Shrinkage, Porosity and Bulk Density of Foodstuffs at Changing Moisture Contents

1983 ◽  
Vol 48 (5) ◽  
pp. 1497-1502 ◽  
Author(s):  
J. E. LOZANO ◽  
E. ROTSTEIN ◽  
M. J. URBICAIN
2015 ◽  
Vol 17 (2) ◽  
pp. 23-28 ◽  
Author(s):  
M. Azam Saeed ◽  
Syed Waqas Ahmad ◽  
Mohsin Kazmi ◽  
Muhammad Mohsin ◽  
Nadeem Feroze

Abstract The concept of different compositional biomass is introduced to enhance the binding properties and utilize the use of different seasonal biomasses. The effect of densification on the heating values of single pure and mixed compositional biomasses is observed with and without applying special type of pretreatment named as ‘Torrefaction’. The moisture contents and bulk densities were also calculated for these briquettes. The effects of average moisture contents and bulk density (which show the swelling nature) on the heating values are also observed. The experiments have been performed on the pelletizer equipment to form briquetted biomass and bomb calorimeter was used to determine the calorific values of different briquettes. Finally, the percentage decrease in the average moisture contents of different categories of torrefied briquettes from non-torrefied briquettes were also calculated and compared.


Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.


2021 ◽  
Vol 37 (3) ◽  
pp. 491-494
Author(s):  
Jonathan Chiputula ◽  
Emmanuel Ajayi ◽  
Ray Bucklin ◽  
Ann R Blount

HighlightsRye grain compaction was measured for three different moisture contents (8%, 12%, and 16% wet basis) at five different compaction pressures (7, 14, 34, and 55 kPa)Bulk densities were found to be statistically significantly dependent (p < 0.0001) on both the moisture content and applied pressure.Compacted bulk densities increased with increasing applied pressure for all moisture contents.Abstract. Bulk density of agricultural grains is needed to determine the quantity of grain in storage structures and to calculate grain pressures. The objective of this study was to investigate the effects of moisture content and applied pressure on bulk density of rye grain at moisture contents and pressures typical of those seen in storage structures. Rye compaction was measured for three moisture contents (8%, 12%, and 16% wet basis) at four compaction pressures (7, 14, 34, and 55 kPa) using a square box (based on the design used by Thompson and Ross, 1983). Data from the compaction tests were used to calculate the bulk densities for the three moisture contents and four compaction pressures. The bulk densities were found to be significantly dependent (p <0.0001) both on moisture contents and the pressure applied. Bulk densities varied with increasing moisture content as has been observed in similar studies for rye and other agricultural grains such as wheat and soybeans. These results provide guidance for estimating bulk density of rye in bins and other storage structures. Keywords: Grain compaction, Grain storage, Kernel rearrangement, Kernel elasticity.


2019 ◽  
Vol 50 (5) ◽  
pp. 853-869 ◽  
Author(s):  
Muhammed Adem ◽  
Sadik J.A. ◽  
Admasu Worku ◽  
Satheesh Neela

Purpose This paper aims to optimize feed moisture contents, barrel temperatures, blending ratios of maize and lupine for processing of protein-rich best quality extruded product using a twin-screw extruder. Design/methodology/approach A three-factor three-level response surface methodology by Box-Behnken Design was applied to evaluate the effect of selected processing conditions of blending ratios of lupine (10-20 per cent), barrel temperatures (120°C-150°C) and feed moisture content (14-18 per cent) on functional, nutritional and sensory characteristics of produced snack food. Findings The results of functional properties such as radial expansion ratio, bulk density, water absorption index, water solubility index observed as 0.71-1.2, 0.33-0.92 g/cc, 4.4-6.4 per cent and 10.2-15.1 per cent, respectively. The snack food showed the moisture 5.6-7.2 per cent, protein 8.1-18.1 per cent, fiber 1.6-2.7 per cent, ash 1.6-2.2 per cent and carbohydrate 64.8-81.4 per cent. The independent variables (lupine blending ratio, barrel temperature and feed moisture content) posed significant effects on expansion ration (p = 0.0030), bulk density (p = 0.0026), water absorption index (p = 0.0075) and water-solubility index (p = 0.0116). Higher blending ratio of lupine was increase in the bulk density and water solubility index, but decrease in expansion ratio and water absorption index of snack food. Higher feed moisture content was led to a reduction in expansion ratio and water-soluble index of snack food. Whereas, higher feed moisture contents was lead to rise in bulk density and water absorption index. Fiber (p = 0.0145), ash (p = 0.0343) and carbohydrate (p = 0.0001) contents were significantly depended on blending ratio. Blending of lupine 15.06 per cent, barrel temperature of 150 °C and feed moisture content of 14.0 per cent produced the snack food with desirability value of 72.8 per cent. Originality/value Protein malnutrition is one of the major problems in child development in under developed countries including Ethiopia. Maize is a top producer in the country but least appreciated for cost. Lupine is one of the undervalued produce consumed in Ethiopia after boiling. Still data on the utilization of maize and lupine in the extruded snack preparation was very limited. Optimization of moisture and barrel temperatures for this snack was not reported clearly yet.


1998 ◽  
Vol 75 (2) ◽  
pp. 254-258 ◽  
Author(s):  
J. Fan ◽  
T. J. Siebenmorgen ◽  
T. R. Gartman ◽  
D. R. Gardisser

2016 ◽  
Vol 25 (4) ◽  
pp. 456 ◽  
Author(s):  
Nuria Prat-Guitart ◽  
Guillermo Rein ◽  
Rory M. Hadden ◽  
Claire M. Belcher ◽  
Jon M. Yearsley

The consumption of large areas of peat during wildfires is due to self-sustained smouldering fronts that can remain active for weeks. We studied the effect of peat moisture content and bulk density on the horizontal propagation of smouldering fire in laboratory-scale experiments. We used milled peat with moisture contents between 25 and 250% (mass of water per mass of dry peat) and bulk densities between 50 and 150 kg m–3. An infrared camera monitored ignition, spread and extinction of each smouldering combustion front. Peats with a bulk density below 75 kg m–3 and a moisture content below 150% self-sustained smouldering propagation for more than 12 cm. Peat with a bulk density of 150 kg m–3 could self-sustain smouldering propagation up to a critical moisture content of 115%. A linear model estimated that increasing both moisture content and bulk density significantly reduced the median fire spread rate (which ranged between 1 and 5 cm h–1). Moisture content had a stronger effect size on the spread rate than bulk density. However, the effect of bulk density on spread rate depends upon the moisture content, with the largest effect of bulk density at low moisture contents.


Author(s):  
Wellytton D. Quequeto ◽  
Valdiney C. Siqueira ◽  
Vanderleia Schoeninger ◽  
Elton A. S. Martins ◽  
Eder P. Isquierdo ◽  
...  

ABSTRACT Buckwheat is a prominent crop in present-day agriculture due to its nutraceutical properties; however, information on this crop regarding the post-harvest process is scarce, as well as the characterization of its physical properties and such information is essential for the development and improvement of machinery used in post-harvest processes. Thus, the objective of this study was to determine the volumetric shrinkage, porosity, bulk density and true density of buckwheat grains throughout the drying process, as well as to fit mathematical models to the experimental values of true and bulk volumetric shrinkages. Buckwheat grains of the cultivar IPR 91 - Baili with an initial moisture content of 0.250 (decimal, dry basis.) were used. The samples used to determine the physical properties were subjected to oven drying with forced air circulation stabilized at 40 ± 1 °C. The mass of the samples was periodically weighed, so that when the product reached predetermined values of moisture content, the samples were removed and their physical properties were determined. It is concluded that the reduction in moisture content during drying causes increase in bulk density, true density and porosity. The reduction of the moisture content influences bulk volumetric shrinkage and true volumetric shrinkage of the grains, causing reductions in their values of approximately 14.47 and 14.70%, respectively, and a linear model can represent both variables satisfactorily.


Author(s):  
José C. de Andrade ◽  
André L. D. Goneli ◽  
Cesar P. Hartmann Filho ◽  
Thalita M. S. de Azambuja ◽  
Valdenise C. Barboza

ABSTRACT The objective of this study was to evaluate the quality of second-crop corn harvested with different moisture contents as a function of time before drying. The corn grains were harvested with moisture content of 28.5, 22.4, 21 and 19%, and submitted to a temporary storage for ten days, simulating the time between harvesting and drying. Quality was subsequently evaluated every two days, based on the commercial classification of the grains, sanity test and dry bulk density. The results showed that: the increase in moisture content at harvest affects the physical and sanitary quality of second-crop corn, and this effect is aggravated over time; the moisture content of 19% is the one that least affects grain quality during the ten days of temporary storage.


2014 ◽  
Vol 34 (5) ◽  
pp. 972-979 ◽  
Author(s):  
Douglas N. Gonçalves ◽  
Osvaldo Resende ◽  
Lílian M. Costa ◽  
Mariana C. Prado

The Knowledge of the physical properties of agricultural products has great importance for the construction and operation of equipment for drying and storage, to achieve increased efficiency in post-harvest operations. The aim was to determine and analyze the physical properties of crambe fruits during drying at different temperatures. Crambe fruits with an initial moisture content of 0.36 (decimal d.b.) which was reduced by drying at 37.0; 58.8 and 83.5 ºC and relative humidity of 29.4; 11.2 and 3.2%, respectively, to 0.09 ± 1 (decimal d.b.). At different levels of moisture contents (0.36; 0.31; 0.26; 0.21; 0.17; 0.13 and 0.09 decimal d.b.), was evaluated the intergranular porosity, the bulk density, the true density as well as the volumetric shrinkage and the fruit mass. The study was installed by the factorial 3 x 7, and three drying temperatures and seven moisture contents in a randomized design. Data were analyzed using regression. The bulk density and the true density decreases along the drying process; the volumetric shrinkage and the mass increased with lower moisture content and the intergranular porosity decreased sharply with the increasing drying temperature.


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