Among foodies or people who are into food, cooking or eating out, with ramen and other Japanese foods being more popular and information easily available on how actual Japanese dishes are made, the words umami and dashi can be found in food and cooking articles and restaurant reviews. This may not apply to most of the country but in most major cities where there is a foodie culture, it might not be that uncommon. I just typed in umami and there was no spellcheck although there still is one for dashi.