Prepared by: Siti Hajar Binti Jelani

Assistant Science Officer

Department of Food Technology (Food Engineering Laboratory)

Faculty of Food Science and Technology

Universiti Putra Malaysia

Food drying is an important preservation method in the food industry, as it extends shelf life and maintains product quality. Various drying methods are available; however, the choice depends on the type of sample, cost, and desired final quality. Common methods include spray drying, drum drying, foam mat drying, freeze drying, and hot air drying.

Spray drying converts liquid into powder using relatively high temperatures and carrier agents. The sample must be in liquid form (without solid particles), and the final product is a powder. It is commonly used to produce coffee powder, milk powder, and fruit juice powder.

Drum drying involves spreading liquid or paste onto a heated drum, forming a thin layer that dries into flakes, which are then ground into powder. This method is suitable for samples such as dhal and tomatoes, and it operates at relatively high temperatures.

Foam mat drying transforms liquid or semi-liquid food into powder with the help of stabilizing agents. The process is typically carried out at moderate temperatures.

Freeze drying involves sublimation, where ice turns directly into vapor. The food is first frozen before drying. This method is well known for preserving nutrients and maintaining high product quality, as it uses very low temperatures.

Hot air drying is the simplest and most commonly used method. It involves heating food and removing moisture through evaporation.

In conclusion, the selection of a drying method depends on the type of food (liquid, solid, or semi-solid), its sensitivity to heat, and the desired final product quality.

Date of Input: 06/05/2026 | Updated: 06/05/2026 | nurulizzah