enrich

:  to make rich or richer especially by the addition or increase of some desirable quality, attribute, or ingredient <the experience will enrich your life>: as a :  to add beauty to :  adorn b :  to enhance the taste of <butter will enrich the sauce> c :  to make (a soil) more fertile d :  to improve the nutritive value of (a food) by adding nutrients (as vitamins or amino acids) and especially by restoring part of the nutrients lost in processing <enriched flour> e :  to process so as to add or increase the proportion of a desirable ingredient <enriched uranium> <enriched natural gas>