scholarly journals Moisture Sorption Isotherms of Yogurt Powder Containing Candied Chestnut Puree

2016 ◽  
Vol 4 (8) ◽  
pp. 676 ◽  
Author(s):  
Aslı Zungur Bastıoğlu ◽  
Safiye Nur Dirim ◽  
Figen Kaymak Ertekin
Keyword(s):  
Freeze Drying ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Sorption Data ◽  
Freeze Dried ◽  
Adsorption Data ◽  
Moisture Sorption Isotherms ◽  
Powder Samples ◽  
Gab Model

Yogurt powder was produced by freeze drying and with added candied chestnut puree at ratios of 5, 10, and 20 % by weight. Moisture sorption isotherms of yogurt powder samples, plain (YP), and containing 5, 10, 20% candied chestnut puree (CCP) were determined at 25°C using the standard, static-gravimetric method. The experimental adsorption data of yogurt powders at 25°C were fitted to 14 sorption equations which are most widely used to fit experimental sorption data of various food materials. The parameters of the sorption models were estimated from the experimental results by using the nonlinear regression analysis. The GAB model gave the closet fit to the sorption data of freeze dried yogurt powders with candied chestnut puree at 25°C. BET, Ferro Fanton, Henderson, Halsey, Oswin and Modified Oswin models are also acceptable for describing the adsorption isotherms for freeze dried yogurt with candied chestnut puree at 25°C.

scholarly journals Experimental Determination of Moisture Sorption Isotherm of Fecal Sludge

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 303 ◽  
Author(s):  
Catherine Bourgault ◽  
Paul Lessard ◽  
Claire Remington ◽  
Caetano C. Dorea
Keyword(s):  
Relative Humidity ◽  
Water Distribution ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Critical Data ◽  
Moisture Sorption Isotherm ◽  
Fecal Sludge ◽  
Moisture Sorption Isotherms ◽  
Gab Model

Dewatering and drying of fecal sludge (FS) is a key treatment objective in fecal sludge management as it reduces volume (thereby reducing emptying frequency and associated transportation costs), inactivates pathogens, and is beneficial and/or necessary to resource recovery activities such as composting and combustion as fuel. However, studies on dewatering performances of FS are limited. The physical water distribution of such matrices is not fully understood, limiting the progress in the development and optimization of FS dewatering technologies. The objective of this study is to present a gravimetric method intended to assess the dewatering characteristics and associated modelling of FS through moisture sorption isotherms. Samples were placed in airtight jars containing different saturated salt (NaOH, CaCl2, NaCl, KCl, K2SO4) solutions to reproduce a range of relative humidity values (6 to 97%). Results confirmed the achievement of characteristic sigma-shaped moisture sorption isotherms with increasing moisture adsorption at higher values of relative humidity. Furthermore, experimental data best fit the three-parameter Guggenheim–Anderson–de Boer (GAB) model. This method can be replicated to contribute critical data about the characterization of fecal sludge, a seriously under-researched matrix.

Determination of Moisture Sorption Isotherms of Jasmine Rice Crackers Using BET and GAB Models

2006 ◽  
Vol 12 (6) ◽  
pp. 459-465 ◽  
Author(s):  
U. Siripatrawan ◽  
P. Jantawat
Keyword(s):  
Moisture Content ◽  
Water Activity ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Sorption Data ◽  
Heat Of Sorption ◽  
Moisture Sorption Isotherms ◽  
Jasmine Rice ◽  
Gab Model ◽  
Best Fit

Moisture sorption isotherms of Thai Jasmine rice crackers were determined at 30, 45 and 60°C over a water activity range of 0.10 to 0.95 using a static gravimetric technique. Moisture sorption isotherms of rice crackers exhibited the sigmoid (Type II) shape. The moisture content of rice crackers decreased as temperature increased at a given water activity of the storage environment. The Brunauer, Emmett and Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models were applied to fit the experimental data. The isosteric heat of sorption at different moisture levels was also determined using the Clausius–Clapeyron thermodynamic equation. A nonlinear regression analysis method was determined to evaluate the parameters of sorption equations. The criteria used to evaluate the goodness of fit of each model were the mean relative percentage deviation modulus (E) and the percentage root mean square error (RMSE). The more extended range of application of the GAB equation over the BET equation was evident. The GAB model gave the best fit to the experimental sorption data for a wide range of water activity (0.10–0.95) while the BET model gave the best fit for a water activity range of less than 0.60. The GAB model is considered suitable to predict the moisture sorption isotherm of rice crackers since it gave low E and RMSE values. The heat of sorption values of rice crackers were found to be large at low moisture content and decreased with an increase in food moisture content.

Moisture Sorption Isotherms and Isosteric Heats of Sorption of High-Pressure Treated Paulownia Wood under Different Storage Conditions

2019 ◽  
Vol 62 (1) ◽  
pp. 105-114
Author(s):  
Xiuping Jiang ◽  
Xiuping Jiang ◽  
Huanhuan Li ◽  
Hosahalli S. Ramaswamy ◽  
Songming Zhu ◽  
...  
Keyword(s):  
High Pressure ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Storage Conditions ◽  
Sorption Behavior ◽  
Adsorption And Desorption ◽  
Moisture Sorption Isotherm ◽  
Moisture Sorption Isotherms ◽  
Paulownia Wood

Abstract. Understanding of moisture sorption isotherms (MSI) is critical for predicting the stability of wood during handling, transport, and storage. The aim of this study was to evaluate the adsorption and desorption isotherm characteristics of high-pressure (HP) treated paulownia wood and to identify the best-fitting model to describe its sorption behavior. The equilibrium moisture contents (EMCs) of HP-treated paulownia wood were obtained using a static gravimetric method under different storage conditions: three temperatures (20°C, 30°C, and 40°C) and five water activity (aw) levels (0.32 to 0.95). Results showed that HP parameters did not significantly affect the MSI trend of treated groups. Eight modified models (modified Chung-Pfost, modified Henderson, modified Oswin, modified Halsey, Chen-Clayton, Guggenheim-Anderson-de Boer (GAB), simply modified GAB, and Peleg) were fitted to the experimental data. The Chen-Clayton model (temperature-dependent) produced randomized residuals and the best prediction performance for both adsorption and desorption among all models. Net isosteric heat of adsorption and desorption decreased from 7.55 to 4.84 kJ mol-1 and from 18.1 to 12.2 kJ mol-1, respectively, with an increase in EMC from 7.5% to 10%. The isosteric temperature (Tß) was 352 K for adsorption and 335 K for desorption, between which all the adsorption and desorption reactions proceeded at the same rate. All thermodynamic functions were adequately characterized by a power law model. Keywords: Equilibrium moisture content, High-pressure treatment, Modeling, Moisture sorption isotherm, Paulownia wood, Temperature, Thermodynamic analysis.

Equilibrium Moisture Content Models for Lafun

2008 ◽  
Vol 4 (2) ◽  
Author(s):  
Olusegun J Oyelade
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Adsorption Isotherms ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Keeping Quality ◽  
Moisture Sorption Isotherms ◽  
Process Operation ◽  
The Relationship

Insights into the relationship between the air relative humidity (water activity (aw)) and equilibrium moisture content of food materials is essential to maintain good keeping quality and optimize process operation. The adsorption isotherms for cassava flour (lafun) were investigated with the static gravimetric method. Concentrated acid (H2SO4) solutions were used to vary the micro-climate in the study and presented in an easy-to-use template-like format over the range of temperature (27- 40oC) and aw (0.10-0.80) usually experienced in the tropical environment. The experimental data were compared with five widely recommended models in the literature for food sorption isotherms (GAB, modified GAB, modified Oswin, modified Henderson & modified Chung-Pfost). The moisture sorption isotherms were sigmoidal in shape and were influenced by temperature. The modified Oswin model was found to be most adequate whilst the modified GAB appears not suitable to model the adsorption isotherms for lafun.

scholarly journals Study on the Effects of Physical Properties of Tenera Palm Kernel during Drying and Its Moisture Sorption Isotherms

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1658
Author(s):  
Mina Habibiasr ◽  
Mohd Noriznan Mokhtar ◽  
Mohd Nordin Ibrahim ◽  
Khairul Faezah Md Yunos ◽  
Nuzul Amri Ibrahim
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Surface Area ◽  
Palm Kernel ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Kernel Length ◽  
Moisture Sorption Isotherms ◽  
Ground Kernel

A study on the effect of the physical properties and moisture sorption isotherm of palm kernels constitutes the critical criteria in evaluating the drying performance. The drying was evaluated as a function of moisture content (MC) in the range of 0.31–0.02 kg/kg (d.b.). Whereas, the equilibrium moisture content (EMC) of palm kernels (whole kernel and ground kernel) was determined experimentally using the standard gravimetric method at different temperatures (50 °C to 80 °C), over a range of relative humidity (RH) from 10% to 81%. Palm kernel length, width, and thickness decrease from 16.08 ± 2.09 mm to 14.17 ± 2.30 mm, 12.06 ± 1.40 mm to 11.24 ± 1.08 mm, and 10.01 ± 1.27 mm to 9.18 ± 1.04 mm, respectively, when MC decreased. Bulk density, surface area, and specific surface area decreased as the MC decreased, while porosity and true density were increased. EMC of palm kernels (whole kernel and ground kernel) decreased with an increase in temperature at constant RH. Modified Oswin and modified Halsey models were found to be the best for predicting desorption moisture isotherms for whole and ground palm kernel, respectively. Therefore, the study of the effect of drying on physical aspects as well as moisture sorption isotherms is important to further analyze the drying performance of Tenera palm kernel (e.g., equipment design and energy requirement).

scholarly journals New approach to the calculation of pistachio powder hysteresis

2016 ◽  
Vol 30 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Hamid Tavakolipour ◽  
Mohsen Mokhtarian
Keyword(s):  
Goodness Of Fit ◽  
Capillary Condensation ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Suitable Model ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures ◽  
Definite Integration ◽  
Increasing Temperature

Abstract Moisture sorption isotherms for pistachio powder were determined by gravimetric method at temperatures of 15, 25, 35 and 40°C. A selected mathematical models were tested to determine the best suitable model to predict isotherm curve. The results show that Caurie model had the most satisfactory goodness of fit. Also, another purpose of this research was to introduce a new methodology to determine the amount of hysteresis at different temperatures by using best predictive model of isotherm curve based on definite integration method. The results demonstrated that maximum hysteresis is related to the multi-layer water (in the range of water activity 0.2-0.6) which corresponds to the capillary condensation region and this phenomenon decreases with increasing temperature.

Thermodynamic Analysis of Water Vapour Sorption of Edible Starch Based Films

2003 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
M. A. Bertuzzi ◽  
M. Armada ◽  
J. C. Gottifredi
Keyword(s):  
Water Sorption ◽  
Corn Starch ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Sorption Process ◽  
Water Vapour Sorption ◽  
Bet Model ◽  
Moisture Sorption Isotherms ◽  
High Amylose

Moisture sorption isotherms of high amylose corn starch (HACS) films at 5, 25, 35 and 45 °C within an approximate water activity ( aw) range of 0.11-0.85 were obtained using a static gravimetric method. HACS films fitted a type III BET model at all temperatures studied. Water sorption process in high amylose based films was exothermic within the range of water activities investigated. There was a continuous decrease of the affinity between film sorbed structure with moisture as water content increased. Negative values of Δ G in the whole range of moisture content studied were indicative of a spontaneous process. The entropy curve exhibited a well-defined minimum corresponding at the completion of the monolayer.

scholarly journals Moisture Sorption Isotherms And Thermodynamic Properties Of Urtica Dioica Leaves

2016 ◽  
Vol 12 (24) ◽  
pp. 376 ◽  
Author(s):  
Abdelkader Lamharrar ◽  
Ali Idlimam ◽  
Mohammed Kouhila ◽  
Lamya Lahnine ◽  
Hind Mouhanni
Keyword(s):  
Water Activity ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Storage Conditions ◽  
Urtica Dioica ◽  
Endemic Plant ◽  
Clapeyron Equation ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures

Urtica dioica is a Moroccon endemic plant of used for its virtues in traditional medicine. Thus, it is necessary to study the effect of preservation processes on the storage conditions of the plant. The static gravimetric method was used to determine sorption isotherms of Urtica dioica leaves at three temperatures (40, 50 and 60 °C) and in the range of water activity ( w a ) ranging from 0.0572 to 0.898. Six mathematical models were used to fit the experimental data. The Enderby and Peleg models were found to be the most suitable for describing the sorption curves. The optimal water activity for conservation of Urtica dioica leaves was determined. Isosteric heats of desorption and adsorption were calculated by applying the Clausius- Clapeyron equation to the sorption isotherms at different temperatures; it decreased with increasing moisture content. A linear relation exists between the enthalpy and entropy of the sorption reaction.

scholarly journals Comparison of moisture sorption isotherm models in freeze-dried pineapple pulp

1969 ◽  
Vol 77 (3-4) ◽  
pp. 113-128
Author(s):  
Humberto Vega-Mercado ◽  
Gustavo V. Barbosa-Cánovas
Keyword(s):  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isotherm Models ◽  
Crystalline Cellulose ◽  
Moisture Sorption Isotherm ◽  
Freeze Dried ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures ◽  
Pineapple Pulp

Moisture sorption isotherms of freeze-dried pineapple pulp were determined at 5, 25, 30, 35 and 55°C. Water activity were controlled by using preselected saturated salt solutions in evacuated glass desskators according to Wolf et al. (20), where micro crystalline cellulose is the reference material for the determination of sorption isotherms. The data were correlated in terms of some empirical models involving two single parameters: models of Henderson, Oswin, Chung-Pfost, Halsey, Iglesias-Chirife, and Smith. Also, the data was correlated by the Guggenheim-Anderson-deBoer (G.A.B.) model involving three adjustable parameters. It was found that the models proposed by Henderson and Iglesias-Chirife were the most useful ones in predicting water activities at different levels and at different temperatures.

scholarly journals Moisture Sorption Characteristics of Weaning Food

2020 ◽  
pp. 45-50
Author(s):  
Kabindra Bhattarai ◽  
Babita Adhikari ◽  
Prabina Ghimire
Keyword(s):  
Moisture Content ◽  
Sorption Isotherm ◽  
Dry Matter ◽  
Gravimetric Method ◽  
Moisture Sorption ◽  
Weaning Food ◽  
Sorption Data ◽  
Moisture Sorption Isotherm ◽  
Gab Model ◽  
Coefficient Of Regression

 Stickiness and caking are the significant problems for food powders due to moisture migration from the storage environment. This study was conducted to determine the moisture sorption isotherm of weaning food (Nutrilac and Superceral) and to fit the sorption data in different sorption isotherm models. Static gravimetric method was used to determine the equilibrium moisture content (EMC) at 22-89% RH at 30°C. The EMC data obtained were plotted to the models Brunauer Emmet Teller (BET), Guggenheim Anderson and De Boer (GAB). Results indicated that sorption isotherms were of type II isotherm according to Brunauer et al., (1940) classification. BET model was fitted to the sorption data with coefficient of regression 0.985 and 0.986 for Nutrilac and Supercereal respectively. The GAB model was fitted with coefficient of regression 0.983 and 0.979 for Nutrilac and Supercereal respectively. Monolayer moisture content determined from the BET and GAB model at 30°C were 1.63 and 2.24 g/100g dry matter for Nutrilac and 1.51 and 2.26 g/100g dry matter for Supercereal respectively.

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