Carlos Tevez need the only goal on the half-hour mark, but Ventura was left aggrieved after Torino were denied a penalty 10 minutes from time when Omar El Kaddouri went down in the box under a challenge from Andrea Pirlo.
The reverse continues Torino's dismal run against Serie A leaders Juve, with no win in 19 years and no goals against their city rivals since February 2002.
However, Ventura was encouraged by Sunday's display.
"Last season we conceded at the last minute, then earlier this term we lost to a goal that was offside," he told Sky Sport Italia.
"Seeing the footage now, I can say they were right, it was a penalty on El Kaddouri.
"It's a shame looking back over the footage, as we could have equalised with that penalty and nobody could have complained."
The result leaves Torino eighth in the Serie A table, four points adrift of Inter in the final UEFA Europa League qualification place, but Ventura insists the setback was all part of his side's development.
He added: "We probably deserved a point, but the derby was always going to be a stepping stone in our growth process."
