For the most part, major food trends tend to compete and supplant. Take healthy foods as an example: fiber and complex carbs were replaced by low carbs and no carbs, which in turn have been supplanted by whole grains -another way of saying fiber and complex carbs. Or beverages: Caffeine-free took a hit from Mountain Dew and Jolt, the trend swung back to caffeine-free, then was replaced by Red Bull and other stimulating drinks using such ingredients as guarana and ginseng.But sometimes it happens that when trends collide, you get a megatrend. At Kosherfest 2005 conference and trade show last month in New York City, we saw what may be the makings of just such an event. Kosher food sales have been growing at a double-digit percentage rate, with an estimated 85,000 products now carrying some sort of certification. And the field has been growing at that rate for years. By some estimates, better than three-fourths of foods being manufactured either have or are under consideration for some sort of kosher designation.