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    Item type:Publication,
    Drying kinetics and quality of cissus quadrangularis linn. Dried by convective hot air
    (2020-09-01)
    Thanimkarn, Setthawat
    ;
    Cheevitsopon, Ekkapong
    ;
    Jongyingcharoen, Jiraporn Sripinyowanich
    This research aimed to determine a suitable drying model of convective hot air drying of Cissus quadrangularis Linn. (CQ), determine the effective moisture diffusivity of the drying process and the activation energy of CQ, and investigate the effects of drying temperatures on energy consumption and quality of dried CQ. Experiments were performed at 40°C, 60°C, 80°C, and 100°C drying temperature and 1 m s<sup>-1</sup> air velocity to dry CQ from 10 g water/g dry matter to 0.1 g water/g dry matter. The generalized linear-plus-exponential-type model has been used to fit the drying kinetics of CQ and demonstrates, among others, the moisture data of hot air drying of CQ at the validation temperature of 50°C satisfactorily with an R<sup>2</sup> of 0.9977. The effective moisture diffusivity was in the range of 0.7302-9.1281 ×10<sup>-9</sup> m<sup>2</sup> s<sup>-1</sup>, a positive relationship was observed between this parameter and drying temperature. The activation energy of CQ was 39.78 kJ mol<sup>-1</sup>. The lowest energy consumption of 3.40 kWh was required when the highest drying temperature of 100°C was applied. The quality was well preserved when CQ was dried at a lower drying temperature. Drying at 60°C produced dried CQ with the lowest total color difference (16.76), shrinkage percentage (88.47%), and bulk density (0.1817 g cm<sup>-3</sup>) as well as the highest total phenolic (1062 mg GAE/100 g dry matter) and quercetin contents (0.955 mg/100 g dry matter).
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    Item type:Publication,
    Increasing energy efficiency of the Cissus quadrangularis drying by hot air fluidization technique
    (2017-01-01)
    Promnuch, Jutamas
    ;
    Junka, Nittaya
    ;
    Wongs-Aree, Chalermchai
    ;
    Soponronnarit, Somchart
    ;
    Srisang, Naruebodee
    The aim of this paper is to increase energy efficiency by reducing specific energy consumption (SEC) during Cissus quadrangularis drying. The fresh sample, with a high moisture content of 90 ± 2 % wet basis (w.b.), was dried by hot air Fluidized bed technique at temperatures of 90, 110, 130 and 150°C to a final moisture content of 5 % (w.b.) and then was compared to the results of tray drying at a low temperature of 50°C, following a method by Tha Sae Hospital in Chumphon province, Thailand. The drying kinetic result revealed that fluidization drying had a higher rate of water removal than the tray drying method. That rate directly correlated with the drying temperature; it increased with an increase of drying temperature. With the increasing of the rate, it resulted in a decreasing of SEC. Although using a drying temperature of 150°C had the highest rate of water removal and subsequently had the lowest SEC, it negatively affected the antioxidant activity of the sample. To dry Cissus quadrangularis with the lowest SEC as possible, it should be dried by hot air fluidization at a drying temperature of 110°C. At this drying condition, there is still a high rate of water removal and a low effect of the desired qualities of the sample.