Convective Hot-air Drying of Green Mango: Influence of Hot Water Blanching and Chemical Pretreatments on Drying Kinetics and Physicochemical Properties of Dried Product

Hot air drying of palm fruit is a simple method but results in low grade palm oil. The steaming of palm fruit results in high grade palm oil but it requires a wastewater treatment process. Both methods have both advantages and disadvantages, therefore if they were combined, it can result in the better grades of oil, which should be encouraged for farmers in Thailand to apply. This research aimed to determine mechanical characteristics of semi-damp dryer for oil palm. The results of a compression and relative humidity tests were used as the criteria for the tests. The oil palm semi-damp dryer was used in this research. The oil palm semi-damp dryer used the aerosolized technique with 100 °C hot water as a sprayer and a humidifier for the oil palm in the dryer. The purpose was to reduced palm fruit hardness. The study use tenera palm from Prachinburi province and neighborhood of Thailand. The drying time for testing was 1, 2, 3 and 4 hours. The temperature for testing was 70, 90 and more than 100 °C. The results of the compression force of oil palm by using a semi-damp dryer were lower than using a hot air drying. The compression was lower than using hot air drying. The best of mechanical characteristics palm was baking with semi-damp dry at 90 °C in 3 hours. Compression force was 0.675 kN and relative humidity value was 57.18%. The palm oil was tested for the %FFA and DOBI and showed that the grade of palm oil by using semi-damp drying was fair but still edible grade.

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The Drying Kinetics of Natural Rubber Sheets under Hot-Air Drying with Forced Convection: Experiments and Modeling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.844.154 ◽

2013 ◽

Vol 844 ◽

pp. 154-157

Author(s):

Warit Werapun ◽

Yutthapong Pianroj ◽

Pinpong Khongchana

Keyword(s):

Natural Rubber ◽

Linear Regression Analysis ◽

Effective Diffusion ◽

Drying Kinetics ◽

Heat Sources ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Liquid Petroleum Gas ◽

Kinetics Of

This study investigated the drying kinetics of the natural rubber sheets under hot air drying, with various heat sources, and included modeling of the kinetics. The heat was generated by combustion, either of charcoal briquettes from coconut shell (biomass) or of liquid petroleum gas (LPG). The hot air entering the drying chamber had its initial temperature controlled at 40, 50, or 60 Centigrade. Five rubber sheets within the chamber were observed during their drying. Howerver, in the case of biomass, the fuctuation of temperature due to charcoal adding. Therfore, the non-linear regression analysis was performed only LPG data with a Weibull distribution and a Modified Handerson and Pabis. They represented the drying kinetics with parametric fits; moreover, an effective diffusion coefficient was determined for each experimental condition.

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