Egg Whites in Sweets

[SugarGirl]

I've been playing around with confections using egg whites recently, and I can't help wondering how the virtually raw egg whites don't go bad after being knocked full of air and left at room temp for prolonged periods of time. I'm wondering, specifically, about nougat, marshmallows, frappe, baked meringue, and royal icing.

I'm assuming that the concentration of sugar and the lack of much free water have a lot to do with it, but is there any kind of guideline for shelf-life or stability?

Does the gelatin in marshmallows make an impact by retarding water activity? I've seen salt in some marshmallow recipes -- would that also help preserve it? I haven't seen salt called for in nougat or frappe recipes. Marshmallows made with egg whites don't seem to stay as fresh for as long as nougat... but then again, Valomilks, which are very runny and have a marshmallow/frappe-like filling (w/o gelatin, but w/ distilled water), seem to last for pretty long.

Also, I made the Frappe recipe on page 324 in the Greweling book, Chocolates & Confections, using fresh egg whites (instead of dry albumen and cold water) as well as the glucose and invert syrup called for. After a day, it separated a little -- there was a syrup-y substance on the bottom of the container. Does that mean that it went bad, per se, or would mixing it together "fix" it temporarily? I did make the frappe again, with slightly less egg white, and there has been no separation (though it is a little denser than the original). He says to store it tightly covered, at room temperature, but I wonder how long it's meant to last for.

Anyway, any thoughts or resources would be appreciated!

[alanamoana]

well, quite a few marshmallow recipes don't require any egg white at all...so there's no question about shelf life. they depend solely on the gelatin and sugar syrup for aeration.

with regard to frappe, because he's using a pasteurized and dehydrated product, again there's no worry about shelf life.

most nougats (either fluffy or chewy) rely on a hot sugar syrup (240F) to set them which, depending on volume of whites and syrup, pasteurizes the fresh egg whites enough to make them shelf stable.

and i think you're right with regard to amount of sugar: a meringue made with different ratios of whites to sugar will give you different amounts of stability and weeping.

[nduran]

Maybe I'm kooky but I've always cooked meringue. Royal icing will probably outlast anything it's put on.