Showing 3 results for Texture.
A Farahanaki, Gh Mesbahi, H Askari,
Volume 12, Issue 46 (1-2009)
Abstract
Date fruit as a high calorie and valuable food source can be one of the main Iranian agricultural commodities for export, if properly processed and packed. The aim of this study was to process Kabkaab date variety from Routab (high moisture dates) to Tamar (known as dates or dry dates) using an industrial cabinet dryer. The Routab samples were dried using hot air at 56, 66, 76, 86 and 96 ˚C and changes in weight, moisture, pH, colour, texture and density of the dried samples were monitored. The results indicated that at 56 and 66 ˚C, drying rate was too low to be economic for an industrial process. At 86 and 96 ˚C the drying rate was high, although quality factors like colour was not acceptable. Therefore 76 ˚C is recommended as the best temperature for drying dates fruit. Moisture range of 24-27% (db) was the critical moisture level where a sharp decrease was observed in drying rate. Textural experiments of dates fruits with a wide range of moisture contents showed that above 30% moisture the hardness does not change with moisture level however, below 30% a small change in moisture can have a considerable impact on texture.
F Goodarzi,
Volume 12, Issue 46 (1-2009)
Abstract
To optimize the use of sulfur in drying of apricot, four following treatments including: sulfiting and drying, sulfiting- blanching and drying, blanching- sulfiting and drying, and finally sulfiting- drying to % 50 of initial moisture- blanching and finish drying were studied. The levels of sulfur addition were from 0 to 1500 ppm, SO2 and drying was carried out at 50 to 74 °C. The quality of dried apricots was judged by extent of browning development and hardness determination. A response surface statistical design was applied to evaluate the quality of slabs and to determine optimum drying conditions. The results showed that sulfite was the major factor in controlling dried apricot quality. At present of sulfur, the role of temperature can be neglected. The amount of used sulfite has no significant effect on drying time of apricots. Blanching reduced drying time of product significantly. By increasing the drying temperature, loss percentage of SO2 was reduced for all treatments. Blanching and then sulfiting, increased loss in residual sulfur of products significantly. Application of sulfiting– drying method, using 900 ppm of SO2 at 50 to 68 °C was found to be the best treatment because of production of slabs whit average hardness and color texture equal to 1.44 N/m2 and 0.07 Od respectively.
E. Nabizadeh, H. Beigi Harchegani,
Volume 15, Issue 57 (10-2011)
Abstract
Selecting an appropriate particle size distribution (PSD) model for a particular soil may be important for a precise estimation of soil hydraulic properties. Various models have been proposed for describing soil PSDs. The objective of this study was to compare the quality of fitting of eight PSD models (Fredlund, Gompertz, van Genuchten, Jaki, Logarithmic, Exponential, Logarithmic-Exponential and Fractal) in 71 soil samples collected from Lordegan and Saman in Charmahal-va-Bakhtiari province, Iran. Coefficient of determination ( ) and Akaike’s information criterion ( ) were used to compare the goodness-of-fit of the models to the experimental data. Results showed that Fredlund model is best for describing PSD of silt loam, silty clay loam, silty clay and sandy loam soil textures. While Fractal, Exponential and Logarithmic-Exponential models produced the poorest-fit in silt loam, silty clay loam and silty clay, they had the best performance in sandy loam texture. The performance of Fredlund and Gompertz models improved with an increase in clay and silt content from 25 and 40 percentage, respectively. The performance of Fractal, Exponential and Logarithmic-Exponential models improved by increasing the sand content. Reverse correlation was observed between silt content and the performance of the Fractal model.
