Mathematical modelling of hot air drying of sweet potato slices

Microwave and steam blanching as pretreatments to hot air drying of orange-fleshed sweet potato (OFSP) were studied. The air-drying experiment was performed at constant temperature of 70°C and airflow of 1.0 m/s. The effective moisture diffusivity varied from 1.5 × 10 − 9 to 4.4 × 10 − 9 m2/s, and 1.1 × 10 − 10 to 7.9 × 10 − 10 m2/s, for the microwave and blanched assisted hot air drying, respectively. The activation energy obtained for the various microwave-assisted hot air drying was 29.1 W/mm for 4 min, 68.1 W/mm for 3 min, and 79.7 W/mm for 2 min. Ascorbic acid degradation and formation of brown pigments in the OFSP slices were lower in microwave than in steam blanch-assisted drying. Microwave-assisted drying of OFSP is best governed by Page model, M R = exp − k t n , while the blanch-assisted followed the logarithmic model, M R = a exp − k t + c . To produce better quality OFSP flour, it is recommended to cut the tubers into 3 mm slices, microwave at a power of 630 W for 2 min or blanch for 1 min, 43 seconds prior to hot air drying.

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Analysis of Equilibrium moisture content and L-ascorbic acid during hot air drying for sweet potato

10.13031/2013.24755 ◽

2008 ◽

Author(s):

Takahiro Orikasa ◽

Daisuke Nei ◽

Poritosh Roy ◽

Nobutaka Nakamura ◽

Takeo Shiina ◽

...

Keyword(s):

Ascorbic Acid ◽

Moisture Content ◽

Sweet Potato ◽

Equilibrium Moisture Content ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air

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Mathematical modelling of thin layer hot air drying of apricot with combined heat and power dryer

Journal of Food Science and Technology ◽

10.1007/s13197-014-1331-9 ◽

2014 ◽

Vol 52 (5) ◽

pp. 2950-2957 ◽

Cited By ~ 16

Author(s):

Saeed Faal ◽

Teymor Tavakoli ◽

Barat Ghobadian

Keyword(s):

Mathematical Modelling ◽

Thin Layer ◽

Combined Heat And Power ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air

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The influence of processing conditions on kinetics, anthocyanin profile and antioxidant activity of purple sweet potato subjected to hot air drying

Journal of Food Process Engineering ◽

10.1111/jfpe.13472 ◽

2020 ◽

Vol 43 (9) ◽

Author(s):

Junmin Wang ◽

Guangxu Wu ◽

Zhineng Wang ◽

Bin Shu ◽

Li Li ◽

...

Keyword(s):

Antioxidant Activity ◽

Sweet Potato ◽

Processing Conditions ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Anthocyanin Profile ◽

Purple Sweet Potato

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Hot Air Drying Characteristics of Sweet Potato Using Moisture Sorption Isotherm Analysis and Its Quality Changes During Drying

International Journal of Food Engineering ◽

10.2202/1556-3758.1748 ◽

2010 ◽

Vol 6 (2) ◽

Cited By ~ 7

Author(s):

Takahiro Orikasa ◽

Long Wu ◽

Yasumasa Ando ◽

Yoshiki Muramatsu ◽

Poritosh Roy ◽

...

Keyword(s):

Ascorbic Acid ◽

Sweet Potato ◽

Acid Content ◽

Sugar Content ◽

Ascorbic Acid Content ◽

Surface Color ◽

Hot Air Drying ◽

Air Drying ◽

Drying Characteristics ◽

Hot Air

Changes in the quality of sweet potato during hot air drying, such as L-ascorbic acid, sugar content, surface color and hardness, and drying characteristics, were investigated at temperatures of 30, 40, 50, and 60°C. Equilibrium moisture contents (EMC) of sweet potato samples in the desorption process were measured by a static method at the four aforementioned temperatures and six selected relative humidity levels. Using both the measured moisture content data in the drying test and the EMC values, hot air drying characteristics of sweet potato was estimated. Changes in L-ascorbic acid content of sweet potato during hot air drying was measured, wherein a first-order reaction rate equation was applied to model the change in decomposition of L-ascorbic acid content. In addition, surface color, sugar content, and surface hardness were also measured. The total color change (?E) of the samples was observed to decrease as drying temperature was increased. The effects of sample sugar concentration on surface hardening during hot air drying of sweet potato are discussed.

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Characterisation of Potato Slices During Drying: Density, Shrinkage, and Thermodynamic of Sorption

International Journal of Food Engineering ◽

10.2202/1556-3758.2349 ◽

2011 ◽

Vol 7 (3) ◽

Cited By ~ 3

Author(s):

Saber Chemkhi ◽

Féthi Zagrouba

Keyword(s):

Experimental Data ◽

Food Product ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Desorption Isotherms ◽

Gab Model ◽

Kinetics Of ◽

Correlation Factors ◽

Potato Slices

In this study, we are interested in a thermo-physic characterisation during hot air drying of one food product: the potato. The drying kinetics of potato slices are determined at three temperatures and three air velocities. The evolution of the density and the material shrinkage are determined and commented. We finish with the equilibrium moisture relations for the product. From experimental data, we have modeled the desorption isotherms using the GAB model. From the results, we notice that this model perfectly describes the measures with correlation factors superior to 97%. A thermodynamic analysis of isotherms has been made: the heat of sorption is calculated; the entropy of sorption has also been determined and has been commented.

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