Big growth in relatively small food categories has long been a bellwether for helping to identify new food trends, the morphing of existing megatrends, and the potential vulnerabilities of major food categories. This column is intended to highlight some of the emerging, high-potential hotspots to watch and work on. It is based on IRI data covering sales in supermarkets, drugstores, mass merchants, military commissaries, and select club and dollar stores for year-long periods ending on various da…