Note: Moisture Sorption Isotherms and Isosteric Heat of Red Bell Pepper (var. Lamuyo)

2007 ◽  
Vol 13 (4) ◽  
pp. 309-316 ◽  
Author(s):  
A. Vega-Gálvez ◽  
R. Lemus-Mondaca ◽  
P. Fito ◽  
A. Andrés
Keyword(s):  
Statistical Evaluation ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Sorption Data ◽  
Clapeyron Equation ◽  
Moisture Contents ◽  
Moisture Sorption Isotherms ◽  
Monolayer Moisture

Sorption isotherms of red pepper (var. Lamuyo) were determined at three temperatures (10, 20 and 30°C) in a range of water activity from 0.10 to 0.96. BET, GAB, Halsey, Herderson, Caurie, Smith, Oswin and Iglesias—Chirife equations were tested for modelling the sorption isotherms. The statistical evaluation of fit quality of the preceding models showed good results using the BET, GAB, Halsey and Iglesias—Chirife models on experimental sorption data. The BET and GAB models showed monolayer moisture contents from 0.07 to 0.10 g water/g (d.b.); however, they did not show direct dependence on temperature. The Clausius—Clapeyron equation satisfactorily determined the sorption isosteric heats, which were found to increase as the moisture content decreased; the desorption heat (74.2kJ/mol) was higher than that of adsorption heat (36.9kJ/mol). The preceding experimental data showed a good quality fit when evaluated with the Tsami equation.

Moisture Sorption Isotherms of Osmotically Dehydrated Sweet Pepper

2007 ◽  
Vol 3 (5) ◽  
Author(s):  
Jatindra Kumar Sahu ◽  
Ajita Tiwari
Keyword(s):  
Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Sweet Pepper ◽  
Coefficient Of Determination ◽  
Clapeyron Equation ◽  
Moisture Sorption Isotherm ◽  
Moisture Sorption Isotherms ◽  
Monolayer Moisture

Moisture sorption isotherms of osmotically dehydrated sweet peppers were determined at 15oC, 30oC and 40oC using static desiccator techniques. In the study, seven levels of water activity in range of 0.08 to 0.91 were used by the use of saturated salt solutions. The isotherms were found to be sigmoid type and of BET classification II. Out of seven sorption models i.e. BET, modified BET, Hasley, Caurie, GAB, Oswin and Smith, fitted to the experimental data, Oswin model was found to be the best for accurate prediction of moisture sorption isotherm with highest value of coefficient of determination (R2) and lowest values of standard error (SE) and relative deviation parentage (Rd). The value of monolayer moisture content of the osmotically dehydrated sweet pepper was found to be 3.037%, 3.934% and 4.432% (db) at 15oC, 30oC and 40oC respectively. The values of net isosteric heat of sorption as calculated by Clausius–Clapeyron equation showed a regular fall with increase in moisture content.

Moisture Sorption Characteristics of Dakuwa (Nigerian Cereal/Groundnut Snack)

2013 ◽  
Vol 9 (4) ◽  
pp. 499-504 ◽  
Author(s):  
Ocheme Boniface Ocheme ◽  
Chukwuma Charles Ariahu ◽  
Emmanuel Kongo Ingbian
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Goodness Of Fit ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Sorption Data ◽  
Moisture Contents ◽  
Monolayer Moisture ◽  
Increasing Temperature ◽  
Sorption Characteristics

AbstractThe moisture sorption characteristics of dakuwa at 10, 20, 30 and 400°C were studied. The experimental sorption data obtained were applied to BET, GAB, Oswin and Henderson equations to test fitness of the equations to moisture sorption of dakuwa. The sorption isotherms of dakuwa were type III isotherms (J shaped), and the equilibrium moisture content increased with increasing water activity but decreased with increasing temperature. The BET and GAB monolayer moisture contents all decreased with increasing temperature. For adsorption, the BET monolayer was higher (3.163–4.158 g/100 g solid) than that of GAB (2.931–3.728 g/100 g solid), but for desorption, the GAB monolayer (4.792–7.741 g/100 g solid) was higher than that of BET (3.962–4.480 g/100 g solid). Evaluation of goodness of fit of models revealed that moisture sorption of dakuwa was best modelled by GAB equation.

Effect of temperature on the moisture sorption isotherms of a heat-treated whole milk product, khoa

1991 ◽  
Vol 58 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Ish K. Sawhney ◽  
Girdhari R. Patil ◽  
Bikram Kumar
Keyword(s):  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Moisture Level ◽  
Effect Of Temperature ◽  
Milk Product ◽  
Heat Treated ◽  
Moisture Sorption Isotherms ◽  
Monolayer Moisture ◽  
Increasing Temperature

SummaryMoisture sorption isotherms of khoa were determined at 15, 25, 35 and 45 °C over a water activity (aw) range of O·l 1–0·97. The isotherms were sigmoid (Type II) and were fitted to the Guggenheim–Anderson–de Boer (GAB) equation (Bizot, 1983). The aw of freshly made khoa was found to be 0·96. The aw of khoa increased with increasing temperature up to 0·9; above this the effect of temperature on aw diminished. The monolayer moisture content of khoa decreased with increasing temperature. The equations describing the temperature dependence of GAB constants were determined in the form of the Clausius–Clapeyron equation. The net isosteric heat of desorption of khoa decreased rapidly until a moisture level of 0·1 g/g solids, and approached a constant value of 0·43 kJ/mol above a moisture level of 0·25 g/g solids.

Modeling of moisture sorption isotherm and evaluation of net isosteric heat for spray-dried fortified coconut (Cocos nucifera L.) powder

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juan Carlos Lucas Aguirre ◽  
German Antonio Giraldo Giraldo ◽  
Misael Cortés Rodríguez
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Fundamental Parameter ◽  
Sorption Data ◽  
Content Type ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures

PurposeIn order to understand interactions aw vs equilibrium moisture content (EMC) in fortified coconut powder, moisture sorption isotherms were constructed under different storage conditions in order to predict the changes in their physical, chemical and microbiological properties that occur during storage and processing, which are unique to each food.Design/methodology/approachFor which the moisture sorption isotherms were determined at three different temperatures (15, 25 and 35 °C), in a range of water activity from 0.1 to 0.90. Nine models, namely, the GAB, BET, Oswin, Smith, Halsey, Henderson, Chung and Pfost, Peleg and Caurie equations, were fitted to the sorption data. Various statistical tests were adopted as criteria to evaluate the fit performance of the models.FindingsOf the models tested, the Peleg model gave the best fit to experimental data (R2 = 0.997; RMSE = 0.276), across the full range of water activities and at different temperatures. Humidity of the monolayer (mo) was found between 2.54 and 2.34%, a fundamental parameter to define the storage and control conditions, given that it is considered the value at which the product is more stable. The net sorption isosteric heat (Qst) increased to maximum and then diminished with increased moisture content (Xw); maximum values were obtained in the Xw interval between 0.48 and 2.87% (db), being between 35.72 and 99.26 kJ/mol, where the maximum value indicates coverage of the strongest bond sites and higher adsorbate-adsorbent interaction.Originality/valueThese results provide reliable experimental data on water absorption isotherms of the CP + FAC important to determine optimal processing, storing and packaging conditions.

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.

Determination of the Moisture-Sorption Isotherms and Isosteric Heat of Henna Leaves

2015 ◽  
Vol 88 (1) ◽  
pp. 52-62 ◽  
Author(s):  
S. Bennaceur ◽  
B. Draoui ◽  
B. Touati ◽  
A. Benseddik ◽  
A. Saad ◽  
...  
Keyword(s):  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Moisture Sorption Isotherms

Moisture Sorption Isotherms of Lentil Extrudates

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Nikolay Penov ◽  
Todorka Petrova ◽  
Milena Ruskova ◽  
Nesho Toshkov ◽  
Nikolay Menkov
Keyword(s):  
Experimental Data ◽  
Relative Humidity ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Processing Conditions ◽  
Moisture Contents ◽  
Moisture Sorption Isotherms ◽  
The Relationship

Abstract The equilibrium moisture contents (EMC) were determined for lentil extrudates produced under different processing conditions at 25°C and eight relative humidity (RH) in the range of 0.113 – 0.902. It was established that for the ten extruded samples the EMC values at the same RH were not statistically equal. Four models – Chung-Pfost, Halsey, Oswin, and Henderson equations were applied for analyzing the experimental data. The Oswin model was most suitable for describing the relationship between the EMC and RH.

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