A week after its premiere, MasterChef Australia on Sunday grabbed the 5th spot on TV Tonight's Top 20 programs as it aired the trimming of contestants from 50 to only 24 master chef hopefuls.

Eighteen-year-old university student, Matt Howell, is the youngest in the promising group of fine dining masters. Fifty-year-old Debra Sederlan, a senior account manager, is the oldest in the diverse group.

The Top 24 comes from all sorts of background. They are not even remotely linked to the food service industry. But everyone will be vying for the title of Australia's best cook.

The night after the Top 24 is revealed, the contestants faced the popular mystery box challenge. The chef hopefuls worked against the clock as usual as they figured out what to do with the mystery box item, a mirror.

Ben Milbourne, a 30-year-old secondary school teacher, won the challenge for having presented his dish in the most spectacular way possible. Ben won the right to fight for immunity with his deconstructed beef taco with tuna tostada.

The contestants will be taken to different places nationwide as they face various cooking challenges. There are reported schedules in Kangaroo Island, as well as Victoria and Tasmania. For their international trip as part of the competition, Italy is reportedly a very likely destination.

Well-acclaimed chefs who will grace the competition this season include chefs Jamie Oliver and Rick Stein, as well as Buddy Valestro of Cake Boss.

MasterChef Australia premiered on May 6 at 7.30pm on Network Ten. (Repeats air on Eleven.)