Determination of effective diffusion coefficient and interfacial mass transfer coefficient of bovine serum albumin (BSA) adsorption into porous polyethylene membrane by microscope FTIR-mapping study

ABSTRACT Banana is one of the most consumed fruits in the world, having a large part of its production performed in tropical countries. This product possesses a wide range of vitamins and minerals, being an important component of the alimentation worldwide. However, the shelf life of bananas is short, thus requiring procedures to prevent the quality loss and increase the shelf life. One of these procedures widely used is drying. This work aimed to study the infrared drying process of banana slices (cv. Prata) and determine the heat and mass transfer coefficients of this process. In addition, effective diffusion coefficient and relationship between ripening stages of banana and drying were obtained. Banana slices at four different ripening stages were dried using a dryer with infrared heating source with four different temperatures (65, 75, 85, and 95 ºC). Midilli model was the one that best represented infrared drying of banana slices. Heat and mass transfer coefficients varied, respectively, between 46.84 and 70.54 W m-2 K-1 and 0.040 to 0.0632 m s-1 for temperature range, at the different ripening stages. Effective diffusion coefficient ranged from 1.96 to 3.59 × 10-15 m² s-1. Activation energy encountered were 16.392, 29.531, 23.194, and 25.206 kJ mol-1 for 2nd, 3rd, 5th, and 7th ripening stages, respectively. Ripening stages did not affect the infrared drying of bananas.

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Study on the diffusion coefficients for ammonia nitrogen and nitrite and nitrate in PVA gels

Water Science & Technology ◽

10.2166/wst.2016.279 ◽

2016 ◽

Vol 74 (8) ◽

pp. 1773-1779 ◽

Cited By ~ 2

Author(s):

Hong Yang ◽

Qingkun Guan

Keyword(s):

Mass Transfer ◽

Diffusion Coefficient ◽

Effective Diffusion Coefficient ◽

Effective Diffusion ◽

Polynomial Equation ◽

Ammonia Nitrogen ◽

Test Device ◽

Surface Method ◽

Cubic Polynomial ◽

Addition Amount

In order to quantify the proliferation of polyvinyl alcohol (PVA) gels in a matrix and optimize the performance of mass transfer, activated carbon (AC) and CaCO3 were selected as adding materials in this experiment. For the performance of mass transfer, the optimal conditions were analyzed using response surface method (RSM) considering the inter-correlated effects of the amount of AC and CaCO3. For RSM, 13 trials resulted in a partial cubic polynomial equation, which best predicted the amount of residual debris after homogenization. The results of the study show that the effective diffusion coefficient test device can analysis the diffusion rate nitrogen, nitrite and nitrate within the PVA gels quantitatively; adding appropriate amounts of AC and CaCO3 in the biological active filter can improve the performance of mass transfer effectively; the maximum effective diffusion coefficient of nitrogen and nitrite and nitrate in the packing were 1.3637 × 10−9 and 1.0850 × 10−9 and 1.0199 × 10−9 m2/s, respectively, at optimal addition amount.

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