Sesame seeds add a toasty flavor to spinach namul (seasoned spinach), but grinding them can help your body absorb more nutrients. Sesame seeds are rich in healthy fats (oleic and linoleic acids), minerals like calcium, iron and magnesium, and unique compounds such as sesamin and sesamol with antioxidant properties. Because sesame seeds have a hard hull, swallowing whole seeds may pass through undigested; crushing or grinding the seeds before eating improves digestion and nutrient uptake. Pre-ground sesame is convenient but loses aroma over time, so to maximize flavor grind roasted seeds just before serving. If you prefer the look of whole seeds, be sure to chew them thoroughly.