From the Foundation for Research, Science and Technology
An Auckland research company has developed an innovative dryer that draws most moisture out of fresh foods, allowing
them to keep almost indefinitely
The dryer, combining a heat pump and microwaves, is the result of a research project by Dried Products Ltd (trading as
FreshDry) with assistance from HortResearch
The project was supported by investment from Technology New Zealand
Dried Products director Ewen Guy says the dryer solves the problem of driving all but 5 percent of final moisture -
which has always resisted removal - to the outside of the product, where the heat pump removes it
It combines "for the first time" two processes
"The heat pump removes the moisture from the product throughout the drying cycle by passing a continuous flow of warm,
dry air over it," Mr Guy says
"That's not new, but the problem has always been getting the moisture level below about 20 percent because the final
moisture is always imbedded deep in the product
"The solution is to use microwaves to drive the moisture out." Mr Guy says the benefits of a completely dry fresh
product include not only an indefinite shelf life: "It also means food keeps its colour, flavour, aroma and nutrients,
without the use of preservatives, without long drying cycles and extensive, expensive pre-treatments such as freezing,
and without it becoming shrivelled - the process should ensure that the product keeps as much as possible its original
shape." He says the dryer will help New Zealand reposition its farm products into new, niche, high-value markets
"In many of even the poorest nations fresh produce is left to rot because there is no affordable way to preserve it
"In modern economies convenience has become a key ingredient of the food industry
Fresh produce typically requires large amounts of time in shopping and then preparation
Fresh, dried foods can be stored indefinitely, can be already mixed or processed according to requirements and contain
all the goodness of the original product." Mr Guy describes the dryer as portable enough to fit into a shipping
container
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