Identifying food, quick and cheap?
Unfortunately, your confidence in what a chemist can, is quite exaggerated. Though flattering.

Analyzing the entire range of parameters that you list, requires several analytical techniques, including sample preparations like homogenization, extraction etc.

A technique like Near-infrared spectroscopy can give an easy and fairly good estimate of some major components (protein, fat etc) in selected types of food. FOSS Analytical (and probably several others) purchases equipment for this.

Routine methods exist for analyzing components like vitamins, pigments or metals, but they require a laboratory setup and often very expensive equipment.