Akademik Veri Yönetim Sistemi
PAMUKKALE UNIVERSITY JOURNAL OF ENGINEERING SCIENCES-PAMUKKALE UNIVERSITESI MUHENDISLIK BILIMLERI DERGISI, cilt.27, sa.7, ss.826-834, 2021 (ESCI)
Plants have been used since ancient times due to their positive effects on health. Herbal teas are most commonly used and have high antioxidant activity due to their high phenolic content. The aim of this study is to produce instant tea from plant extracts obtained from St. John's Wort (Hypericum perforatum) and geranium (Perlargonium graveolens) by using microwave and ultrasound assisted extraction. Extracts obtained by maceration method were used as control group. Different microwave powers (90, 180 and 270 W) and different processing times (10, 20, 30, 40 and 50 min.) were used for the microwave assisted extraction. For the same purpose, different ultrasound powers (14, 35 and 56 W) and different processing times (1, 10, 20, 30 and 60 min.) were applied in ultrasound assisted extraction. The most proper processing conditions were determined according to the total phenolic content obtained from extraction processes. In the microwave-assisted extraction, 270 W-40 min. was the most proper process condition for St. John's Wort while it was 270 W-50 min. for the geranium which resulted in highest phenolic content including extract. For ultrasound-assisted process, the appropriate conditions were 56 W-60 min. for St. John's Wort plant and 35W-60 min. for geranium. In the light of the results of the study, it was concluded that the new technologies provide extracts with higher phenolic content obtained in a shorter time and microwave assisted extraction method is found to be more preferable due to its suitability for instant tea production.