Ok well some options for you are courgettes, cucumbers, bananas, carrots, squashes and aubergines
If you use a peeled banana (and it's ripe) or a carrot please for the love of god put a condom over the top. If the carrot snaps or you get squishy banana everywhere it won't be fun.
Alot of the girls I work with do this - you'd be surprised how much money you can make for putting on a show with vegetables or strange objects (screwdrivers are easy and guys seem to love it for example - though not very satisfying so I would advise against for masturbation purposes)
Here's a link with masturbation tips - some of them seem a little strange to me but hey if it helps /shrug
Sex with Food: How to Masturbate with Food
Mainly for men in regards to the food section but there was an entire different section on women that might help