I don't own, nor have ever operated an air drier, so I first checked to see what temperature can be set and the one I found said the lowest temperature is 80C. I think that is too high to preserve many vitamins, but it is low enough to prevent the brown discolouration, so it will look "dried" not "cooked".
But, you also need to let moist air escape... no idea if that is possible, and you need each piece to be separated so air can flow around it. In a big oven, I just put them on mesh trays (or even on the oven shelves direct if they are clean). But I have also put/hung them on a skewer.
Of course, in the summer, you could just put them out of a sunny day ... but fruit usually arrives in the Autumn when the weather is not ideal.
Another way to dry food is to use cat litter (before use) or even rice. The basic idea is to use the cat litter or rice to dehydrate your veg. I've not done it for veg, but I have used the disiccant to dry rose petals.
I don't know whether this works, but I would use about 10x the weight of desiccant to that of veg. The steps are as follows:
- Get a large airtight container, big enough to hold the desiccant, (spaced out) veg and any shelves/trays.
- Get 20x as much desiccant as veg as you plan to do at a go. Cat litter should work, but I used rice as we had a big bag.
- heat half (or all) the cat litter or rice for at least two hours at around 120C to drive off all the moisture. What I did was to put it in the oven until the air coming out didn't mist up a cold glass. I also checked the temperature in the centre was over 100C
- Then allow to cool in a sealed container.
- Cut up the veg into small pieces - if it goes brown dip in water+lemon juice and allow to drip dry
- Place the desiccant into the large airtight container, put in the shelves and veg. Leave for a day.
- Heat the other half of desiccant, allow to cool in an air tight bag, and then replace the desiccant.
- Repeat 7 until the veg is dry or if it isn't drying, chuck it and start again using twice as much desiccant and leaving it in the oven for twice as long to dry better.
I just want a supply of mushrooms, peppers and onion to go with my rice or noodles.
No vac sealer, sadly.
Sudden thought. Could I bottle veg for a short term?
I've bought dried mushrooms in a supermarket. I searched on ebay and easily found dried onions. So, you can easily buy some of them.
There is no reason why you couldn't boil veg and then seal it (whilst hot) in a jar - but some like potatoes will turn to mush.
You could preserve veg by putting them into vinegar/alcohol (vodka) or using Salt or Sugar (or a mix). I preserved our own strawberries & other fruits by just popping them fresh into vodka - but done that way, they are an acquired taste. I think the same would work with vinegar. I'd probably heat the veg if using sugar or salt ... there will be recipes for "jam" or "fruit preserve" and Chutney, which I'd adapt.