Abstract

Celery is a rich source of vitamins, carotene, protein, cellulose along with some secondary metabolites used for medicinal purposes. It contains a significant amount of essential oils and is recognized as a healthy plant and a spice. The present study was conducted during 2019 in Labone Scientific Co. Ltd, Vietnam on the effect of blanching time and temperature, CaCl2 concentration in blanching; leaf size and temperature in drying, and storage condition to flavonoid (mg/100g) content in the herbal tea. Raw celery leaves were blanched in water solution with 0.3% CaCl2 at different temperature and time (100°C for 5 secs, 95°C for 10 secs, 90°C for 15 secs and 85°C for 20 secs) with different CaCl2 concentration (0.25, 0.30, 0.35, 0.40 and 0.45%) and dried at different size (1.0, 1.5, 2.0, 2.5 and 3.0 cm) by hot-air at 55°C until 8.5% moisture was attained. From this, sample of 2.0 cm size was hot-air dried at different temperature (45, 50, 55, 60 and 65°C) until 8.5% moisture was attained. The results indicated that blanching at 95°C, 10 secs with 0.4% CaCl2, heat pump drying at 50°C in dimension of 2.0cm, storage at 4°C in Polyester (PET)/Aluminium (AL)/Polyethylene (PE) under vacuum conditions could maintain the saponin content in herbal tea for 12 weeks without any decomposition.