REVIEW OF LITERATURE ON COWPEA PRODUCTS & NUTRITIONAL QUALITY | Oiet_facts
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REVIEW OF LITERATURE ON COWPEA PRODUCTS & NUTRITIONAL QUALITY

REVIEW OF LITERATURE

The literature pertinent to the present study has been reviewed under the following heads and sub-heads:2.1 Cowpea 2.2 Nutritional quality of cowpea seeds2.3 Cowpea products2.4 Malnutrition 2.4.1 Causes of malnutrition 2.4.2 Nutritional status of pre-school children2.4.3 Supplementary feeding to children2.5 Assessment of nutritional status2.5.1 Dietary assessment2.5.2 Anthropometric assessment(Weight, Height and MUAC) 2.5.3 Classification of nutritional status2.6 Factors affecting nutritional status of children 2.6.1 Socio-economic factors 2.6.1.1  Income and occupation 2.6.1.2  Family size and birth order 2.6.1.3  Education of parents2.7 Utilization of protein rich flour in formulation of biscuits2.8 Bakery Products 2.8.1 Biscuits2.8.2 Biscuit ingredients2.1 CowpeaCowpea (Vigna unguiculata) is one of the oldest source of human food, has most likely been used as a crop since, Neolithic times. Cowpea is known by a number of common names, viz., crowdel pea, black-eyed pea, southern pea and internationally as lobhia. Charka (700 B.C.) documented cowpea with its Sanskrit name rajmash and since then rajmash is the name used for cowpea in all Ayurvedic texts (Vidyalankar, 1994). Other Sanskrit names are mahamash and Chapala. The Jain literature (200 B.C.-300 A.D.) mentioned cowpea as chavala (Jain, 1984). Currently the popular names of cowpea are lobia and chaura. In other languages the names are chola or chorap (Gujrati), chavalya (Marathi), alasandulu (Telugu), alasande (Kannada) and karamani (Tamil). Cowpea growing countries in the Asian region are India, Sri Lanka, Bangladesh, Myanmar, China, Korea, Thailand, Indonesia, Nepal, Pakistan, Philippines, and Malaysia. India alone accounts almost half of the total Asian acreage. It is difficult to estimate the precise statistics on area and production of cowpea because of the fact; same is grown as mixed and intercrop. In India, it is mainly grown in semi-arid regions, however, Western, Central and peninsular regions are the major contributors. The total global area under food legume crops and their production in 2006-08 show that dry beans cover 46 per cent followed by chickpeas and cowpea, which each cover 18 per cent of total area. In terms of production, dry beans still dominate at 46 per cent, followed by chickpeas (22 per cent). The share of all the other food legume crops viz., faba beans, lentils, and pigeon peas in global production is no more than 10 per cent each. World cowpea production was estimated at 3319375 MT and 75 per cent of that production is from Africa followed by South America, Asia, North America and Europe (Figure 2.1).In India, cowpea is grown in about 0.5 million hectares of land with an average productivity of 500- 700 kg / hectare with a maturity period of 120-150 days. The major areas concentrated in cowpea production are Karnataka, Andhra Pradesh, Uttar Pradesh and Bihar. In India, cowpea is raised as a mixed crop along with either cereals or oilseeds (Ahlawat and Shivakumar, 2005). According to Pandey and Singh (2006) cultivating food legumes in the existing niches between wheat and rice systems may solve the problem of inadequate pulse production with limited land. Out of the major pulses, only green gram and cowpea have early maturing varieties, which mature in 65 to 75 days and can fit in between wheat rice cropping system.  Figure 2.1. World cowpea production (FAOSTAT, 2000)
2.2 Nutritional quality of cowpea seedsThe values of the proximate principles in cowpea as reported in the literature are presented in table and the detailed description of the proximate principles is given in following text.MoistureThe literature reviewed showed that the moisture content of cowpea seeds ranged from 8.9 to 14.31 per cent. Gopalan et al. (1998) reported an average moisture content of 13.4 per cent in cowpea. Akinjayeju and Bisiriyu (2004) found in their comparative study on unhulled, mechanically dehulled and manually dehulled brown and white colored cowpea that moisture content of unhulled white cowpea. Meiners et al. (1976) had reported that the moisture content of dried pulses is greatly affected by the relative humidity of the surrounding atmosphere at harvest and during storage.The Improved varieties of cowpea have been developed at International Institute of Tropical Agriculture (IITA). Shefali, 2007 studied the nutritional composition of the cowpea varieties and it was reported that average moisture content of three varieties viz. IT1042, IT205 and IT452 ranged from 12.17 to 12.50 per cent. Total ashThe inorganic constituent in the food-stuff is generally referred to as ash content. According to Omueti and Singh (1987), the ash content in cowpea ranged from 2.6-4.2 per cent. Bressani (1985) and Tindall (1983), had given the ash content in the range of 3.4-3.9 per cent. Jogyabathi et al. (2001) and Abbey and Ibeh (1988) reported the ash content of 3.5 per cent.It is reported that the mineral content of the legume is related to the mineral absorption by the roots which in turn is influenced by the composition of the soil at absorbing surface of the roots (Tiwari et al., 1977).According to Shefali (2007), the ash content of improved varieties of cowpea viz. IT1042, IT205 and IT452 ranged from 3.07 to 3.47 per cent.Crude proteinPulses have high protein content, which is about twice that in cereal therefore they can help to improve the protein intake of meals wherein cereals are eaten in combination with pulses (Kushwaha et al., 2002).Cowpea seeds contain varied amount of protein ranging from 16.4 per cent to 35 per cent. According to Ofuya and Akhidue (2005), the protein content of cowpea varieties varied between 20 to 34.2 per cent. The protein content of improved varieties of cowpea viz. IT1042, IT205 and IT452 ranged from 25.87 to 29.57 per cent (Shefali, 2007).Crude fatThe term crude fat includes true fat or glycerol, various fatty acids, chlorophyll and other pigments, sterols and esters of fatty acids. Most pulses contain only small quantities of fats which generally account to less than 3 per cent (Aykroyd and Doughty, 1982). In pulses, lipids are comprised of several classes i.e. neutral lipids, phospholipids and glycolipids. Total lipid content of pulses varies with variety, origin, location, climate, seasonal and environmental conditions and the type of soil in which they are grown. Cowpea seeds contain 2.05 per cent total lipid and the major fatty acids are linolenic and linolenic acid.Shefali, 2007 reported fat content of improved varieties ranged from 1.13 to 1.47 per cent.Crude fibreCrude fibre is the residue that remains after a food sample has been subjected to the treatment by acid and subsequently followed by an alkali. It comprises of only 1/5 to ½ of the total dietary fibre.Various workers had reported that crude fibre content in cowpea in the range of 1.7 to 7.3. Gopalan et al. (1989) had reported 3.8 per cent of crude fibre in cowpea seeds.  Shefali (2007) had reported range from 2.22 to 4.11 per cent in improved cowpea varieties.Carbohydrate  The carbohydrate content of pulses is high and contributes a great deal to the energy supply of pulses (Reddy et al., 1984; Oke et al., 1995). Total carbohydrate content of pulses varied from 56 to 68 per cent, with starch content in the range of 32 to 48 per cent and more than 50 per cent of the starch occurs in form of amylase (Bressani, 1985). Cowpea contains 54.5 per cent carbohydrate; however some of the varieties in drier zones contain only 39 % carbohydrate.EnergyPulse seeds are not only good source of protein but also of energy. Though not many reviews are available on energy content, the high energy content of 340 Kcal was reported by Phillips and Mc Watters (1991) and the low energy value of 323 Kcal had been reported by Gopalan et al. (1989). Minerals Pulses contain reasonable amounts of nutritionally important minerals such as calcium and iron. The literature reviewed showed that calcium content of cowpea seeds lie in the range of 69 to 116 per cent. The value of 69 per cent was reported by Akpapunam and Markakis (1981). Calcium content of 77 per cent was reported in Gopalan et al. (1989). Cowpea seeds are considered to be a rich source of iron. The level of iron as reported by Tindall (1983) was 5mg per cent while the high level of 8.6 per cent was reported by Gopalan et al. (1989) and Jogyabhathi et al. (2001). The iron content ranged from 6.9 to 7.9 in improved varieties viz. IT1042, IT205 and IT452 while 7.2 per cent in local variety was reported by Shefali, 2007.The micro minerals like copper, zinc, manganese, sodium, potassium are also present in fair amounts in cowpea. Manganese content had been reported in the range of 1.25 per cent to 1.7 per cent. The value of 1.34 per cent was reported in Gopalan et al. (1989). The zinc content in cowpea varies from 2.89 per cent to 4.6 per cent. The value of 0.8 per cent was reported by Gopalan et al. (1989). Zinc content in improved varieties of cowpea viz. IT1042, IT205 and IT452 in the range of 4 to 5.7 per cent was reported by Shefali, 2007. The copper content in cowpea ranges from 0.8 to 1 per cent. The low value had been reported by Phillps and Mc Watters (1991) and the high value was reported by Akpapunam and Markakis (1981). The value of 0.87 per cent was reported in Gopalan et al. (1989).VitaminsThe vitamins present in appreciable quantities in pulses are thiamin, riboflavin, pyridoxine and folic acid, vitamin E and K are also found in pulses. With the exception of germinated seeds, the pulses consumed are almost devoid of ascorbic acid. According to Akpapunam and Markakis (1981) the ground raw cowpea seeds and the processed flour had thiamine content of 0.91 and 0.81, riboflavin of 0.10 and 0.09, niacin of 2.30 and 1.59 mg per 100 g, respectively. Bressani (1985) reported the thiamine content in the range of 0.41 to 0.99 mg per 100 g, riboflavin in the range of 0.29 to 0.76 mg per 100g and niacin in the range of 2.15 to 3.23 mg per 100 g.Cowpea is of major importance to the nutrition and livelihoods of millions of people in less-developed countries of the tropics. Cowpea is consumed in many forms. Young leaves, green pods and green seeds are used as vegetables whereas dry seeds are used in a variety of food preparations (Nout, 1996; Nielsen et al., 1997). Trading of fresh produce and processed cowpea foods and snacks provides rural and urban women with an opportunity for earning cash income. Cowpea is also a major source of protein, minerals and vitamins (Bressani, 1985). With all these attributes, cowpea positively impacts on the nutrition and health of poor people, particularly children. The bulk of the diet of the rural and urban poor in Africa consists of starchy foods such as cassava, yams, plantain, bananas, millet, sorghum and maize. The addition of even a small amount of cowpea improves the nutritional balance of the diet, and enhances protein quality by the synergistic effect of high protein and lysine from cowpea and the energy from starchy foods. Cowpea is considered a poor man’s pulse, though its nutritional value matches several other high esteemed pulses. A comparative account of cowpea in relation to certain other pulses is given in Table 2.1.2.3 Cowpea ProductsPulses form excellent supplement to cereal diet, as they are rich source of lysine. Thus, the combination of cereals and pulses in the diet improves the protein quality. Legumes are consumed in various ways. The utilization pattern of cowpea can be grouped as follows:Whole/green cowpea (fresh, boiled and roasted);Table 2.1: Nutritive value of Cowpea in relation to Bengal gram and Green gram (per 100 g of edible portion)
NUTRIENTS COWPEA BENGAL GRAM GREEN GRAM   Protein (g) 24.1 17.1 24   Lysine (mg/g) 430 440 460   Methionine (mg/g) 90 80 80   Arginine (mg/g) 420 570 500   Histidine (mg/g) 200 160 170   Tryptophan (mg/g) 70 50 60   Phenylalanine (mg/g) 320 360 350   Tyrosine (mg/g) 230 180 100   Cystine (mg/g) 80 80 60   Threonine (mg/g) 230 220 200   Leucine (mg/g) 480 580 510   Iso leucine (mg/g) 270 320 350   Valine (mg/g) 310 310 320   Fat (g) 1.0 5.3 1.3   Minerals (g) 3.2 3.0 3.5   Magnesium (mg) 210 119 127   Zinc (mg) 4.6 6.1 3.0   Calcium (mg) 77 202 124   Iron (mg) 8.6 4.6 4.4   Phosphorus (mg) 414 312 326   Vitamins   Carotene (µg) 12 189 94   Thiamine (mg) 0.51 0.30 0.47   Riboflavin (mg) 0.20 0.15 0.27   Niacin (mg) 1.3 2.9 2.1   Fibre (g) 3.8 3.9 4.1   Carbohydrate (g) 54.5 60.9 56.7   Energy (Kcal) 323 360 334  Source: Kumar and Singh, 2004 sprouted and germination (boiled and fried);puffed and roasted (spiced/salted);milled and cooked (steamed, boiled and fried); andfermented products (idli, dhokla)A number of cowpea preparations based on common Indian diets are possible to be prepared (Goyal, 1996). Common products made from cowpea include cowpea vegetable, cutlets, bonda, sprouted pulses salad, kachori, porridge, wheat and cowpea vadai, ladoos, biscuits, puri, batti, stuffed parantha, mathri, muffin, chikki, dahi vada, halwa, gattaa curry, poshtik soup, dhokala, idli, and burfi.2.4 MalnutritionSixty years after independence, nearly half of India’s children under three are malnourished (Table 2.2). India has the largest number of children in the world who are malnourished. Even more significantly, India’s rate of malnutrition is worse than the number of malnourished is likely to have actually increased.Table 2.2: Trends in Childhood (0–3 Years of Age): Malnutrition in India
Nutritional parameter 1992-93NFHS-1 1998–99NFHS-2 2005-06NFHS-3   Stunted 52.0 45.5 38.4   Wasted 17.5 15.5 19.1   Underweight 53.4 47.0 45.9  Note: Figures of NFHS-1 above are for 0–4 years. However, NFHS-1 later generated data for below 3 years children with 51.5% children being underweight.Source: NFHS surveys, IIPS, MoHFW, GoI.The World Bank estimates that India is ranked 2nd in the world of the number of children suffering from malnutrition, after Bangladesh (in 1998), where 47% of the children exhibit a degree of malnutrition (www.wikipedia.com). Malnutrition is frequently part of a vicious cycle that includes poverty and disease. These factors are interlinked in such a way that each contributes to the presence and permanence of the others. Socio-economic and political changes that improve health and nutrition can break the cycle; as can specific nutrition and health interventions. WHO, 2003 defined malnutrition as a term that usually refers to a number of diseases, each with a specific cause related to one or more nutrients. Malnutrition is synonymous with protein-energy malnutrition which signifies an imbalance between the supply of protein and energy and the body’s demand for them to ensure optimal growth and function. This imbalance includes both inadequate and excessive energy intake: the former leading to malnutrition in the form of wasting, stunting and low weight, and the latter resulting in overweight and obesity.Malnutrition in children is the consequence of a range of factors that are often related to poor food quality, insufficient food intake, and severe and repeated infection diseases, or frequently same combinations of the three. These conditions, in turn, are closely linked to the overall standard of living and whether a population can meet its basic needs, such as access to food, housing and health care. Growth assessment, thus, not only does it serve as a means for evaluating the health and nutritional status of children but also provides an indirect measurement of the quality of life of an entire population (WHO, 2003).Child nutritional status is an essential component of a country’s overall human development. There is a growing consensus that poor nutritional status during childhood (and in utero) can have long-lasting scarring consequences into adulthood, both in terms of health and mortality, and in terms of other measures of human capital such as schooling and productivity (Glewwe and Miguel, 2007).Malnutrition is characterized by cellular imbalance between the supply of nutrients and energy on the one hand (WHO, 2003), and the body’s demand for them to ensure growth, maintenance, and specific functions on the other.Undernutrition in India is observed primarily in the form of protein energy malnutrition and micronutrient deficiencies (Muller and Krawinkel, 2005). Prevalence rates of undernutrition among children in India (47.5%) are far greater than that of Sub-Saharan Africa (30%) (Rosegrant and Meijer, 2002 ; Claeson et al., 2000). Almost three quarters of Indian children are underweight due to undernutrition. Undernutrition here is not just related to access to food, but is also due to poor access to health care, poor sanitation, early weaning, and poor maternal nutritional status during pregnancy (World Bank, 2007). Protein energy malnutrition accounts for higher mortality rate in India (95/1000 live births) compared to developed countries (Bhandari et al., 1988; Dahiya and Kapoor, 1994).Undernutrition in young children is usually determined by measurements of height, weight, and skinfold thickness (de Onis and Blossner, 2003). The most commonly used measures of undernutrition are: low height-for-age, low weight-for-height, and low weight-for-age. NNMB, 1998 has indicated that pre-school children consume nearly 75% of the recommended energy. Energy consumption less than 80% of the requirement is reported to be a risk factor for malnutrition of pre-school children (Khabdiat et al., 1998).2.4.1 Causes of MalnutritionThe causes of undernutrition in India are multifactorial. Some of the factors are: poor maternal nutritional status (80% of women are iron-deficient); low birth weight (30% of children are born underweight); social and economic status that limits the ability to access resources for health and nutrition; and poor hygiene and sanitation leading to infections and compromised health status (Khokhar et al., 2003). Among the undernourished, more than 50% live in rural areas, 49% are girls, and 53% are from the lower socioeconomic status.2.4.2 Nutritional Status of Pre-School ChildrenPreschool children constitute the most vulnerable segment of any community. Their nutritional status is a sensitive indicator of community health and nutrition (Sachdev, 1995). During the pre-school age (3-5 years), growth continues in spurts. The child spends quite a bit of energy in play. Annual gain in height and weight is only about 6-7 cm and 1.5 to 2 kg, respectively (Khanna et al., 1997). According to ICMR, 2000 RDA of 4- 6 years children for energy and protein are 1690 Kcal and 30 g, respectively.2.4.3 Supplementary feeding to childrenThe infant and the pre-school children are extremely vulnerable group. A majority of infants and pre-school children in the developing countries consume inadequate diets. Consequently they grow at a sub normal rate and are stunted. They also suffer from signs and symptoms of dietary deficiencies (Jelliffe, 1966). In view of the shortage in the supply of milk and other protein rich foods of animal origin in the developing countries, successful attempts have been made on the development of processed protein foods based on locally available legumes and their use as supplements to the diets of children. Recent investigations indicate that the utilization of oilseeds and legumes as supplementary feeds to the children could help meet the nutritional requirements and promote satisfactory growth of infants. The nutritional value of cowpea, which is mainly the high protein level, rich in lysine, represents its major advantage for use in supplementary food for children besides its easy availability and lower cost. 2.5 Assessment of Nutritional StatusNutritional status of a person refers to the state of health as determined by the person’s dietary intake. The common parameters used for routine direct assessment of nutritional status include diet and nutrient intake, anthropometric measurements, clinical symptoms of nutritional deficiency and biochemical profile of nutrient and/or metabolites in body fluids or tissues. Assessment of nutritional status thus helps to identify the possible occurrence, nature and extent of impairment, if any, of nutritional status, which may range from deficiency to excess, so that appropriate dietary interventions may be, initiated (Seth and Singh, 2005). 2.5.1 Dietary AssessmentThe 24 hours diet recall is one of the most commonly used techniques for measuring dietary intake, used in routine dietary assessment, in the community. It is a recollective technique where the interviewer questions the respondent to name with approximate amounts the foods eaten during the previous day at each meal and between meals. Quantities are stated in household units. It is repeated for 3-5 days a week to obtain the habitual intake pattern, which can be ensured by recall of the day’s diet on a working day as well as holiday. To increase the representativeness of this method, it may be used along with food frequency questionnaire. The dietary data gathered is used to calculate the nutrient content of the diet, using nutritive value tables based on raw food weights or cooked food portions. Nutritional adequacy of diets can be assessed by comparison with RDA (Seth and Singh, 2005).2.5.2 Anthropometric AssessmentIn the determination of nutritional status and development of a child and to assess if the child is at risk of nutritional deficiencies like PEM, anthropometry is generally used. While malnutrition manifests its diverse forms, protein energy malnutrition (PEM) ranks foremost in terms of socioeconomic consequences and the enormity of its effects. Numerous criteria have been suggested for the assessment of PEM in a population group. Nutritional anthropometry is concerned with the measurement of the variations of the physical dimensions and the gross composition of the human body at different age levels and degrees of nutrition (Jelliffe, 1966). Nutritional anthropometric (body measure) parameters such as weight-for-age (W/A), height-for-age (H/A), weight-for-height (W/H), mid upper arm circumference-for-age (MUAC/A) and body mass index (BMI) are commonly used for assessing malnutrition and evaluating the effects of dietary treatment on children (Kaur et al., 2005).WeightWeight is the anthropometric measurement most in use because of it’s potential value, especially for children. In developing regions, the prevalence of protein-calorie malnutrition appears to be best indicated by weight deficiency in all age-groups and by growth failure in children. Weighing is the key anthropometric measurement in relation to age, as body weight indicates current nutritional status (Jelliffe, 1966).HeightThe height of the individual is made up of the sum of four components: legs, pelvis, spine and skull. In field nutritional anthropometry usually only the total height (or length) is measured (Jelliffe, 1966). MUACThe arm contains subcutaneous fat and muscle; a decrease in MUAC may therefore reflect either a reduction in muscle mass, subcutaneous tissue, or both. Some investigators claim that mid-upper-arm circumference can differentiate normal children from those with protein-energy malnutrition as reliably as weight for age (Gibson, 1990).2.5.3 Classification of nutritional statusThe classification of prolonged and severe energy deficiency is very important to identify the incidence of protein energy malnutrition and dimensions for treatment. Categorization of the disease as acute, chronic or acute with chronic base is done by anthropometry to assess current nutritional level and degree of growth retardation among children (Torum and Viteri, 1988). Anthropometric indices, simple numerical ratio of two anthropometric measurements such as weight/height2, weight for age, height for age and weight for height are used to evaluate the nutritional status of the individuals of population (Gibson, 1990; WHO, 1986). Specially weight for age is widely used in most of the developing countries to assess the nutritional status of children. According to Waterlow (1972) the best anthropometric classification system to assess the nutritional status is based on two indices ‘height for age’ and ‘weight for height’. The term ‘stunting’ and ‘wasting’ were suggested for a deficit in height for age and weight for height respectively. According to this classification system, patients may fall into four categories: normal, wasted but not stunted (acute PEM), wasted and stunted (acute and chronic PEM) and stunted but not wasted (past PEM with present adequate nutrition or nutritional dwarf’s). Various other classifications based on anthropometric measurements are given by authors to assess the nutritional status of children. Some of the commonly used classifications, based on weight for age as an index are given by Gomez (1955) and Jelliffe (1966). Waterlow (1976) and McLaren and Read (1972) used weight/height/age index to classify the children. Velzeboer et al. (1983) considered the preschool children with MUAC less then 13.5 cm as undernourished. 2.6 Factors affecting Nutritional Status of Children2.6.1 Socioeconomic FactorsAccording to Reddy et al. (1993), socioeconomic status and expenditure pattern of the family are the important determinants of child’s nutritional status. Protein energy malnutrition was found to be seriously prevalent among the preschool children belonging to poor socio-economic status than those belonging to the higher socioeconomic status (Choudhary and Rao, 1983). Valverde et al. (1977); Garon et al. (1978) and Mazur and Sanders (1988) have also reported socio-economic status to be correlated with child health and nutrition. 2.6.1.1 Income and OccupationPoverty is the main cause of wide spread malnutrition among the children in India (Devadas and Easwaran, 1967; Devadas et al., 1980).2.6.1.2 Family size and birth order Family size has been found to be positively correlated with the prevalence of malnutrition along with morbidity and infections among children belonging to the poor socioeconomic status (Kumar, 1976). In rural and urban communities around Bombay, Mudkhedkar and Shah (1975) observed higher percentages of preschool children weighing less than 70 per cent of the standard. Protein inadequacy in the diet and the clinical symptom anemia were also highly prevalent. Devadas et al. 1991 observed lower incidence of various infections and deficiency diseases among the children with birth order less than three against the children with birth order above three. Similar conclusion drawn by Easwaran et al. (1975) and Sadasivam et al. (1980) that youngest child was more at the risk of malnutrition.2.6.1.3  Education of ParentsDevadas and coworkers (1980) concluded that parental education level was correlated with immunization and health status of the young children. Higher the educational level better was the nutritional status of the children.2.7 Utilization of Protein Rich Flour in Formulation of Biscuits
Fortification of foods is of current interest because of nutritional awareness of consumers. Supplementation with legumes is one way to meet the needs of protein in the diet. Baked foods like biscuits, cookies, cakes are widely consumed that have relatively long shelf life and good eating qualities. Such qualities of food products make large scale production and distribution possible, in the short period.  Biscuits can be easily fortified (Mishra et al., 1991) with protein rich flours to provide convenient food in order to supplement protein in the diet. Akubor and Onimawo (2003) reported that cookies prepared from the 60% soybean flour (SF) and 40% maize flour (MF) blends were the most acceptable. The protein contents of the composite flour cookies increased from 10.2% in the 100% maize cookie to 28.3% for the 60% soybean substitution and evaluated for their nutrient contents, and physical and sensory properties. However, cookie weight increased with increasing level of SF in the SF/MF cookies. Sensory evaluation showed that the cookies (SF/MF) were not significantly different (p > 0.05) in color, flavour and taste but differed significantly (p < 0.05) in texture and overall acceptability. Akubor (2003) demonstrated that cowpea/plantain flour (CPF) and wheat flour (WF) can be combined to produce acceptable biscuits with good physical and sensory qualities with improved nutritional quality. CPF could substitute upto 90% WF without adversely affecting product quality. The protein content increased from 13.4% for the 100% WF biscuit to 18.9% for CPF/WF biscuit with the highest level of WF substitution.Shakuntala and coworkers (2009) reported that supplementation of wheat biscuits with Bengal gram flour at 15 to 20% level, not only improved protein quality but also improved the dough texture and sensory parameters in the final product.A research study conducted by Banureka and Mahendran (2009) to evaluate the quality characteristics of protein enriched biscuits, which could be used as a protein supplemented cereal snack food, found protein, fat and energy (calorie) value of soy flour supplemented biscuits increased with progressive increase in proportion of soy flour and 10% soy flour added biscuits obtained values of 9.9%, 20% and 453.58 kcal/g respectively, while lowest values of 5%, 14.5% and 417.36 kcal recorded for the wheat flour biscuits. The moisture and ash content decreased with corresponding increase in the percentage of soy flour. From the overall acceptance rating, 10% soybean flour incorporated biscuit obtained the highest preference compared to other combinations.Nazni et al. (2010) studied the effect of weaning biscuits supplementation of the nutritional parameters and cognitive performance of the selected children. Three varieties of weaning biscuits were developed using the proportion of potato flour (I), wheat flour (II), ragi flour (III) with soya flour in the ratio of 80:30. About 80 pre-schoolers with grade-II malnutrition were selected for the experimental study. They were divided into four groups with twenty subjects in each group. Group I – Control group, Group II – Supplemented with potato flour biscuits, Group III – supplemented with wheat flour biscuits, and Group IV – supplemented with ragi biscuits for the period of three months. The result for group I showed no significant difference in weight, height and clinical picture and cognitive performance whereas in group II, III, and IV significant increase in all parameters was noticed. More increase was found in group II (potato flour biscuits). The study concluded that such weaning biscuits made with potato flour, wheat flour and ragi can form a daily ingredient in their diets to bring out better all round development of the children.In a randomized controlled (intervention) trial Adom and coworkers in 2010 investigated the effect of iron- fortified maize- cowpea blend in controlling iron deficiency anemia in children aged 6- 18 months in two peri- urban communities who were randomly assigned in iron fortified and non- iron fortified food, fed daily for six months. Hemoglobin concentration (Hb), serum iron, total iron-binding capacity (TIBC), transferrin saturation, weight, length and MUAC were measured at baseline and at the end of intervention. Significant differences were observed in hemoglobin concentration and the risk of developing anemia was about 3 times less likely in iron-fortified group compared to the non-fortified group.2.8 Bakery Products Bakery products are increasingly become popular in India as indicated by over two and a half fold increase in their production during the last decade. The popularity of these products is their ready to eat convenience nature, unique taste and ready availability. Biscuits and cookies are one of the most popular products because of their convenience, ready to eat nature and long shelf life.2.8.1 BiscuitsBiscuits are small baked products made principally from flour, sugar and fat and they typically have a moisture content of less than 4% and when packaged in moisture proof containers have a long shelf life perhaps 6 months or more. Biscuits are made in many shape and sizes and after baking they may be coated with chocolate, sandwiched with a fat based filling or have other pleasantly flavoured additions (Manley, 1996). The term biscuit covers a large variety of sweet, salted, filled and coated biscuits. It is difficult to classify biscuits based on chemical composition and processing methodologies due to overlap. However, varietal differences can be distinguished well by their sensory attributes; the different varieties can be broadly classified as type I (sweet), type II (semi-sweet), type III (crackers), type IV (cookies) and type V (speciality biscuits)  (IS 1011: 2002).  The approximate time required for baking a biscuit is 8-9 minutes and temperature should be 200 °C in a baking oven (Whitley, 1970).According to Kure and coworkers (1998) biscuits are nutritive snacks produced from unpalatable dough that is transformed into appetizing product through the application of heat in an oven. They are ready-to-eat, convenient and inexpensive food product, containing digestive and dietary principles of vital importance (Kulkarni, 1997). The principal ingredients are flour, fat, sugar and water; while other ingredients include milk, salt, flouring agent and aerating agent. Biscuits are a rich source of fat and carbohydrate, hence are energy giving food and they are also a good source of protein and minerals (Kure et al., 1998).2.8.2 Biscuit Ingredients used in Biscuit makingThe basic ingredients of biscuits include refined wheat flour, shortenings (fats and oils), sugars, chemicals and flavours.2.8.2.1 Refined wheat flourA flour of good colour is essential for confectionary work. The water absorbing power of the flour depends, in part, on the quality of gluten in the flour and the amount of moisture already present in the flour (Bennion et al., 1966). White wheat flour is the largest ingredients in nearly all biscuits.2.8.2.2  ShorteningShortening i.e. solid or liquid may be classified as fats or oils, referring to their state and condition at room temperature (750F – 800 F). The state may of course be changed by heating or cooking. The fats and oils used in bakery products are either animal or vegetable. Fats, oils and shortenings are used in bakery products to impart shortness, richness, and tenderness to the products; improve the eating quality of the products; provide for aeration and resulting leavening of the product; promote a desirable grain and texture; provide for the development of the flakiness in products; and act as emulsifiers for the holding of liquids (Sultan, 1986).  2.8.2.3  SugarsSugars are important in the taste and structure of most biscuits. Relatively large quantities of sucrose and syrups are used in all short doughs, smaller quantities in semi-sweet doughs and to a much lesser extent in cracker doughs and wafer batters. (Manley, 1996).2.8.2.4  Chemicals Biscuit making involves the use of a number of chemicals, the most generally used of which are leavening agents and fruit acids.Baking powderBaking powder is a mixture of chemicals varying in nature and composition which reacts in the presence of moisture and heat and release a gas (CO2), which assists in raising the product.  Sodium bicarbonateThe common name of sodium bicarbonate is baking soda. In the presence of moisture, soda will react with any acidic material to liberate carbon dioxide. As many biscuit ingredients, including flour, have an acidic reaction it is often useful to use sodium bicarbonate as a means of adjusting the acidity of the dough and hence the taste of the resulting biscuits. (Manley, 1996). 2.8.2.5 FlavoursFlavour extracts are solutions of the flavour in the ethyl alcohol or some other solvent. The base of these flavours is the extracted essential oils of the fruit or bean, or imitation of the same. There are some flavours that are found to be better than other in baked products, notably vanilla (or synthetic ethyl vanillin), butter, cheese, almond essence and roasted material like chocolate, coffee, caramel and also smoke flavours (Manley, 1996). Vanilla flavour is highly volatile. The mixture of vanillin with vanilla has been beneficial. These synthetics do not bake out as rapidly and do enhance the flavour (Sultan, 1986).

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