Nutritional Efficacy of Maize based Functional Flour Developed for Minimizing the Risk of Lifestyle Diseases in Relation to Normal Wheat Flour

Goodness of health status understands the perfect peace of mind, body and soul. Lifestyle diseases are the ailments that are primarily centered on regular habits of people which detract them from physical activity and ultimately push towards a sedentary routine pattern that can cause numerous health related problems. According to World Health Organization (WHO) the most prevalent lifestyle diseases are diabetes, cardiovascular diseases, obesity, colon cancer, depression etc. However, the glycemic index of normal wheat flour is higher, although it contains protein gluten which acts as a binding agent and improves the quality or texture of food products.
 
Cereals are playing a key role in our daily life by providing energy and other macro or micro nutrients which defeats our body from various causative factors. Globally, maize is known as “queen of cereals”. After rice and wheat maize is the third most important food crop (ICAR-IIMR, 2017). However, maize is the most multi-skilled emergent crop which is widely accepted under various agro-climatic environments and required lesser water content for its cultivation as compared to other cereals. The cultivation of maize takes place in every season (kharif, rabi, zaid) in Bihar hence availability is not the problem. The total area, production and productivity under maize crop in Bihar is about 669478 ha, 3193911 million tones, 4771 kg/ha respectively (Directorate of Economics and Statistics, 2018-19).
 
Functional flours are the amalgamation of several kind of flours prepared from cereals, pulses, oilseeds etc. which serves numerous nutritional and therapeutic properties and protects the body from hazards. As reported by FAO application of composite mixes in food products will be advantageous economically (Noorfarahzilah et al., 2014). Flaxseed or “Linseed” (Linum usitatissimmum) is an oilseed crop which is richer in specific nutrients and plays a beneficial role for cardiovascular patients such as omega-3 fat, ALA (a- linolenic acid) and lignan which possess plant estrogen along with antioxidant qualities (Gutte et al., 2015). Chickpea (Cicer arietinum) is a legume mostly consumed by people in various form of products. It had beneficial effects if consumed in combination with cereals against diseases mainly cardiovascular diseases, cancers, type-2 diabetes and various digestive disorders (Jukanti et al., 2012). Barley (Hordeum vulgare) is one of the oldest and cheapest grains having various health benefits against type 2 diabetes, obesity, colon cancer, atherosclerosis, coeliac disease etc. due to presence of flavonoids, selenium, total fibre both, proteins, copper, vitamin B, E, magnesium (Annapurna et al., 2011). Finger millet (Eleusine coracana) or “Ragi’ is rich in mainly calcium which needs for older people because it enhances bone mineral density. Phytochemicals elements present in finger millet are alkaloids, cardiac glycosides, phenols, tannins, terpenoids and steroids (David et al., 2014). Wheat (Triticum aestivum) is a staple crop. It contains protein gluten which provides better texture and rolling capacity of product prepared from it.

Considering the necessity and availability of grains the present investigation has been designed to develop functional flour of maize in combination with other food materials so that it can be utilized by people who have been suffering from lifestyle diseases or are at the verge of these diseases.

The specific research work on “Nutritional efficacy of maize based functional flour developed for minimizing the risk of lifestyle diseases in relation to normal wheat flour” was conducted during 2020-2021 in the laboratory of Department of Food and Nutrition, College of Community Science, Dr. RPCAU, Pusa, Bihar. The raw ingredients for the development of functional flour such as maize (variety ‘Lakshmi’), chickpea, wheat, barley, flaxseed and finger millet were procured from local market or directly from farmers.
 
Processing of raw materials
 
The raw grains were processed by different methods viz. soaking, boiling, roasting and oven drying. Firstly, all grains were cleaned to remove inedible parts; washed under tap water for 2 to 3 times. However, maize was steeped in double amount of water for 10 to 15 minutes, boiled and then oven dried for 10 hours at 60-65°C. Flaxseed were roasted, cooled at room temperature and grounded. Chickpea, ragi, barley and wheat were soaked in water (1:2 w/v) for overnight (8-10 hours). Next day water was drained and grains were oven dried at 60-65°C. Chick pea required 12 hours for drying whereas finger millet, barley and wheat used to take 7 hours at 60-65°C for drying. Oven dried grains were milled and stored in air tight containers.
 

 
Development of functional flour in different proportions
 
After processing of grains, functional flour was prepared at varied combinations by using different flour of grains. Combination of both cereals and millets provide more nutrients, phytochemicals and antioxidants which helps to maintain better health status (Agarwal et al., 2016). For the development of flour, wheat flour (100%) was taken as control, the portions of maize (50%) and flaxseed (10%) had been fixed since, maize is the base material for the development of flour and flaxseed have been decided to be added compulsorily because of its nutritional properties (omega-3 fat). Variations were there in rest 40 per cent for the development of flour. The flour was mixed properly in each combination and kept in airtight container to prevent from spoilage. Different combinations of flour are shown in Fig 1.
 

 
 
Physico-chemical analysis
 
The physico-chemical properties of functional flour have been ascertained by determining bulk density and water absorption capacity.
 
Bulk density
 
As per protocol stated by Wang and Kinsella (1976) bulk density was determined. Fifty gram flour sample was taken into 100 ml of measuring cylinder. The bottom of cylinder was mechanically tapped 15 to 20 times to remove the air spaces between the sample. The volume was noted at which flour sample was settled (tapped volume) thereafter, bulk density was evaluated as mass per unit volume of the flour sample.
Water absorption capacity
 
It was determined by the procedures followed by Rosario and Flores (1981). One gram of sample was mixed with 10 ml of distilled water. The content was allowed to stand at 30°C in a water bath for 30 minutes and was further centrifuged at 3000-5000 rpm for 20 to 30 minutes. After centrifuging, the volume of the supernatant was recorded and used for determination of water absorption and the results were expressed as g/ml.
 
Proximate composition
 
Different flour combinations were analyzed for nutritional characteristics such as moisture, ash, crude fibre and fat by the method prescribed by AOAC (2000). Crude protein content was estimated by Micro-Kjeldahl method (NIN, 1983). The micronutrient content (Fe and Zn) was determined by using Atomic Absorption Spectrophotometer (Lindsay and Norvell, 1978) whereas whereas calcium was analysed by complexo-metric titration method (Chang and Bray, 1951).
 
Statistical analysis
 
All the analyses were carried out in three replication (triplicate) of samples and results were shown on dry weight basis. The data obtained from bulk density and water absorption capacity were analyzed by student t-test (p<0.05) and presented at the level of p<0.01 for significance. OPSTAT software and completely randomized design (CRD); one way ANOVA (Analysis of Variance) was used for data obtained from different treatments of flour to assess the significance.

Bulk density of flour
 
The bulk density of different treatments of flour has been presented in Table 2. The highest bulk density was seen in treatment T₅ and T₃ (0.67 g/ml each) followed by T₁ (0.65 g/ml), T₄ (0.62 g/ml) and T₂ flour (0.60 g/ml). As compared with other treatments, wheat flour (0.57 g/ml) had lower bulk density. Significant difference was found between T₁, T₅ treatment (p<0.05) and T₂ treatment (p<0.01) as compared to control.
 

 
Water absorption capacity (WAC) of flour
 
The water absorption capacity of flour has been presented in Table 3. The amount of water absorbed by treatment T₅ flour was 2.16 g/ml subsequently higher than T₄ flour (2.13 g/ml), T₂ flour (1.86 g/ml), T₃ flour (1.86 g/ml), T₁ flour (1.80 g/ml) and control (1.03 g/ml) which absorbed less amount of water. The WAC of different treatments of flour was higher compared to wheat flour because of higher carbohydrate content in millet flour (maize and ragi) including barley flour. Statistically significant (p<0.01) difference was observed in T₃, T₄, T₅ and T₂ flour (p<0.05) compared to control.
 

 
Proximate composition of functional flour
 
The proximate composition of functional flour prepared from different proportions of grains was shown in Table 4. Meanwhile, the moisture content of T₀ was 11.55 g/100 g and  observed higher than T₂ flour (7.97 g/100 g) followed by T₁ flour (7.60 g/100 g) T₃ flour (6.96 g/100 g), T₅ flour (6.79 g/100 g) and T₄ flour (6.53 g/100 g) which holds least moisture content. Statistically, all treatments are significant (p<0.05) when compared with control. The highest ash content among five treatments of flour was found in T₅ flour i.e. 1.94 g/100 g, subsequently T₂ flour (1.89 g/100 g), T₄ flour (1.85 g/100 g), T₁ flour (1.84 g/100 g) and T₃ flour (1.82 g/100 g) and T₀ (1.26 g/100 g) which was lowest among all treatments. Statistically non-significant difference was found among each other as compared to control.
 

 
In case of protein content, T₂ flour i.e. 11.08 g/100 g found to be highest as compared to others followed by T₀ (10.97 g/ 100 g), T₁ flour (8.78 g/100 g), T₃ flour (8.75 g/100 g), T₄ flour (7.58 g/100 g) and lower protein content encompassed in T₅ flour (5.83 g/100 g) respectively. The data depicted, statistically all treatments are significant (p<0.05) compared with control except T₂ flour. Comparatively, T₂ flour contains highest fat content i.e. 5.33 g/100 g than T₃ flour (5.30 g/100 g) followed by T₄ flour (5.28 g/100 g), T₁ flour (5.27 g/100 g), T₅ flour (4.92 g/100 g) and T₀ (1.60 g/100 g) which was lowest in fat content. Statistically, all treatments showed significant difference (p<0.05) among themselves when compared with control.

In the case of fibre, it was found highest in T₁ flour i.e. 18.27 g/100 g followed by T₄ flour (17.64 g/100 g), T₃ flour (17.36 g/100 g), T₂ flour (17.26 g/100 g), T₅ flour (16.37 g/100 g) and T₀ (11.09 g/100 g) which had lower amount of fibre content. There was significant (p<0.05) difference among each treatment when compared with T₀ (Control). Carbohydrate content was seen highest in T₀ i.e. 65.09 g/100 g followed by T₅ flour (64.15 g/100 g), T₄ flour (61.10 g/100 g), T₃ flour (59.97 g/100 g), T₁ flour (58.22 g/100 g) and T₂ flour (56.45 g/100 g) which holds lower carbohydrate content as compared to others. Significant (p<0.05) difference was found in all treatments of flour except T₅ flour.
 
Mineral content of the flour
 
The iron, zinc and calcium content of different flour blends have been presented in Table 5. The iron (Fe) content was highest in T₁ flour (5.96 mg/100 g) followed by T₅ flour (5.71 mg/100 g), T₄ flour (5.57 mg/100 g), T₃ flour (5.31 mg/100 g), T₂ flour (4.34 mg/100 g) and T₀ (3.68 mg/100 g). The statistically analyzed data manifested that except T₂ flour all treatments were found to be significant (p<0.05). In case of zinc (Zn) content, it had been observed highest in T₂ flour viz. 3.76 mg/100 g followed by T₁ flour (3.67 mg/100 g), T₄ flour (3.66 mg/100 g), T₅ flour (3.10 mg/100 g), T₃ flour (2.93 mg/100 g) and lowest zinc content was found in T₀ (2.83 mg/100 g). The T₃ and T₅ flour are significantly (p<0.05) different as compared with control.
 

 
Calcium content was found highest in T₃ flour (132.28 mg/100 g) followed by T₂ flour (98.39 mg/100 g), T₅ flour (85.91 mg/100 g), T₄ flour (64.11 mg/100 g), T flour (63.57 mg/100 g) and the lowest amount of calcium was found in T₀ flour (25.73 mg/100 g) respectively. When compared with control each treatment was significantly different (p<0.05).

Based on the findings, it can be concluded that functional flour developed from using maize as a base material in combination with other raw ingredients were rich in nutritional characteristics. However T₁, T₂ and T₃ treatments were found best because they are rich in fibre, iron, zinc (T₁), protein, omega-3 fats (T₂) and calcium (T₃). Due to natural sources of nutrients and antioxidants, it may be utilized to overcome causative factors of lifestyle diseases.

The authors are very thankful to the Department of Food and Nutrition because of providing laboratory facilities for smooth conduct of work in time.

None.