Yes, sure 100%
For the Jews, Passover is the first day of the week of the "unleavened bread", when it is strictly forbidden to eat leavened bread.
In the
Passover Seder (the official meal the first evening of Passover, when Passover starts) the Jews eat only the unleavened bread, said
matza.
Anyway it is from a few days before that in all Jewis look for crumbs of leavened bread to fire.
To clean the house from any trace of leavened bread is very important for the Jews: (Ex 12:15
Seven days shall you eat unleavened bread; even the first day you shall put away yeast out of your houses,).
From
wiki:
In accordance with the mitzah of not eating or owning leavened products during Passover, religious Jewish families typically spend the weeks before the holiday in a flurry of housecleaning. The purpose is to remove every morsel of fermented grain products (called chamets) from all the cupboards and corners in the home. The search for chametz is often a thorough one, as children's rooms and kitchens are cleaned from top to bottom and forgotten packages or pieces of cookies or crackers are uncovered under beds and inside closets.
Probably Jesus Last Supper was a Passover Seder (
Now on the first day of Unleavened Bread the disciples came to Jesus), and so absolutly without even any crumbs of leavened bread, but also if it was the dinner of one or two days before, for sure no leavened bread was used.
Probably many centuries before Chirst, probably before the Babilon exile), Passover and Unleavened Week were two different feasts (perhaps in different days). But at Jesus time Passover was (and still is for the Jews) the first day of the Unleavened Week. And, as I told, even if the last supper has been one o two days before, we can presume the strict use only of unleavened bread.
There are better sources for the ancient Jewish uses than St Athanasius