Effect of Thermal Treatment on Selected Cereals and Millets Flour Doughs and Their Baking Quality

Selected cereals (rice and sorghum) and millets (finger millet and pearl millet) were steamed for 20 min at ambient pressure. The rheological properties of doughs, made from these steamed as well raw grain flours, were characterized in addition to examining their baking quality. The two-cycle compression test was employed and instrumental values were correlated with sensory attributes (color, aroma, taste, stickiness, chewiness, tearing strength, cohesiveness, and rollability) using principal component analysis (PCA). Rice doughs made from both raw as well as thermally treated flour imparted maximum hardness (96.6–99.3 N) and least cohesiveness (0.05–0.09) with highest stickiness values (105–110°) among all the dough samples at the same moisture content. Pearl millet and raw sorghum flour doughs possessed the least instrumental hardness, adhesiveness, and stickiness and were the easiest to flatten. The PCA biplot showed that sensory and instrumental cohesiveness formed a cluster on the left side on the x axis while shear force, and sensory attributes like tearing strength, chewiness, stickiness, and rollability formed another cluster on the other side of the axis. Raw rice and finger millet doughs were associated with the high extent of instrumental and sensory stickiness. Thermally treated pearl millet and sorghum doughs were the best followed by treated rice and finger millet samples to give the desirable dough characteristics, and were quite close to wheat chapathi in texture.     

Changes During Accelerated Storage in Millet–Wheat Composite Flours for Bread

Two millet–wheat composite flours, CF1 and CF2, were formulated based on the rheological and textural properties of dough using response surface methodology. The optimized contents of composite flour CF1 were 61.8% barnyard millet flour, 31.4% wheat flour, and 6.8% gluten, respectively. The optimized components of the composite flour CF2 were barnyard millet flour 9.1%, finger millet flour 10.1%, proso millet flour 10.2%, and wheat flour 70.6%. Millet–wheat composite flours were stored in three different packaging materials, namely, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and metallized polyester (MP), at 90% RH and 40 °C temperature for 90 days. For the packaging of millet–wheat composite flour CF1, MP was found best among the tested packaging materials, where moisture gain in samples was minimum (55%) as compared with materials LDPE (124%) and HDPE (100%). Vitamin loss among the different packaging materials was not significantly different at the 5% level of significance. The shelf lives of the composite flours were estimated based on their critical moisture contents. After 90 days of storage of CF1, the highest retention of starch (91.85%) was recorded in MP packaging followed by HDPE (87.5%) and LDPE (84.8%). However, in CF2, the retention was not significant in all three packaging materials (P?相似文献   

Development And Characterization of Extruded Fura From Mixtures of Pearl Millet and Grain Legumes Flours

Dehulled pearl millet flour (100%) and blends of pearl millet, cowpea, groundnut and soybean flours at 80:20, 70:30 were extruded at 30 g moisture/100 g sample using a Brabender Laboratory single screw extruder to develop extruded fura products. The fura extrudates and fura produced in the traditional way were analyzed for their physical and chemical and sensory properties. There were significant differences (p < 0.05) in the puff ratio of the extruded fura products. Pearl millet: cowpea (80:20) fura had the highest puff ratio (4.71) while the pearl millet: groundnut (80:20) fura had the lowest (2.90). The bulk density of the pulverized extruded fura was lower than that of the dried and pulverized traditional fura. The hydration power of the extrudates increased significantly (p < 0.05) at 28°C and 50°C. Extrusion increased the hydration power of products. Fura extrudate containing 100% pearl millet flour had the highest hydration power of 63.9% at 28°C, while the traditional fura had the lowest of 15.8% at 28°C. Protein content of samples increased with supplementation of pearl millet with grain legumes. Sensory evaluation results showed that there were no significant differences among the fura extrudates and the traditional fura with respect to color, texture and overall acceptability except for flavor. Extruded products were still acceptable after 12 weeks storage in polyethylene and cellophane bags at 30 ± 2°C. Extrusion and supplementation processes are therefore one way of producing a convenient shelf stable nutrient rich fura in the areas where fura is commonly consumed.     

Effect of γ-Irradiation on Colour, Functional and Physicochemical Properties of Pearl Millet [Pennisetum glaucum (L) R. Br.] Cultivars

Effect of γ-irradiation dose (0–8 kGy) on seed colour, functional and pasting properties of two selected pearl millet cultivars (SOSAT and ZATIV) was investigated. Colour (L*a*b*) of the non- and γ-irradiated pearl millet cultivars was measured, and the deltachroma (?C), colour intensity (?E) and hue angle were calculated. Also, loose and tapped bulk densities, swelling capacity, water (WAC) and oil (OAC) absorption capacities of the flours were determined. Pasting characteristics were determined using Rapid Visco Analyser, respectively. The effect of γ-irradiation on L*, a* and b* values within ZATIV cultivar was almost never significant. ?C and ?E increased up to 4 kGy but decreased with increased γ-irradiation dose up to 8 kGy. Loose and packed bulk densities, and WAC were not significantly affected by γ-irradiation. The OAC of the SOSAT (1.16–1.36 g/g) was not significantly affected but the ZATIV (0.94–1.34 g/g) was significantly affected by γ-irradiation. The WACs of non-irradiated SOSAT and ZATIV pearl millet flours were 1.42 and 1.33 g/g while the irradiated counterparts varied from 1.15 to 1.42 and 1.24 to 1.39 g/g, respectively. Peak, trough, final, and setback viscosities decreased significantly (p?<?0.05) with increased γ-irradiation dose. As irradiation dose increased, the peak time of SOSAT and ZATIV pearl millet cultivars significantly (p?<?0.05) decreased from 5.84 to 5.07 and 5.58 to 4.94 min, respectively. However, pasting temperature of non-irradiated (61.80 °C) pearl millet was not significantly higher than the γ-irradiated (61.58–62.08 °C) samples.     

Phenolic content,antioxidant potential and DNA damage protection of pearl millet (<Emphasis Type="Italic">Pennisetum glaucum</Emphasis>) cultivars of North Indian region

Total phenolic contents, condensed tannin content, antioxidant activity and DNA damage protection of twelve pearl millet cultivars from North Indian region were assayed. All pearl millet cultivars showed considerable amount of bioactive compounds with antioxidant potential. PUSA-415 showed the presence of maximum amount of extractable total phenolic content (7.32 mg GAE/g DWB), whereas HHB-223 cultivar depicted the highest amount of condensed tannin contents (138.45 mg CE/100 g DWB). Antioxidant activity was measured using different methods viz., DPPH, ABTS, FRAP, TAC and HFRSA. A clear correlation was observed between total phenolic content and antioxidant activity of different pearl millet cultivars. The extracts of all cultivars prevented the oxidative damage to plasmid DNA (pBR322) against DNA damaging Fenton’s reagent. However, cultivars PC-383, PUSA-415, PUSA-605, PC-612 and 841-B showed prominent DNA damage protection activity. The results of this study provide a scientific basis of the traditional use of pearl millet as a natural antioxidant mitigating DNA damage.     

The pasting behaviour of lactic‐fermented and dried uji (an East African sour porridge)

The effects of sun‐, cabinet‐, and drum‐drying on the behaviour of submerged culture lactic‐fermented pure cassava, maize and finger millet and composites of maize–finger millet and cassava–finger millet were investigated in a Brabender amylograph. The cereal flours and maize–finger millet composite had higher onset and peak gelatinization temperatures but lower peak viscosities than cassava or cassava–finger millet composites. Fermentation alone or in combination with drying increased the viscosity of the flours, except for the fermented and drum‐dried cassava–finger millet composite flour. This increased viscosity of uji on fermentation and drying makes it more difficult to cook. Fermented and drum‐dried flours recorded high initial viscosities, at 30 °C, when the amylograph was switched on. Copyright © 2003 Society of Chemical Industry     

Effect of drying lactic fermented uji (an East African sour porridge) on some carboxylic acids

Maize, finger millet, cassava, maize–finger millet and cassava–finger millet flours were fermented and sun‐, cabinet‐, or drum‐dried. Total titratable acidity (TTA), fixed acidity (FA), pH and carboxylic acids were determined. The TTA of the non‐fermented flours ranged from 0.22%(w/w) lactic acid in cassava to 0.36%(w/w) lactic acid in the maize–finger millet composite. After fermentation the TTA ranged from 3.26%(w/w) lactic acid in cassava–finger millet to 4.54% in maize‐finger millet while FA ranged from 2.86% in cassava–finger millet to 4.26% in cassava and maize–finger millet. Fermentation decreased the pH from about 5.5 to 3.7–4.1. Drying did not change the pH but TTA decreased by 20–60%. Acetic acid levels in the fermented slurries varied from 0.80 to 0.95 µg per 5 µg while those of hexanoic acid varied from 0.9 to 1.8 µg per 5 µg. Propionic acid was absent in the fermented slurries. Acetic and formic acids were completely lost when the fermented slurries were dried. On average hexanoic acid losses on drying varied from 33% in maize to 91% in cassava fermented slurries. These losses were not significantly influenced by the drying system. In sensory evaluation panellists could not detect flavour loss as a result of drying. © 2000 Society of Chemical Industry     

A study on functional,pasting and micro-structural characteristics of multigrain mixes for biscuits

The four different multigrain mixes were developed by combining whole cereals (barely, sorghum, maize, oats,wheat germ), pulses (chickpea dhal, green gram, peas, soya flour) and millets (finger millet, pearl millet) to get mutual supplementation benefits. The protein content of different mixes ranged from 22.91 to 27.84 % and dietary fiber ranged from 16.82 to 18.72 %. The functional, pasting and micro-structural characteristics of different mixes have been studied to predict its suitability for the preparation of biscuits. The results indicated that the water absorption capacity of these mixes varied from 1.51 to 1.57 g/g, oil absorption capacity varied from 0.84 to 1.03 g/g, water absorption index varied from 3.54 to 3.70 g/g, water solubility index varied from 3.54 to 3.70 g/g, bulk density varied from 0.53 to 0.62 g/ml, peak viscosity varied from 63.83 to 84.79 RVU. Among the different multigrain mixes studied, Mix III had the desired functional characteristics as indicated by its higher water absorption index, water solubility index, bulk density, α-amylase activity and lower alkaline water retention capacity, breakdown viscosity suggesting thereby its suitability for the preparation of biscuits. The biscuit making trials conducted on different multigrain mixes at 20 % level of incorporation have also confirmed that among different multigrain mixes, the multigrain mix III containing barley, sorghum, chickpea, pea and soya flour gave best quality biscuits.     

Physicochemical,functional and antioxidant properties of flour from pearl millet varieties grown in India

Indian pearl millet varieties were selected, milled to flour and studied for their proximate composition, hunter color, functional, and antioxidant properties. Proximate composition and hunter color values differed significantly (p < 0.05) among varieties. Hunter L* value was found the highest for HHB-223 flour whereas a*, b* and ΔE was the highest for W-445 flour. Flours also showed significant variations in their total phenolic content (TPC), total flavonoids content (TFC), antioxidant activity (DPPH) and metal chelating activity. Variety GHB-732 showed the highest values for TPC (3137 µg GAE/g) and DPPH (46.7 %) activity. TFC was, however, found the highest for HC-10 (2484 µg CE/g) variety. Several significant correlations were observed among different flour properties as revealed by both pearson correlations and principal component analysis. Formulation of chapatti resulted in decrease in TPC, TFC, DPPH values when compared to its flour. However, reverse was observed for metal chelating activity.     

Physicochemical and pasting properties of maize flour as a function of the interactive effect of natural-fermentation and roasting

The effect of natural-fermentation and roasting on maize physicochemical and functional properties were evaluated. Natural fermented maize seeds were soaked for variable times (0, 24 and 48 h) and directly decorticated or roasted before milling into flour. Generally during the 24 to 48 h natural fermentation, total sugars (80.3–92.0 g/100 g) and proteins contents (4.0–7.6 g/100 g) decreased while they significantly increased with soaking. Soluble sugars content of the unroasted maize significantly decreased with fermentation while that of roasted maize significantly increased. Reverse observations were made on soluble proteins. The antinutrients (phytates and total polyphenols) contents of the grains as well as the functional properties of their flours were observed to have been significantly changed following fermentation and roasting. In particular the least gelation concentration (6 to 18 g/100 mL), an important reverse index of gelating power significantly increased with fermentation and roasting. As consequence the viscosity of the fermented maize flours were systematically significantly lower than that of the unfermented flour. Generally while the effects of duration of fermentation and roasting on the viscosity were not consistent, the 48 h natural fermented and roasted flour was observed to particularly produce flours of much lower viscosity. This highlighted the positive effect of combining fermentation and roasting to improve the quality of weaning flour made from maize.     

Natural Antioxidants in Edible Flours of Selected Small Millets

Investigations were carried out on the natural antioxidants in edible flours of small millets. Total carotenoids content varied from 78–366 μg/100 g in the millet varieties with an average of 199 + 77, 78 + 19, 173 + 25, and 366 + 104 μg/100 g in finger, little, foxtail, and proso millets respectively. Analysis of carotenoids by HPLC for the presence of β-carotene showed its absence in the millets. HPLC analysis of vitamin E indicated a higher proportion of γ?and α-tocopherols; however, it showed lower levels of tocotrienols in the millets. Total tocopherol content in finger and proso millet varieties were higher (3.6–4.0 mg/100 g) than in foxtail and little millet varieties (～1.3 mg/100 g). Total antioxidant capacity in finger, little, foxtail and proso millets were 15.3 + 3.5, 4.7 + 1.8, 5.0 + 0.09, and 5.1 + 1.0 mM TE/g, respectively. From these studies it could be concluded that edible flours of small millets are good source of endogenous antioxidants.     

Aflatoxins and ochratoxin A in flour: a survey of the Serbian retail market

This report presents data on the occurrence of aflatoxins (AF) and ochratoxin A in different types of flour marketed in Serbia. A total of 114 samples of wheat, buckwheat, rye, oat, barley, rice, millet and corn flour were collected in the period 2012–2016 and analysed using high performance liquid chromatography with fluorescence detection. Among flours other than corn, AFB1 was quantified only in rice, while ochratoxin A (OTA) was found in 29% of the samples. In corn flours the percentage of positive samples varied greatly over the years: AFB1 7.1–80.0%, OTA 30.0–40.6%, with a co-occurrence of 7.1–34.4%. Overall 5.2% of flours other than corn and 10.7% of corn flours exceeded the maximum levels (MLs) for AFB1 and/or OTA. The highest recorded levels were 8.80 μg kg^?1 of AFB1 (corn) and 23.04 μg kg^?1 of OTA (rye). Overall mean contamination levels of corn flours were 0.53 μg kg^?1 of AFB1 and 0.46 μg kg^?1 of OTA.     

Nutritional,Functional and Physical Properties of Extrudates from Blends of Cassava Flour with Cereal and Legume Flours

Low protein and poor functionality limit the use of cassava flour in snack foods, which were modified using blends with cereal and/or legume flours. Native, malted (using alpha-amylase) as well as malted and pre-gelatinized was blended with cereal (finger millet and whole wheat flours) and/or legume (chick pea flour). Extrudates were prepared at a screw speed of 100 rpm and die temperature of 180 °C. Malted flour based extrudates had lower starch content than native flour. Gram malted cassava based blends gave products with the highest protein. In vitro starch digestibility was the highest for pre-gelatinized flour based mixes. Extrudates with low fat and energy have scope as low calorie snacks for obese and diabetic people.     

The Effect of Root Maturity, Preprocess Holding and Flour Storage on the Quality of Cassava Biscuit

Effect of root maturity (12 and 23 months) and flour storage on physical, chemical, and sensory attributes of cassava biscuits was evaluated. Pulp and flour of 12 months were higher than the 23 months mature roots. Moisture, crude protein, crude fat, and cyanide contents of the cassava flour varied between 10.1% and 10.3%, 2.2% and 2.4%, 0.2% and 0.3%, and 12.1 and 13.4 mg HCN/100 g, respectively. Diastatic activity of the flour ranged from 115 to 243 mg maltose for fresh and roots stored for 3 days. Water-holding capacity of the roots and peak viscosity of flours decreased during storage. Sensory results showed that cassava biscuits were acceptable and compared favorably with the wheat biscuits.     

Iron fortification of finger millet (Eleucine coracana) flour with EDTA and folic acid as co-fortificants

Fortification of staple foods with iron is a feasible strategy to enhance the intake of this mineral. In the present investigation, finger millet flour was explored for its suitability as a vehicle for fortification with iron. Ferrous fumarate and ferric pyrophosphate were added at levels that provided 6 mg of iron per 100 g of the flour, and both were found to be equally effective. Inclusion of EDTA and folic acid, along with the iron salts, significantly increased the bioaccessibility of iron from the fortified flours. The fortified flours were stable up to a period of 60 days. There was a decline in the bioaccessible iron content in the flour fortified with ferric pyrophosphate after 30 days of storage. Heat processing of the flours improved the bioaccessibility of iron from the unfortified and fortified flours. Fortification with iron did not affect the bioaccessibility of the native zinc from the flours.     

Nutritional and functional performance of high β-glucan barley flours in breadmaking: mixed breads versus wheat breads

The ability of high β-glucan barley (HBGB) flour versus regular commercial barley (CB) to make highly nutritious wheat (WT) blended breads meeting functional and sensory standards has been investigated. Mixed breads obtained by 40 % replacement of WT flour by HBGB flours are more nutritious than those replaced by CB flours and much more than regular WT flour breads in terms of elevated levels of dietary fibre fractions (soluble, insoluble, resistant starch and β-glucans), slowly digestible starch subfraction and bioaccessible polyphenols providing higher antiradical activity. WT/CB and WT/HBGB breads can be, respectively, labelled as source of fibre (3 g DF/100 g food) and high-fibre breads (6 g DF/100 g food), according to Nutritional Claims for dietary fibre foods. The consumption of 100 g of WT/HBGB can meet up to almost 50 % the required dietary fibre, providing a β-glucan intake high enough to meet the requirements of the EFSA health claim (3 g/day), contributing a reduced blood cholesterol level. The techno-functional performance of fresh blended breads and the sensory appreciation were in general preserved or even improved.     

Influence of storage on the protein quality of pearl millet flour

Whole grain flours of two cultivars of pearl millet (Pennisetum typhoides Rich) were stored in cans for 8 days at the prevailing room temperature (25±5°C), until the flours developed an off-flavour and bad taste. The flour samples were then evaluated for protein quality. The values of protein efficiency ratio, true digestibility, biological value, net protein retention and protein utilisation fell markedly during storage. The protein quality of the cultivar with the higher amount of oil was affected more severely.     

Organoleptic and nutritional evaluation of wheat breads supplemented with soybean and barley flour

Supplementations of soy (full fat and defatted) and barley flours to wheat flours at 5, 10, 15 and 20% levels were carried out to test the effects on organoleptic and nutritional evaluation of the supplemented bread. Additions of 15% barley flour, 10% soy flour (full fat and defatted), 15% barley plus full fat soy flour and 15% barley plus defatted soy flour to wheat flour produced acceptable breads. However, substitution of soy (full fat and defatted) and barley flours to wheat flour separately and in combinations at 20% levels did not produce organoleptically acceptable bread. Various nutritional parameters, such as protein, fat, total lysine, protein digestibility (in vitro), sugars, starch digestibility (in vitro), total and available minerals, antinutrients, dietary fibre and β-glucan were determined in supplemented and control bread. Increasing the level of substitution from 5 to 10% of full fat and defatted soy flour to wheat flour significantly (P<0.05) increased protein (from 12.1 to 13.7 and 12.4 to 13.8%), lysine (from 2.74 to 3.02 and 2.76–3.05 mg/100 g protein) and total calcium (from 70.2 to 81.4 and 71.9–81.8 mg/100 g) contents. However, there was also an increase in phytic acid (238–260 and 233–253 mg/100 g), polyphenol (324–331 and 321–329 mg/100 g) and trypsin inhibitor activity (193–204 and 193–198 TIU/g). When barley flour was substituted separately, and in combinations, with full fat and defatted soy flour up to 15%, this significantly increased the contents of protein, total lysine, dietary fibre and β-glucan. It may be concluded that breads supplemented with barley and defatted soy flour, up to a 15% level, are organoleptically and nutritionally acceptable.     

Influence of depigmentation of pearl millet (Pennisetum gluacum L.) on sensory attributes, nutrient composition and in vitro digestibility of biscuits

Presence of high concentration of pigments in the pericarp and endosperm regions of pearl millet imparts undesirable gray color to its products. This study attempts to improve the acceptability of pearl millet products through processing technique and to study its effect on nutritional composition of pearl millet product. Pearl millet grains were depigmented by soaking in 0.2 N HCl for 18 h followed by washing, blanching at 98°C for 30 s and sun drying. Three different types of biscuits were prepared from refined flour (Reference), native or unprocessed pearl millet (T-I) and depigmented pearl millet (T-II). Results indicated that depigmentation improved the sensory attributes especially the color of pearl millet biscuits (T-II). The protein, fat, ash and total dietary fiber of pearl millet based biscuits (T-I as well as T-II) were significantly (P?0.05) higher than the reference biscuits. Depigmentation significantly improved the in vitro starch digestibility, in vitro protein digestibility and the soluble dietary fiber content of pearl millet biscuits (T-II) by 14.50, 6.56 and 6.18%, respectively. On the other hand, a significant decrease of 6.73, 2.43 and 17.03 g/100 g in protein, starch and insoluble dietary fiber was detected in pearl millet biscuits (T-II) due to depigmentation.     

Composition and functional properties of raw and heat processed velvet bean (Mucuna pruriens (L.) DC. var utilis) flours

Summary The proximate composition and functional properties of raw and heat-processed velvet bean (M ucuna pruriens (L.) DC. var utilis ) flours were studied. The flours were prepared by soaking raw beans for 14 h, boiling for 30 min (heat-processed), manual dehulling, oven-drying (65 °C) and milling. The heat-processed flour contained 6.8% moisture, 24.3% protein, 4.9% fat, 1.3% crude fibre, 3.5% ash and 61.2% carbohydrate. The flour was rich in potassium (125 mg/100 g), zinc (9.8 mg/100 g) and phosphorus (361 mg/100 g). Differences in proximate and mineral composition of raw and heat-processed flours were not significant. The flours showed minimum protein solubility at pH 4.5 and formed reasonably stable emulsions and foams. Compared to raw flour, heat-processed flour had better water and fat absorption capacities, but lower protein solubility, emulsion and foam capacities. The flours have potential for food product development.