Desorption Isotherm of Mango Soy Fortified Yoghurt

2005 ◽  
Vol 1 (5) ◽  
Author(s):  
Pradyuman Kumar ◽  
H. N. Mishra

Desorption isotherms of three yoghurt samples viz. plain yoghurt, mango soy fortified yoghurt (MSFY) and MSFY containing 0.4 % gelatin stabilizer (MSFYG) were determined by gravimetric static method at 20, 30, 40 and 50 °C in the range of 0.11 – 0.81 water activity. It was found that desorption isotherm of yoghurt samples follow a typical type III sigmoid curve. Experimental data were fitted to five mathematical models i. e. modified Henderson, modified Chung Pfost, Oswin, Smith and Guggenheim-Anderson-deBoer (GAB). Equations were developed for the prediction of the GAB constants as a function of temperature and these equations were used during modeling. Standard error of estimate (SE), mean relative percentage error (P), percent root mean square (% RMS) and trend of residual plots were used to compare the goodness of fit. It was found that the GAB models were acceptable in describing equilibrium moisture content – water activity relationships for yoghurt samples over the entire experimental temperature range.

Author(s):  
Karine F. Barbosa ◽  
Juliana de F. Sales ◽  
Osvaldo Resende ◽  
Daniel E. C. de Oliveira ◽  
Jacson Zuchi ◽  
...  

ABSTRACT The objective of this study was to determine the desorption isotherms of 'cajuzinho-do-cerrado' achenes (Anacardium humile St. Hil.) in various conditions of temperature and water activity, as well as to select the one that best represents the phenomenon and to determine the isosteric heat of desorption. The fruits were collected at the Emas National Park, in the municipality of Mineiros-GO, Brazil, pulped and then subjected to drying in silica gel at temperature of 25 ± 2 °C until the moisture contents of 17.6, 13.6, 11.1, 8.7 and 5.3 (d.b.%). After drying, the desorption isotherms were determined by the indirect static method. The water activity (Aw) was determined at different temperatures, and the achenes were placed in a B.O.D. chamber, regulated at 10, 20, 30 and 40 °C. Data of hygroscopic equilibrium moisture content were fitted to different mathematical models through non-linear regression analysis, using the Gauss-Newton method. The Copace model was the one that best represented the hygroscopicity of 'cajuzinho-do-cerrado' achenes, while the integral isosteric heat of desorption of 'cajuzinho-do-cerrado' achenes for the moisture content range of 4.51 to 13.40 (% d.b.) varied from 2,734.82 to 2,548.49 kJ kg-1.


2020 ◽  
Vol 32 (12) ◽  
pp. 3087-3092
Author(s):  
Nanduri Gayatri Devi ◽  
N.V.N.B. Srinivasa Rao ◽  
D. Ramachandran

Densities (ρ), ultrasonic speeds of sound (u) of binary mixtures containing propiophenone with o-xylene, m-xylene and p-xylene were measured over the entire composition range at temperatures from 303.15-318.15 K and at atmospheric pressure 0.1 MPa. Experimental data of ultrasonic velocity was used to compute the theoretical velocities by using the various theories like Nomoto’s relation (UNOM), impedance relation (UIMP), Van Dael and Vangeel’s relation (UVDV), Rao’s specific velocity relation (URAO), Jouyban-Acree’s (UJOE) and Junjie’s theory (UJUN). The results are in good agreement with the experimental data. The relative percentage error, chi square test for goodness of fit and the molecular interaction parameter (α) values for non-ideality in the binary mixtures were computed and analyzed in terms of intermolecular interactions between the molecules of the binary mixtures.


2021 ◽  
Vol 2 (108) ◽  
pp. 75-85
Author(s):  
Q.H. Jebur ◽  
M.J. Jweeg ◽  
M. Al-Waily ◽  
H.Y. Ahmad ◽  
K.K. Resan

Purpose: Rubber is widely used in tires, mechanical parts, and user goods where elasticity is necessary. Some essential features persist unsolved, primarily if they function in excessive mechanical properties. It is required to study elastomeric Rubber's performance, which is operational in high-level dynamic pressure and high tensile strength. These elastomeric aims to increase stress breaking and preserve highly pressurised tensile strength. Design/methodology/approach: The effects of carbon black polymer matrix on the tensile feature of different Rubber have been numerically investigated in this research. Rubber's material characteristics properties were measured using three different percentages (80%, 90%and 100%) of carbon black filler parts per Hundreds Rubber (pphr). Findings: This study found that the tensile strength and elongation are strengthened as the carbon black filler proportion increases by 30%. Practical implications: This research study experimental tests for Rubber within four hyperelastic models: Ogden's Model, Mooney-Rivlin Model, Neo Hooke Model, Arruda- Boyce Model obtain the parameters for the simulation of the material response using the finite element method (FEM) for comparison purposes. These four models have been extensively used in research within Rubber. The hyperelastic models have been utilised to predict the tensile test curves—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model. Numerical Ogden model results have shown that the relative fitness error was the case with large strains are from 1% to 2.04%. Originality/value: In contrast, other models estimate parameters with fitting errors from 2.3% to 49.45%. The four hyperelastic models were tensile test simulations conducted to verify the efficacy of the tensile test. The results show that experimental data for the uniaxial test hyperelastic behaviour can be regenerated effectively as experiments. Ultimately, it was found that Ogden's Model demonstrates better alignment with the test data than other models.


Author(s):  
Fernando M. Botelho ◽  
Nilso J. Boschiroli Neto ◽  
Silvia de C. C. Botelho ◽  
Gabriel H. H. de Oliveira ◽  
Michele R. Hauth

ABSTRACT Knowledge of the water sorption phenomenon in Brazil nut seeds will allow proper handling of this product, especially with regard to adequate conditions for safe storage. Thus, the present study aimed to determine the sorption isotherms (desorption and adsorption) of Brazil nuts, fitting different mathematical models to the experimental data, as well as to examine the hysteresis effect. To obtain the sorption isotherms, the static method was employed at temperatures of 25, 35, 45 and 55 °C and air relative humidities varying from 10 to 80%. The psychrometric conditions of the air were acquired with the aid of acid solutions and specific saturated saline left inside desiccators with the samples. It was verified that for a given isotherm, the equilibrium moisture content of Brazil nuts increases with water activity increment. In addition, at a constant water activity, equilibrium moisture content decreases with temperature increase. The Copace, Henderson and Oswin are the models that best describe the hygroscopicity of the Brazil nut seed for both the adsorption and desorption processes. Hysteresis was more pronounced at lower temperatures and higher values of water activity. The moisture content value for storage at temperatures less than 55 °C, without the risk of fungal development, must be lower than 8.2% (d.b.).


2018 ◽  
Vol 12 (1) ◽  
pp. 352-365 ◽  
Author(s):  
Karn Chalermwongphan ◽  
Prapatpong Upala

Aim: This research aimed to present the process of estimating bicycle traffic demand in order to design bike routes that meet the daily transportation needs of the people in Nakhon Sawan Municipality. Methods: The primary and secondary traffic data were collected to develop a virtual traffic simulation model with the use of the AIMSUN simulation software. The model validation method was carried out to adjust the origin and destination survey data (O/D matrix) by running dynamic O/D adjustment. The 99 replication scenarios were statistically examined and assessed using the goodness-of-fit test. The 9 measures, which were examined, included: 1) Root Mean Square Error (RMSE), 2) Root Mean Square Percentage Error (RMSPE%), 3) Mean Absolute Deviation (MAD), 4) Mean Bias Error (MBE), 5) Mean Percentage Error (MPE%), 6) Mean Absolute Percentage Error (MAPE%), 7) Coefficient of Determination (R2), 8) GEH Statistic (GEH), and 9) Thiel’s U Statistic (Theil’s U). Results: The resulting statistical values were used to determine the acceptable ranges according to the acceptable indicators of each factor. Conclusion: It was found that there were only 8 scenarios that met the evaluation criteria. The selection and ranking process was consequently carried out using the multi-factor scoring method, which could eliminate errors that might arise from applying only one goodness-of-fit test measure.


2011 ◽  
Vol 236-238 ◽  
pp. 2505-2509
Author(s):  
Xin Yi He ◽  
Jin Fu Liu ◽  
Li Li Cheng ◽  
Bu Jiang Wang

Drying characteristics of crispy winter jujube dried by explosion puffing drying at different vacuum drying temperature were investigated. Selection of the best model was examined by comparing the determination of coefficient (R2), root means square error (RMSE), and mean relative percentage error (P) between the experimental and predicted values. As expected, higher drying rates were obtained with higher vacuum drying temperature. The results showed that the Modified Henderson and Pabis model provided better simulation of drying curves for crispy winter jujube according to thin-layer drying theory. The effective moisture diffusivity of crispy winter jujube dried by explosion puffing drying with higher vacuum drying temperature was higher than the others.


Author(s):  
Maisa D. Cavalcante ◽  
Geovana R. Plácido ◽  
Daniel E. C. de Oliveira ◽  
Bheatriz S. M. de Freitas ◽  
Caroline Cagnin ◽  
...  

ABSTRACT Yellow mombin has high nutritional value but is very perishable. Foam mat drying is a method that has been widely used to preserve liquid and semi-solid powdered foods. In this context, the aim of this study was to determine desorption isotherms and isosteric heat of yellow mombin (Spondias mombin L.) foam for different conditions of temperature and water activity. Powdered yellow mombin pulp was obtained by drying in forced-air oven regulated to 60 ° C. The indirect static method was used to determine the isotherms and isosteric heat, whereas water activity (aw) was determined using the Hygropalm-HP23AW-A analyzer. A B.O.D. incubator, set at 10, 20, 30 and 40 °C, was used to control the temperature, and the water activity for each temperature was between 0.220 and 0.832. The experimental data were fitted to mathematical models frequently used to represent the hygroscopicity of agricultural products, and the best model was the Modified Halsey. Integral isosteric heat of desorption of yellow mombin powder, within the water content range of 17.22 to 57.58 (% d.b.), ranged from 3198.56 to 2598.38 kJ kg-1. It was concluded that the equilibrium water content of yellow mombin pulp powder increased with the increment in water activity; desorption isotherms obtained for yellow mombin pulp powder showed sigmoid form and, with the reduction of water content, the isosteric heat increases.


1978 ◽  
Vol 56 (14) ◽  
pp. 1853-1855 ◽  
Author(s):  
Doan Thi An ◽  
Tjoon Tow Teng ◽  
James Malcolm Sangster

Vapour pressures of concentrated solutions (up to I = 14) of the Systems CaCl2 + NaCl + H2O and MgCl2 + NaCl + H2O have been measured at 25 °C by the static method. By means of reverse application of the Reilly–Wood–Robinson and Zdanovskii–Stokes–Robinson equations to these data, water activities of supersaturated NaCl solutions up to ∼15 m have been deduced, and are represented in polynomial form.


Author(s):  
J. Ramachandran ◽  
V. Ravikumar ◽  
R. Lalitha

In this paper, six drip lateral design methods were selected and a comparative assessment was done to find its practical applicability for finding accurate uniformity coefficient. Step-By-Step (SBS) method, Differential method (DM), Constant Discharge method (CDM), Variable discharge method (VDM), Outlet variation method (OVM) and Statistical method (STM) were the different methods assessed. The percentage relative error in calculating the uniformity coefficient by different methods were obtained as the difference between step-by-step method (true) value and alternate method (observed) value. These errors were tabulated. VDM and OVM method performed well with equal accuracy to SBS method at different slopes. For L=250m, DM method performed well. The STM performed good for down slope and lateral length of 250m with 6 per cent relative error. The method having lesser relative percentage error can be selected by the design engineers for designing the laterals from the relative percentage error tables.


2016 ◽  
Vol 79 (1) ◽  
Author(s):  
Nur Arina Bazilah Kamisan ◽  
Muhammad Hisyam Lee ◽  
Suhartono Suhartono ◽  
Abdul Ghapor Hussin ◽  
Yong Zulina Zubairi

A pairwise comparison is important to measure the goodness-of-fit of models. Error measurements are used for this purpose but it only limit to the value, thus a graph is used to help show the precision of the models. These two should show a tally result in order to defense the hypothesis correctly. In this study, a fractional residual plot is proposed to help showing the precision of forecasts. This plot improvises the scale of the graph by changing the scale into decimal ranging from -1 to 1. The closer the point to 0 will indicate that forecast is robust and value closer to -1 or 1 will indicate that the forecast is poor. Two error measurements which are mean absolute error (MAE) and mean absolute percentage error (MAPE) and residual plot are used to justify the results and make comparison with the proposed fractional residual plot. Three difference data are used for this purpose and the results have shown that the fractional residual plot could give as much information as the residual plot but in an easier and meaningful way. In conclusion, the error plot is important in visualize the accurateness of the forecast.  


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