How about making sure each person who signs up as a deliverer of food passes a little training session in the app about food safety, e.g. 'don't pick up cold chicken and then leave it sitting in your hot car for 2 hours, because that carries a high risk of bacteria growing and causing food poisoning'. I think a lot of people aren't that familiar with safe food handling guidelines. If they're picking up from cooks/chefs they'd be able to give instructions. But not if you're picking up from people without that sort of training.
Hi Neil, I really like your ideas here. Simple and practical.
I just have a few comments regarding the smart fridge potential, as I discussed this with a friend who is a food microbiologist.
There are metabolic signs that food is starting to go off, however this becomes very complex for a mixed environment - i.e. different foods, foods all together rather than being packaged separately, fridge being opened and closed all the time, etc. Different fruits and vegetables emit all sorts of things naturally, so when you are dealing with one specific food by itself this is not so complex. When you are dealing with that whole mixture together in a fridge it is very complex.
One existing/well known way of tracking when things are likely to go off now is by tracking the temperature history of the item, but again, this would have started before you purchase it and is also different for each food type. If you google 'food freshness indicator' you should be able to find what we know currently.
That's all - just thought it might be helpful to highlight the complexity.
Just a note on voice recognition - best to think about where the app will be used. I've recently done some user research on a voice-input device (with older users, though, aged 65-75), and they don't really feel comfortable talking to a device when there is no other human or at least feedback involved. Certainly while out of the home, and also even while in the home it can make them feel a bit silly.