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Convective Drying and Water Adsorption Behavior of Unripe Banana: Mathematical Modeling
Author(s) -
Zabalaga Rosa F.,
Carballo Sergio C.
Publication year - 2015
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/jfpp.12352
Subject(s) - adsorption , moisture , thermal diffusivity , shelf life , water content , chemistry , sorption , thermodynamics , convection , food science , organic chemistry , geology , physics , geotechnical engineering
In this study, we modeled the convective drying of unripe banana slices and the water adsorption behavior of the banana flour. Drying experiments were conducted at temperatures from 30 to 60C with an air velocity of 1.5 m/s, and adsorption isotherms were measured at 15, 25 and 35C. A four‐parameter empirical model that we proposed fitted quite satisfactorily with the experimental drying data. In addition, the drying behavior during the first hours was described by an effective diffusivity coefficient, which ranges from 1.2 × 10 −10 m 2 /s to 6.6 × 10 −10 m 2 /s. The observed sigmoid adsorption isotherms of unripe banana flour were modeled quite well by the GAB equation. Estimated monolayer moisture content has values between 0.08 and 0.09 g/g. Practical Applications Since unripe banana is easily transported and stored, it has become a potential food product for industrialization. Drying is one of the most important unit operations and classical methods for preserving foods, which extends their shelf‐life, decreases their weight for transportation, and reduces their volume for storage. Studying the drying kinetics of fruits is necessary in order to provide information about the time required for attaining low and safe moisture content. On the other hand, adsorption isotherm predicts the shelf‐life stability, which involves moisture changes that may occur during storage, and thus it is useful for selection of packaging materials. Sorption isotherms are important for modelling drying processes, as well for designing and optimizing drying equipment helping us to understand how a food material behaves during drying, but also how a dried product behaves after the drying process to maintain its quality and acceptability is essential.