Effects of Drying Temperatures and Drying Methods on Physicochemical and Antioxidant Properties of Celery Powder

Abstract

ABSTRACT The Celery (Apium graveolens Linn.) were hot air dried at 60, 70, and 80°C. Drying temperatures had no significant impact on the bulk density, water holding capacity, or swelling capacity of celery powder. High drying temperatures (80°C) generated a significant color shift, whereas antioxidants were decreased at a low temperature (60°C). Thus, the temperature of 70°C was recommended because the powder had satisfying green color, high phenolic content (597.35 mg GAE/100 g), and DPPH inhibition (39.37%). Subsequently, celery samples were dried using hot air drying (at 70°C) and freeze-drying and the juice was foam mat dried. The foam mat dried powder had less water holding capacity, whereas the hot air and freeze-dried powders had similar characteristics. But the freeze-dried powder had a pleasant green color, low bulk density, high swelling and water holding capacity, and remarkably high phenolic content (718.00 mg GAE/100 g) and DPPH inhibition (64.14%).