Their research was complicated by the fact that of the five primary taste sensations salty, sweet, sour, bitter, and umami the taste of salt is the least understood.

NEWYORKER: Snacks for a Fat Planet

Ketchup ignites the palate as one of the few foods to stimulate all five sensations inside the mouth: salty, sweet, sour, bitter and umami, the latter of which gives body to food and is the savory taste found in cured meat and MSG.

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