A software based startup sounds like an excellent idea.
The very fact that you have a good team and you feel you are contributing towards it in your fullest capacity indicates you are going through a purple patch.
My friends and i started a dotcom way back in 1998 when we were still doing our undergraduate course, and again in 2002 the most promising engineering graduates amongst our batch all decided to do something on our own.
Bottom line is that the euphoria that surrounds doing things independently is unmistakable and can draw you into making some very interesting decisions with regards to your career, which might in the long run create difficulties for you , especially financial and social
The three biggest problem ive faced is that sooner or later,
1) one or the other talented persons will back out due to personal / professional reasons
2)the projects / revenues become very seasonal
3) as amateurs the trouble is not in writing good software, but to get customers to sign the cheque.
If you feel that the three reasons mentioned above are not applicable in your case, then i think you should give your startup a try. What you should be looking for is to come up with a good valuation (>500K -1Million $)for your startup within a year or so if possible, considering you have a superb team in place and already have a foothold in the food processing industry. That way you guys will have enough focus to last a year out , even if your fortunes dwindle.
The technical / managerial skills you learn in the year you are not employed, and are at your startup will ensure that you are not treated as a fresher.
But do your friends a favour, and give them a sign very much well in advance if you are planning to quit the startup, coz at the end of the day friends are far more important than making money!
Hope this advice was helpful.