The Volume Expansion decreased when the salt concentration increased.
While The Volume Expansion increase when dehydration time increase until the maximum point around 4.5 hr on this graph but after that the volume expansion decrease this result can explain that 1. The dehydration time is affect on moisture content the cause of change volume expansion. if less dehydration time, the moisture content still high percent inside the sample. So,if water received the microwave radiation the water will be adsorb microwave radiation and evaporation but if use stable power of microwave to puffing it, the water product have high moisture content. It may not puffing because the high moiture content don’t formulate become to vapor. So, the volumn expansion lower than