Sixteen start-ups were awarded a total of $1 million from MassChallenge Inc. Tuesday night to help them develop products such as an all-terrain wheelchair, a job networking site for military personnel, and a nonstick coating that allows food to slip out of packaging without leaving a residue trace behind.

The top four companies won $100,000 apiece, and 12 were given $50,000 each in the third annual competition sponsored by MassChallenge, a Boston nonprofit that provides resources to entrepreneurs.