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

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%).