267
0-8493-1902-1/05/$0.00+$1.50
© 2005 by CRC Press
9
Water and Its Relation
to Fresh Produce
Mawele Shamaila
Nestlé R&D Center, Inc., Solon, OHCONTENTS
9.1 Introduction .................................................................................................. 268
9.2 Chemical Composition, Structure, and Properties of water........................ 269
9.2.1 Polar Nature of Water ...................................................................... 269
9.2.2 Properties of Water........................................................................... 269
9.3 Factors Responsible for Water Movement in Plant Systems ...................... 271
9.3.1 Diffusion, Bulk/Mass Flow, and Osmotic Movement
of Water ............................................................................................ 271
9.4 Water Migration in Plant Tissues ................................................................ 272
9.5 External Factors Affecting Water Migration in Fresh Produce .................. 274
9.5.1 Temperature...................................................................................... 274
9.5.2 Relative Humidity ............................................................................ 276
9.5.3 Pressure, Air Movement, and Light................................................. 276
9.6 Effect of Injury on Water Loss .................................................................... 277
9.7 Methods of Preventing Water Loss from Fresh Produce ............................ 278
9.7.1 Temperature...................................................................................... 279
9.7.1.1 Cooling of Harvested Fresh Produce ............................... 280
9.7.2 Elevated Relative Humidity ............................................................. 281
9.7.3 Packaging of Fresh Produce ............................................................ 282
9.7.3.1 Modified Atmosphere Packaging (MAP)
in Reducing Water Loss ................................................... 283
9.7.4 Waxing of Fresh Produce ................................................................ 283
9.7.5 Processing Treatments...................................................................... 284
9.7.6 Air Movement and Air Pressure ...................................................... 285
9.8 Water Loss and Its Impact on Produce Quality .......................................... 285
9.8.1 Appearance and Color ..................................................................... 286
9.8.2 Texture .............................................................................................. 286
9.8.3 Nutritive Value ................................................................................. 287
9.9 Conclusion.................................................................................................... 287
References.............................................................................................................. 287