Academic literature on the topic 'Pearl millet – Nutrition'

Background: Millets are small-seeded cereals having excellent nutritional quality. They are comparable or superior to some commonly consumed cereals like wheat and rice. Millets are gluten-free, have low Glycemic Index and are a good source of calcium, iron, potassium, zinc magnesium and B vitamins. Natural fermentation of millets can improve their lower cooking quality, taste, low bioavailability and palatability. Objective: This study was undertaken to evaluate the effect of natural fermentation on antioxidant activity of Pearl millet (Pennisetum glaucum). Methods: The present work has been done to standardize the natural fermentation process of pearl millet using response surface methodology for enhanced iron content and antioxidant activity. Pearl millet was treated with natural fermentation process at varying temperature (30-50°C), time (4-12 hrs) and pH (3-7). The effect of these fermentation treatments were studied on total reducing sugar, iron content, antioxidant activity (Total Phenolic content and DPPH), tannin content and antinutritional factors of pearl millet using a second order central composite design. Results: The cofficient of determination, R2 values for Total reducing sugar, iron content, antioxidant activity and tannin content was greater than 0.900. Statistical analysis showed that sugar, iron content, antioxidant activity and tannin content varied significantly (p <0.05) with a change in pH, temperature and time. pH was found to be the most important factor affecting the quality parameters of the pearl millet during fermentation as it exerted a strong influence (p < 0.01) on all the dependent variables. Conclusion: Increase in total reducing sugar, iron content, antioxidant activity and decrease in tannin content of pearl millet were observed along with a decrease in pH and temperature of fermentation. On the basis of response surface and contour plots, the fermentation conditions of pearl millet were optimized at a temperature of 40°C, pH 5 and time duration of 8 hours.

Pearl millet is an important food crop in the arid and semi-arid tropical regions of Africa and Asia. Iron and zinc deficiencies are widespread and serious public health problems worldwide, including in India and Africa. Biofortification is a cost-effective and sustainable agricultural strategy to address this problem. The aim of this review is to provide the current biofortification breeding status and future directions of the pearl millet for growing nutrition markets. Research on the pearl millet has shown that a large genetic variability (30–140 mg kg−1 Fe and 20–90 mg kg−1 Zn) available in this crop can be effectively utilized to develop high-yielding cultivars with high iron and zinc densities. Open-pollinated varieties (Dhanashakti) and hybrids (ICMH 1202, ICMH 1203 and ICMH 1301) of pearl millet with a high grain yield and high levels of iron (70–75 mg kg−1) and zinc (35–40 mg kg−1) densities have been developed and released first in India. Currently, India is growing > 70,000 ha of biofortified pearl millet, and furthermore more pipeline cultivars are under various stages of testing at the national (India) and international (west Africa) trials for a possible release. Until today, no special markets existed to promote biofortified varieties and hybrids as no incentive price to products existed to address food and nutritional insecurity simultaneously. The market demand is likely to increase only after an investment in crop breeding and the integration into the public distribution system, nutritional intervention schemes, private seed and food companies with strong mainstreaming nutritional policies. The following sections describe various aspects of breeding and market opportunity for addressing micronutrient malnutrition.

Purpose Pearl millet (Pennisetum glaucum) is a rich source of nutrients as compared to the major cultivated cereal crops. However, major factors which limit its utilization are the presence of anti-nutritional factors (phytate, tannins and polyphenols) which lower availability of minerals and poor keeping quality because of higher lipase activity. Therefore, this paper aims to focus on the impact of different processing methods on the nutrient composition and anti-nutritional components of pearl millet. Design/methodology/approach This is a literature review study from 1983 to 2017, focusing on studies related to pearl millet processing and their effectiveness in the enrichment of nutritional value through reduction of anti-nutritional compounds. Findings From the literature reviewed, pearl millet processing through various methods including milling, malting, fermentation, blanching and acid as well as heat treatments were found to be effective in achieving the higher mineral digestibility, retardation of off flavor, bitterness as well as rancidity problems found during storage of flour. Originality/value Through this review paper, possible processing methods and their impact on the nutrient and anti-nutrient profile of pearl millet are discussed after detailed studied of literature from journal articles and thesis.

Purpose – The purpose of this paper is to explore farmer acceptance of a biofortified staple food crop in a developing country prior to its commercialization. The paper focuses on the hypothetical introduction of a high-iron pearl millet variety in Maharashtra, India, where pearl millet is among the most important staple crops. Design/methodology/approach – A choice experiment is used to investigate farmer preferences for and trade-offs among various production and consumption attributes of pearl millet. The key pearl millet attributes studied include days it takes pearl millet to mature, color of the roti (flat bread) the grain produces, the presence of high-iron content (nutritional attribute), and the price of the pearl millet seed. Choice data come from 630 pearl millet-producing households from three purposefully selected districts of Maharashtra. A latent class model is used to investigate the heterogeneity in farmers’ preferences for pearl millet attributes and to profile farmers who are more or less likely to choose high-iron varieties of pearl millet. Findings – The results reveal that there are three distinct segments in the sample, and there is significant heterogeneity in farmer preferences across these segments. High-iron pearl millet is valued the most by larger households that produce mainly for household consumption and currently have lower quality diets. Households that mainly produce for market sales, on the other hand, derive lower benefits from consumption characteristics such as color and nutrition. Research limitations/implications – The main limitation of the study is that it uses a stated preference choice experiment method, which suffers from hypothetical bias. At the time of implementing this study biofortified high-iron pearl millet varieties were not yet developed, therefore the authors could not have implemented revealed preference elicitation methods with real products and payment. Originality/value – The method used (stated preference choice experiment method) is commonly used to value non-market goods such as environmental goods and products that are not yet in the market. It’s application to agriculture and in developing countries is increasing. As far as the authors know this is the first choice experiment implemented to investigate farmer/consumer preferences for biofortified crops. The study presents valuable information for development and delivery of biofortified crops for reducing micronutrient deficiencies.

Recently, the nutraceutical sector of the food trade is unfolding, and designer foods such as nutrition bars have found their place in this competitive industry. The inclusion of underutilized food sources in the development of new value-added products is ingenious. Millets, the indigenous crop, are a good source of nutrients. The Nutri-cereal is still lacking commercial success and deserves recognition in the food-processing sector. In the current study, foxtail and pearl millet are used to develop foxtail millet meal replacement bar (FMRB) and pearl millet protein bar (PPB), respectively. Three variants of each type (25%, 27.5%, and 30% incorporation of millets) were developed to derive the nutritionally preferred variants. Estimation of macronutrients, essential amino acids, and vitamin content was done. The storage stability of the selected variants was evaluated for 42 days under accelerated conditions. The peroxide value, moisture content, water activity, total plate count, and yeast & mold count was assessed. The result revealed, among the variants, 30% FMRB (V-3) and 25% PPB (V-4) are the nutritionally finest bars. The shelf-life testing pointed out that the protein bar deteriorates rapidly than the meal replacement bar. The correlation between the nutrient composition and shelf-life assessment factors indicated the shelf-life parameters negatively correlate with carbohydrates present in the bars. However, fat and protein have a positive correlation with shelf-life parameters (r= 1.00, p<0.01). Favorable storage conditions and appropriate packing material that is conducive to retain the stability of the product can extend the shelf-life. Millet nutrition bars would revolutionize the agriculture and food industry. Thus, increasing the consumption of millets.

Millet mix was prepared for its traditional values. The prepared sample was analyzed for its chemical and nutritional value, and by using the cost-efficient method, the nutritional content of the final product was enhanced. The improved sample was checked for its nutritional content. The objective is to make a comparison between standard and enhanced samples. ingredients were prepared in a powdered form of a sample in four different ratios. The standardized ratio of the ingredients used to make the samples were found by using tests. In the standardized ratio normal (S1) and nutrition enhanced (S2) samples were prepared using the three ingredients. For nutrition enhancement, the method of sprouting was used. Various tests were conducted for the standardized sample to verify its nutritional content, commercializing ability, microbial analysis, analysis etc. The nutritional content Analysis of the normal and nutrition enhanced samples (S1) and (S2) was done. The sample (S2) was nutritionally rich when compared to the normal sample (S1). All other test had more or less coinciding results for both the samples (S1) and (S2). By comparing the nutritional content, a conclusion arrives that the sample (S2is nutritionally rich when compared to (S1). Microbial and Physical properties results show that the product is efficient to be commercialized and stored to a specific period without microbial contamination in powdered form. The nutrient-rich mass is suitable for all age group.

Pearl millet and other minor cereal production is marginalized in the Sahara of Algeria (Tidikelt and Hoggar regions). Their productions in these areas depend on traditional harvesting and processing. Pearl millet seeds are used as animal feed and rarely for human consumption. This work was to assess the starch digestion of pearl millet cultivated in the arid areas of Algeria.The seeds from this cereal could provide broad potential benefits to human health. However, their digestion properties have not been reported. Therefore, in this study, the in-vitro starch digestibility of pearl millet flour and the effect of processing on the expected glycemic index (eGI) were investigated. Grains from six pearl millet samples were chosen from two regions: Tidikelt and Hoggar. Five flours were prepared by dry milling (MF) and different treatments after dry milling such as extraction of phenolic compounds (MF-PP), lipid extraction (MF-L), protein hydrolysate extraction (MF-P) or lipid plus protein hydrolysate extraction (MF-L-P). The flours were then subjected to digestion, and the effects of grain treatments on the in vitro starch digestion were investigated. For all pearl millet samples, the kinetics of in vitrostarch digestion displayed first-order model as substrates were digested to different extents; k(kinetic constant), C∞(percentage of starch hydrolyzed at infinite time), HI (hydrolysis index) and eGI (expected glycemic index) of the samples were also calculated. Significant increases in C∞, HI and eGI (P<0.05) of the samples were observed after extraction of proteins or proteins plus lipids from flour. Four flours obtained after lipid extraction and five flours from extraction of phenolic compounds had low glycemic index (<55), with values ranging between 31.36 and 44.97.In contrast,flours obtained from protein hydrolysate extraction or lipids plus protein hydrolysates had the highest glycemic index (>69), with values ranging between 77.50 and 121.44.This study confirmed that some of the processed pearl millet seed flours have acceptable nutritional values suitable for human health and nutrition due to the low glycemic index values.

ABSTRACT Background Pearl millet is the chief source of energy in the diet in some developing regions, but has a limited amount of indispensable amino acid lysine. Complementation with pulses like lentils can improve the protein quality of millet diets, but the knowledge of lysine bioavailability (BA) in millet and lentils is lacking. Objectives The study objectives were to determine the BA of lysine in millet and lentils separately and to assess the effect of complementation of millet and lentils in a mixed meal format. Methods We studied 9 healthy young men (≤30 y; BMI &lt;25) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject completed 7 or 8 experiments in random order. On the reference diet, subjects received 4 graded levels of L-lysine (5, 8, 12, and 15 mg·kg−1.d−1) from a crystalline amino acid mixture patterned after egg protein; on the test diets, they received 3 levels of lysine (10, 12, and 15 mg·kg−1.d−1) from either steamed millet or stewed lentils; and on the complementation diet, they received 1 level of lysine from a mixed meal of steamed millet and stewed lentils. The BA of lysine and the effect of complementation were assessed by comparing the IAAO responses to the test diets and the complementation diet with the IAAO response to L-lysine intakes in the reference protein, using the slope ratio method. Results The BA of lysine was 97% from millet and 80% from lentils. Complementation of steamed millet with stewed lentils decreased the oxidation of L-[1-13C] phenylalanine by 27% (P &lt; 0.05), signifying improved quality of the combined millet and lentil protein. Conclusions Lysine has high BA but is still limiting in steamed pearl millet. Complementation with lentils in a 2:1 ratio is recommended to meet the lysine and protein requirements for adult men consuming a millet-based diet. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03339167.

This research evaluated millet as forage source for ruminants. Four studies were conducted using two cultivars of forage millet [i.e. brown midrib (BM) and regular (RM)]. The first investigated the effect of seeding rate on yield, chemical composition and in vitro degradability of the two forage millet cultivars. Yield of RM was 56% more than BM due to taller plants and more tillers m-2. A 25% increase in yield as seeding rate increased from 5 to 10 or from 10 to 15 kg ha-1 was observed for two millet cultivars. Brown midrib millet contained 15% more CP, and 4, 13 and 31% less NDF, ADF and ADL than RM cultivar. In vitro DM digestibility was 10% higher in BM due to differences in chemical composition. The second study determined the effect of stage of development at harvest [i.e. vegetative (VS) and heading stage (HS)] on the two millet cultivars yield and cell wall composition in leaves and stems. Yield of BM was lower than that of RM at both stages of development. Concentrations of NDF, ADF and ADL were reduced in BM stems by 8, 16, and 58%, respectively, compared to RM stems. Leaves ADF and ADL concentrations were 6 and 49% less in BM than RM. Increase in fibre fractions with advancing stage of development was most pronounced in RM stems. Brown midrib trait affected cell wall structure of BM leaves and stems by increasing arabinose and xylose proportion as well as concentrations of ester- linked p-coumaric acid and ether-linked ferulic acids. Cell wall content of arabinose, xylose and glucose in leaves and stems, and phenolics in stems was higher at VS than at HS. This effect was more pronounced for stems of RM than BM. In situ DM and NDF disappearances were higher in leaves and stems of BM than RM and were higher in leaves and stems of millet harvested at VS than at HS. Lignin concentration had negative linear impact on in situ DM and NDF degradability. Ensilability of forage millet as affected by cultivar and stage of development at harvest was investigated
Cette recherche constitue a évalue millet comme une source de fourrage pour les ruminants. Quatre études ont été effectuées en utilisant deux variétés de millet [par exemple midrib brun (BM) et régulier (RM)]. La première étude constituait une évaluation de l'effet de la vitesse de semer les graines de millet sur le rendement, la composition chimique et la degradabilité in vitro des deux variétés de millet. Le rendement de RM était 56% plus haut en comparaison de BM en raison des plus grandes plantes et plus de feuillage par m-2. Le midrib brun de millet contenait 15% plus de CP, et 4, 13 et 31% moins de NDF, ADF et ADL que la variété RM. La digestibilité in vitro de DM était 10% plus haut chez BM en raison de ces différences. La deuxième étude avait pour objectif de déterminer l'effet du niveau de développement à la moisson [par exemple végétal (VS) et niveau d'en-tête (HS)] sur le rendement des deux variétés de millet et la composition de membrane cellulaire dans les feuilles et les tiges. Le rendement de BM était plus bas en comparaison de RM aux deux niveaux de développement. Les concentrations de NDF, ADF et ADL ont été réduits dans les tiges de BM par 8, 16, et 58%, respectivement, en comparaison des tiges de RM. Les concentrations de ADF et ADL dans les feuilles étaient 6 et 49% moins dans BM que RM. Les contenus des différentes fibres ont augmenté avec le niveau de développement, mais l'augmentation été plus prononcée dans les tiges de RM. Le millet brun a eu un effet sur les membranes cellulaires des feuilles et tiges de BM en augmentant la concentration d'arabinose et xylose ainsi que les concentrations d'ester- acides de p-coumaric et d'ester- acides de ferulic. Les contenus d'arabinose, xylose et le glucose dans les membranes cellulaires chez les feuilles et les tiges, et de phenolics dans les tiges était plus haut à VS qu'à HS. Cet effet été plus prononcé pour les tiges de RM que BM. In situ DM et NDF

Agricultural production is the main source of income and major employer in many countries in Africa, including Senegal. Commercial sweet corn (Zea mays L. ssp. saccharata) production in Senegal is increasing in response to global marketing opportunities and offers producers the ability to increase income and diversify the cropping base. Production of optimum sweet corn yield and quality depends on adequate nutrient supply, particularly, nitrogen (N). Current N recommendations are based on recommendations specific to corn for grain. This study aimed to identify tools to estimate sweet corn N status and determine the most appropriate fertilizer dosage for sweet corn. Non-destructive remote sensing tools and ion exchange resin membranes (IEMs) were used to evaluate the effect of fertilizer dose. No differences in ear yield or yield components, normalized difference vegetation index (NDVI) values, biomass, N uptake or leaf N concentration due to fertilizer dose were detected at Ndiol. However, significant relationships existed between NDVI values and yield, biomass, and N uptake at the V9 growth stage. Only yield was affected by fertilizer dose at Sangalkam, and no consistent relationships were found between chlorophyll meter readings and others measured parameters. Treatment differences due to fertilizer dose for available NH4+ at V9 (Ndiol), and NO3- at V5 (Sangalkam) were found, however further research is needed to fully evaluate the usefulness of IEMs to measure available soil N. Based on these studies, sweet corn fertilizer rates should likely be based on 75% of the dose applied to field corn, however more work is needed to confirm this finding. Pearl millet (Pennisetum glaucum (L) R. Br.) is the most widely grown staple crop in Senegal. Introduction of drought tolerant millet genotypes has helped mitigate the effect of increased water shortage in the region, but little is known about the nutritional composition of these genotypes. Our objective was to compare millet grain nutritional composition among and between putative drought tolerant and drought sensitive pearl millet lines under drought stress and well-watered conditions. One field experiment was conducted in 2014 at the National Center for Agronomic Research (CNRA) of Bambey, Senegal (16°30' and 16° 28' N; 15o44' and 15o42' W). The experiment utilized a split-plot design with four replications. Water regime was the main plot experimental factor while genotype, a total of 20 was the sub-plot. Pearl millet genotypes were divided into three contrasting groups based on drought tolerance for comparisons. Water stress did not affect 100-grain weight, test weight, protein, soluble protein, starch, sugars, amino acids or vitamin B2 content of grains among VPD-groups. Accumulation of these constituents of pearl millet grain appear to be genetically controlled and are probably not affected by late drought stress. However, differences were noted among genotypes as the sensitive VPD-group accumulated greater soluble protein, starch and soluble sugars (except sucrose) than the tolerant and medium VPD-groups. The tolerant VPD-group, however, accumulated greater protein and vitamin B2 content. Arginine, proline and serine content was greater in the sensitive VPD-group, while lysine, aspartic acid, and glutamic acid were greater in the tolerant VPD-group. Glycine, histidine, threonine, alanine, tyrosine, valine, methionine, leucine, isoleucine, and phenylalanine were relatively equal in tolerant and sensitive VPD-groups. Calcium and Na levels were affected by water stress in the sensitive VPD-group, but differently. Calcium content was greatest for the sensitive group under drought stress, while sodium was the lowest. Iron accumulation in sensitive VPD-group increased under water stress. Potassium decreased for all VPD-groups under stress, while across water regime, K levels in the drought-sensitive group were lower. Selection for drought appears to effect many of the nutritional constituents of pearl millet grain, however many of these differences appear to be directly related to parameters known to effect plant water relations.
Master of Science

Two studies were conducted to investigate the effects of partially or totally replacing corn with pearl millet (PM) in broiler diets, alone or in combination with exogenous enzymes, on growth performance, ileal dry matter (DM), CP and amino acid digestibility, and intestinal digesta viscosity, morphological development and microbial populations. In experiment 1, dietary treatments included: a standard corn-soybean meal diet and one in which corn was replaced with 25, 50, 75 or 100% PM. In experiment 2, dietary treatments were: 1) a standard corn-soybean meal diet; 2) a PM-soybean meal diet; 3) diet 1 + exogenous enzymes; and 4) diet 2 + exogenous enzymes. All diets were formulated to be isonitrogenous and isocaloric. PM diets contained less soybean meal because PM grains were richer in CP and amino acids than corn. Total replacement of corn with PM significantly improved (P < 0.05) growth and feed conversion. However, there were no additional benefits due to enzyme supplementation. Feeding broilers PM diets did not have any detrimental effects on digesta viscosity, villus height, villus width and villus surface area of the jejunum. On the contrary, in experiment 2, villi were longer (P < 0.05) in PM-fed birds than those fed corn diets with or without enzymes. Intestinal loads of E. coli were not altered by any of the dietary treatments. But, in experiment 2, both PM diets, with or without enzymes, significantly increased (P < 0.05) Lactobacilli loads. In both studies, DM, CP and amino acids digestibility were similar between corn and PM diets. However, enzyme supplementation to corn or PM diets increased (P < 0.05) DM and CP digestibility. Amino acid digestibility was increased (P < 0.05) only in birds fed the corn diet containing enzymes in comparison with those fed the corn diet without enzymes. In conclusion, total replacement of corn with PM in broiler diets caused significant improvements in growth parameters, and Lactobacilli populations and villus development of the intestines. Additionally, enzyme supplementation to PM diets increased intestinal DM and CP digestibility.
Deux études ont été entreprises pour étudier les effets de replacer le maïs par le millet perlé (MP), soit partiellement ou totalement, dans des régimes du poulet de chair, sans ou en combinaison avec des enzymes exogènes sur la croissance, la digestibilité de la matière sèche, protéines brut (CP) et acides aminé dans l'iléon, la viscosité intestinale, et le développement morphologique et les populations bactériennes dans l'intestin. Dans l'expérience 1, les traitements diététiques étaient: un régime standard de maïs-soja, et la même diète dans laquelle le maïs a été remplacé par le MP à 25, 50, 75 ou 100%. Dans l'expérience 2, les traitements diététiques comprenait: 1) un régime de maïs-soja; 2) un régime de MP-soja; 3) le régime 1+enzymes; et 4) le régime 2+enzymes. Tous les régimes avaient la même teneur en azotes et calories. Les régimes de MP contenaient moins de soja parce que les graines de MP étaient plus riches en CP et acides aminés que le maïs. En remplaçant le maïs totalement par le MP a permis d'améliorée (P < 0.05) la croissance et indice de conversion alimentaire. Toutefois, l'utilisation des enzymes n'avait aucun bénéfice. Les régimes de MP n'avaient aucun effet néfaste sur la viscosité intestinale et la longueur, largeur ou superficie du villus dans le jéjunum. Au contraire, dans l'étude 2, les villus étaient plus longs (P < 0.05) chez les poulets consommant les régimes du MP que celles nourrit avec les diètes de maïs contenant des enzymes ou pas. Les concentrations d'E.coli étaient semblables parmi tous les traitements diététiques. Par contre, dans l'expérience 2, les deux régimes de MP, avec ou sans enzymes, ont augmenté (P < 0.05) les concentrations de lactobacilles. Dans les deux études, la digestibilité de la matière sèche, CP et acides aminés étaient semblables entre les régimes de maïs et MP. Cependant, l'ajout des enzymes dans les régimes de maïs et MP avait améliorée (P < 0.05) la digestibilité de la matière sèche et de CP. La digestibilité d'acides aminés été élevée (P < 0.05) seulement entre les oiseaux alimentés des régimes de maïs contenant des enzymes ou pas. En conclusion, un remplacement total du maïs par le MP dans la moulée du poulet de chair a causé une amélioration dans les paramètres de croissance, et les populations de lactobacilles et le développement de villus dans l'intestin. En plus, l'ajout des enzymes dans les régimes de MP a permis d'augmenter la digestibilité intestinale de la matière sèche et de CP.

Submitted in partial fulfilment of the requirements for the Doctrate Degree in Technology: Food Technology - Durban University of Technology, 2013.
A pearl millet (Pennisetum glaucum) based instant beverage powder (PMIBP) was prepared from two different varieties of pearl millet (Agrigreen (AgG) and Babala (Ba)) by a combination of malting and extrusion cooking. The millet grains were germinated (30oC and 98% RH for 36 h), kilned (50oC for 48 h), cooled to room temperature, ground and stored in a chiller at 5oC until used. The raw and malted pearl millet grains were extruded under different parameters to accommodate the types of pre-treatment applied to the pearl millets. Combination processing of the pearl millet grain was achieved by extrusion of malted pearl millet of both varieties individually, and as a mixture of raw and malted pearl millet (50:50). The effect of the processing methods on the physical, functional, nutritional and biochemical properties of the raw and processed pearl millets varieties were evaluated. Combination processing led to a significant (p ≤ 0.05) decrease in total fat and total dietary fibre (TDF) (3.85 and 22.99 g/100 g, respectively) content of AgriGreen (AgG) extruded malted pearl millet (EMPM); a decrease in TDF (18.12 g/100 g) content of AgG extruded raw pearl millet-malted pearl millet mix (ERPMMPM). Combination processing led to a decrease in ash, total fat, total dietary fibre, Fe and Zn (1.76, 3.48, 14.26 g/100 g, 7.78 and 4.74 mg/100 g, respectively) content of Babala (Ba) EMPM. It also led to a significant (p ≤ 0.05) decrease in ash, total fat, TDF, Fe and Zn (1.88, 4.22, 21.71 g/100 g, 7.24 and 4.14 mg/100 g, respectively) content of Ba ERPMMPM. Regardless of the pearl millet variety, malting led to a significant (p ≤ 0.05) decrease in moisture, total, saturated, mono- and polyunsaturated fats, total dietary fibre iron, zinc and protein digestibility; a significant (p ≤ 0.05) increase in total carbohydrates, total phenolic content, antioxidant activity (TEAC) and water solubility index. Extrusion however, led to a significant (p ≤ 0.05) decrease in total dietary fibre, zinc, total phenolic content and protein digestibility; a significant (p ≤ 0.05) increase in ash, total, saturated and monounsaturated fats, total carbohydrates, iron, starch digestibility water absorption index (WAI) and water solubility index (WSI). The beverages of 10% total solids (8% pearl millet + 2% sugar for taste) prepared from the processed pearl millet were offered to an untrained consumer panel consisting of students and staff of the Cape Peninsula University of Technology, under similar sets of conditions in a sensory evaluation room at the Food Technology Department. The following characteristics of the products were rated and scored on a 9-point hedonic scale (1 – like extremely and 9 – dislike extremely): appearance, colour, aroma, flavour, mouth-feel and overall acceptability. In general, Ba RPM was rated 4 - like slightly, and AgG malted pearl millet (MPM) was rated 6 - dislike slightly and all other pearl millet samples from both varieties were rated 5 - neither like nor dislike.

Worldwide, millets are regarded as significant grains; however, they are the least exploited. Millet grain is abundant in nutrients and health-beneficial phenolic compounds, making it suitable as food and feed. The diverse contents of nutrients and phenolic compounds present in finger and pearl millet are good indicators that the variety of millet available is important when selecting it for use as food or feed. The phenolic properties found in millets comprise of phenolic acids, flavonoids, and tannins, which are beneficial to human health. Research has shown that millet phenolic properties have high antioxidant activity. Phytochemicals present in millet grains have positive effects on human health by lowering the cholesterol and phytates in the body. The frantic demands on maize and its uses in multiple industries have merit the search for alternative grains, to ease the pressure. Substitution of maize with pearl and finger millets in the diets of different animals resulted in positive impact on the performance. Of late, millet grain has been incorporated in other foods and used to make traditional beverages. In Chapter 1, the topic of the research was introduced, stating the importance of the study and to motivate on the significance of millet grains. Aims and objectives were also listed. Chapter 2 presented extensive literature review on millet and their uses in human and livestock nutrition. In addition, the use of tannin as alternative feed was also reviewed. Different studies have been conducted to investigate the suitability of millet grain as an energy source, in the animal industry. However, studies on the Southern African types of millet are limited; this might be due to lack of information on their nutritional composition and their suitability as animal feed. Overall, the aim of this study was to profile the nutritional characteristics of selected millet grains in South Africa and Zimbabwe, their suitability as energy source for human and livestock and to study the effect of pearl millet type on the performance indices of Ross 308 broiler chickens. In Chapter 3, the general materials and methods used to reach the scientific conclusion for this study was summarised. In Chapter 4, physical and chemical analysis were conducted on millet grains obtained from South Africa and Zimbabwe, the results revealed that the physiochemical characteristics of the millet grain qualify it as a suitable candidate in replacing maize as an energy source. To further understand the characteristics of the millet grain, Chapter 5 analysed the phenolic compounds available in the millet grain obtained from South Africa and Zimbabwe. The results showed that the grain is endued with valuable phenolic compounds beneficial in the nutrition of both human and animals and aid as health benefit. Chapter 6 investigated the various inclusion levels of pearl millet in a bid to establish the most suitable combination for the poultry sector. Pearl millet grain used in this experiment went through different breeding improvements and selections conducted at the Grain Crop Institute in Potchefstroom, South Africa. Pearl millet grain was used as the main source of energy for Ross 308 broiler chicks for a period of 42 days with performance indices investigated. The results revealed that pearl millet can be incorporated in the diets of broiler chickens, in replacement of maize, without adversely affecting the performance. In addition, the economic justification of replacing maize with pearl millet was studied. The cost of the grains was determined and the cost per weight gain was determined. The results showed that indeed it is economically sound to replace maize with pearl millet in the diet of poultry. The quadratic function best fitting optimum treatment combination in relation to performance parameters such as body weight, body weight gain, feed conversion ratio and internal organs was also examined. In Chapter 7, the research was generally discussed to tie up the conclusions of the experiments conducted. General recommendations were also given on the compounds of millet varieties and their health benefits to both humans and animals.
Kuwo wonke umhlaba, amabele athathwa njengezinhlamvu ezibalulekile, kodwa awasetshenziswa kakhulu. Uhlamvu lwebele lunemisoco eminingi kanye nenzuzo yempilo ngama-phenolic compound, okwenza ukuthi afaneleke kakhulu njengokudla kwabantu kanye nemfuyo. Imisoco eminingi equkethwe kanye nama-phenolic compound atholakala eminweni kanye nezinhlamvu zebele ayizinkomba ezinhle zokuthi izinhlobo zamabele ezitholakalayo zibaluleke kakhulu ekukhethweni njengokudla kanye nokudla kwabantu noma imfuyo. Amaphenolic properties atholakala kumabele aqukethe ama-phenolic acids, ama-flavonids, kanye nama-tannins, ayinzuzo kakhulu empilweni yabantu. Ucwaningo luthole ukuthi ama-phenolic properties amabele anomsebenzi wezinga eliphezulu lama-antioxidant. Ama-phytochemicals atholakala kwizinhlamvu zamabele anenzuzu enhle kakhulu kwimpilo yabantu ngokwehlisa izinga le-cholesterol kanye nama-phytate emzimbeni. Ukudingeka kakhulu kombila kanye nokusetshenziswa kwawo kwizimboni eziningi, kubangele ukuthi kwenziwe ucwaningo ngezinye izinhlamvu ukwehlisa ingcindezi. Ukuthatha isikhundla sombila, sithathwa amabele kwidayethi yezilwane ezehlukene kwaba nomphumela omuhle kakhulu ngokusebenza. Kamuva nje, izinhlamvu zamabele zifakelwe kwezinye izidlo ezisetshenziswa ukwenza iziphuzo zomdabu. Kwisahluko 1, isihloko socwaningo sethulwa khona, ukuchaza ukubaluleka kocwaningo kanye nokuqikelela ngokubaluleka kwezinhlamvu zamabele. Izinhloso nezinjongo nazo zifakelwe kuhla. Isahluko 2, sethula ukubuyekezwa kwemibhalo ngamabele kanye nokusetshenziswa kwawo kubantu kanye nokudla kwemfuyo. Nangaphezu kwalokho, ukusetshenziswa kwe-tannin njengokunye ukudla kwemfuyo kuye kwabuyekezwa. Kwenziwe ucwaningo olwehlukene ukuphenyisisa ngokufaneleka kwezinhlamvu zamabele njengomthombo wamandla (we-eneji) kwimboni yezilwane. Kodwa, ucwaningo ngezinhlobo zamabele eNingizimu ne-Afrika alukenziwa ngokwanele; lokhu kungenzeka kungenxa yokuswelakala kolwazi ngemisoco equkethwe kanye nokufaneleka njengokudla kwezilwane. Kanti ngokwengamele, inhloso yalolu cwaningo bekuwukwenza iprofayili yemisoco ngezinhlamvu zamabele athile eNingizimu Afrika kanye naseZimbabwe, ukufaneleka kwawo njengomthombo wamandla (we-eneji) kubantu kanye nemfuyo, kanye nokwenza ucwaningo ngemiphumela yenhlobo yamabele ngama-performance indices wamachwane e-ROss 308. Kwisahluko 3, kusetshenziswe imetheriyali kanye namamethodi asetshenzisiwe ukufinyelela isiphetho sezesayense kulolu cwaningo, kwafinyezwa. Kwisahluko 4 kwenziwe uhlaziyo lokubambekayo kanye namakhemikhali ngezinhlamvu zamabele ngokutholakale eNingizimu Afrika kanye naseZimbabwe, imiphumela ikhombise ukugqama kwe-physiochemical kwezinhlamvu zamabele ukufaneleka kwazo njengekhandideti ekuthatheni isikhundla sombila njengomthombo wamandla. Ukuqhubeka nokuqondisisa ukuphawuleka kwezinhlamvu zamabele, iSahluko 5 sihlaziye ama-phenolic compound kwizinhlamvu zamabele aseNingizimu Afrika neZimbabwe. Imiphumela ikhombisa ukuthi uhlamvu lwamabele lunama-phenolic compound ayinzuzo ekudleni okunomsoco kubantu kanye nezilwane, kanye nokuba wusizo lwenzuzo kwimpilo. Isahluko 6 siphenyisise ngamazinga okubandakanywa kwamabele ukwenzela ukuthola ukufaneleka kwawo kumkhakha wezinkukhu. Izinhlamvu zamabele e-pearl zisetshenziswe kule ekspirimenti, eyenziwa ezigabeni ezehlukene zokuthuthukisa ukuzalisa kanye nokhetho olwenziwe ngabe-Grain Crop Institute ePotchefstroom, eNingizimu Afrika. Amabele e-pearl asetshenziswe njengomthombo omkhulu we-eneji kumachwane eRoss 308 isikhathi sezinsuku ezingu 42 kanti kwaphenyisiswa ngokusebenza kwama-indices. Imiphumela iveze ukuthi amabele epearl angafakelwa kwidayethi yamachwane, ukuthatha isikhundla sombila, ngaphandle kokuphazamisa ukusebenza. Nangaphezu kwalokho, ukufaneleka kwezomnotho ngokuthatha isikhundla zombila sithathwa ngamabele e-pearl kuye kwacwaningwa. Izindleko zezinhlamvu ziye zabekwa kanti futhi nesisindo ngezinhlamvu kuye kwabekwa. Imiphumela ikhombisa ukuthi kuyinto enhle kwezomnotho ukuthatha isikhundla sombila sithathwa ngamabele e-pearl kwidayethi yezinkukhu. Ukusebenza kwe-quadratic function kufaneleke kakhulu kwi-optimum treatment combination mayelana nama-parameter okusebenza afana nokwenyuka kwesisindo somzimba, ukuguqula i-feed conversion ratio kanye nezitho zangaphakathi nazo ziye zahlolwa. KwiSahluko 7, ucwaningo kuye kwaxoxwa ngalo ukuhlanganisa iziphetho zama-ekspirimenti enziwe. Izincomo ezinabile, ziye zanikezwa ngama-compound ezinhlobo zamabele kanye nezinzuzo zawo kwezempilo kubantu kanye nezilwane
Lefaseng ka bophara, leotša le bonwa bjalo ka mabele a bohlokwa kudu; le ge go le bjale, ke dibjalo tšeo di sa bjalwego kudu. Dithoro tša leotša di tletše ka phepo ye ntši le ditswaki tša fenoliki tšeo di nago le mohola maphelong, gomme se sa dira gore di be maleba bjalo ka dijo le phepo. Dikagare tša lona tšeo di fapafapanego le ditswaki tša fenoliki tšeo di whetšagalago ka gare ga leotša la finger le la pearl ke dilaetši tše kaone tša gore mehutahuta ya leotša yeo e hwetšagalago e bohlokwa ge e kgethwa bjalo ka sejo le phepo. Diteng tša fenoliki tšeo di hwetšwago ka agre ga leotša di na le diesiti tša fenoliki, difolabanoite, le dithaninse, tšeo di lego mohola go maphelo a batho. Dinyakišišo di laeditše gore diteng tša fenoliki tša leotša di na le mošomo wa godimo wa dihlwekišammele tšeo di bitšwago dianthioksitente. Difaethokhemikhale tšeo di lego gona ka gare ga dithoro tša leotša di na le diabe tše kaone go maphelo a batho ka go fokotša kholesterole le difaetheite mmeleng. Dinyakwa tša ka pela go lefela le mešomo ya lona ka diintastering tše ntši di dirile gore go be le nyakego ye kgolo ya dithoro tše dingwe tšeo di ka emelago lefela legato, go nolofatša kgatelelo yeo e beilwego go lefela. Go tšeela lefela legato ka leotša la pearl le la finger ka dijong tša diphoofolo tšeo di fapafapanego go feleleditše ka seabe se sekaone ka ga go šoma ga lona. Go fihla mo lebakeng le, dithoro tša leotša di tsentšwe ka dijong tše dingwe gomme tša šomišwa go dira dino tša setšo. Ka go Kgaolo ya 1, hlogotaba ya dinyakišišo e tsebagaditšwe, ya fa bohlokwa bja dinyakišišo tše le lebaka mabapi le bohlokwa bja dithoro tša leotša. Maike mišetšo le dinepo le tšona di filwe. Kgaolo ya 2 e hlagišitše tekodišišo ya dingwalwa ye e tseneletšego ka ga leotša le mešomo ya lona go phepo ya batho le ya diphoofolo. Godimo ga fao, tšhomišo ya tannin bjalo ka phepo ya boikgethelo le yona e lekodišišitšwe. Dinyakišišo tše di fapafapanego di dirilwe go nyakišiša go ba maleba ga thoro ya leotša bjalo ka methopo wa enetši, ka intastering ya diphoofolo. Le ge go le bjale, dinyakišišo tš0e di dirilwego mabapi le mehuta ya leotša ka Borwa bja Afrika ke tše nnyane; se se ka ba se bakwa ke tlhoklego ya Tshedimošo mabapi le sebiopego sa phepo ka hare ha leotša le go ba maleba ga lona bjalo ka phepo ya diphoofolo. Ka kakaretšo, maikemišetšo a dinyakišišo tše e bile go lebeledišiša dikokwane tša phepo tša dithoro tša leotša tšeo di kgethilwego ka Afrika Borwa le ka Zimbabwe, go ba maleba ga lona bjalo ka methopo wa enetši go batho le go diruiwa le go nyakišiša ka ga seabe ka ga mohuta wa leotša wa pearl go go šoma ga dipalopalo go dikgogo tša nama tša Ross 308. Ka go Kgaolo ya 3, ditlabelo le mekgwa ka kakaretšo yeo e šomišitšwego go fihlelela sephetho sa tša mahlale sa dinyakišišo tše di filwe kakaretšo. Ka go Kgaolo ya 4, tshekatsheko ya naga le ya dikhemikhale e dirilwe mabapi le dithoro tša leotša tšeo di hweditšwego ka Afrika Borwa le ka Zimbabwe, dipoelo di utollotše gore dikagare tša dikhemikhale tša thoro ya leotša di le dira le be lebele leo le loketšego go tšeela legato lefela bjalo ka methopo wa enetši. Go kwešiša go tšwela pele dikagare tša thoro ya leotša, Kgaoilo ya 5 e sekasekile diteng tša fenoliki tšeo di hwetšagalago ka gare ga thoro ya leotša leo le hwetšago ka Afrika Borwa le ka Zimbabwe. Dipoelo di laeditše gore thro ya leotša le tletše ka dikagare tša fenoliki tšeo di lego mohola go phepo ya bobedi batho le diphoofolo le gore le thuša bjalo ka kholego ya tša phepo. Kgaolo ya 6 e nyakišišitše maemo a mehutahuta a kakaretšo a leotša la pearl ka nepo ya go hwetša motswako wa maleba kudu ka lekaleng la dikgogo. Dithoro tša leotša la pearl tšeo di šomišitšwego ka mo tekodišišong ye di sepedišitšwe ka go dikaonafatšo tše di fapanego tša monontšha gomme dikgetho di dirilwe ka go Sehlongwa sa Dibjalo tša Dithoro ka Potchefstroom, ka Afrika Borwa. Dithoro tša leotša la pearl di šomišitšwe bjalo ka mothopo wa enetši go matswiana a nama a Ross 308 mo matšatšing a 42 fao go dirilwego dinyakišišo ka ga dipalopalo tša go gola ga dikgogo. Dipoelo di laeditše gore leotša la pearl le ka tsenywa ka dijong tša dikgogo tša nama, go tšeela legato lefela, ka ntle le go ama gampe go gola ga dikgogo. Godimo ga fao, lebaka la tša ekonomi la go tšeela lefela legato ka leotša la pearl le nyakišišitšwe. Theko ya dithoro e hweditšwe gomme theko ka boima bjo itšego le yona e hweditšwe. Dipoelo di laeditše gore ka nnete go tloga go kwagalago kudu go tša ekonomi go tšeela lefela legato ka leotša la pearl. Mošomo wa tekanelo wa wo o loketšego bokaone motswako wa tlhokomelo ya godimo mabapi le mahlakore a kgodišo ya dikgogo a go swana le boima bja mmele, go nona, rešio ya go fetošetša dijo le ditho tša ka gare le ona o lekodišišitšwe. Ka go Kgaolo ya 7, dinyakišišo di hlalošitšwe ka kakaretšo gore go fihlelelwe sephetho ka ga ditekodišišo tšeo di dirilwego. Ditšhišinyo ka kakaretšo le tšona di filwe mabapi le dikagare tša mehutahuta tša leotša le dikholego tša ona go tša maphelo go bobedi batho le diphoofolo
College of Agriculture and Environmental Sciences
D. Phil. Agr. (Animal Science)

Obesity and nutrition-related non-communicable diseases continue to be major challenges that are increasing in severity worldwide. Science-centered carbohydrate dietary strategies may be a viable approach to help address such challenges. Recent reports from our laboratory indicate that certain carbohydrates with slow digestion profiles have the ability to trigger the gut-brain axis and reduce food intake and to slow gastric emptying and potentially affect appetite. Slow carbohydrate digestion may have other impacts on energy metabolism that have not been explored. In the current investigations, we sought to better understand the delayed gastric emptying profile of pearl millet-based foods as well as to understand how altering carbohydrate digestion rate impacts substrate utilization for energy.

In the first study, the physical breakdown of pearl millet couscous particles in a simulated gastric environment (Human Gastric Simulator) was studied compared to wheat couscous matched in particle size, and select physicochemical properties of each type of couscous were characterized. Because we previously showed that pearl millet couscous had a marked delay in gastric emptying compared to white rice, boiled potatoes, and pasta in a human study in Mali, the objective of the first investigation was to test the hypothesis that pearl millet couscous was more resistant to breakdown in the stomach than wheat couscous and would take longer to empty. Our findings indicated that pearl millet couscous instead broke down into smaller, more numerous particles than wheat couscous. However, pearl millet had a slower starch hydrolysis property compared to wheat couscous per unit surface area. Pearl millet also had a smaller amylose chain length (839-963 DP) compared to wheat (1225-1563 DP), which may enable a denser packing of millet starch molecules that hinders hydrolysis. We also visually observed that the pearl millet particles formed a paste while breaking down that could reasonably generate viscosity in the stomach to potentially delay gastric emptying.

Based off the findings from simulated gastric digestion, we next conducted a human study (n=14) in the U.S. to test the hypothesis that pearl millet-based foods (couscous – commercial and self-made, thick porridge) would reduce glycemic response, increase satiety, and delay gastric emptying compared to wheat couscous and white rice. We complemented this human study with additional in vitro work using an advanced gastrointestinal digestion system (TIMagc) to determine if the viscosity of pearl millet couscous particles as they were breaking down in the stomach was contributing to a decrease in gastric emptying. Our findings indicated that all the pearl millet-based foods and wheat couscous had lower overall glycemic response than white rice, but only the self-made millet couscous showed higher satiety through subjective appetitive response ratings. Surprisingly, there were no differences in gastric emptying among the foods. Additionally, the half-emptying times for these foods were all ~3 h, which is similar to the comparably low half-emptying times observed for white rice, boiled potatoes, and pasta in the previous Mali study. We now hypothesize that there may be diet-induced changes in gut-brain axis signaling when slowly digestible carbohydrates are consumed repeatedly over time, perhaps through modulating the number or sensitivity of small intestinal L-cells. We also found that millet couscous did not exhibit high viscosity in the TIMagc, suggesting that viscosity was not impacting its rate of gastric emptying. We conclude that at least some pearl millet-based foods possess a slow digestion property that may act to trigger the gut-brain axis or ileal brake to increase feelings of satiety or slow gastric emptying, but the discrepancy between U.S. and Malian populations requires further study.

In the final investigation, we examined how altering carbohydrate digestion affected partitioning of carbohydrate versus fat for oxidation as well as the efficiency of switching oxidation between these two substrates (termed “metabolic flexibility”) in mice. Metabolic flexibility has been associated with good health related to decreased adipose tissue in the body and improved insulin sensitivity and may have implications on weight management. Carbohydrate digestion was adjusted by: (1) testing mice that lacked a complete set of enzymes by knocking out maltase-glucoamylase (Mgam; null) for moderating starch digestion versus testing wild-type mice; (2) using diets in these two groups of mice to moderate starch digestion that had different levels of resistant starch (53%, 35%, and 18%), had only raw corn starch or sucrose, or were high in fat; and (3) providing a supplement of fungal amyloglucosidase (AMG) to the mice treatment groups to increase starch digestion. Respiratory exchange ratio (RER) was measured through indirect calorimetry and mathematical modeling was used to characterize the diurnal shifts in RER (sine equation) as well as carbohydrate versus fat oxidation and metabolic flexibility (percent relative cumulative frequency [PRCF] with Weibull and Mixed Weibull Cumulative Distribution functions). Our results suggest that null mice lacking Mgam had somewhat increased metabolic flexibility than wild-type mice despite exhibiting minimal to no effects on carbohydrate oxidation. Intriguingly, the raw corn starch diet increased fat oxidation and generally promoted metabolic flexibility, although it did not increase carbohydrate oxidation relative to the other carbohydrate-predominant diets. Increasing carbohydrate digestion through AMG supplementation increased carbohydrate oxidation, and generally prompted earlier shifts to carbohydrate oxidation than without AMG supplementation. These findings provide a basis for better understanding the metabolic consequences of altering carbohydrate digestion and establish novel tools that can be utilized in future investigations. Overall, we propose that moderating carbohydrate digestion provides the ideal combination of balancing carbohydrate and fat oxidation while promoting metabolic flexibility.

In conclusion, a slow digestion property may enable some types of pearl millet to trigger the ileal brake and gut-brain axis feedback systems to decrease glycemic response and increase satiety. Moreover, consuming carbohydrates with slow digestion may optimize substrate utilization for energy by the body. In addition to triggering the ileal brake and gut-brain axis, modulating carbohydrate digestion to more effectively switch between carbohydrate and fat for oxidation may be beneficial for weight management and metabolic disease prevention.