What is the solvent with the lowest Mohs' hardness whose instance of is food ingredient ?
select ?ent where { ?ent wdt:P31 wd:Q146505 . ?ent wdt:P1088 ?obj . ?ent wdt:P31 wd:Q25403900. } ORDER BY ASC(?obj)LIMIT 5 
solvent: Q146505 food ingredient: Q25403900