Modeling of moisture sorption isotherm and evaluation of net isosteric heat for spray-dried fortified coconut (Cocos nucifera L. ) powder
ISSN: 0007-070X
Article publication date: 22 February 2021
Issue publication date: 29 June 2021
Abstract
Purpose
In 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/approach
For 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.
Findings
Of 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/value
These results provide reliable experimental data on water absorption isotherms of the CP + FAC important to determine optimal processing, storing and packaging conditions.
Keywords
Citation
Lucas Aguirre, J.C., Giraldo Giraldo, G.A. and Cortés Rodríguez, M. (2021), "Modeling of moisture sorption isotherm and evaluation of net isosteric heat for spray-dried fortified coconut (
Publisher
:Emerald Publishing Limited
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