You just need to check which in the past ,had these occupations possess a higher rate of invites and potentially can give you more chance na mainvite. Just do a research separately -that can give you the key in deciding which one to go.
On my research just now - one was invited for Food Technologist in VIC -190 last 19 Oct 2023 and one in WA (under Graduate Stream -PHD and Masters ) last 14 Oct 2023 , while for 189 the last round was in Dec 8 2022.
you can check it here:
https://smartvisaguide.com/australia-visa-grants/occupations/234212
while for Prod Manager (i assume is under manufacturing?)
is eligible for 190/491 recent invites were coming from ACT and WA (Under WASMOL 2 Stream) April and May 2024 ,while in VIC i saw one in Jan 2023
you can check it here:
https://smartvisaguide.com/australia-visa-grants/occupations/133512
If considering the above data - Food Technologist seems to be eligible in more pathways than Production Manager - while the latter is being invited in states that are hardly open for offshore applicants (ACT and WA)