An Investigation on Physical Ageing of ?-Lactoglobulin and Implications for Its Storage

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
Asgar Farahnaky ◽  
Mahsa Majzoobi
Keyword(s):  
Moisture Content ◽  
Functional Properties ◽  
Manufacturing Industry ◽  
Glassy State ◽  
Synthetic Polymers ◽  
Peak Temperature ◽  
Physical Ageing ◽  
Different Temperatures ◽  
Main Protein ◽  
Β Lactoglobulin

Due to the importance of physical ageing in functional properties of the globular protein of β-lactoglobulin as the main protein of whey powder (the by product of cheese manufacturing industry) the possible occurrence of physical ageing in dry powder of β-lactoglobulin with moisture content of 15.9% was studied at different temperatures below and close to the glass transition.Endothermic peaks that corresponded to relaxation enthalpy were observed for a β-lactoglobulin with 4 % moisture. Enthalpy and peak temperature increased on storage of β-lactoglobulin when it was held in the glassy state at different temperatures (20, 40, 60 º C). The general characteristics of the endothermic peaks were similar to those previously reported for synthetic polymers.

scholarly journals Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Drying Process ◽  
Drying Time ◽  
Oven Drying ◽  
Sun Drying ◽  
Different Temperatures ◽  
Final Water Content ◽  
Drying Curves ◽  
Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

scholarly journals Influence of Temperature and Moisture Content on Thermal Performance of Green Roof Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2421
Author(s):  
Bohan Shao ◽  
Caterina Valeo ◽  
Phalguni Mukhopadhyaya ◽  
Jianxun He
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Green Roof ◽  
Green Roofs ◽  
Power Functions ◽  
Thick Substrate ◽  
Different Temperatures ◽  
Test Cells ◽  
Substrate Moisture ◽  
Phase Transition Zone

The influence of moisture content on substrate thermal conductivity at different temperatures was investigated for four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 and −10 °C, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature. Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature’s amplitude for the green roof with 150 mm thick substrate. When a sedum mat was added, there was a 20% reduction in the amplitude of the inner temperature as compared with the cell without a sedum mat.

scholarly journals Investigations on the Effects of Seasonal Temperature Changes on the Electrical Resistance of Living Trees

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 550 ◽  
Author(s):  
Xiaoquan Yue ◽  
Lihai Wang ◽  
Xiaolong Shi ◽  
Mingxian Xu ◽  
Zhiming Zhu
Keyword(s):  
Moisture Content ◽  
Regression Model ◽  
Cross Sections ◽  
Electrical Resistance ◽  
Freezing Point ◽  
Seasonal Temperature ◽  
Populus Simonii ◽  
Standing Trees ◽  
Different Temperatures ◽  
The Cross

In order to use the electrical resistance method to accurately and timely detect and evaluate the internal decay defects of living trees, the effects of the seasonal temperature and moisture content on the electrical resistance of standing trees were investigated. At the Northeast Forestry University Experimental Forest Farm, Harbin, Heilongjiang Province of China, Populus simonii Populus simonii Carr. and Larix gmelinii (Rupr.) Rupr. were selected as the objects and the electrical resistance of standing trees was tested through different seasons from December 2016 to December 2017. Meanwhile, the effects of changes in the seasonal temperatures (−20 to −10 °C, −10 to −5 °C, −5 to 0 °C, 0 to 5 °C, 5 to 10 °C, 10 to 15 °C, 15 to 25 °C) as well as changes in the moisture content (MC) (Populus simonii, MC ≥ 103%; Larix gmelinii, MC ≥ 77.5%) on the electrical resistance in the cross-sections of living trees were studied. The influence of temperature at different moisture contents, the moisture content at different temperatures, and their combined effects on electrical resistance were analyzed, following which a regression model was also established. The obtained results indicated that ambient temperature had a significant effect on the average value of electrical resistance in the cross-section of living trees when temperatures were below the freezing point. There was a sudden discontinuity near the freezing point, and logR (logarithm value of electrical resistance) in the cross-sections of sound trees and decayed trees changed in a similar trend with variations in the temperature. While the effect of moisture content on logR in the cross-sections of threes was insignificant at different temperatures because of the moisture content above FSP (fiber saturation point). It indicated that the temperature and moisture content had interactive effects on logR in the cross-sections. The binary linear regression model between moisture content, temperature, and logR was highly fitted with a correlation coefficient (R2) higher than 0.8. The outcome of this investigation indicates that when non-destructive testing is performed on living trees using electrical resistance at different seasonal temperatures, the measured results need to consider both the temperature and moisture content. For practical work, it is not recommended to consider testing living trees near the freezing point temperature using the electrical resistive tomography. Below the freezing point, the electrical resistance changes with temperature greatly relative to the normal temperature. Therefore, when performing the detection of electrical resistance, it is necessary to calibrate the effects of temperature

scholarly journals Mechanical Properties of Grains Sorghum Subjected to Compression at Different Moisture Contents

2019 ◽  
Vol 11 (4) ◽  
pp. 279
Author(s):  
Gabrielly B. Rodrigues ◽  
Osvaldo Resende ◽  
Daniel E. C. de Oliveira ◽  
Lígia C. de M. Silva ◽  
Weder N. Ferreira Junior
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Uniaxial Compression ◽  
Deformation Modulus ◽  
Grain Sorghum ◽  
Parallel Plates ◽  
Compression Force ◽  
Moisture Contents ◽  
Rest Position ◽  
Different Temperatures

This study aimed to evaluate the influence of drying at different temperatures on the mechanical properties of grains of grain sorghum subjected to compression at the natural rest position. Grains dried at temperatures of 60, 80 and 100 °C with different moisture contents (0.515; 0.408; 0.315; 0.234; 0.162 and 0.099 (d.b.)) were subjected to uniaxial compression between two parallel plates, applied at their natural rest position, at a rate of 0.001 m s-1. The force required to rupture in grains of grain sorghum increased as their moisture contents decreased, with values of 47.17 to 78.44 N, 61.81 to 69.66 N and 52.07 to 70.89 N for the temperatures of 60, 80 and 100 °C, respectively. The compression force required to deform grain sorghum decreased with the increment in moisture content, and the proportional deformation modulus increases with moisture content reduction. Within the studied range of moisture content, the values were 87 × 10-7 to 354.99 × 10-7 Pa, 132.63 × 10-7 to 465.98 × 10-7 Pa and 80.18 × 10-7 to 429.85 × 10-7 Pa for the temperatures of 60, 80 and 100 °C, respectively.

scholarly journals HIGROSCOPICITY OF CHARCOAL PRODUCED IN DIFFERENT TEMPERATURES

CERNE ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 423-430 ◽  
Author(s):  
Ananias Francisco Dias Júnior ◽  
Lucas Pereira Pirola ◽  
Saly Takeshita ◽  
Artur Queiroz Lana ◽  
José Otávio Brito ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Adsorption Capacity ◽  
Carbonization Temperature ◽  
Salt Solutions ◽  
Final Temperature ◽  
Different Temperatures ◽  
Humidity Environment ◽  
Adsorbed Moisture

ABSTRACT This research aimed to evaluate hygroscopicity of charcoal produced under four different final carbonization temperatures. For evaluation of hygroscopicity charcoal samples were conditioned in environments with controlled temperature and relative humidity, using saturated salt solutions. The final carbonization temperature significantly influenced the products yields and the properties of charcoal. The charcoal produced in the final temperature of 750 °C showed the highest adsorption capacity of water, indicated by the moisture content after conditioning, in the higher relative humidity environment. Correlations were observed between adsorbed moisture and the porosity of charcoal produced.

scholarly journals Moisture sorption isotherms of castor beans. Part 1: Mathematical modeling and hysteresis

2016 ◽  
Vol 20 (8) ◽  
pp. 751-756 ◽  
Author(s):  
André L. D. Goneli ◽  
Paulo C. Corrêa ◽  
Gabriel H. H. de Oliveira ◽  
Osvaldo Resende ◽  
Munir Mauad
Keyword(s):  
Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Environmental Condition ◽  
Adsorption And Desorption ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures ◽  
The Difference ◽  
The Stability ◽  
And Storage

ABSTRACT Sorption isotherms are of great importance in post-harvest procedures, especially for predicting drying and storage, which help to establish the final moisture content of the product under certain environmental condition. Hysteresis is a phenomenon that occurs due to the difference between adsorption and desorption curves, which aids the evaluation of chemical and microbiological deteriorations, indicating the stability of stored products. Moisture sorption isotherms of castor beans were determined and hysteresis was analyzed. Static gravimetric technique at different temperatures (25, 35, 45 and 55 ± 1 °C) was used. Saturated salt solutions in the range of 37-87% ± 2% were utilized to create the required controlled relative humidity environment. Equilibrium moisture content data were correlated by different mathematical models and the Modified Halsey model presented good adjustment for the data, according to statistical procedures. Hysteresis between adsorption and desorption isotherms is present over the range of 0.2-0.9 of water activity, regardless of the temperature. This phenomenon decreases with temperature increase.

scholarly journals Functional properties of parsley fortified homemade Turkish noodles (Erişte)

2019 ◽  
Vol 11 (1) ◽  
pp. 88-96
Author(s):  
Safiye Nur Dirim ◽  
Gülşah Çalişkan Koç
Keyword(s):  
Chemical Composition ◽  
Vitamin C ◽  
Moisture Content ◽  
Physical Properties ◽  
Water Absorption ◽  
Functional Properties ◽  
Consumer Preferences ◽  
Total Chlorophyll ◽  
Total Carotenoid ◽  
Swelling Volume

Turkish noodle is a staple traditional dish in the Turkish cuisine and generally made out of wheat flour, egg, salt and vegetable oil. The aims of this study were to improve the formulation of Turkish noodles by the addition of minced parsley (2, 4, 6 and 8% weight), to improve their functional properties and swelling volume, to determine the effect on the physical properties (moisture content, water activity, and colour) and chemical composition (vitamin C, total chlorophyll, total carotenoid, and protein content) of the homemade plain and fortified Turkish noddle dough (FHTD) and the fortified homemade Turkish noodles (FHTN), to determine the traditional and microwave cooking characteristics and to indicate consumer preferences of FHTN with fresh parsley. The results showed that the amount of addition of fresh parsley caused a significant increase in the moisture content values of FHTD (31.59-36.08%) (P<0.05). The vitamin C, total chlorophyll and total carotenoid contents of the FHTD and FHTN were improved with the addition of fresh parsley. The traditionally cooked FHTN have got higher water absorption (30.25-38.90g) and swelling volume values (237.50-267.50%) than microwave cooked FHTN (WA=29.03–34.77g, SV=240.00-265.00%) (P<0.05). The noodles containing 2% parsley had the highest rating compared to both plain and other samples.

scholarly journals Study on Dimensional Stability of Veneer Rice Straw Particleboard

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 558 ◽  
Author(s):  
Xianqing Xiong ◽  
Yiting Niu ◽  
Yingying Yuan ◽  
Liangting Zhang
Keyword(s):  
Moisture Content ◽  
Rice Straw ◽  
National Economy ◽  
Dimensional Stability ◽  
Manufacturing Industry ◽  
Furniture Industry ◽  
Moisture Contents ◽  
Furniture Manufacturing ◽  
Cyclobalanopsis Glauca ◽  
Better Than

As an important industry of the national economy, the development of furniture manufacturing industry is very rapid. In particular, with the development of panel furniture industry, wood-based panels have become a necessary choice for furniture material for modern families in recent years. As a new particleboard material, in order to be more widely used in the furniture industry, it is not enough to have the characteristics of environmental protection. The material should also have excellent appearance and dimensional stability, so as to change people’s dependence on traditional wood-based panels. In this study, the rice straw particleboard (RSP) substrate was veneered by Betula sp. and Cyclobalanopsis glauca. In the process of veneering, different RSP specimens were treated by different sanding thicknesses and moisture contents of the RSP substrate, glue spread, species and thickness of veneer. The dimensional stability of different RSP specimens after veneering was analyzed. Based on the same variables, the change in the panel dimension and warp degree of the specimens of RSP which the sanding thickness was 0.2 mm were higher than the specimens with a sanding thickness of 0.6 mm. The dimensional stability of specimens of Cyclobalanopsis glauca veneer was better than that of Betula sp. veneer. A certain degree of change within the appropriate moisture content had a little effect on dimensional stability of veneered RSP. The greater of the amount of glue, the worse the dimensional stability of veneered RSP. The thinner the veneer, the worse was the dimensional stability of the veneered RSP.

Far-Infrared Drying Effects onto the Physical Characteristics of Aquilaria malaccensis Leaves

2019 ◽  
Vol 797 ◽  
pp. 196-201
Author(s):  
Habsah Alwi ◽  
Nurul Shazana Mohd Zain ◽  
Hanafiah Zainal Abidin ◽  
Jefri Jaafar ◽  
Ku Halim Ku Hamid
Keyword(s):  
Moisture Content ◽  
Manufacturing Industry ◽  
Food Product ◽  
Far Infrared ◽  
Color Difference ◽  
Drying Process ◽  
Infrared Drying ◽  
Aquilaria Malaccensis ◽  
Before And After ◽  
Very High

Drying also known as dehydration is commonly used as a unit operation in herbs manufacturing industry to preserve the food product by removing the moisture content in the herbs. Unfortunately, most drying process degraded the product quality because the feedstock is exposed to a very high temperature within a long period of time by using conventional oven Therefore this research has focused on the alternatives technique in overcoming the degradation of nutrients by applying the irradiation concepts. The objectives of this research were to investigate the effect of drying onto the physical properties of Aquilaria Malaccensis leaves by using fabricated far-infrared dryer. The experiments were conducted at various temperature ranging from 40, 50 and 60°C. The color difference and the moisture content of the leaves before and after drying were examined. The color measurements data shows that at 60°C, the brightness and the chroma were the highest. On the other hand, the hue angles were the highest for 60°C when the time was reached 100 minutes.

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