Searching for substring in field that contains variable length of arrays of json objects

I am trying to construct a sql query, that searches for a substring within a field. The issue is that the field contains an array of one or more json objects.

For example the table looks like so:

day     |   items ____________________ Sunday  | [{"apples":5, "bananas":2}, {"pears":12, "cucumbers":9}, ...] Monday  | [{"apples":6, "bananas":1}, {"watermelon": 1}] Tuesday | [{"apples":4, "bananas":3}, {"tomatoes": 1}] 

How do I construct a SQL query that searches for a substring in items given it is not a string ?