Index

• Introduction
• Origin and Distribution of Millets
• Nutritional Values of Millets
• Health Benefits of Millets
• Nutritional Bioavailability
• Consumption of Millets
• Conclusion
• References

Abstract

In the era of 21st century, rapid urbanisation, climate change, increased population, scarcity of water and increased dry land are the factors responsible for the worldwide agricultural and nutritional challenges. As a widely cultivated popular grain in arid and semiarid regions across the globe, Millets can act as a multifaceted solution to the above global challenges because of their rich vitamins, minerals, phytochemicals and anti-oxidant content. In addition to vitamins, Millets are the rich source of flavanoids such as apigenin, catechin, daisein, orientin, isoorientin, lutolin, quercetin, vitexin, isovitexin, myricetin sponarin, violanthin, lucenin-1, and tricin. Further, the presence of essential amino acids enriches the nutritive potential of Millets. The rich anti-oxidant content in Millets reduces oxidative stress in human and animal models by significantly minimizing Reactive Oxygen Species (ROS) generation. Several bioactive principles in Millets are known to decrease cardiovascular risk, diabetes, ageing and even cancer. However, nutritive and therapeutic potentials of bioactive compounds found in Millets are underexplored and a systematic review encompassing available data in literature is grossly missing. The aim of this review is to compile the recent advances that have been carried out covering nutritional properties, processing technologies and their effects in reducing anti-nutritional factors enhancing nutrient bioavailability along with the potential health benefits of millets. Consumption of various traditional and modern millet based food and studies conducted in examining the bioavailability of minerals after consuming millet based food is also discussed in this review.

Keywords: Bioavailability of minerals, Health benefits, Micronutrient deficiency, Millets, Nutritional value.

Received: 2 August 2022 / Revised: 22 September 2022 / Accepted:5 October 2022 / Published: 20 October 2022

Contribution/ Originality

Millets though are widely cultivated in arid and semiarid regions, its nutritional values and potential health benefits have been poorly investigated. The major and minor millets vary widely in their nutritional contents and other bioactive phytochemicals.  The present review is an attempt to compile first hand data related to nutritional composition and its role as a potent phytotherapeutics against numerous diseases.

1. INTRODUCTION

The progression of Millennium Development Goal (MDG) led to the emergence of Sustainable Development Goal (SDG). In 2015, as the second goal of SDG, the United Nations committed to achieve zero hunger and improve nutrition by 2030. This changed the food security measure of total calorie (prevalent during MDG) to nutrient content food for adequate nourishment [1] as the overall physical and mental well-being of human being depends on the consumption of nutritious food [2]. The 2016 global nutrition report explains that around 44% population of 129 countries experience the high level of under nutrition due to nutrient imbalanced diet [3]. The problems of nutritional challenges are likely to be compounded as a result of rise in population, reduced production and exposure to climate change [1]. Further, climate change induced erratic alteration in pattern of rain, intensity and distribution of rain over the globe reportedly increasing the dry land mass and significant loss of water table. The possibility of having increased staple cereal production is highly compromised with the gradual increase in dry land and deepening of ground water level [3, 4]. As Millets can grow luxuriantly on dry and less fertile soil,  Millets can serve as preferable alternative where major cereals fail to provide sustainable yield [3, 5].

Millets cultivation has several agrarian importances in comparison to the cultivation of major cereals. For example, the yield of rice is known to be low on a soil having salinity higher than 3dS/m. On the contrary, millets (pearl millet and finger millet) can grow and provide better yield up to a soil salinity of 11-12 dS/m. The rainfall requirement of rice (120-140 cm) is several folds higher than the average rainfall requirement of millets (proso millet and pearl millet) of 20 cm. Additionally, millets fall under the C4 group of cereals, having the characteristics of taking more carbon dioxide and converting that into oxygen, high water holding capacity, and require low input. This makes them environment friendly and accessible. Thus, millets can be useful in addressing the issues like climatic uncertainties and reducing atmospheric carbon dioxide [3]. Along with the agricultural advantage, nutrient content in terms of richness in amino acids, minerals, anti-oxidants and with various health benefits [2, 6-9] make millets superior than staple cereals like rice and wheat.

Studies have been carried out describing nutritional and biological roles of millets, processing technologies, consumption of various millet based food and health benefits of millets [2, 3, 10-13]. However, a single study compiling all aspects of millets is scantly available. Thus, to breeze the above conspicuous gap, this review has been carried out. The remainder of the paper is as follows. Section 2 provides information on origin and distribution of millets. Section 3 explains the nutritional values of millets vis-à-vis makes a comparison with rice and wheat. Section 4 portrays the health benefits of millets. Section 5 throws a light on nutritional bioavailability explaining how different processing techniques affect the bioavailability of nutrients in millets. Consumption of various millet based foods and studies conducted in examining the bioavailability of minerals after consuming millet based food is explained in section 6 and section 7 concludes.

2. ORIGIN AND DISTRIBUTION OF MILLETS

Millets are basically grown in arid and semi-arid regions of Africa and Asia [14]. Pearl millet (Pennisetum glacum), proso millet (Panicum miliaceum), foxtail millet (Setaria italic L.), and finger millet (Eleusine Corocana) are the four major types of millets. Further, little millet (Panicum Sumatrense), kodo millet (Paspalm Scrobiculatum L.), and barnyard millet (Echinochloa Frumentacea) are regarded as minor millets [11]. Pearl millet is cultivated in more than 30 countries of Asia, Africa, and Australia, constituting 95% of the total millet production at global level [15-17]. Foxtail millet is the second largest crop in millet category cultivated in semi-arid regions of Asia, North America, Australia, and North Africa [18, 19]. Finger millet is grown in the rural population of East and Central Asia and is the sixth largest crop [19]. Alike pearl millet, proso millet is also cultivated in all continents except South America and Antarctica. Among all millets, barnyard millet is the fastest growing crop and can grow under unfavourable condition and cultivated in Egypt [11. Kodo millet is native to South America and later domesticated in India [20]. It is draught resistance and can grow in poor soils. It is mainly cultivated in arid and semi-arid regions of India and African countries [11].  Little millet plants are shorter and can grow in sandy loam and saline nature of soil, cultivated throughout India [11.

3. NUTRITIONAL VALUES OF MILLETS

Consumption of nutritious food is highly essential to lead a healthy life [21]. Millets are known to have enormous nutritive values in comparison to rice and wheat [2]. In addition, presence of gluten free proteins with high fibre and richness in bioactive compounds makes millets a healthy food [3]. The macro and micro nutrient content of millets in comparison to major cereals are presented below.

3.1. Macronutrients

Carbohydrate, protein, lipids, and dietary fibre are known as macronutrients. Carbohydrates are essential part of our diet as it contributes approximately 50% of the daily calorie intake [22]. Carbohydrates contain carbon, hydrogen, and oxygen in the ratio of 1:2:1 [23]. Based on the degree of polymerisation, carbohydrates are categorised as monosaccharaides, disaccharides, oligosaccharides, and polysaccharides [23]. The carbohydrate content in millets ranges from 55.0gm/100gm (barnyard millet) to 72.6gm/100gm (Sorghum). Proteins are the most essential component of tissue in human and animal [24]. The dietary protein can be useful only when it gets hydrolysed by proteases and peptides to amino acids¹ and dipeptides. Thus, the nutritional value of dietary protein depends on the proportions of amino acid. The presence of essential amino acid in different millets in comparison to wheat is presented in Table 2. It is evident that even though the protein content of wheat is comparable with protein contents of foxtail and little millet (Table 1), the presence of essential amino acids like leucine, isoleucine, valine, and phenylalanine make millets superior. Fibre is also essential element for maintenance like digestion, body weight, blood sugar, triglycerides and cholesterol [25]. Complex carbohydrate such as polysaccharides forms the fibre. Millet seed coats are the sources of dietary fibre [26]. Barnyard millet is having the highest crude fibre content of 9.8 g/100 g, which is several times higher than wheat and rice. The macronutrient contents of different millets are compared with rice and wheat in Table 1.

Crops	Protein (g/100g)	Carbohydrate (g/100g)	Fats (g/100g)	Crude Fibre (g/100g)	Total energy (Kcal)	Reference
Pearl millet	11.4-11.8	67.0-69.10	4.87-5	1.2-2.3	361-363	[1-4]
Foxtail millet	11.2-15	60.9-67.3	3.3-4.3	6.7-8.23	352-391
Finger millet	7.3-7.7	71.52-72	1.3-1.5	3.6	328-336
Proso millet	10.0-13.0	67.09	3.09	8.47	352.5
Barnyard millet	6.2-13.0	55-65.5	2.2-3.9	9.8-13.6	300-307
Kodo millet	8.3-10.0	63.82-66.6	3.03-3.6	5.2-8.2	349.5-353
Little millet	6.2-15.0	60.9-67	4.7-5.2	7.6	329-341
Rice	4.99-7.9	78.2-82.8	0.5-1.9	0.2-1.63	345-369
Wheat	11.6-13.78	69.88-73.9	0.9-2.81	0.3-1.77	348-438
Sorghum	10.4-10.82	70.7-72.9	1.9-3.1	1.6-2.0	329-349

3.2. Micronutrients

The minerals and vitamins are considered as the micronutrients due to their small requirements for human body. Minerals play important roles in human body starting from bone formation, clotting of blood, normalising heartbeat, enhancing immunity and helping nervous system to work properly [3, 25]. Therefore, deficiencies of the minerals may cause several health issues. Calcium and iron deficiencies are the most common micronutrient deficiencies found both at global and national level [27, 28]. Calcium content of finger millet is the highest (350 gm/100gm) amongst cereal category, which is several folds higher than wheat and rice. The calcium content of finger millet can meet around 50% of the recommended dietary allowance (RDA) prescribed by Indian council of Medical Research (ICMR) for men and women, boys, and girls and can meet around 40% of lactating and pregnant women [25]. Thus, consumption of finger millet can address the calcium deficiency and osteoporosis problem. Barnyard millet, little millet, pearl millet and foxtail millets are the rich sources of iron. The highest iron content (amongst millet category) is found in little millet of 9.3mg/100gm, which can meet around one-third of the daily iron required for pregnant women (35mg/d, which is the highest iron requirement among all categories of people). Long term exposure to zinc deficiency enhances the possibility of exposure to diarrhoea, low physical growth, and suppressed immune function [29]. The highest zinc content is found in little millet (3.7 mg/100gm) followed by pearl millet (3.1 mg/100gm), barnyard millet (3.0 mg/100gm) and finger millet (2.3 mg/100 gm). Millets are also good source of water soluble vitamins like thiamine, riboflavin, and niacin.

Foxtail millet has the highest thiamine content (0.59 mg/100gm) amongst millet category. The highest riboflavin content is found in pearl millet (0.25 mg/100gm) followed by finger millet (0.19 mg/100gm) and foxtail millet (0.11 mg/100gm), which is several folds higher than staple cereals like rice and wheat.  Niacin content is found to be the highest (4.2 mg/100gm) in barnyard millet amongst millet category. The above nutrient contents make millets nutricereals. The micronutrient contents of millet crops are presented in Table 3.

Amino acids	Wheat flour refined	Foxtail Millet (defatted flour)	Proso Millet (dehulled grain)	Pearl Millet (true prolamine)	Finger Millet (native grain)	Reference
Histidine	1.2	1.3-2.11	2.1	1.4-1.7	1.3-2.3	[4, 5]
Lysine	1.1	1.4-1.59	1.5	0.5-1.9	2.2
Isoleucine	2.2	4.59-4.8	4.1	2.6-5.1	4.0-4.3
Threonine	1.5	1.9-3.68	3	2.4-3.3	2.4-4.3
Methionine	0.9	1.8-3.06	2.2	1-1.5	2.5-2.9
Valine	2.4	4.3-5.81	5.4	3.3-4.2	4.8-6.3
Tryptophan	0.6	0.6	0.8	1.1-1.2	1
Leucine	4	10.4-13.6	12.2	7.5-14.1	6.5-10.8
Phenylalanine	2.9	4.2-6.27	5.5	2.9-7.6	3.1-6

3.3. Phenolic Compounds

Phenolic compounds contain phenol function group as a fundamental component. These are secondary metabolites of plants responsible for color, nutritional and anti-oxidant properties [3, 11, 30]. Phenolic acid, flavonoid and tannins are the classifications of phenolic compound [3]. Table 4 presents the data related to total phenolic content (TPC) of free, hydrolysed (etherified and esterified), and bound phenolic compounds of different millet grains. It is apparent from the table that TPC of kodo millet is found to be the highest in free, esterified and insoluble fraction; whereas, the TPC of pearl millet is the highest in etherified fraction.

Benzoic and cinnamic acids are the derivatives of phenolic acids. Hydrobenzoic acid and hydrocinnamic acids are further sub classifications of phenolic acids [31]. The highest amount of hydrooxybenzoic acid and its derivatives (62.2µg/g) are found in the soluble  fraction of finger millet; whereas, the highest amount of hydrooxycinnamic acid and derivatives (171µg/g) is found in foxtail millet [7].

Crops	Ca (mg)	Fe (mg)	Na (mg)	K (mg)	Mg (mg)	Zn (mg)	Carotene (µg)	Thiamine (µg)	Riboflavin (µg)	Niacin (µg)	References
Pearl millet	42.0	8-11	10.9	307.0	137.0	3.1	132.0	0.33-0.38	0.21-0.25	2.3-2.8	[2, 4]
Foxtail millet	31.0	2.8	4.6	250.0	81.0	2.4	32.0	0.59	0.11	3.2
Finger millet	344-350	3.9	11.0	408.0	137.0	2.3	42.0	0.42	0.19	1.1
Proso millet	-	-	-	-	-	-	-	-	-	-
Barnyard millet	20-22	5.0-18.6	-	-	82.0	3.0	0	0.33	0.10	4.2
Kodo millet	35.0	1.7	-	-	-	-	-	0.15	0.09	2.0
Little millet	17.0	9.3	8.1	129.0	133.0	3.7	0	0.30	0.09	3.2
Rice	10-33	0.7-1.8	-	-	90.0	1.4	0	0.06-0.41	0.04-0.06	1.9-4.3
Wheat	23-30	2.7-3.5	20.0	315.0	132.0	2.2	25.0	0.12-0.41	0.07-0.10	2.4-5.1
Sorghum	25.0	4.1-5.4	7.3	131.0	171.0	1.6	47.0	0.37-0.38	0.13-0.15	3.1-4.3

Millet type	Free	Esterified	Etherified	Insoluble bound	Reference
Pearl millet	1.27±0.2	1.82±0.2	3.94±0.1	9.14±0.2	[6]
Finger millet	9.67±0.4	0.41±0.1	2.15±0.1	3.20±0.2
Foxtail millet	4.49±0.2	0.37±0.1	0.32±01	11.6±0.2
Proso millet	0.55±0.2	0.7±0.1	2.05±0.1	2.21±0.1
Kodo milet	16.2±0.5	2.2±0.1	1.55±0.1	81.6±0.2
Little millet	5.77±0.7	1.37±0.2	2.48±0.1	9.64±0.2

Flavonoids are considered as more powerful antioxidants than vitamin E & C [32]. Apigenin,  catechin, daisein, orientin, , isoorientin, lutolin, quercetin, vitexin, , isovitexin, myricetin sponarin, violanthin, lucenin-1, and tricin are the commonly found flavonoids in millets [7, 11, 33, 34]. Soluble fraction of finger millet contains the highest amount of flavonoid (1896 µg/g). Along with polyphenols and flavonoids, presence of carotenoid and vitamin E enhances the antioxidant capacity of millets [35]. The average carotenoid content of proso millet is the highest amongst millet category, which is higher than wheat but lesser than maize, Table 5. Moreover, vitamin E characterisation reveals that the total anti-oxidant activity of finger millet is the highest. Further, tocopherols constitute the major component in vitamin E of millet grains [35].

Cereal grains	Average carotenoid content(µg/100g)	Avg. total anti-oxidant activity	Reference
Finger millet	199±77	15.3±0.6	[35, 36]
Foxtail millet	173±25	5.0±0.4
Little millet	78±19	4.7±1.1
Proso millet	366±104	15.3±0.6
Wheat	150-200	13a
Maize	1800-5500	10a
Rice	-	29a

Note: a The percentage contribution of free bound fraction to total anti-oxidant activity and the values are extracted from Adom and Liu [36].

4. HEALTH BENEFITS OF MILLETS

Urbanisation has significantly affected the consumption pattern in India declining the consumption of some cereals like millets and increasing the consumption of animal-based products, oil, refined sugar, fat, and alcohol [37-39]. This pattern of consumption has contributed to the increased burden of non-communicable diseases [39] attributing around 71% of the total deaths globally [40]. Further, the present consumption pattern plays an important role in oxidative stress induction [41]. Oxidative stress is caused by imbalance between production and accumulation of reactive oxygen species (ROS) in cells and tissues [42]. Further, ROS contribute to cellular aging, diabetes, mutagenesis, Deoxy Ribonucleic Acid (DNA) damage, and carcinogenesis [43-46]. DNA, the genetic materials in human body when damaged leads to numerous diseases including cancer. In cue of above literature, it can be articulated that increase in the oxidative stress can significantly contribute to the inflammatory diseases (arthritis, vasculitis, adult respiratory disease syndrome), cardiovascular diseases, gastric ulcer, neurological disorder diseases (Alzheimer, parkinson, muscular dystrophy) , acquired immune deficiency syndrome, and many more [47].

To counteract oxidative stress, human body has several mechanisms of producing antioxidants (naturally produced/ externally supplied through food), which act as free radical scavengers in preventing and repairing the damages caused by ROS. Thus, it helps in enhancing the immune defence system lowering the risk of degenerative diseases [48]. Millets serve as a natural source of antioxidants [2, 7].  Moreover, free radical scavenging property of millets can not only reduce ROS, but also can provide effective means in the prevention and treatment of radical-mediated disease [11, 49]. Thus, millet consumption will inhibit the oxidative stress reducing the risk of the above degenerative diseases.

4.1. Millets against Diabetes & Cardiovascular Disease

Diabetes mellitus is a chronic metabolic disorder characterised by hyperglycaemia with alteration of protein, carbohydrate and lipid metabolism [2, 50, 51]. Use of natural inhibiting diet is preferably safer in the management of hyperglycaemia [2] as dietary glycaemic load is directly correlated with increased risk of diabetes [50, 52]. Further, fibre plays a significant role in glycaemic control [53]. Richness of millets in dietary fibre and minerals [9] and slowly digestible starch [54] with leucine [50, 55] make millet a healthy diet for diabetics.  Pradeep and Sreerama [33] in an in vitro study concluded millets as a functional food ingredient in regulating postprandial hypoglycaemia. Further, some In vivo studies [56-60] have shown hypoglycaemic effect of millet based food after intervention.

It is evident that diabetes increases the risk of cardio vascular disease (CVDs) by three to eight folds [61]. In the context of CVDs, low density lipoprotein (LDL) and high density lipoprotein (HDL) have opposite influences on the risk of CVDs. That means, every 1 mg/dL increase in LDL enhances the risk of CVDs by 2%; whereas, every 1 mg/dL increase in HDL declines the risk of CVDs by 2-3% [62]. Triglyceride is another factor responsible for the risk of CVDs; as association of increased level of triglyceride and the risk of CVDs exist from decades [63]. Amongst different strategies in combating against CVDs, lowering of LDL has received the highest success [64]. Therefore, diet that lowers LDL should be preferred to minimise the risk of CVDs. Niacin improves the lipoprotein abnormalities lowering LDL and triglyceride [65]. Thus, niacin rich food should be recommended in lowering the risk of CVDs. Millets, amongst the cereal category is a good source of Niacin [9]. Thus, millet has the potential to address CVDs lowering LDL.

In line with the above literature, in vivo studies [58, 66]  provide evidence on the effect of millet based foods in lowering LDL and triglyceride increasing HDL (without enhancing LDL level). On the contrary, [67] in an in vivo study found a significant decrease in the blood glucose and lipid level without changing HDL. In a nut-shell, millets can be recommended to lower the risk of CVDs.

4.2. Millets against Cancer

Millet grains are rich with phenolic compounds like phenolic acids, flavonoids, and tannins which make it anti-nutrients [68] that reduces the risk of colon and breast cancer in animals [2, 69]. In an in vivo study [70] explained the anti-cancer property of a novel 35kD protein named Fibroin-modulator-binding protein (FMBP) extracted from foxtail millet supresses the growth of colon cancer cells inducing G1 phase arrest and through the loss of mitochondrial trans membrane potential that results in apoptosis (programmed cell death) in the colon cancer cells through caspase activation. In another in vivo study, [71] concluded that dietary supplementation of foxtail millet helps in treating colitis-associated colorectal cancer through the activation of gut receptor. It was also found from the study that millet based diet helped in supressing Signal Transducer and Activator of Transcription (STAT) -3 signaling pathway² . STAT are a family of transcription factor that play a crucial role in uncontrolled cell proliferation, angiogenesis and evasion of apoptosis in cancer cells.

4.3. Millets and Antimicrobial Activity

The secondary metabolites of millets exhibit antibacterial and anti-fungal activities [11, 73]. Studies of Amadou, et al. [10]; Bisht, et al. [74] provide information on the inhibitory effect of millets against bacterial pathogens such as, E.coli, B. cereus, L. monocytogens, P. mirabilis, S. typhi, P. aeruginosa, and Y. enteroclitica. Moreover, antifungal effect of millet is reported in Viswanath, et al. [75].

4.4. Millets against Celiac Disease and Aging

Celiac disease is the most common disorder and has affected humans across the world [76]. It is an auto-immune disorder originated by an unusual adaptive response against gluten containing grains [77]. Gluten free diet can be a solution to this problem [78]. Since millets are gluten-free, millet based beverages can be the best suitable option for individuals suffering from celiac disease [2, 7, 79].

Richness of antioxidants and β carotene helps individuals in maintaining their health and age [80] and millet grains are rich in antioxidants [2]. In an in vitro study, [81] found the inhibitory effect of methanolic extract effect of finger millet and kodo millet on glycation and cross-linking of collagen. Hence, millet based diet can be useful for individuals in protecting against aging. From the above literature, in a nut-shell, it can be articulated that consumption of millet can help in protecting and combating against various diseases; and can act like a nutraceuticals. A summary on different health benefits of millets is presented in Table 6.

Disease	Millets responsible for	References
Diabetes	Proso millet, finger millet, little millet	[56-60]
Cardio vascular diseases	Proso millet, foxtail millet	[58, 66]
Cancer	Proso millet, foxtail millet	[71, 82]
Anti-microbial activity	Proso millet, finger millet, foxtail millet	[6, 10, 74, 75]
Aging	Finger millet and kodo millet	[81]

5. NUTRITIONAL BIOAVAILABILITY

Bioavailability refers to the quantity of ingested nutrients which get absorbed and utilised through normal metabolic pathways [12]. Therefore, in the assessment of adequacy of dietary intake, more importance is given to the bioavailability of nutrients than nutrient contents of the food [83]. Millets are good source of minerals [2, 3, 9]. However, due to the presence of anti-nutrients like phytates, polyphenols, and tannins, a very small quantity is available for human being via absorption [12]. Bioavailability of nutrients in millets is affected by both dietary and physiological factors [12]. Therefore, minimising the anti-nutrients and enhancement of nutrient content should be the objective. Further, it is evident that processing of millets significantly affects the bioavailability of nutrients in human [12]. Thus, the effect of various processing techniques on nutritional value and bioavailability is discussed below.

5.1. Effect of Processing of Millets on Nutritional Value and Bioavailability

Mechanical and traditional technologies are used to process the millets. Decortication, milling, and sieving are the mechanical processing techniques; whereas, germination, fermentation, malting, popping, and soaking & cooking are the traditional techniques [2].

5.2. Mechanical Processing Techniques

Decortication is a process where the pericarp of the crop is removed. Reduction of dietary fibre, minerals and anti-oxidant activity was evident after decortication, which declines the applicability of pearl millet as functional food. However, significant reduction in the phytic acid, poly phenols, & tannins were found [84, 85]. That means, decortication declines both nutrient and anti-nutrient contents. Milling is the most traditional method of processing where wooden or stool mortar and pestle is used to convert dried or moistened grains into flour. Reduction of anti-nutrients and enhancement in bio-accessibility of minerals was evident in semi refined pearl millet flour [12].  Further, increase in protein and starch digestibility was found to a significant extent after milling [86]. Sieving (another processing method) records increase in both nutrients and anti-nutrients in finger millet whole flour [87].

5.3. Traditional Processing Techniques

Anti-nutrients are supposed to hinder the availability of minerals. However, they are catabolised through the process of germination and enhance mineral availability [88]. In line with Grewal and Jood [88] an increase the in vitro bio-accessibility of minerals like calcium, zinc, and iron was found in pearl millet and finger millet [89]. In proso millet, germination increased the total sugar, free amino acids, lysine, and tryptophan declining the starch content [90]. Further, a decline in the crude protein and fat content after germination was found in foxtail millet [91]. Fermentation is a natural traditional method of processing. Fermentation of pearl millet causing remarkable changes in the chemical composition enhances in vitro protein digestibility and nutritional value. Further, it declines anti-nutritional and mineral contents [92]. Duration of fermentation also affects the nutrient and anti-nutrient contents of pearl millet [93]. Soaking of grains is a popular technique for reducing anti-nutritional compounds and improving minerals bioavailability [2]. Soaking before dehulling and milling degrades phytates; however, no effect of increase in phytate degradation was found after cooking the flour with the water used for soaking [2, 84]. Popping or puffing is another traditional method used for the production of ready-to-eat products which are crunchy and porous [94].  Increment in the dietary fibre content and fall in the anti-nutritional factors is recorded in the final puffed products [91, 95].

In a comparative note, the reduction of tannin content in pearl millet, finger millet, and sorghum is found in the order: untreated > soaked > germinated millets [12, 96]. To enhance iron and zinc bioavailability, [97] advocates the use of fermentation as an ideal strategy. Further, combining fermentation with germination not only increased the nutrient content and energy densities of fura (a Nigerian food made with pearl millet) but also significantly declines the phytic acid. Thus, in a nut-shell it can be concluded that germination of millet can be used as a method of processing alone or in combination in preparing nutrient rich food products. Malting is an example of combination of methods used to process millet. It is a combination of germination, milling and sieving to achieve high quality nutritional and starch digestible product; as malting increases fibre, minerals and vitamins (B and C) content declining tannin and phytic acid significantly in brown finger millet  [94].

Apart from the above mentioned processing techniques, exogenous enzymes (like phytases, poly phenol oxidase, tannases and cellulases, xylanases and proteases) can also be used in the processing of millets to improve the nutrient bioavailability. Addition of phytase in millet based food enhances zinc absorption [98]. Use of polyphenol oxidases (PPO) increases iron absorption and use of tannases is used to decline tannin content [12, 99]. Improvement in the protein digestibility, reduction in anti-nutritional factors enhancing mineral extractability is evident after the introduction of cellulases [100]. Alike phytases and PPO, diet supplemented with xylanase, enhances iron and zinc accessibility [101]. Presence of anti-nutritional factors of pearl millet, finger millet, barnyard millet, and foxtail millet inhibit the proteolytic enzyme in breaking down protein into amino acids; thereby declining amino acid accessibility in the body. This problem can be addressed through the supplementation of proteases in human [12].

6. CONSUMPTION OF MILLETS

From ancient times, millets have been used as a staple food in diets of Asian and African people. Millet porridge is the most common traditional food in India, China, Russia, & Germany [3]. Due to wide acceptance and awareness, millets have almost replaced commonly used cereals in local dishes like idli, dosa,, putta. Modernisation has changed the dietary pattern of people, which has increased the consumption of modern food items. With the changing pace of time, researchers have developed millet based modern food items (like cookies, bread, biscuit, snack foods) depending on the changed preference and interest of people. A summary on different millet based products is presented in Table 7.

6.1. Acceptability of Millet Based Products

Development of modern food is not sufficient unless it is not consumed. Consumption depends on the acceptability of any product; and it is determined through the sensory evaluation [102]. Studies based on sensory acceptability of millet based products are scantly available. Mixed results have been found from the studies based on the sensory evaluations of millet based products. Pearl millet and sorghum based cookies [103, 104] finger millet based flakes, vermicelli, and khakhra [105, 106] and proso millet based pizza show decent acceptability in terms of taste, colour and texture. Similarly, from a study where millet based south Indian food items, i.e., idli, upma, khichdi, and bisibela bath were introduced replacing rice in school was  accepted by the children [107]. However, McSweeney, et al. [108] doing the sensory evaluation of proso millet based snacks and biscuits found that the acceptability of the product in terms of texture and taste decreased due to the increase in millet proportion which made the taste bitter.

6.2. Studies Examining the Mineral Bioavailability of Millet Based Food 

The acceptability of millet based products will be increased in terms of nutritional value along with taste if it could enhance the minerals’ bioavailability; because it is evident that anti-nutrients content of millets affect the bioavailability [12]. Iron deficiency anaemia is a global public health threat affecting varied age group of male and female [13]. Moreover, osteoporosis  remains a major public health concern  among women due to low dietary calcium intake (less than 400 mg/day) in most of the Asian countries in general and India in particular [109-111]. Along with calcium and iron, zinc has been identified as a contributing factor to the burden of disease both at regional and global level [112].

Millets are good source of minerals. Thus, millet based food (both traditional and modern) can mitigate the above global health issue enhancing the bioavailability. In vivo studies report an increase in the haemoglobin level in the study participants intervening pearl and finger millet based ladoo [102, 113] pearl millet based bhakri [114] sorghum upma/ khichdi [115] finger millet based flakes and vermicelli [105] millet mix porridge taking little millet, finger millet, foxtail millet, and kodo millet [116] finger millet powder [117]. Moreover, from the interventions of finger millet based pan cake and ladoo, an increase in the calcium absorption are evident [118, 119]. Additionally, an increase in the zinc absorption is found after the intervention of zinc fortified millet based porridges [98]. Thus, it is evident from the above literature (in vivo studies) that the bioavailability of minerals (calcium, iron and zinc) derived from millet based food is not affected by the anti-nutrient contents of millets. Therefore, the problem of micronutrient deficiencies can be addressed through the millet consumption both at national and global level.

Food items	Type of millets used	References
Cookies	Foxtail millet, finger millet, proso millet, pearl millet and barnyard millet	[7, 8]
Bread	Foxtail millet	[1]
Biscuits	Foxtail millet, finger millet, pearl millet and barnyard millet	[2]
Lohoh (fermented bread)	Pearl millet	[9]
Lajia noodles	Foxtail millet and pros millet	[10]
Appalu	Pearl millet and Bengal gram flour	[1]
Sami payasam	Little millet

7. CONCLUSION

Millets have several agrarian importances than staple cereals in terms of productivity and climate susceptibility. Presence of essential amino acids (like leucine, isoleucine, valine, and phenylalanine), minerals (calcium, iron, and zinc), vitamins, phytochemical, and anti-oxidant properties make it superior than other cereals.

Moreover, applications of millets can also be found in combating against chronic diseases like diabetes, CVDs, and cancer. Effectiveness of millets against antimicrobial activity, celiac disease and aging are also found. Notwithstanding all positive aspects of millet, presence of anti-nutrients is supposed to hinder the bioavailability of minerals. Different traditional and mechanical processing methods along with intervention of exogenous enzymes are available to decline the anti-nutrient contents enhancing bioavailability of minerals. However, more research needs to be carried out not only to develop a novel method of processing but also in examining the minerals bioavailability of millet based food through in vivo studies. Thus, the paper concludes with the recommendation of increasing millet consumption for healthy life and sustainable environment.

Funding: This study received no specific financial support.

Competing Interests: The authors declare that they have no competing interests.

Authors’ Contributions: AM initiated the idea of constructing a scoping review. All authors contributed towards the design of the study. All authors did the collection and screening of literature. AM wrote the first draft of the manuscript and all authors reviewed and commented. All authors read and approved the final version of the manuscript.

REFERENCES

[1]         H. Ritchie, D. Reay, and P. Higgins, "Sustainable food security in India—domestic production and macronutrient availability," PloS One, vol. 13, p. e0193766, 2018.Available at: https://doi.org/10.1371/journal.pone.0193766.

[2]         A. Saleh, Q. Zhang, J. Chen, and Q. Shen, "Millet grains: Nutritional quality, processing, and potential health benefits," Comprehensive Reviews in Food Science and Food Safety, vol. 12, pp. 281–295, 2013.Available at: https://doi.org/10.1111/1541-4337.12012.

[3]         A. Kumar, V. Tomer, A. Kaur, V. Kumar, and K. Gupta, "Millets: A solution to Agrarian and nutritional challenges," Agriculture & Food Security, vol. 7, pp. 1-15, 2018.Available at: https://doi.org/10.1186/s40066-018-0183-3.

[4]         J. Huang, H. Yu, X. Guan, G. Wang, and R. Guo, "Accelerated Dryland expansion under climate change," Nature Climate Change, vol. 6, pp. 166-171, 2016.Available at: https://doi.org/10.1038/nclimate2837.

[5]         P. B. Devi, R. Vijaya bharathi, S. Sathyabama, N. Malleshi, and V. Priyadarisini, "Health benefits of finger millet (Eleusine coracana L.) polyphenols and dietary fiber: A review," Journal of Food Science and Technology, vol. 51, pp. 1021-1040, 2014.Available at: https://doi.org/10.1007/s13197-011-0584-9.

[6]         S. Banerjee, K. R. Sanjay, S. Chethan, and N. G. Malleshi, "Finger millet (Eleusine coracana) polyphenols: Investigation of their antioxidant capacity and antimicrobial activity," African Journal of Food Science, vol. 6, pp. 362-374, 2012.

[7]         A. Chandrasekara and Shahidi, "Determination of antioxidant activity in free and hydrolyzed fractions of millet grains and characterization of their phenolic profiles by HPLC-DAD-ESI-MSn," Journal of Functional Foods, vol. 3, pp. 144–158, 2011.Available at: https://doi.org/10.1016/j.jff.2011.03.007.

[8]         I. Jideani, "Digitaria exilis (acha/fonio), Digitaria iburua (iburu/fonio) and Eluesine coracana (tamba/finger millet) –Non-conventional cereal grains with potentials," Scientific Research and Essays, vol. 7, pp. 3834-3843, 2012.

[9]         C. Gopalan and S. B. B. Rama, Nutritive value of Indian foods. Hyderabad: National Institute of Nutrition, 2018.

[10]       I. Amadou, M. Gounga, and G. Le, "Millets: Nutritional composition, some health benefits and processing-a review," Emirates Journal of Food and Agriculture, vol. 25, pp. 501-508, 2013.Available at: https://doi.org/10.9755/ejfa.v25i7.12045.

[11]       S. Nithiyanantham, P. Kalaiselvi, M. F. Mahomoodally, G. Zengin, A. Abirami, and G. Srinivasan, "Nutritional and functional roles of millets—A review," Journal of Food Biochemistry, vol. 43, p. e12859, 2019.Available at: https://doi.org/10.1111/jfbc.12859.

[12]       S. A. Tharifkhan, A. B. Perumal, A. Elumalai, J. A. Moses, and C. Anandharamakrishnan, "Improvement of nutrient bioavailability in millets: Emphasis on the application of enzymes," Journal of the Science of Food and Agriculture, vol. 101, pp. 4869-4878, 2021.Available at: https://doi.org/10.1002/jsfa.11228.

[13]       S. Anitha, J. Kane-Potaka, R. Botha, D. I. Givens, N. L. B. Sulaiman, S. Upadhyay, M. Vetriventhan, T. W. Tsusaka, D. J. Parasannanavar, and T. Longvah, "Millets can have a major impact on improving iron status, hemoglobin level, and in reducing iron deficiency Anemia–a systematic review and meta-analysis," Frontiers in Nutrition, vol. 8, p. 725529, 2021.Available at: https://doi.org/10.3389/fnut.2021.725529.

[14]       N. Sharma and K. Niranjan, "Foxtail millet: Properties, processing, health benefits, and uses," Food Reviews International, vol. 34, pp. 329-363, 2018.Available at: https://doi.org/10.1080/87559129.2017.1290103.

[15]       O. Yadav, K. Rai, F. Bidinger, S. Gupta, B. Rajpurohit, and S. Bhatnagar, "Pearl millet (Pennisetum glaucum) restorer lines for breeding dual-purpose hybrids adapted to arid environments," Indian Journal of Agricultural Sciences, vol. 82, pp. 922-927, 2012.

[16]       O. Yadav and K. Rai, "Genetic improvement of pearl millet in India," Agricultural Research, vol. 2, pp. 275-292, 2013.Available at: https://doi.org/10.1007/s40003-013-0089-z.

[17]       S. Nedumaran, M. C. S. Bantilan, S. K. Gupta, A. Irshad, and J. S. Davis, "Potential welfare benefit of millets improvement research at ICRISAT: Multi country - economic surplus model approach," Socioecon Discuss Pap Series No. 1–372014.

[18]       D. Austin, "Fox-tail millets (Setaria: Poaceae) - abandoned food in two hemispheres," Economic Botany, vol. 60, pp. 143–158, 2006.Available at: https://doi.org/10.1663/0013-0001(2006)60[143:FMSPFI]2.0.CO;2.

[19]       A. Vinoth and R. Ravindhran, "Biofortification in millets: A sustainable approach for nutritional security," Frontiers in Plant Science, vol. 8, pp. 1–13, 2017.Available at: https://doi.org/10.3389/fpls.2017.00029.

[20]       J. M. De Wet, D. Brink, K. Rao, and M. Mengesha, "Diversity in kodo millet, Paspalum scrobiculatum," Economic Botany, vol. 37, pp. 159-163, 1983.

[21]       A. Mishra, S. K. Mishra, I. Baitharu, and T. K. Das, "Food security and nutritional status among rural poor: Evaluating the impact of rural livelihood mission in Odisha, India," Journal of Reviews on Global Economics, vol. 9, pp. 141-148, 2020.

[22]       S. Shafaeizadeh, L. Muhardi, C. J. Henry, B. J. Van de Heijning, and E. M. Van der Beek, "Macronutrient composition and food form affect glucose and insulin responses in humans," Nutrients, vol. 10, p. 188, 2018.Available at: https://doi.org/10.3390/nu10020188.

[23]       D. Ludwig, F. Hu, L. Tappy, and J. Brand-Miller, "Dietary carbohydrates: Role of quality and quantity in chronic disease," BMJ, vol. 361, p. k2340, 2018.Available at: https://doi.org/10.1136/bmj.k2340.

[24]       G. Wu, "Dietary protein intake and human health," Food & Function, vol. 7, pp. 1251-1265, 2016.Available at: https://doi.org/10.1039/c5fo01530h.

[25]       I. F. M. ICMR, "Nutrient requirements and rcommended dietary allowances for Indians," A Report of the Expert group of the Indian Council of Medical Rearch. Hyderabad2010.

[26]       S. Chethan and N. Malleshi, "Finger millet polyphenols: Optimization of extraction and the effect of pH on their stability," Food Chemistry, vol. 105, pp. 862-870, 2007.Available at: https://doi.org/10.1016/j.foodchem.2007.02.012.

[27]       V. Aggarwal, A. Seth, R. K. Marwaha, B. Sharma, P. Sonkar, S. Singh, and S. Aneja, "Management of nutritional rickets in Indian children: A randomized controlled trial," Journal of Tropical Pediatrics, vol. 59, pp. 127-133, 2013.Available at: https://doi.org/10.1093/tropej/fms058.

[28]       M. Domellöf, I. Thorsdottir, and K. Thorstensen, "Health effects of different dietary iron intakes: A systematic literature review for the 5th nordic nutrition recommendations," Food & Nutrition Research, vol. 57, p. 21667, 2013.Available at: https://doi.org/10.3402/fnr.v57i0.21667.

[29]       M. Hambidge, "Zinc and health: Current status and future directions: Introduction," The Journal of Nutrition, vol. 130, pp. 1344–1349, 2000.

[30]       R. D. Reichert, "The pH-sensitive pigments in pearl millet," Cereal Chemistry, vol. 56, pp. 291-294, 1979.

[31]       L. Dykes and L. Rooney, "Phenolic compounds in cereal grains and their health benefits," Cereal Foods World, vol. 52, pp. 105-111, 2007.Available at: https://doi.org/10.1094/CFW-52-3-0105.

[32]       A. Sokół-Łętowska, J. Oszmiański, and A. Wojdyło, "Antioxidant activity of the phenolic compounds of hawthorn, pine and skullcap," Food Chemistry, vol. 103, pp. 853-859, 2007.Available at: https://doi.org/10.1016/j.foodchem.2006.09.036.

[33]       P. Pradeep and Y. N. Sreerama, "Soluble and bound phenolics of two different millet genera and their milled fractions: Comparative evaluation of antioxidant properties and inhibitory effects on starch hydrolysing enzyme activities," Journal of Functional Foods, vol. 35, pp. 682-693, 2017.Available at: https://doi.org/10.1016/j.jff.2017.06.033.

[34]       R. K. Pathak, A. Gupta, R. Shukla, and M. Baunthiyal, "Identification of new drug-like compounds from millets as Xanthine oxidoreductase inhibitors for treatment of Hyperuricemia: A molecular docking and simulation study," Computational Biology and Chemistry, vol. 76, pp. 32-41, 2018.Available at: https://doi.org/10.1016/j.compbiolchem.2018.05.015.

[35]       V. Asharani, A. Jayadeep, and N. Malleshi, "Natural antioxidants in edible flours of selected small millets," International Journal of Food Properties, vol. 13, pp. 41-50, 2010.Available at: https://doi.org/10.1080/10942910802163105.

[36]       K. K. Adom and R. H. Liu, "Antioxidant activity of grains," Journal of Agricultural and Food Chemistry, vol. 50, pp. 6182-6187, 2002.Available at: https://doi.org/10.1021/jf0205099.

       B. Pandey, M. Reba, P. Joshi, and K. C. Seto, "Urbanization and food consumption in India," Scientific Reports, vol. 10, pp. 1-12, 2020.Available at: https://doi.org/10.1038/s41598-020-73313-8.

[38]       A. Misra, N. Singhal, B. Sivakumar, N. Bhagat, A. Jaiswal, and L. Khurana, "Nutrition transition in India: Secular trends in dietary intake and their relationship to diet-related non-communicable diseases," Journal of Diabetes, vol. 3, pp. 278-292, 2011.Available at: https://doi.org/10.1111/j.1753-0407.2011.00139.x.

[39]       C. Alae-Carew, F. A. Bird, S. Choudhury, F. Harris, L. Aleksandrowicz, J. Milner, E. J. Joy, S. Agrawal, A. D. Dangour, and R. Green, "Future diets in India: A systematic review of food consumption projection studies," Global Food Security, vol. 23, pp. 182-190, 2019.Available at: https://doi.org/10.1016/j.gfs.2019.05.006.

[40]       W. K. Balwan and S. Kour, "Lifestyle diseases: The link between modern lifestyle and threat to public health," Saudi Journal of Medical and Pharmaceutical Sciences, vol. 7, pp. 179-84, 2021.Available at: https://doi.org/10.36348/sjmps.2021.v07i04.003.

[41]       M. Sharifi-Rad, N. V. Anil Kumar, P. Zucca, E. M. Varoni, L. Dini, E. Panzarini, and J. Sharifi-Rad, "Lifestyle, oxidative stress, and antioxidants: Back and forth in the pathophysiology of chronic diseases," Frontiers in Physiology, vol. 11, pp. 1–21, 2020.Available at: https://doi.org/10.3389/fphys.2020.00694.

[42]       G. Pizzino, N. Irrera, M. Cucinotta, G. Pallio, F. Mannino, V. Arcoraci, and A. Bitto, "Oxidative stress: Harms and benefits for human health," Oxidative Medicine and Cellular Longevity, pp. 1-13, 2017.Available at: https://doi.org/10.1155/2017/8416763.

[43]       J. Sastre, F. V. Pallardó, and J. Viña, "Mitochondrial oxidative stress plays a key role in aging and apoptosis," IUBMB life, vol. 49, pp. 427-435, 2000.Available at: https://doi.org/10.1080/152165400410281.

[44]       W. Takabe, E. Niki, K. Uchida, S. Yamada, K. Satoh, and N. Noguchi, "Oxidative stress promotes the development of transformation: Involvement of a potent mutagenic lipid peroxidation product, acrolein," Carcinogenesis, vol. 22, pp. 935-941, 2001.Available at: https://doi.org/10.1093/carcin/22.6.935.

[45]       S. Kawanishi, Y. Hiraku, and S. Oikawa, "Mechanism of guanine-specific DNA damage by oxidative stress and its role in carcinogenesis and aging," Mutation Research/Reviews in Mutation Research, vol. 488, pp. 65-76, 2001.Available at: https://doi.org/10.1016/S1383-5742(00)00059-4.

[46]       K. Heim, A. Tagliaferro, and D. Bobilya, "Flavonoid antioxidants: Chemistry, metabolism and structure-activity relationships," Journal of Nutritional Biochemistry, vol. 13, pp. 572–584, 2002.Available at: https://doi.org/10.1016/S0955-2863(02)00208-5.

[47]       V. Lobo, A. Patil, A. Phatak, and N. Chandra, "Free radicals, antioxidants and functional foods: Impact on human health," Pharmacognosy Reviews, vol. 4, pp. 118–126, 2010.Available at: https://doi.org/10.4103/0973-7847.70902.

[48]       L. A. Pham-Huy, H. He, and C. Pham-Huy, "Stem cell," Ataturk University Journal of Veterinary Sciences, vol. 14, pp. 221–228, 2008.Available at: https://doi.org/10.17094/ataunivbd.483253.

[49]       M. Subba Rao and G. Muralikrishna, "Evaluation of the antioxidant properties of free and bound phenolic acids from native and malted finger millet (Ragi, Eleusine coracana Indaf-15)," Journal of Agricultural and Food Chemistry, vol. 50, pp. 889-892, 2002.Available at: https://doi.org/10.1021/jf011210d.

[50]       J. Kam, S. Puranik, R. Yadav, H. Manwaring, S. Pierre, R. Srivastava, and R. Yadav, "Dietary interventions for type 2 diabetes: How millet comes to help," Frontiers in Plant Science, vol. 7, pp. 1-14, 2016.Available at: https://doi.org/10.3389/fpls.2016.01454.

[51]       A. Kharroubi and H. Darwish, "Diabetes mellitus: The epidemic of the century," World Journal of Diabetes, vol. 6, pp. 850–867, 2015.Available at: https://doi.org/10.4239/wjd.v6.i6.850.

[52]       D. Greenwood, D. Threapleton, and C. Evans, "Glycemic index, glycemic load, carbohydrates, and type 2 diabetes: Systematic review and dose-response meta-analysis of prospective studies," Diabetes Care, vol. 36, pp. 4166–4171, 2013.Available at: https://doi.org/10.2337/dc13-0325.

[53]       M. Chandalia, A. Garg, D. Lutjohann, K. Von Bergmann, S. M. Grundy, and L. J. Brinkley, "Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus," New England Journal of Medicine, vol. 342, pp. 1392-1398, 2000.Available at: https://doi.org/10.1056/nejm200005113421903.

[54]       P. Liu, T. Perry, and J. Monro, "Glycaemic glucose equivalent: Validation as a predictor of the relative glycaemic effect of foods," European Journal of Clinical Nutrition, vol. 57, pp. 1141-1149, 2003.Available at: https://doi.org/10.1038/sj.ejcn.1601656.

[55]       G. Ejeta, M. Hassen, and E. Mertz, "In vitro digestibility and amino acid composition of pearl millet (Pennisetum typhoides) and other cereals," Proceedings of the National Academy of Sciences, vol. 84, pp. 6016-6019, 1987.Available at: https://doi.org/10.1073/pnas.84.17.6016.

[56]       M. Abdelgadir, M. Abbas, A. Järvi, M. Elbagir, M. Eltom, and C. Berne, "Glycaemic and insulin responses of six traditional Sudanese carbohydrate-rich meals in subjects with type 2 diabetes mellitus," Diabetic Medicine, vol. 22, pp. 213-217, 2005.Available at: https://doi.org/10.1111/j.1464-5491.2004.01385.x.

[57]       K. Geetha, G. M. Yankanchi, S. Hulamani, and N. Hiremath, "Glycemic index of millet based food mix and its effect on pre diabetic subjects," Journal of Food Science and Technology, vol. 57, pp. 2732-2738, 2020.Available at: https://doi.org/10.1007/s13197-020-04309-5.

[58]       M. Jali, M. Kamatar, S. M. Jali, M. Hiremath, and R. K. Naik, "Efficacy of value added foxtail millet therapeutic food in the management of diabetes and dyslipidamea in type 2 diabetic patients," Recent Research in Science and Technology, vol. 4, pp. 03-04, 2012.

[59]       S. Shobana, Y. Sreerama, and N. Malleshi, "Composition and enzyme inhibitory properties of finger millet (Eleusine coracana L.) seed coat phenolics: Mode of inhibition of α-glucosidase and pancreatic amylase," Food Chemistry, vol. 115, pp. 1268-1273, 2009.Available at: https://doi.org/10.1016/j.foodchem.2009.01.042.

[60]       K. Shukla and S. Srivastava, "Evaluation of finger millet incorporated noodles for nutritive value and glycemic index," Journal of Food Science and Technology, vol. 51, pp. 527-534, 2014.Available at: https://doi.org/10.1007/s13197-011-0530-x.

[61]       F. Giacco and M. Brownlee, "Genetic alterations NIH public access," Bone, vol. 23, pp. 1–7, 2012.

[62]       D. J. Gordon and B. M. Rifkind, "High-density lipoprotein—the clinical implications of recent studies," New England Journal of Medicine, vol. 321, pp. 1311-1316, 1989.Available at: https://doi.org/10.1056/nejm198911093211907.

[63]       M. Miller, N. J. Stone, C. Ballantyne, V. Bittner, M. H. Criqui, H. N. Ginsberg, and P. M. Kris-Etherton, "Triglycerides and cardiovascular disease: A scientific statement from the American heart association," Circulation, vol. 123, pp. 2292–2333, 2011.Available at: https://doi.org/10.1161/CIR.0b013e3182160726.

[64]       A. Chait and R. H. Eckel, "Lipids, lipoproteins, and cardiovascular disease: Clinical pharmacology now and in the future," The Journal of Clinical Endocrinology & Metabolism, vol. 101, pp. 804-814, 2016.Available at: https://doi.org/10.1210/jc.2015-3940.

[65]       J. McKenney, "New perspectives on the use of Niacin in the treatment of lipid disorders," Archives of Internal Medicine, vol. 164, pp. 697-705, 2004.Available at: https://doi.org/10.1001/archinte.164.7.697.

[66]       N. Nishizawa, M. Oikawa, and S.-i. Hareyama, "Effect of dietary protein from proso millet on the plasma cholesterol metabolism in rats," Agricultural and Biological Chemistry, vol. 54, pp. 229-230, 1990.Available at: https://doi.org/10.1080/00021369.1990.10869914.

[67]       S. Joshi and S. Srivastava, "Hypoglycemic and hypolipidemic effect of barnyard millet consumption in type 2 diabetic subjects," International Journal of Current Microbiology and Applied Sciences, vol. 10, pp. 467-477, 2021.

[68]       L. U. Thompson, "Potential health benefits and problems associated with antinutrients in foods," Food Research International, vol. 26, pp. 131-149, 1993.Available at: https://doi.org/10.1016/0963-9969(93)90069-U.

[69]       E. Graf and J. Eaton, "Antioxidant functions of phytic acid," Free Radical Biology & Medicine, vol. 8, pp. 61–69, 1990.Available at: https://doi.org/10.1016/0891-5849(90)90146-A.

[70]       S. Shan, Z. Li, I. P. Newton, C. Zhao, Z. Li, and M. Guo, "A novel protein extracted from foxtail millet bran displays anti-carcinogenic effects in human colon cancer cells," Toxicology Letters, vol. 227, pp. 129-138, 2014.Available at: https://doi.org/10.1016/j.toxlet.2014.03.008.

[71]       B. Zhang, Y. Xu, and S. Liu, "Dietary supplementation of foxtail millet ameliorates colitis-associated colorectal cancer in mice via activation of gut receptors and suppression of the STAT3 pathway," Nutrients, vol. 12, pp. 1–20, 2020.Available at: https://doi.org/10.3390/nu12082367.

[72]       M. Kamran, P. Patil, and R. Gude, "Role of STAT3 in cancer metastasis and translational advances," Biomed Research International, vol. 2013, pp. 421821-421821, 2013.Available at: https://doi.org/10.1155/2013/421821.

[73]       W. Xu, L. Wei, W. Qu, Z. Liang, J. Wang, X. Peng, Y. Zhang, and K. Huang, "A novel antifungal peptide from foxtail millet seeds," Journal of the Science of Food and Agriculture, vol. 91, pp. 1630-1637, 2011.Available at: https://doi.org/10.1002/jsfa.4359.

[74]       A. Bisht, M. Thapliyal, and A. Singh, "Screening and isolation of antibacterial proteins/peptides from seeds of millets," International Journal of Current Pharmaceutical Research, vol. 8, pp. 96-99, 2016.

[75]       V. Viswanath, A. Urooj, and N. Malleshi, "Evaluation of antioxidant and antimicrobial properties of finger millet polyphenols (Eleusine coracana)," Food Chemistry, vol. 114, pp. 340-346, 2009.Available at: https://doi.org/10.1016/j.foodchem.2008.09.053.

[76]       C. Catassi and A. Fasano, "Celiac disease," Curr Opin Gastroenterol, vol. 24, pp. 687–691, 2008.Available at: https://doi.org/10.1097/MOG.0b013e32830edc1e.

[77]       I. Parzanese, D. Qehajaj, F. Patrinicola, M. Aralica, M. Chiriva-Internati, S. Stifter, L. Elli, and F. Grizzi, "Celiac disease: From pathophysiology to treatment," World Journal of Gastrointestinal Pathophysiology, vol. 8, pp. 27-38, 2017.Available at: https://doi.org/10.4291/wjgp.v8.i2.27.

[78]       G. Samasca, G. Sur, I. Lupan, and D. Deleanu, "Gluten-free diet and quality of life in celiac disease," Gastroenterology and Hepatology From bed to Bench, vol. 7, pp. 139-143, 2014.

[79]       A. Taylor, B. Lebwohl, C. Synder, and P. Green, "Celiac disease," pp. 1–20, 2019.

[80]       B. L. Tan and M. E. Norhaizan, "Carotenoids: How effective are they to prevent age-related diseases?," Molecules, vol. 24, p. 1801, 2019.Available at: https://doi.org/10.3390/molecules24091801.

[81]       P. S. Hegde, G. Chandrakasan, and T. Chandra, "Inhibition of collagen glycation and crosslinking in vitro by methanolic extracts of Finger millet (Eleusine coracana) and Kodo millet (Paspalum scrobiculatum)," The Journal of Nutritional Biochemistry, vol. 13, pp. 517-521, 2002.Available at: https://doi.org/10.1016/S0955-2863(02)00171-7.

[82]       S. Liang and K. Liang, "Millet grain as a candidate antioxidant food resource: A review," International Journal of Food Properties, vol. 22, pp. 1652-1661, 2019.Available at: https://doi.org/10.1080/10942912.2019.1668406.

[83]       H. Schönfeldt, B. Pretorius, and N. Hall, "Bioavailability of nutrients," Encyclopedia of Food and Health, pp. 401–406, 2015.Available at: https://doi.org/10.1016/B978-0-12-384947-2.00068-4.

[84]       I. Lestienne, M. Buisson, and V. Lullien-Pellerin, "Losses of nutrients and anti-nutritional factors during abrasive decortication of two pearl millet cultivars (Pennisetum glaucum)," Food Chemistry, vol. 100, pp. 1316–1323, 2007.Available at: https://doi.org/10.1016/j.foodchem.2005.11.027.

[85]       A. ElShazali, A. Nahid, H. Salma, and E. Elfadil, "Effect of radiation process on antinutrients, protein digestibility and sensory quality of pearl millet flour during processing and storage," International Food Research Journal, vol. 18, pp. 1401-1407, 2011.

[86]       S. Chowdhury and D. Punia, "Nutrient and antinutrient composition of pearl millet grains as affected by milling and baking," Nahrung - Food, vol. 41, pp. 105-107, 1997.Available at: https://doi.org/10.1002/food.19970410210.

[87]       M. Oghbaei and J. Prakash, "Bioaccessible nutrients and bioactive components from fortified products prepared using finger millet (Eleusine coracana)," Journal of the Science of Food and Agriculture, vol. 92, pp. 2281-2290, 2012.Available at: https://doi.org/10.1002/jsfa.5622.

[88]       A. Grewal and S. Jood, "Effect of processing treatments on nutritional and antinutritional contents of green gram," Journal of Food Biochemistry, vol. 30, pp. 535-546, 2006.Available at: https://doi.org/10.1111/j.1745-4514.2006.00080.x.

[89]       P. Mamiro, J. Van, S. Mwikya, and A. Huyghebaert, "In vitro extractability of calcium, iron, and zinc in finger millet and kidney beans during processing," Journal of Food Science, vol. 66, pp. 1271-1275, 2001.Available at: https://doi.org/10.1111/j.1365-2621.2001.tb15200.x.

[90]       K. P. Parameswaran and S. Sadasivam, "Changes in the carbohydrates and nitrogenous components during germination of proso millet, Panicum miliaceum," Plant Foods for Human Nutrition, vol. 45, pp. 97-102, 1994.Available at: https://doi.org/10.1007/BF01088466.

[91]       M. Choudhury, P. Das, and B. Baroova, "Nutritional evaluation of popped and malted indigenous millet of Assam," Journal of Food Science and Technology, vol. 48, pp. 706–711, 2011.Available at: https://doi.org/10.1007/s13197-010-0157-3.

[92]       A. I. Ahmed, A. A. Abdalla, and A. Tinay, "Effect of traditional processing on chemical composition and mineral content of two cultivars of pearl millet (Pennisetum glaucum)," Journal of Applied Sciences Research, vol. 5, pp. 2271–2276, 2009.

[93]       M. A. Osman, "Effect of traditional fermentation process on the nutrient and antinutrient contents of pearl millet during preparation of Lohoh," Journal of the Saudi Society of Agricultural Sciences, vol. 10, pp. 1-6, 2011.Available at: https://doi.org/10.1016/j.jssas.2010.06.001.

[94]       S. E. Ramashia, T. A. Anyasi, E. T. Gwata, S. Meddows-Taylor, and A. I. O. Jideani, "Processing, nutritional composition and health benefits of finger millet in Sub-Saharan Africa," Food Science and Technology, vol. 39, pp. 253-266, 2019.

[95]       P. Sarkar, D. C. DH LK, S. Panigrahi, and R. Choudhary, "Traditional and ayurvedic foods of Indian origin," Journal of Ethnic Foods, vol. 2, pp. 97–109, 2015.Available at: https://doi.org/10.1016/j.jef.2015.08.003.

[96]       A. Singh, S. Gupta, R. Kaur, and H. Gupta, "Process optimization for anti-nutrient minimization of millets," Asian Journal of Dairy and Food Research, vol. 36, pp. 322-326, 2017.

[97]       M. Gabaza, M. Muchuweti, P. Vandamme, and K. Raes, "Can fermentation be used as a sustainable strategy to reduce iron and zinc binders in traditional African fermented cereal porridges or gruels?," Food Reviews International, vol. 33, pp. 561-586, 2017.Available at: https://doi.org/10.1080/87559129.2016.1196491.

[98]       M. Brnić, R. F. Hurrell, L. T. Songré-Ouattara, B. Diawara, A. Kalmogho-Zan, C. Tapsoba, C. Zeder, and R. Wegmüller, "Effect of phytase on zinc absorption from a millet-based porridge fed to young Burkinabe children," European Journal of Clinical Nutrition, vol. 71, pp. 137-141, 2017.Available at: https://doi.org/10.1038/ejcn.2016.199.

[99]       K. Baye, J.-P. Guyot, C. Icard-Vernière, I. Rochette, and C. Mouquet-Rivier, "Enzymatic degradation of phytate, polyphenols and dietary fibers in Ethiopian injera flours: Effect on iron bioaccessibility," Food Chemistry, vol. 174, pp. 60-67, 2015.Available at: https://doi.org/10.1016/j.foodchem.2014.11.012.

[100]     U. Antony and T. Chandra, "Enzymatic treatment and use of starters for the nutrient enhancement in fermented flour of red and white varieties of finger millet (Eleusine coracana)," Journal of Agricultural and Food Chemistry, vol. 47, pp. 2016-2019, 1999.Available at: https://doi.org/10.1021/jf980564a.

[101]     X. Yu, J. Han, H. Li, Y. Zhang, and J. Feng, "The effect of enzymes on release of trace elements in feedstuffs based on in vitro digestion model for monogastric livestock," Journal of Animal Science and Biotechnology, vol. 9, pp. 1-8, 2018.Available at: https://doi.org/10.1186/s40104-018-0289-2.

[102]     D. Singh-Ackbarali and R. Maharaj, "Sensory evaluation as a tool in determining acceptability of innovative products developed by undergraduate students in food science and technology at the University of Trinidad and Tobago," Journal of Curriculum and Teaching, vol. 3, pp. 10-27, 2014.Available at: https://doi.org/10.5430/jct.v3n1p10.

[103]     F. Suma and U. A, "Sensory, physical and nutritional qualities of cookies prepared from pearl millet (Pennisetum Typhoideum)," Journal of Food Processing & Technology, vol. 5, pp. 1-6, 2014.Available at: https://doi.org/10.4172/2157-7110.1000377.

[104]     L. Okpala, E. Okoli, and E. Udensi, "Physico-chemical and sensory properties of cookies made from blends of germinated pigeon pea, fermented sorghum, and cocoyam flours," Food Science & Nutrition, vol. 1, pp. 8-14, 2013.Available at: https://doi.org/10.1002/fsn3.2.

[105]     S. Shobana, R. P. Selvi, V. Kavitha, N. Gayathri, G. Geetha, R. Gayathri, V. Parthasarthy, K. G. Balasubramaniam, R. Vaidya, and V. Sudha, "Development and evaluation of nutritional, sensory and glycemic properties of finger millet ('Eleusine coracana'L.) based food products," Asia Pacific Journal of Clinical Nutrition, vol. 27, pp. 84-91, 2018.Available at: https://doi.org/10.6133/apjcn.032017.18.

[106]     P. Giridhar, "Preparation and sensory evaluation of finger millet khakhra," Journal of Food Science and Nutrition Research, vol. 2, pp. 61-64, 2019.Available at: https://doi.org/10.26502/jfsnr.2642-1100009.

[107]     S. Anitha, J. Kane-Potaka, T. W. Tsusaka, D. Tripathi, S. Upadhyay, A. Kavishwar, A. Jalagam, N. Sharma, and S. Nedumaran, "Acceptance and impact of millet-based mid-day meal on the nutritional status of adolescent school going children in a peri urban region of Karnataka State in India," Nutrients, vol. 11, p. 2077, 2019.Available at: https://doi.org/10.3390/nu11092077.

[108]     M. B. McSweeney, L. M. Duizer, K. Seetharaman, and D. Dan Ramdath, "Assessment of important sensory attributes of millet based snacks and biscuits," Journal of Food Science, vol. 81, pp. S1203-S1209, 2016.Available at: https://doi.org/10.1111/1750-3841.13281.

[109]     D. Dhanwal, C. Cooper, and E. Dennison, "Geographic variation in osteoporotic hip fracture incidence: The growing importance of Asian influences in coming decades," Journal of Osteoporosis, pp. 1–5, 2010.Available at: https://doi.org/10.4061/2010/757102.

[110]     K. Ramsubeik, N. S. Keuler, L. A. Davis, and K. E. Hansen, "Factors associated with calcium absorption in postmenopausal women: A post hoc analysis of dual-isotope studies," Journal of the Academy of Nutrition and Dietetics, vol. 114, pp. 761-767, 2014.Available at: https://doi.org/10.1016/j.jand.2013.07.041.

[111]     E. Balk, G. Adam, V. Langberg, A. Earley, P. Clark, P. Ebeling, A. Mithal, R. Rizzoli, C. Zerbini, and D. Pierroz, "Global dietary calcium intake among adults: A systematic review," Osteoporosis International, vol. 28, pp. 3315-3324, 2017.Available at: https://doi.org/10.1007/s00198-017-4230-x.

[112]     M. Ezzati, A. Lopez, and A. Rodgers, "Selected major risk factors and global and regional burden of disease," Lancet, vol. 360, pp. 1347–1360, 2002.Available at: https://doi.org/10.1016/S0140-6736(02)11403-6.

[113]     A. Moharana, M. Nursing, S. College, and O. Siksha, "Effect of finger millet [Ragi] Ladoo consumption on the level of Hemoglobin," European Journal of Molecular & Clinical Medicine, vol. 7, pp. 1018–1022, 2020.

[114]     J. L. Finkelstein, S. Mehta, S. A. Udipi, P. S. Ghugre, S. V. Luna, M. J. Wenger, L. E. Murray-Kolb, E. M. Przybyszewski, and J. D. Haas, "A randomized trial of iron-biofortified pearl millet in school children in India," The Journal of Nutrition, vol. 145, pp. 1576-1581, 2015.Available at: https://doi.org/10.3945/jn.114.208009.

[115]     R. Prasad MP, D. Benhur, K. Kommi, R. Madhari, V. Rao M, and J. Patil, "Impact of Sorghum supplementation on growth and micronutrient status of school going children in Southern India—a randomized trial," The Indian Journal of Pediatrics, vol. 83, pp. 9-14, 2016.Available at: https://doi.org/10.1007/s12098-015-1782-7.

[116]     M. Durairaj, G. Gurumurthy, V. Nachimuthu, K. Muniappan, and S. Balasubramanian, "Dehulled small millets: The promising nutricereals for improving the nutrition of children," Maternal & Child Nutrition, vol. 15, p. e12791, 2019.Available at: https://doi.org/10.1111/mcn.12791.

[117]     S. Karkada, S. Upadhya, S. Upadhya, and G. Bhat, "Beneficial effects of ragi (Finger Millet) on hematological parameters, body mass index, and scholastic performance among anemic adolescent high-school girls (AHSG)," Comprehensive Child and Adolescent Nursing, vol. 42, pp. 141-150, 2019.Available at: https://doi.org/10.1080/24694193.2018.1440031.

[118]     K. Joseph, P. P. Kurien, M. Swaminathan, and V. Subrahmanyan, "The effect of partial or complete replacement of rice in poor vegetarian diets by ragi (Eleusine coracana) on the metabolism of nitrogen, calcium and phosphorus," British Journal of Nutrition, vol. 16, pp. 361–368, 1962.Available at: https://doi.org/10.1079/bjn19620037.

[119]     G. Gayathri and A. Hemamalini, "Plant based indigenous dietary calcium supplementation on Bone turnover markers among peri and postmenopausal women: A randomised controlled trial," Indian Journal of Community Health, vol. 32, pp. 705-712, 2020.

Views and opinions expressed in this article are the views and opinions of the author(s), Journal of Nutrients shall not be responsible or answerable for any loss, damage or liability etc. caused in relation to/arising out of the use of the content.

---

Footnotes: