Effects of Peeled and Unpeeled Garlic Cloves on the Changes of Drying Rate and Quality

Abstract

Reducing moisture content as fast as possible, together with minimizing loss of quality, is important to food processing. To reach these objectives, experimental investigations were conducted to examine the effects of both peeled and unpeeled garlic cloves as well as operating parameters such as temperature and superficial velocity on the drying rate and quality of dried product. Peel resistance to moisture diffusion is considerably dominated and yields the longer drying time. Drying at high temperature shows the shrinkage of garlic clove to be lower than that at low temperature, whereas the product color is browner and the sizes of produced pores as revealed by scanning electron microscope are larger. The loss of volatile oil is insignificantly different among low- and high-temperature drying. The peel effect exhibits negative results on the product color, giving lower luminosity than the peeled sample, in particular at low temperature, because of longer drying time.

Keywords:

• Dehydration
• Garlic
• Shrinkage
• Volatile oil

ACKNOWLEDGEMENTS

The authors thank King Mongkut's University of Technology Thonburi and The Thailand Research Fund for their financial support.