Assuming that Adam conducted an interview with John Doe and Adam is the only source.
Should I source the direct quotation separately?
The chocolate rain machine was invented by John Doe in 1980 and was regarded by Doe as "the most significant invention of the 20th century" (Adam, 2017). He constructed it from wooden bars that were...[several sentences] (Adam, 2017)
Or is the source at the end of the paragraph enough?
The chocolate rain machine was invented by John Doe in 1980 and was regarded by Doe as "the most significant invention of the 20th century". He constructed it from wooden bars that were...[several sentences] (Adam, 2017)

