Increase In Moisture Level Research Articles

Microwave Heating-Dependent Properties of Tilapia (Oreochromis niloticus) and Catfish (Clarias gariepirus)

Some microwave heating-dependent properties of Tilapia and Catfish, as a function of moisture content and frequency, were studied, using the capacitance technique. Results show that electrical resistance, dielectric constant (e1) and dielectric loss factor (e11) were all influenced by moisture and frequency changes. For Tilapia, dielectric constant and dielectric loss factors increased from 2.19 to 10.97 and 0.10 to 23.42 for respective moisture levels of 6.2% to 16.5% db. Similarly, for catfish, dielectric constant and loss factors changed from 1.35 to 54.15 and 75.28 to 168.38 for corresponding increase in moisture levels of 6.2% to 16.5% db.

Desorption isotherms for fresh beef: An experimental and modeling approach

Desorption isotherms for fresh beef were determined at 30, 40 and 50°C by the static gravimetric method. The resulting isotherms exhibited a type II sigmoid shape. The BET, GAB and Halsey models were used to fit these experimental data. The GAB model was most accurate for all temperatures and all levels of water activity, followed by the BET and Halsey models. The temperature dependence of GAB constants was estimated. The isosteric heat of desorption and its evolution in relation to moisture content were calculated using Clausius–Clapeyron equations. The monolayer moisture content was determined using the GAB model: it decreased as the temperature increased. The density of bound water, the number of adsorption sites, the sorption surface area and the percentage of bound water were calculated using the Caurie equation: all these quantities decreased as the temperature increased. The Kelvin and Halsey equations were used for calculation of pore size, which increases with an increase in moisture levels and sorption temperature.

Improved Storage Stability of Pearl Millet Flour Through Microwave Treatment

Due to the high fat content and lipase activity, the pearl millet (Pennisetum typhoides) flour had limited shelf-life at ambient conditions. The present study was aimed to inactivate lipase in pearl millet grains through microwave treatment. Microwave heating of pearl millet grains decreased lipase activity significantly (p < 0.05) with an increase in moisture level from 12 to 18 % and maximum reduction (92.9 %) was observed at 18 % moisture level for 100 s. Based on lipase inactivation and pasting properties, 80-s duration of microwave exposure at 18 % grain moisture was considered optimum. Significantly (p < 0.05) lower change in free fatty acid (FFA, % oleic acid) value (20.80–22.25) during storage up to 30 days was observed in flour of grains treated for 80 s at 18 % moisture level as compared to control flour (20.11–32.43). Subjective evaluation of overall acceptability of flour samples showed that microwave-treated flour (18 % moisture level, 80 s) was acceptable up to 30 days of storage at ambient conditions, while control flour had unpleasant off odor and bitter taste at the 10th day of storage.

Physical properties of coriander seeds at different moisture content

Abstract Physical properties of coriander seeds were determined at moisture content of 3.5-17.7%, d.b. The major axis and 1 000 seeds mass were found to decrease nonlinearly with increase in seed moisture. The medium and minor axes, geometric mean diameter, sphericity, unit volume, surface area and angle of repose increased linearly. Bulk density decreased linearly, however the true density increased non-linearly. The coefficient of static friction increased nonlinearly for different surfaces with increase in moisture level and its maximum was found for plywood surface. The rupture force and energy absorbed decreased linearly with increasing moisture content.

Physical properties of pellets made from sorghum stalk, corn stover, wheat straw, and big bluestem

Densification of biomass feedstocks, such as pelleting, can increase bulk density, improve storability, reduce transportation costs, and make these materials easier to handle using existing handling and storage equipment for grains. The objectives of this research were to study (1) the physical properties of pellets made from corn stover, sorghum stalk, wheat straw, and big bluestem, (2) the effect of moisture content on bulk density, true density, and durability of the biomass pellets, and (3) the effect of hammer mill screen size and die thickness on bulk density, true density, and durability of the pellets. Biomass pelleting can significantly improve the bulk density from 47 to 60kg/m3 for biomass grinds to 360 to 500kg/m3 for biomass pellets. Of the four types of biomass pellets, wheat straw pellets had the highest bulk density value of 495.8kg/m3, and sorghum stalk pellets had the lowest bulk density value of 365.2kg/m3. An increase in moisture level resulted in a decrease in bulk density and true density of the pellets. The effect of moisture content on durability of the pellets made from corn stover, wheat straw, and big bluestem showed a similar trend; the maximum durability value was 96.8% at the equilibrium moisture content (EMC) range of 9% (d.b.) to 14% (d.b.) for corn stover and wheat straw, and 9% (d.b.) to 11% (d.b.) for big bluestem. A further increase in EMC value resulted in a decrease in pellet durability. For sorghum stalk pellets, the durability value increased initially with increased EMC and reached a maximum of 89.5% at EMC values between 14% (d.b.) and 16% (d.b.). Use of a larger hammer mill screen size (from 3.2mm to 6.5mm screen openings) resulted in increases of bulk density, true density, and durability of biomass pellets, but not in significant levels. Use of a thicker die size (from 31.8mm to 44.5mm in thickness) resulted in significant increase of bulk density, true density, and durability of biomass pellets.

Relationship of physicochemical properties of rhizosphere soils with native population of mineral phosphate solubilizing fungi

Phosphate solubilizing fungi (PSF) were enumerated in 78 rhizosphere soil samples collected from various sites of Bhavnagar district with agro climatic zone of hot, semi-arid region of Gujarat. 81% of samples were inhabited with indigenous PSF; the count varied ranging from 0.01 to 90 × 10(3) PSF g(-1). PSF population in the rhizosphere soils were maximal at pH 7.4-8.4, electrical conductivity (EC) 1.2 dS m(-1) wherein PSF population decreased with a rise in EC. Optimal moisture content ranged ≤10-30% where the abundance of PSF always decreased with increase in moisture levels while suitable organic matter content ranged from ≤0.5-4.5%. Available P range 100-300 mg kg(-1) was the most suitable for occurrence of PSF as being noticed from number of soil samples harboring them in rhizosphere soils. Amongst the various rhizosphere soil properties studied, a highly signifi cant positive correlation was established between PSF and soil available P as well as pH. A signifi cant positive association observed between total fungal population and organic matter as well as soil available P. Both abundance and number of PSF were more pronounced in descending order in plant covers: oilseeds, flowers, orchards, vegetables, pulses and cereals.

Effect of microwave heating of wheat grains on the browning of dough and quality of chapattis

SummaryStudies were conducted to evaluate the effect of microwave (900 W, 2450 MHz) heating of wheat grains conditioned to different moisture levels on the activity of polyphenol oxidase (PPO) and subsequent colour changes during storage of wheat dough. The results showed that microwave heating of wheat grains for 80 s decreased the PPO activity significantly (P ≤ 0.05) with an increase in moisture level from 12 to 18%. Whole wheat flour milled from microwave treated wheat grains (80 s, 18% MC) had 93.39% less activity of PPO. The dough balls (40 g), pressed and rolled into circular form (150.00 mm diameter and 2.00 mm thickness) and stored at 5–6 °C for 72 h. The colour of flattened circular dough was measured using Hunter Colour Meter and it was found that L‐value (lightness) decreased from 64.21 to 60.23 in treated and from 64.79 to 47.93 in control samples after 72 h of storage. The results showed that the microwave heating effectively controlled the enzymatic browning in dough and improved the consumer acceptability of chapattis prepared from the same during refrigerated (5–6 °C) storage for 72 h.

Fluxes of CO2and CH4in soil profiles of a mountainous watershed of Nepal as influenced by land use, temperature, moisture and substrate addition

Effects of land use, moisture, temperature and substrate on production of CO2 and consumption of CH4 were measured in a series of laboratory incubation experiments on bulk soil samples from 0–10, 10–20, 20–40, 40–60, 60–80 and 80–100 cm soil depths under four dominant land uses [forest, grazing land, irrigated rice on level terraces (Khet), and upland maize–millet on sloping terraces (Bari)] of Mardi watershed (area=144 km2), Nepal. In addition, baseline physical and chemical properties of these soils were measured. The production of CO2-C day−1 per unit soil organic carbon (SOC) content in topsoil was lowest in grazing land, indicating a possibility of higher C sequestration with this land use than with other land uses. There was a decreasing trend of CO2 emission with soil depth in all land uses, as was also the case with the SOC content. The CO2 emission was increased by 90, 58, 27 and 23% for Bari, Khet, grazing and forest soil, respectively, with increase in moisture level from 40 to 60% (w/w). The CO2 release from forest soil went up from 15 to 50 μg CO2 g−1 dry soil with increase in temperature from 5 to 15 °C and it further increased to 67 μg CO2 g−1 at 20 °C with estimated Q10 values of 3.4 and 1.8, respectively. Significantly higher amounts of CO2 were emitted from all the land use types upon addition of glucose to the soil, indicating high potential of microbial activity. Consumption of CH4 was more rapid in the soil from 10 to 20 cm depth for all the land use types. There was a 89% increase in CH4 consumption in forest soil with increase in moisture level from 40 to 60%, while it was decreased by 38, 73, and 40% for Khet, Bari and grazing soil, respectively. Addition of (NH4)2SO4 inhibited CH4 oxidation in soils of all land uses, indicating a negative effect of N fertiliser input on CH4 uptake in soil.

Processing and nutritive evaluation of broiler litter as livestock feed

Broiler litter was deep stacked at 30 and 40% moisture or ensiled at 40% moisture for 6 weeks in quadruplicate and subsequently evaluated for changes in chemical composition, pathogenic microbial load and in vitro dry matter degradability (IVDMD). A metabolism trial was conducted with lambs, in which a low-protein basal diet supplemented with litter, deep stacked at 30% and 40% moisture for 6 weeks or ensiled were compared with an isocaloric, isonitrogenous soybean meal supplemented diet. The maximum stack temperature of 65°C (irrespective of moisture level) was attained on day 7 at 45 cm depth and 60.5°C on day 10 at 80 cm depth, which eliminated coliforms. Increases in lactic and acetic acids were recorded with increase in moisture levels and advancement of stacking period. A small increase in crude protein (CP) content was associated with considerable declines in organic matter (OM), cellulose, neutral detergent fiber (NDF) and hemicellulose in deep-stacked litters. The apparent digestibility of nutrients and N-retention in the litter-supplemented diets were similar to those of the soybean meal supplemented diet. It is concluded that by deep stacking at 30 or 40% moisture, or ensiling, the litter was rendered free of pathogens and could be incorporated in the diet of livestock without adversely affecting digestibility of fiber and efficiency of N utilization.

Humidity conditions and the development of bacterial communities in soils of contrasting texture

The influence of different moisture conditions on the development of whole bacterial communities, as determined by the size of their biomass, was investigated in loamy sand and loose sandy soil. During the 4 months of the trial the soils were: (A) continuously stored at field-moist state (control); (B) constantly kept at about 59% of the maximum water holding capacity (WHO, corresponding to 100% of the capillary water capacity (CWC); (C) repeatedly air-dried and remoistened to 50% of the WHC at 2 week intervals ; (D) continuously stored at air-dry state. In untreated control loamy sand the mean bacterial biomass was found to be 0.19 mg dry mass g −1 dry soil, one third larger than the biomass found in loose sandy soil. This resulted both from the greater numbers as well as the larger mean size of the bacterial cells inhabiting the heavier soil. At persistent moistening of the samples to 100% of the CWC a doubling of the bacterial biomass was noted in both soils. The moisture level corresponding to the natural field-moist state thus limited the development potential of bacterial communities. After four drying-remoistening cycles the mean bacterial biomass was for air dry samples smaller than in the control: by one fourth and one third in the heavier and lighter soil, respectively. For remoistened samples the mean values were found to be higher than the control - by 16% in the heavier and by 18% in the lighter soil. The recurring increase in moisture level following a period of severe water deficit thus favoured bacterial biomass development, and that to a larger extent in the lighter soil than in the heavier one. In continuously air-dry samples the bacterial biomass in the soil decreased by one third and in the lighter soil by as much as four fifths in relation to the control. The diminishing of biomass size resulted primarily from the decrease in the mean size of bacterial cells. The reaction of bacterial communities to changes in moisture conditions was clearly dependent on soil type.