Effects of different drying techniques on the composition of giloy leaf powder and their utilization as a nutritive food colour

¹ Research Scholar, Nutrition and Dietetics, University Institute of Allied Health Sciences, Chandigarh University, Gharuan
² Associate Professor, Department of Nutrition and Dietetics, University Institute of Allied Health Sciences, Chandigarh University, Gharuan.

^* Corresponding author: mdeepsibian@yahoo.com

Abstract

Tinospora cordifolia or Guduchi or Giloy is an ayurvedic medicine plant highly appreciated for its immunomodulatory, antioxidant, anti-inflammatory, and other medicinal properties. The current study investigates how various drying methods—shade drying, sun drying, hot air oven drying, and microwave drying—influence the functional, physicochemical, and microstructural characteristics of T. cordifolia powder. Drying kinetics was performed at different temperatures (40-60⁰C) in hot air oven. Shade drying had the high fat and water absorption values, while microwave drying produced greater gelatinization temperatures because of increased structural modifications. Microwave drying also maintained the largest protein and fiber contents but produced lesser fat content, while hot air oven drying maintained greater carbohydrates and calcium. Phytochemical retention was different in all treatments, hot air oven drying retained maximally alkaloids and phenolics, sun drying retained maximally flavonoids, and microwave drying retained maximally tannins. SEM micrographs showed porous microstructures in microwave-dried material, reflecting extreme internal water loss. Overall, hot air oven drying offered a best-possible combination of preserving nutrients and maintaining structural integrity, and the three processes had some benefits depending on the intended use in herbal or nutraceutical products.