Mathematical Modelling, Moisture Transport, Shrinkage and Nutrient Content Properties in Drying Selected African Leafy Vegetables

2020 ◽  
Vol 36 (1) ◽  
pp. 95-104
Author(s):  
Gibson P Mutuli ◽  
Duncan O Mbuge ◽  
Ayub N Gitau
Keyword(s):  
Activation Energy ◽  
Moisture Content ◽  
Air Temperature ◽  
Moisture Transport ◽  
Leafy Vegetables ◽  
Moisture Loss ◽  
List Type ◽  
Drying Pattern ◽  
Page Model ◽  
And Storage

HighlightsPage model best described their drying pattern at moisture content above 0.5 w.b.Shrinkage linearly correlates to moisture loss.Activation energy correlates to air temperature.Vitamins A, C, and E are preserved by drying and storage. ABSTRACT. The study investigated physical, thermodynamic, and nutritional properties with drying and storage of selected African green leafy vegetables. The vegetables studied were: (Jute Mallow), (Slender Leaf), (Cowpea), (Nightshade), and (Amaranthus). Drying experiment was done at 30°C, 40°C, and 50°C in a convective laboratory dryer and drying was pattern fitted to existing models, moisture diffusivity, and activation energy trends were determined, shrinkage was determined from change in leaf thickness, and vitamins A, C, and E were analyzed using spectroscopy and high-pressure liquid chromatography as freshly harvested and after drying at 40°C and storage for 60 days. Results showed that drying occurred in the falling rate period and Page model could simulate the drying pattern of the vegetables with a ˜97% correlation between the empirical and predicted values with the model prediction being precise above 0.5 moisture content on wet basis (w.b.). Shrinkage was found to be a function of moisture loss at a range of 89% to 98% linear correlation. The rate of moisture loss and activation energy correlated with air temperature. The trend in the drying characteristics and moisture transport of the vegetables was unique with each vegetable. Drying at 40°C and storage for 60 days realized a retention in the scale range of 50% to 75% for vitamins A, C, and E. The study showed that drying is an effective way to preserve the vegetables. Keywords: Mathematical modeling, Mass transfer, Nutrient preservation, Shrinkage, Thermodynamic properties.

scholarly journals Drying Kinetics of Indigenous Fermented Foods of the Himalaya region (Gundruk, Sinki, and Maseura)

2021 ◽  
Vol 4 (2) ◽  
pp. 01-12
Author(s):  
Arjun Ghimire ◽  
Ashish Niroula ◽  
Prajwal Pokharel ◽  
Ranjana Poudel ◽  
Arjun Ghimire
Keyword(s):  
Activation Energy ◽  
Mathematical Models ◽  
Air Temperature ◽  
Effective Diffusivity ◽  
Moisture Loss ◽  
Fermented Foods ◽  
Drying Process ◽  
Statistical Parameters ◽  
Kinetics Of ◽  
The Himalaya

Indigenous fermented foods Gundruk (fermented mustard leaves), Sinki (fermented radish taproot), and Maseura (fermented lentils) are mostly sun dried, and thus often deteriorate during the uncontrolled drying process. Herein, cabinet drying was done at 50, 55, and 60°C after fermentation, and the moisture loss was systematically recorded. The data were converted to moisture ratio and fitted to five semi-theoretical drying mathematical models: Modified Henderson and Pabis, Logarithmic, Two-Term, Midilli et al., and Approximate diffusion. All the models were validated using statistical parameters, namely: R2, RMSE, χ2, and SSE. The Midilli et al. model gave excellent fit for all three products, with R2 greater than 0.97. The effective diffusivity values increased with an increase in air temperature for all the samples. The activation energy values were found to be 56.25, 21.63 and 15.08 kJ/ mol while the diffusivity constants were found to be 1268.51, 0.028, and 8.655× 10-3 m2/s for Gundruk, Sinki, and Maseura, respectively.

Thin-Layer Drying Characteristics of Fresh and Sun-Dried Buckwheat Hay

2021 ◽  
Vol 37 (4) ◽  
pp. 713-724
Author(s):  
Fuji Jian ◽  
Mehul Patil ◽  
Digvir S. Jayas ◽  
Jitendra Paliwal
Keyword(s):  
Activation Energy ◽  
Moisture Content ◽  
Thin Layer ◽  
Growth Time ◽  
List Type ◽  
Experimental Conditions ◽  
Drying Time ◽  
Drying Characteristics ◽  
Sun Drying ◽  
Thin Layer Drying

Highlights Thin-layer drying of fresh and sun-dried buckwheat hay was studied at 30°C to 180°C and 12.5% to 60% relative humidities. Buckwheat hay drying occurred in the falling-rate period. Partial sun-drying of the hay could reduce drying time by 50%. The D eff values of fresh flowers, leaves, and stems ranged from 1.4×10 -10 to 60×10 -10 m 2 /s. Abstract. Thin-layer drying characteristics of fresh and sun-dried buckwheat hay were studied at 30°C to 180°C, 12.5 to 60% relative humidities, and 0.2 m/s constant air velocity. The hay was harvested on three different times with a 10 to 12 d interval between the harvesting times. Half of the harvested hay was sun-dried on the field for 4 d (referred to as sun-dried hay). The drying behavior of flowers, leaves, and stems of the fresh and sun-dried hay was characterized. Moisture content of the fresh buckwheat flower was 0.777 to 1.633 (decimal dry basis), and fresh stems had a maximum moisture content of 5.64. Moisture content of the fresh hay decreased with the increase of growth time. Sun-drying on field could decrease more than half of the moisture content of the harvested fresh hay. Flowers, leaves, and stems needed varying drying times to reach their equilibrium moisture contents. The order of the drying time from the fastest to the slowest was flowers, leaves, then stems. Sun-dried and later harvested hay needed less drying time. The logarithmic model was the best fit for all drying processes of the flowers, leaves, and stems at different harvesting times and drying conditions. The effective moisture diffusivity of both fresh and sun-dried hay ranged from 1.4×10-10 to 60× 10-10 m2/s depending on different experimental conditions. The activation energy of the hay was from 21.08 to 33.85 kJ/mol. A power equation was the best equation to describe the drying constant of hay with their drying temperature. Keywords: Activation energy, Combination drying, Hay drying, Thin-layer drying, Water diffusivity.

Effects of Blending Dairy Manure Compost and Canola Meal on Pellet Quality and Nutrient Concentrations

2021 ◽  
Vol 64 (2) ◽  
pp. 353-363
Author(s):  
Femi P. Alege ◽  
Gilbert J. Miito ◽  
Lisa W. DeVetter ◽  
Haiying Tao ◽  
Pius M. Ndegwa
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Total Nitrogen ◽  
Dairy Manure ◽  
Nutrient Concentrations ◽  
Canola Meal ◽  
List Type ◽  
Nutrient Contents ◽  
Unit Density ◽  
And Storage

HighlightsNutrient contents and unit density were positively correlated with canola meal blending ratio.Pellet durability, bulk density, and length were inversely correlated with canola meal blending ratio.Pellets produced from compost and 20% canola meal blend were 67% denser than the compost.Pelleting dairy manure and canola meal blends improved nutrient transport and storage.Abstract. The potential for adverse environmental impacts from excess manure nutrients generated in regions with large concentrations of animal production is enormous and real. The goal of this research was to investigate ways of alleviating such threats via pelleting and blending of excess dairy manure nutrients to enhance their value, utilization, transport, and storage. In this study, composted dairy manure was blended with canola meal in ratios ranging from 0% to 40% canola meal prior to pelleting. The pre-pelleting moisture content was set at 21% (wet basis) and an 8 mm diameter die was selected for pelleting, based on previous studies. The effect of canola blending ratio was evaluated against moisture content, unit and bulk densities, recovery, durability, and nutrient concentrations (total nitrogen and phosphate) of the resulting pellets. Results indicated positive correlations between the blending ratio and pellet recovery (r = 0.83), moisture content (r = 0.75), unit density (r = 0.74), total nitrogen (r = 0.99), and phosphate (r = 0.87). In contrast, inverse correlations were observed between the blending ratio and pellet durability (r = -0.93), bulk density (r = -0.99), and length (r = -0.76). No significant differences were observed between the blending ratio and all these parameters for blending ratios of 0% to 15%. However, data indicated significant differences between pellet durability and recovery at blending ratios above 20%. Overall, this study showed that blending dairy manure with up to 15% canola meal significantly (p < 001) improved the nutrient value, storage, and transport. Keywords: Blending, Dairy manure, Durability, Environmental pollution, Pelleting.

scholarly journals EFFECTIVENESS OF A MICROWAVE FLUIDISED BED DRYER IN ERADICATION OF SEED-BORNE BOTRYTIS GREY MOLD OF LENTILS

2019 ◽  
Author(s):  
Saeedeh Taheri ◽  
Graham Ian Brodie ◽  
Dorin Gupta
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Process Parameters ◽  
Microwave Power ◽  
Microwave Processing ◽  
Moisture Loss ◽  
Microwave Cavity ◽  
Factorial Regression ◽  
Seed Moisture ◽  
Grey Mold

Lentil is one of the important pulse crops in the world with a high proportion of easily digestible protein. However, there are several pests and pathogens which cause losses during crop growth, harvesting and post-harvest storage. Microwave processing has shown great potential to eradicate pests and pathogens from grains; however, there is still concerns about its heat uniformity, which is of crucial importance in pest and pathogen control. Fluidization using forced hot air is one of the potential solutions for having uniform temperature during microwave processing. In this study, a single mode microwave cavity, with a 2.45 GHz microwave source, was modified to have a microwave fluidized bed and used to evaluate its potential to eliminate the Botrytis grey mold (BGM) pathogen, which is one of the important seed-borne pathogens of lentil crops in Australia. Air speed was maintained to be constant during the experiment and was just enough to fluidize 100g of red lentils in the sample holder. Two wet based (w.b.) seed moisture contents (m.c.) of 10.5% and 18.5% were prepared and the process parameters were selected as: air temperature at 50 and 60°C; microwave power at 0, 300, 400 W for 18.5% m.c. and 0, 400, 500 W for 10.5% m.c.; and exposure times of 5 and 10 min. These parameters were chosen to reach the final temperature of below 70°C. The effect of process parameters on seed moisture loss, seed germination, electrical conductivity of seed soaking water and percentage of infected seeds (IS%) were analyzed using general factorial regression and analysis of variance. The results showed that the most effective factors on moisture loss, after seed moisture content, was exposure time, followed by microwave power and air temperature. While final bed temperature was affected mostly by air temperature, and then by microwave power. Furthermore, based on general full factorial regression and pareto chart of standardized effects, moisture content had by far the most influence on the reduction of IS%. Seed pathogen inoculum reduction, without significant seed viability loss, was obtained by applying microwave power of 300W and set air temperature of 60°C (actual inlet air temperature of 57±1°C) on seeds with m.c. of 18.5% for 10 min. This gave a 27% reduction in IS% (from 82% to 55%).

scholarly journals Heat Transport and Water Permeability during Cracking of the Landfill Compacted Clay Cover

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Haijun Lu ◽  
Jianjun Liu ◽  
Yuan Li ◽  
Yiqie Dong
Keyword(s):  
Hydraulic Conductivity ◽  
Intensity Factor ◽  
Moisture Content ◽  
Heat Transport ◽  
Moisture Transport ◽  
Crack Depth ◽  
Moisture Loss ◽  
Compacted Clay ◽  
Soil Columns ◽  
Clay Cover

The heat-moisture transport through the compacted clay was observed in laboratory. The hydraulic conductivity of cracked clay under wetting-drying cycles was also investigated. At the early phase of heating, the temperature of soil columns rose fast and moisture decreased dramatically; after this phase, the temperature rose at a lower speed and moisture loss stabilized gradually. The moisture content of compacted clay at 25 cm depth decayed to 0. The crack intensity factor (CIF) of compacted clay was 0.043 and 0.097; the crack depth was about 6.5 cm and 8.2 cm at 50°C and 60°C, respectively. The hydraulic conductivity of compacted clay was within 8.3 × 10−7to 1.5 × 10−5 cm/s after four wetting-drying cycles. This value was 2~3 orders of magnitude higher than that of uncracked clay.

scholarly journals 310 Effect of Scionwood Moisture and Cut-end Waxing on Pecan Bark Graft Success

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 445D-445
Author(s):  
Monte L. Nesbitt ◽  
Larry Stein ◽  
William D. Goff
Keyword(s):  
Moisture Content ◽  
Success Rate ◽  
Packing Material ◽  
Controlled Experiment ◽  
Moisture Loss ◽  
Spring Season ◽  
Treatment Regimes ◽  
Polyethylene Bags ◽  
Graft Success ◽  
And Storage

Pecan is a difficult species to propagate by grafting. The whip graft, bark graft, and four-flap graft, the most often-used techniques for pecan grafting, require dormant scions, collected and stored for 60 to 120 days prior to spring-season grafting. Poor graft success is often blamed on handling and storage environment of the scionwood. Moisture content of packing material, waxing of cut ends, and use of polyethylene bags was evaluated in a controlled experiment in 1998 and 1999. Scions were cut in early February each year, and stored for 60 to 70 days in a household refrigerator under different treatment regimes. Scion viability was tested by bark grafting mature pecan trees in Fairhope, Ala., and Uvalde, Texas. In 1998, graft success rate was equally good among scions stored in polyethylene bags with different amounts of added moisture, whether cut ends were waxed or not. Moisture loss of the scions during storage was affected each year by the amount of water added to packing material and by waxing the cut-ends, but the differences did not impact graft success. An interaction of not waxing the cut ends and very wet packing material reduced graft success at Fairhope, Ala., but not Uvalde, Texas, in 1999.

scholarly journals Drying Kinetics of Indigenous Fermented Foods of the Himalaya region (Gundruk, Sinki, and Maseura)

2021 ◽  
Vol 4 (2) ◽  
pp. 01-12
Author(s):  
Arjun Ghimire
Keyword(s):  
Activation Energy ◽  
Mathematical Models ◽  
Air Temperature ◽  
Effective Diffusivity ◽  
Moisture Loss ◽  
Fermented Foods ◽  
Drying Process ◽  
Statistical Parameters ◽  
Kinetics Of ◽  
The Himalaya

Indigenous fermented foods Gundruk (fermented mustard leaves), Sinki (fermented radish taproot), and Maseura (fermented lentils) are mostly sun dried, and thus often deteriorate during the uncontrolled drying process. Herein, cabinet drying was done at 50, 55, and 60°C after fermentation, and the moisture loss was systematically recorded. The data were converted to moisture ratio and fitted to five semi-theoretical drying mathematical models: Modified Henderson and Pabis, Logarithmic, Two-Term, Midilli et al., and Approximate diffusion. All the models were validated using statistical parameters, namely: R2, RMSE, χ2, and SSE. The Midilli et al. model gave excellent fit for all three products, with R2 greater than 0.97. The effective diffusivity values increased with an increase in air temperature for all the samples. The activation energy values were found to be 56.25, 21.63 and 15.08 kJ/ mol while the diffusivity constants were found to be 1268.51, 0.028, and 8.655× 10-3 m2/s for Gundruk, Sinki, and Maseura, respectively.

scholarly journals Artificial drying of safflower seeds at different air temperatures: effect on the physiological potential of freshly harvested and stored seeds

2019 ◽  
Vol 41 (4) ◽  
pp. 397-406 ◽  
Author(s):  
Guilherme Cardoso Oba ◽  
André Luís Duarte Goneli ◽  
Tathiana Elisa Masetto ◽  
Cesar Pedro Hartmann Filho ◽  
Karina Laís Leite Sarath Michels ◽  
...  
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Air Temperature ◽  
Safflower Seed ◽  
Water Removal ◽  
Drying Process ◽  
Moisture Contents ◽  
Air Temperatures ◽  
Physiological Quality ◽  
And Storage

Abstract: The air temperature used in the drying process can determine the initial physiological quality and storage potential of a seed lot, which is the object of this study. Safflower seeds, harvested at a moisture content of 25.8%, were subjected to drying in an experimental dryer at air temperatures of 40, 50, 60 and 70 °C until reaching a moisture content of 6.6 ± 0.6%. Immediately upon drying and every 60 days after that, up to 240 days of storage under uncontrolled conditions, seed samples were collected to determine physiological quality. Increasing drying air temperature resulted in higher water removal rates, promoting immediate and latent damage to seed physiological quality, evidenced by the reduction in the percentage and speed of root protrusion, first count, and germination, mainly at temperatures of 60 and 70 °C. For the maintenance of safflower seed germination and vigor up to 240 days of storage, it is recommended that drying air temperature does not exceed 40 °C, especially when seeds present moisture contents close to or higher than 25.8% at the drying moment.

Barley seed storage under controlled conditions

2019 ◽  
pp. 140-150 ◽  
Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov
Keyword(s):  
Hordeum Vulgare ◽  
Moisture Content ◽  
Spring Barley ◽  
Seed Storage ◽  
Growing Season ◽  
Storage Conditions ◽  
Meteorological Conditions ◽  
Hordeum Vulgare L ◽  
The Relationship ◽  
And Storage

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.

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