We found a very nice article about pandan from Food52 website so here is the best explanation :
“Vanilla might be the most pervasive dessert flavor in Western cultures, but in Southeast Asia, where I live, there’s another ingredient that trumps vanilla in its ubiquity and in being, well, just as basic as vanilla.I’m talking about pandan.
Pandan—the more common term forpandanus amaryllifolius, a species of screwpine shrub—is a plant with long, slender leaves. Imagine the languid leaf segments of a palm tree bundled up into a waist-high shrub—that’s what pandan looks like. It’s sometimes referred to as “Asian vanilla,” and though pandan is as popular in this region of the world as vanilla is in the rest, the similarities between the two end there.
While vanilla has a creamy, musky, caramel fragrance, pandan’s is a cross between freshly steamed rice and freshly mowed lawn. And, when blended down into a paste or extract, will lend its striking, grassy hue to whatever it touches...”
Food52.com (https://food52.com/blog/25488-what-is-pandan)
