Effect of processing on protein digestibility,biological value and net protein utilization of millet and legume based infant mixes and biscuits

Effect of combinations of millet and legume and processing on digestibility, biological value and net protein utilization was evaluated using albino rats. The millets and legumes selected for the study include sorghum, pearl millet, finger millet, chickpea and green gram (P radiatus). The processes tested include dehulling, boiling, roasting, malting and baking. Among the combinations tested, the sorghum-chickpea combination had significantly (p<0.05) higher digestibility. Between the processes tested, roasting resulted in significantly higher net protein utilization. Results of biological study on biscuits prepared by using millet and legume combination flours, indicated the biscuits to be of good protein quality.     

Chemical composition and nutrient digestibility of pearl millet (Pennisetum glaucum) fed to growing pigs

Pearl millet grown at two different locations in the U.S.A., pearl millet A (PMA) and pearl millet B (PMB), were analyzed for chemical composition and nutrient content and compared to corn. The two samples of pearl millet and corn were incorporated into diets and fed to 24 growing pigs in a metabolism trial to determine nitrogen and mineral balance and digestibilities of energy, fat and amino acids. Pearl millet (PMA and PMB) was found to be richer in crude protein, gross energy, ether extract, acid detergent fiber, amino acid profile and mineral content than corn. However, digestibilities of dry matter (corn, 86·8%; PMA, 80·5%; PMB, 82·0%) and energy (corn, 85·3%; PMA, 78·8%; PMB, 80·5%) were higher (P<0·05) for corn than either of the pearl millet samples. Fat digestibility was much higher in pearl millet than corn. Although nitrogen intake and absorption were higher (P<0·05) for pearl millet, the digestibility of nitrogen was similar for pearl millet and corn. Net protein utilization was lower (P<0·05) in pearl millet when compared to corn (corn, 44·8%; PMA, 34·6%; PMB, 39·9%). Digestibilities of the essential amino acids, arginine, threonine, valine, isoleucine and lysine were higher in pearl millet than corn. Phosphorus retention, expressed as a percentage of intake and absorption, was higher in corn than pearl millet. Calcium intake and absorption were similar for pearl millet and corn. Intake and absorption of magnesium and managanese were also similar in pearl millet and corn. Zinc and copper retention, when expressed as a percentage of intake, were higher in corn, but absorption for both minerals was similar in corn and pearl millet. Pearl millet was found to supersede corn in nutrient content and amino acid digestibility.     

Nutritional quality of pearl millet flour and bread

Market samples of pearl millet flour and bread from Saudi Arabia were analysed for chemical composition and nutritional quality. Pearl millet flour contained, on a dry weight basis, 17.4% protein, 6.3% fat, 2.8% fiber and 2.2% ash. Lysine was the most limiting essential amino acid with a chemical score of 53 (FAO/WHO, 1973). Linoleic acid (44.8%), oleic acid (23.2%) and palmitic acid (22.3%) were the dominant fatty acids in millet oil followed by stearic acid (4.0%) and linolenic acid (2.9%). The invitro protein digestibility (IVPD) of millet flour was 75.6% and the calculated protein efficiency ratio (C-PER) was 1.38 in comparison to ANRC casein values of 90% and 2.50, respectively. Baking at 300°C for 15 min had only little effect on the proximate and fatty acid composition of the bread but decreased the arginine, cystine and lysine contents by 31.3%, 15.8% and 13.8%, respectively. The IVPD was not affected but the C-PER decreased by 18% on baking.     

Biological utilisation of pearl millet fluor fermented with yeasts and lactobacilli

Mixed culture fermentation of pearl millet flour withSaccharomyces diastaticus, Saccharomyces cerevisiae, Lactobacillus brevis andLactobacillus fermentum brought about an improvement in its biological utilisation in rats. Protein efficiency ratio, feed efficiency ratio, apparent protein digestibility, true protein digestibility, net protein utilisation, net protein retention, protein retention efficiency and utilisable protein values in case of pure culture fermented pearl millet four were higher than the control. Feeding of the fermented products did not bring about physiological, histopathological and haematological changes in rats.Chapaties and cutlets prepared from the fermented products were organoleptically acceptable.     

Influence of particle size and blend composition on quality of wheat semolina-pearl millet pasta

Effect of particle size and blend composition (wheat semolina: pearl millet flour) on quality of pasta were investigated in this study. Initially, the pasta was prepared from 100% pearl millet flour of different particle sizes (241–780 μm). Observation indicated that it was not possible to make pasta from 100% pearl millet flour as these disintegrated after cooking. Particle sizes of pearl millet flour showed significant effect on nutritional and cooking quality of pearl millet pasta. Pasta from pearl millet flour of particle size 425 μm had least cooking loss, high protein, iron and zinc contents. Further, with increase in the level of pearl millet flour in the blend composition, protein, ash and cooking loss of pasta increased whereas hardness, cohesiveness, springiness, gumminess and chewiness showed decreasing trend. Blend composition (wheat semolina: pearl millet flour) in the ratio of 70:30 was found to be satisfactory for making pasta with desirable quality characteristics like cooking loss (<8%), protein content (>10%), ash content (<0.7%), colour and texture. However, with the objective of maximum incorporation of pearl millet flour in the final product, a blend composition of 50:50 could be used to make pasta with acceptable quality.     

Importance of seed-borne fungi of sorghum and pearl millet in Burkina Faso and their control using plant extracts

Seed-borne fungi of sorghum and pearl millet in Burkina Faso were surveyed. A total of 188 seed samples from various locations, collected in 1989 (42) and 2002 (146), were tested, using the blotter, dry inspection and washing methods. Infection experiments were carried out with the major fungi recorded on each crop by the blotter test. Six essential oils of plants were investigated for their inhibitory activity against eight pathogenic fungi. Thirty four and 27 fungal species were found in seed samples of sorghum and pearl millet, respectively. Phoma sp. and Fusarium moniliforme infected 95 to 100% of the seed samples of both sorghum and pearl millet. Sphacelotheca sorghi and Tolyposporium ehrenbergii were encountered in respectively, 75 and 33% of seed samples of sorghum. T. penicillariae, Sclerospora graminicola and Claviceps fusiformis were present in 88, 41 and 32% of seed samples of pearl millet, respectively. Seeds inoculated with Acremonium strictum, Curvularia oryzae, F. equiseti, F. moniliforme and F. subglutinans and sown in sterilized soil, showed considerable mortality of the seedlings. Three essential oils inhibited in vitro the mycelial growth of all the fungi used by 85 to 100% and reduced significantly sorghum and pearl millet seed infection rates of Phoma sp., Fusarium sp., Curvularia sp., Colletotrichum graminicola and Exserohilum sp. Presence of many pathogenic fungi in considerable number of seed samples indicates the need of field surveys for these and other pathogens. Development of plant extracts for the control of seed-borne pathogens and public awareness on seed-borne diseases management measures for maintaining quality seed should be increased.     

Nutritive value of malted millet flours

The changes in proximate composition, phytate phosphorus, thiamine and ascorbic acid content of finger millet, pearl millet and foxtail millet during progressive germination were studied. Germination resulted in a slight decrease in total protein and minerals, a marked fall in phytate-phosphorus and a significant increase in the ascorbic acid content of the millets. An increase in lysine and tryptophan but no appreciable changes in threonine and sulfur amino acid content of the millets were observed as a result of germination. However, the protein efficiency ratio values of ungerminated control seeds, 48 h germinated green malt and kilned malt were not significantly different.     

Isolation and characterization of a 20 kD prolamin from kodo millet (Paspalum scrobiculatum) (L.): Homology with other millets and cereals

The homologus 20 kD prolamin from kodo millet and other minor millets viz. barnyard, little and foxtail millets, were purified using preparative gel electrophoresis and reversed phase high performance liquid chromatography (RP-HPLC). The amino acid composition of the purified 20 kD prolamin protein from different minor millets revealed higher content of glutamic acid, alanine, leucine and serine and lower quantity of lysine and methionine. They contain 55 to 58 percent of non-polar amino acids which make them more hydrophobic than other protein fractions. The total number of amino acid residues per polypeptide chain ranged from 152 to 155 based on theoretical calculation. Peptide mapping of the 20 kD prolamin hydrolyzed with trypsin gave fewer cleavage products than expected. The antigenic relationships among these minor millets and cereals viz. wheat, maize, rice, sorghum, finger millet and pearl millet were studied using the antibody raised against the 20 kD prolamin. Cross reactivity was seen in all the minor millets at the 20 kD region. But in barnyard and little millets lower molecular weight polypeptides also cross reacted with the antibody. Immunoblotting studies revealed that the prolamins from other cereals and millets are related to the 20 kD prolamin of kodo millet. Rice was the only common cereal that did not cross react immunologically with the antibody raised against 20 kD prolamin of kodo millet.     

Effect of consumption of finger millet on hyperglycemia in non-insulin dependent diabetes mellitus (NIDDM) subjects

The effect of consumption of finger millet based diets on hyperglycemiawas studied in 6 noninsulin dependent diabetes mellitus (NIDDM) subjects.All the experimental diets were planned to be isocaloric and also tocontain 75 g equivalent of carbohydrate load so that glycemic responsecould be compared with a 75 g glucose load. The glycemic response tobreakfast items compared to that of glucose was determined by comparingthe areas under the 2 hr glucose response curve. Consumption of fingermillet based diets resulted in significantly lower plasma glucose levels,mean peak rise, and area under curve which might have been due to thehigher fiber content of finger millet compared to rice and wheat. Thelower glycemic response of whole finger millet based diets may also havebeen due to the presence of antinutritional factors in whole finger milletflour which are known to reduce starch digestibility and absorption.     

Protein,calcium, iron,and amino acid content of selected wild and domesticated cultivars of finger millet

Two wild and eight domesticated cultivars of finger millet were analyzed to determine their proximate composition and calcium, iron, and amino acid content. Wide variations were observed in the protein (mean values ranged from 7.5 to 11.7%), calcium (376 to 515 mg/100 g), and iron (3.7 to 6.8 mg/100 g) content of the wild and domesticated cultivars. A wild progenitor of finger millet, Ecoracana subsp.africana was significantly higher in protein than four of the six domesticated accessions analyzed. The calcium and iron content of the wild progenitor was also significantly greater than that of two domesticated cultivars. The wild species was also found to be higher in lysine and five other essential amino acids. These results indicate that the nutritional value of finger millet may be significantly improved by selective crossbreeding of the cereal's wild and domesticated cultivars.     

Effect of fermentation on protein,fat, minerals and thiamine content of pearl millet

Natural as well as single, mixed and sequential pure cutlure (S. diastaticus, S. cerevisiae, L. brevis andL. fermentum) fermentations of pearl millet flour for 72h lowered pH and raised titratable acidity. The fermentation either decreased or did not change the protein content of pearl millet flour. Natural fermentation increased whereas pure culture fermentation decreased the fat content. Ash content did not change. Natural fermentation at 20°C and 25°C increased whereas at 30°C it decreased the thiamine content of the pearl millet flour. Yeast fermentation raised the level of thiamine two- to three-fold, while lactobacilli fermentation lowered it significantly.     

Relevance of fermented food products in southwest Nigeria

Samples of extruded high protein weaning foods were produced using blends of peanuts, maize and soybean to achieve the desired level of protein. The extruded products, based on a raw and a preroasteds mix of ingredients, were developed and characterized in terms of the hot paste viscosity characteristics, chemical and nutritional quality, amino acid composition, and storage stability. A comparative evaluation of the extruded products was undertaken in relation to two similar existing products: the traditional roasted maize flour weaning food, and thecommercial version. In general, the extruded products were found to have better nutritional quality as indicated by the high protein content of 16.5–18.7% and quality, and excellent rat growth response. For both types of extruded weaning foods developed, between sixty- and one hundred-fold increases in mean weight gain of test rats were recorded over those eating the traditional sample. Correspondingly, the PER values which were between 2.3 and 2.5, were almost thrice the values obtained for the existing products. Significantly higher feed efficiency ratios were also obtained for the extruded products. Hematological data of test animals showed normal values for white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb) levels and packed cell volume (PCV) for all the weaning foods studied, except the existing traditional roasted maize flour. In terms of storage stability of the extruded products, predicted shelf life periods of 7.8–10.4 months were obtained for the extruded raw blend, and 5.6–7.1 months for the extruded preroasted blend when stored at the average ambient temperature of about 30,°C in Ghana. In general, the preroasting treatment was found to reduce the quality characteristics of the extruded product.     

Development,acceptability and nutritional value of weaning mixtures

Low cost weaning mixtures were prepared by mixing (i) malted pearl millet (Penicitum typhidium L), roasted amaranth (Amaranthus sp.); roasted green gram (Vigna radiata); jaggery and (ii) malted barley (Dehusked barley); roasted amaranth grain; roasted green gram; jaggery in proportion 60204045 wt/wt and were nutritionally evaluated. Both the blends had a nutrient composition within the range prescribed by the Indian Standard Institute (ISI) for processed weaning foods. The processing of grains resulted in lower levels of phytic acid, polyphenols and saponins and higher in vitro protein digestibility than those of the raw grains used for preparing mixtures. Both the mixtures were acceptable to trained panelists and children.     

Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

The objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty‐two uncastrated mixed‐breed lambs at 4 to 5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60 g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p < .05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p < .05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p < .05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry‐matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.     

Responses of maize, sorghum and millet host plants to infestation by Striga hermonthica

Twelve samples of Striga hermonthica seed were collected from four host crops [millet (4), sorghum (4), a sorghum/millet intercrop (3) and maize (1)] from all the main areas of S. hermonthica infestation in Nigeria and were tested on eight genotypes of three test crops [maize (4), sorghum (2) and millet (2)] in two screenhouse trials. Plants of each test genotype were sown in pots and heavily infested with S. hermonthica. Emergence count of the parasite, test crop damage rating (1–9), and test crop plant height were measured at 9 weeks after planting. The effects of genotypes, samples and their interaction for all three traits measured were highly significant (p = 0.001). Of the 12 samples of S. hermonthica, all have high emergence on both maize and sorghum. Seven samples gave low emergence on millet genotypes and two none at all. Three of the four samples from millet sources gave higher parasite emergence on sorghum and maize than on millet. For Striga damage rating, millet had the lowest average scores, followed by maize and sorghum. The responses of maize genotypes to samples from millet and sorghum sources were significantly different. Millet genotypes also had different responses to the samples from millet sources. For plant height differences, samples from sorghum sources interacted significantly with test maize genotypes, and millet samples with sorghum genotypes. The results indicate that both intercrop and intracrop strains of S. hermonthica are present in Nigeria.     

Traditional production and chemical composition ofNdaleyi,a Nigerian fermented pearl millet food

Ndaleyi, a fermented, sun dried agglomerated powder produced from pearl millet or sorghum is one of the most popular foods consumed in Nigeria, mostly by the Kanuri people of Borno State. Its traditional production is described. The mean yields ofndaleyi (mainly starch),chir (millet gluten) and bran (overtail orbina) were 30.6, 22.5 and 21.5%, recpectively. A mean yield loss of 20% was observed. Chemical analysis revealed thatchir and bran have higher protein, fat and ash contents thanndaleyi. The titratable acidities (as percent lactic acid) ofndaleyi andchir were 0.9 and 0.3, while their pH values were 3.3 and 3.5, respectively.     

The effect of reducing agent DTT on pasting,hydration and microstructure properties of foxtail millet

Protein-protein crosslinks, especially disulfide bonds, widely exist and influence the quality of cereal-based food. In order to investigate the effect of disulfide bonds on pasting properties of foxtail millet, ten typical varieties were selected and separated into three groups according to their eating quality, and then reducing agent dithiothreitol (DTT) was used to disrupt disulfide bonds. Disulfide and sulfhydryl groups’ variations, pasting, and hydration properties were determined. Scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also used to analyze the microstructure of foxtail millet paste. Results showed that foxtail millet with poor eating quality was more prone to form disulfide bond linkage at a higher rate and degree during cooking. Disrupting disulfide bonds increased peak viscosity, breakdown, water absorption, and swelling power of granules. Meanwhile, pasting temperature, setback, and final viscosity decreased significantly. The larger size of swollen starch granules and breakage of protein networks were found under CLSM, and firmer lamellar structures with less connections and pores were illustrated under SEM in DTT-treated paste. After DTT-treatment, disulfide bonds were believed to restrict hydration and pasting properties of foxtail millet, and strengthen the swollen granules and paste rigidity as well as a high level of starch reassociation.     

Biological evaluation of pearl millet protein: effect of different treatments and storage

Whole grain flour of one variety (HC-4) of pearl millet (Pennisetum americanum L. Leeke) after giving different treatments (defatting, butylated hydroxyanisole, ascorbic acid and thermal) was stored in earthen pots at prevailing room temperature (28–34°C) and relative humidity (70–80%) for 30 days. The flour samples were evaluated for protein quality using rats. Storage of flour for 30 days markedly reduced the protein quality. The values of protein efficiency ratio, true digestibility, biological value, net protein retention and net protein utilisation were significantly (P<0.05) higher in fresh and treated flour than untreated flour. Among treated flours, defatted flour showed best growth followed by butylated hydroxyanisole, thermal and ascorbic acid treated flour.     

Changes in micro- and macronutrient composition of pearl millet and white sorghum during in field versus laboratory decortication

Traditional decortication of pearl millet and white sorghum by hand pounding or using a mechanical device were performed in Burkina Faso, and compared to abrasive decortication in the laboratory using the same kernel lots. Using some nutrients as histological markers, the decortication characteristics and nutritional composition (iron, zinc, phytates, lipids, ADF fibres and starch) of decorticated grains were measured. Decortication had numerous effects on grain composition but no significant differences were observed between the two traditional methods of decortication. The effects varied according to the type of grain mainly due to the fact that more germ was removed in sorghum than in millet, as the millet germ is more embedded in the endosperm. During abrasive decortication, zinc and lipid losses increased rapidly due to removal of the germ, particularly in sorghum. Phytates were shown to be located mainly in the bran and germ but also in the endosperm in millet. In both sorghum and millet, half the iron was removed when only 10% of grain DM was abraded. The method of decortication, shock or friction vs. abrasion, influenced the fractions removed and thus the chemical composition of the decorticated kernels.