1. Nurul Hanisah Juhari 1, Ola Lasekan 2, Sharifah Kharidah Syed Muhammad 3, Muhammad Shahrim Ab Karim 4 OPTIMIZATION OF HOT-AIR DRYING CONDITIONS ON THE PHYSICOCHEMICAL PROPERTIES OF TORCH GINGER (Etlingera eliator) For some years, herbs and spices have played a major role in cooking, medicines, cosmetics, perfumery, global exploration as well as economics. Basically, spices and herbs added flavour and enhanced the palatability of food. Besides that, the usage of spices among population have also increased due to renew interest in dishes that use a variety of spices and to the ability of spices to act as antioxidants. Torch ginger is also known as ‘kantan’ in Malaysia. It’s widely grown for both flavouring and medicinal purposes. It can be consumed as condiment, eaten raw or cooked (Noweg et al., 2003). However, these spices are highly perishable in nature and therefore have very short shelf life. Usually, it deteriorates rapidly after harvesting and leads to loss of flavour and quality. So, drying is an important technology for preserving the product quality and also to prevent the spoilage of the product during storage as well as to facilitate its packaging and distribution. Thus, this study aimed to examine the effect of hot-air drying conditions on the physicochemical characteristics of Torch ginger (E. eliator) and to find the optimum conditions for drying and production of high quality dried material that could be used for a high food grade spicing material. 1,4 Department of Food Service and Management, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor. 2 Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM Serdang, 43400 Selangor. 3 Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM Serdang, 43400 Serdang. Corresponding author: lasekan@food.upm.edu.my; nurulhanisah.juhari@gmail.com MATERIALS AND METHODS INTRODUCTION RESULTS AND DISCUSSION CONCLUSION programmable oven after separated from stalks and cleaned dried torch ginger using perforated tray dryer fresh torch ginger Different drying conditions: i) Loading capacity (0.5-2.0 kg/m 2 ) ii) Drying temperatures (40-60°C) iii) Drying times (3-5 hrs) Prepared for optimization procedure based on Central Composite Design (CCD), Response Surface Methodology (RSM) Type of analysis:  Moisture content  Water activity  Texture (brittleness)  Colour (L a b) Effect of hot-air drying (time, temperature and loading capacity) on the moisture content of Torch ginger Effect of hot-air drying (time, temperature and loading capacity) on the colour-a of Torch ginger Effect of hot-air drying (temperature and loading capacity) on the water activity, texture and colour-L of Torch ginger The results revealed that the linear terms exhibited significant (P<0.05) effect on moisture content. The quadratic terms showed significant (P<0.05) effect on water activity, texture (brittleness), colour-L and colour-b values while for colour-a values, the interaction terms of drying condition was the most significant (P<0.05) factor. The optimization results indicated that the best response, within the range studied, was reached when the drying time was 4.1h, the drying temperature, 79°C and loading capacity, 0.7kg/m 2 respectively. ACKNOWLEDGMENT The authors are grateful to Universiti Putra Malaysia and the Ministry of Higher Education for financial support.