining 20%_30% being procambarus zonagulus (white river crawfish). (The Louisiana State University Agricutural Center 2007).

Crayfish are commonly sold and used as bait, either live or with only the tail meat, and are good at attracting channel cat shish, wallege, trout, large mouth bass, smallmouth bass, pike and muskellunge. Sometimes the claws are removed so that the crayfish do not stop fish from biting the hook. Crayfish easily fall off the hook, so casting should be slow.

The result of using crayfish as bait has led to various ecological problems at times. According to a report prepared by Illinois State University, on the Fox River and Des Plaines River watershed, ‘The rusty crayfish (used as bait) has been dumped into the water and its survivors outcompete the native Clearwater crayfish’. (‘Fox and Des Plaines Rivers Watershed’ 2001). This situation has been repeated elsewhere, as the crayfish bait eliminates native species. (Tennessee Aquatic Nuisance Species Task Force 2007).

The use of crayfish as bait has been cited as one of the ways zebra mussels have spread to different waterways, as members of this invasive species are known to attach themselves to crayfish (Thompson et al., 2007).

Crayfish are kept as pets in freshwater aquariums. Crayfish kept as pets in the US from local waters are usually kept with bluegill or bass, rather than goldfish or tropical or subtropical fish. They prefer foods like shrimps pellets or various vegetables, but will also eat tropical fish food, regular fish food, algae wafers, and small fish that can be captured with their claws. They will sometimes consume their old exoskeleton after it has molted. Their disposition towards eating almost anything will also cause them to explore the edibility of aquarium plants in a fish tank.

However, most species of dwarf, such as cambarellus patzcuarensis, will nondestructively dig or eat live aquarium plants (Gerald 2010). They are also relatively non-aggressive and can be kept safely with dwarf shrimp. Because of their very small size of 1.5inches (38mm) or less, some fish are often a threat to the crayfish.

Since crayfish are accustomed to being in ponds or rivers, they will have a tendency to shift gravel around on the bottom of the tank, creating will often try to climb out of the thank, especially if an opening exists at the top that they can fit through.

In some nations, such as the United Kingdom, United States, Australia, and New Zealand, imported alien crayfish are a danger to local rivers. The three species commonly imported to Europe from the Americas are Oreonectes limosus, Pacitadtacus leniusculus and Procambarus clarki (James 2008). Crayfish may spread into different bodies of water because specimens captured for pets in one river are often released into a different catchment. There is a potential for ecological damage when crayfish are often released into non-native bodies of water (e.g crayfish plague in Europe) (James 2008).

Crayfish have been recorded as an invasive species from Louisiana to consume local rice crops in China (Flatow 2014).

HEALTH BENEFITS OF CRAWFISH

• Crawfish is packed with high-quality protein. A5-ounce serving of crayfish contains close to 25 grams of protein.
• Crawfish are low in fat and contain only trace amounts of carbohydrates.
• Crawfish are high in B vitamins and minerals such as calcium, magnesium, iron, zinc and phosphorus.
• A 3-ounce serving of cooked crawfish contains 70 calories and 14 grams of protein.

MORE FACTS ABOUT CRATFISH

• The average person eats 3lbs. of boiled crawfish, which equals approximately 6-8 02 of meat; 6-7lbs. of crawfish is approximately 15% meat.
• Boiled crawfish are approximately 15% meat.
• When you suck the heads, you are actually getting some of the fatty organ surrounding the brain that absorbs the flavor.
• It’s a good idea to soak the crawfish before boiling to wash off slit and mud, but you can skip the added salt bath. Purging crawfish by bathing them in a salty brine doesn’t actually expel more mud.
• Like some sea food, crawfish is high in cholesterol. A 5-ounce serving contains close to 200 milligrams.