Another Answer to the question raised by Bards, R' Yeruchim, and R' Chaim Shmulevitz:
It is indeed mind-boggling that a young orphan being sold out as a slave -BY HIS OWN BROTHERS and being sent to the most degrading place on earth (Ervas Ha'aretz) should give a damn about the aroma of the merchandise.....
The answer is that yes, It did matter to Yosef Hatzadik.
Bec to him the ride down to Mitzraim was a ride like any other; he was calm and relaxed and in just the right frame of mind to enjoy the aroma of spices... -HE HAD FULL FAITH THAT HIS HIGHER POWER WILL SEND HIM TO EXACTLY WHERE HE BELONGED!!!!
There was nothing to fear....