Slide 1

Azarpazhooh, E. and Ramaswamy, H.S. Osmotic Dehydration, in Drying of Foods, Vegeta-

bles and Fruits - Volume 1, Ed. Jangam, S.V., Law, C.L. and Mujumdar, A.S. , 2010 , ISBN -

978 -981-08-6759-1, Published in Singapore, pp. 89-116.

Chapter 4

Osmotic Dehydration

E. Azarpazhooh and H.S. Ramaswamy

Department of Food Science and Agricultural Chemistry, Macdonald Campus, McGill University,

21,111 Lakeshore Ste-Anne-de-Bellevue,

Quebec, Canada H9X 3V9

Contents

4.1. INTRODUCTION ....................................................................................................................... 85

4.2. BASIC PRINCIPLES OF OSMOTIC DEHYDRATION ........................................................ 86

4.2.1. Osmotic pressure ........................................................................................................................... 87

4.2.2.The plant tissue structure ........................................................................................................... 87

4.2.3. Osmotic dehydration mass transport phenomena .......................................................... 88

4.3. FACTORS AFFECTING OSMOTIC DEHYDRATION ......................................................... 89

4.3.1. Influence of size and shape on the mass transfer ............................................................. 89

4.3.2. Type of osmotic agent .................................................................................................................. 90

4.3.3. Contact time ..................................................................................................................................... 90

4.3.4. Temperature of the solution ..................................................................................................... 91

4.3.5. Agitation and food/ solution ratio .......................................................................................... 91

4.4. ENHANCEMENT OF OSMOTIC DEHYDRATION .............................................................. 91

4.4.1. Application of ultrasound during osmotic dehydration ................................................ 91

4.4.2. Application of blanching as a pretreatment ....................................................................... 92

Azarpazhooh, E. and Ramaswamy, H.S. Osmotic Dehydration, in Drying of Foods, Vegetables and
Fruits - Volume 1, Ed. Jangam, S.V., Law, C.L. and Mujumdar, A.S. , 2010 , ISBN - 978 - 981 - 08 - 6759 -
1, Published in Singapore, pp. 83- 110.