Bulk density and friction coefficients of selected minor millet grains and flours

Data on the characterization of seaweed, wheat bran, and other food processing byproducts as feasible biosorbents

Traditionally, biosorbents have been used to remove contaminants from polluted water, such as wastewater, landfill leachate, rainwater or drinking water. However, two alternative uses of biosorbents have been proposed relatively recently: the removal of heavy metals from fruit juices by biosorption and the use of saturated biosorbents as animal feed. Because these biosorbents are in contact with food or are used as animal feed, the concentration of contaminants in biosorbents must be known. In addition, the characterization of biosorbents is crucial because biosorbent properties affect both adsorption efficiency and the performance of full-scale biosorbent systems. This article presents data from Fourier transform infrared spectroscopy (FTIR) analysis, and the concentration of toxic metals (determined by ICP-MS) as well as pesticide residues was determined in ten biomass samples, namely, pea skins, straw, seaweed Fucus vesiculosus, wheat bran, rye bran, raspberry seeds, peat, buckwheat husks, highbush blueberry pulp, and blackcurrant pulp. Selected biomass samples were also characterized by scanning electron microscopy (SEM), nitrogen physisorption analysis, and pyrolysis-gas chromatography-mass spectrometry (Py-GC/ MS/FID) analysis.

Modulation of Physical and Thermal Properties in Wild Banana (Musa balbisiana Colla) Seed Powder by Moisture Variations

Engineering and flow properties of banana seed powder as a function of moisture content are important for processing, handling, packaging, and transport processes. The bulk density, tapped density, and porosity increased from 377.37 to 427.36 kg m-3, 622.08 to 746.33 kg m-3, and 38.99-43.74%, respectively, within the increasing moisture content range. The Hausner ratio (Hr) and Carr's compressibility index (CI) significantly (p < 0.05) increased with an increase in moisture content (6.16-19.56% db) of banana seed powder, whereas HR fell in the range of 1.4-2.0, indicating cohesive characteristics of banana seed powder. The angle of repose, angle of spatula, and angle of fall exhibited a linear increase, ranging from 40.6° to 49°, 33.4° to 39.4°, and 35.6° to 42.6°, respectively, with increasing moisture content. The static coefficient of friction was found to be highest for aluminium and glass surfaces and least for stainless steel. The water activity and swelling power of banana seed powder showed a significant increase, while the solubility and oil absorption capacity exhibited a significant decrease within the range of increasing moisture content. The thermal characteristics of wild banana seed powder, such as thermal conductivity (0.16 to 0.20 Wm-1 K-1) and volumetric specific heat (0.58 to 0.99 MJm-3 K-1), demonstrated an increasing trend as the moisture content increased. However, the thermal diffusivity showed a decrease from 0.31 to 0.19 (×10-6 m2s-1) with the increase in moisture content.

Generalized Mathematical Model of the Grain Drying Process

Convective cereal grain drying is an energy-intensive process. Mathematical models are applied to analyze and optimize grain drying processes in different types of dryers and in different stages of drying to improve final grain quality and reduce energy consumption. The aim of the present study was to develop a generalized mathematical model of the grain drying process that accounts for all drying stages, including loading and unloading of unprocessed grain, drying, and cooling of dry grain. The developed mathematical model is a system of algebraic equations, where the calculated coefficients are determined by the thermophysical and diffusive properties of dried grain. The model was validated for batch drying of wheat, canola, and corn grain, as well as continuous flow drying of wheat grain. The results were compared with published findings. The relationships between energy consumption during drying and drying time vs. air temperature at the dryer inlet and air stream volume were determined. Dryer capacity and drying conditions specified by the manufacturers, as well as loading and unloading capacity, were considered during batch drying. Continuous flow drying simulations were conducted in counter-flow, parallel-flow, and cross-flow mode. Simulation results indicate that the proposed models correctly depicted process flow in both batch and continuous flow dryers.

Comparative study of physicochemical and functional properties of soaked, germinated and pressure cooked Faba bean

Faba bean flours (germinated, soaked, cooked and raw) were evaluated for physiochemical and functional properties. The flour samples exhibited considerable amounts of carbohydrates (58.79-66.19 g/100 g) and proteins (21.9-29.1 g/100 g). Soaked faba bean (SFB) (29.1 g/100 g) and raw faba bean (RFB) (25.70 g/100 g) flour contained significantly higher amount of protein than germinated faba bean (GFB) and pressure cooked faba bean (PCFB). The physicochemical and functional composition of GFB and PCFB were improved compare to raw flour. Physical and functional properties such as water absorption index (2.97 g/g) and foaming stability (140.13 mL/100 mL) were increased by germination. The functional properties of pressure-cooked faba bean such as water solubility index (2.12 g/100 g) and water absorption capacity (2.02 g/g) were higher than other flour samples. The microstructure of legume flour samples explained that the starch granules of raw flours were smooth, oval and granular structure whereas soaked, germinated and cooked flours showed damaged starch granules. The effect of soaking, germination and pressure-cooking demonstrated significant variations in functionals characteristics of faba bean flour. Therefore, various processing conditions can be combined to obtain the desired characteristics in faba bean-based food products.

Nutritional Significance and Antioxidant-Mediated Antiaging Effects of Finger Millet: Molecular Insights and Prospects

Aging is a multifaceted process that is associated with progressive, lethal, and unalterable changes like damage to different molecules (DNA, proteins, and lipids), cells, tissues, and organs. It is an inevitable process but can be delayed by both genetic and dietary interventions. Besides aging, premature death and age-associated diseases can be dealt with diet regulation and the use of compounds that inhibit the stress responsiveness or promote the damage repair signaling pathways. Natural compounds offer a repertoire of highly diverse structural scaffolds that can offer hopeful candidate chemical entities with antiaging potential. One such source of natural compounds is millets, which are minor cereals with an abundance of high fiber, methionine, calcium, iron, polyphenols, and secondary metabolites, responsible for numerous potential health benefits. The present review article elucidates the nature and significance of different phytochemicals derived from millets with a major focus on finger millet and highlights all the important studies supporting their health benefits with special emphasis on the antiaging effect of these compounds. The present article also proposes the possible mechanisms through which millets can play a significant role in the suppression of aging processes and aging-related diseases by influencing genetic repair, protein glycation, and stress-responsive pathways. We further discuss well-established natural compounds for their use as antiaging drugs and recommend raising awareness for designing novel formulations/combinations from them so that their maximum antiaging potential can be harnessed for the benefit of mankind.

Effect of Tempering Conditions on White Sorghum Milling, Flour, and Bread Properties

The effects of room temperature water, hot water, and steam tempering methods were investigated on sorghum kernel physical properties, milling, flour, and bread-making properties. Overall tempering condition and tempering moisture content were found to have a significant effect on the physical properties. Milling properties were evaluated using a laboratory-scale roller milling flowsheet consisting of four break rolls and eight reduction rolls. Room temperature tempering (18% moisture for 24 h) led to better separation of bran and endosperm without negatively impacting flour quality characteristics i.e., particle size distribution, flour yield, protein, ash, damaged starch, and moisture content. Bread produced from the flour obtained from milling sorghum kernels tempered with room temperature water (18% m.c for 24 h) and hot water (16% m.c at 60 °C for 18 h) displayed better bread-making properties i.e., high firmness, resilience, volume index, higher number of cells, and thinner cell walls when compared to other tempering conditions. Room temperature water tempering treatment (18% m.c for 24 h) could be a better pretreatment process for milling white sorghum kernels without negatively impacting the flour and bread-making quality characteristics.

The influence of cooking on the antioxidant properties and polyphenol content in buckwheat, barley and millet groats and the transfer of the compounds to the water

The research subject was the influence of the cooking process on the polyphenol content and antioxidant properties of groats (buckwheat groats, barley groats, millet groats) and on the colour parameters of the products. After groats cooking, also the water was tested for the polyphenol content and antioxidant properties that permeated into the decoction of the cooked raw material. The evaluation of the antioxidant properties of groats was conducted with the DPPH radical assay, the polyphenol content was determined with the Folin-Ciocalteu reagent, and the colour was determined with the trichromatic colorimetry method using the Konica Minolta CM-5 colorimeter (Osaka, Japan). The cooking process significantly lowered the content of polyphenolic compounds and antioxidant properties of the ready products. The best antioxidant properties after cooking were found in buckwheat groats and the weakest in millet groats. The polyphenol content in cooked products depended on the type of groats. Cooking significantly decreased the polyphenol content, but only in buckwheat and barley groats, as well as causing a change of groats colour as compared to uncooked samples. The most antioxidant properties were found in the water from cooking barley groats, and the least - from cooking millet groats. The most polyphenols permeated into the water from cooking buckwheat groats, and the least from cooking millet groats. All groats, except millet groats, darkened after cooking. In all types of groats, the correlation coefficients between colour parameter and general polyphenol content and the ability to scavenge DPPH radicals showed very strong negative dependences. The conducted research can help in designing the technological process of cooking buckwheat, barley and millet groats, and a way of using the water from cooked groats for consumption.

Hydration kinetics of little millet and proso millet grains: effect of soaking temperature

Hydration characteristics of little millet (Panicum sumatrense) and proso millet (Panicum miliaceum) were studied at different soaking temperatures (30, 40, 50, 60 and 70 °C) and fitted into hydration models. From the initial moisture contents of 11.02 (d.b.) and 10.45% (d.b), little millet and proso millet grains attained the equilibrium moisture content of 38-50.17% (d.b) and 39.11-47.15% (d.b.), respectively. Little millet took 18.5 h to reach equilibrium moisture content at soaking temperature of 30 °C and 3.5 h at 70 °C. For proso millet, it took 4 h at 70 °C and 19 h at 30 °C. The data of moisture content with time fitted to Lewis, Page, modified Page and Peleg models shown higher coefficient of determination values ranging from 0.92 to 0.99. Among the models, the Peleg model is more suitable for the little millet grains and both Page and Peleg models are more suitable for the proso millet grains, to represent the hydration kinetics in the soak water temperature range of 30-70 °C. The dependency of the coefficients of the hydration models with temperature of soaking was found to be linear for both little and proso millets with coefficient of determination values ranging from 0.88 to 0.97.

Significance of composition and particle size on the shear flow properties of wheat flour

BACKGROUND

Size-based fractionation of flour particles is an important process in wheat milling. Inter-particle cohesion could affect the dynamic separation process and result in loss in throughput. This study quantifies the effect of particle properties that includes physical and chemical characteristics on the shear flow behavior of wheat flour.

RESULTS

The cohesion and flow function values of wheat flour at three moisture contents (10%, 12%, and 14%), three particle sizes (75-106, 45-75, and <45 µm) and three sifter loads (0.5, 1.0, and 1.0 kPa) were significantly different (P < 0.05). The triggering moisture content and particle size where the flowability shifts from 'easy flowing' to 'very cohesive' were found to be 12% (wet basis) and 45 µm, respectively.

CONCLUSION

The high correlation observed between the chemical composition (damaged starch, protein, and fat) on the physical (bulk and tapped densities) and flow properties (cohesion, flow function, and angle of internal friction) demonstrates that chemical composition significantly contributes towards the differences in dynamic flowability of wheat flours. In addition, fat composition had a significant effect on the differences in flowability of wheat flours due to the increased inter-particulate cohesion. © 2016 Society of Chemical Industry.