There’s a good article about umami in The Guardian today.
It points out that MSG is the cheapest and simplest way to get umami, but by no ways the only one.
This is excellent news for people like me who suspect they’re allergic to MSG!
Key common ingredients rich in umami include fish, such as sardines (glutamate 280mg/100g and inosinate 193mg/100g) or mackerel (inosinate 215mg/100), meats such cured hams (glutamate 337mg/100g) and vegetables including ripe tomatoes (glutamate 246mg/100g). Sauces such as Bovril, soy sauce and anchovy sauce will all provide over 500mg of glutamate per 100g and parmesan cheese contains small white glutamate crystals, providing about 1200mg/100g.