Alternatives to borax for minced protein recipes (fish balls, kebabs, etc.)? Borax (sodium salt of boric acid) is used in some recipes as a texturizing agent.
From Wikipedia:

borax imparts a firm, rubbery texture to food.

It does this by binding polymers in the food:

Borax acts on these polymers just as it acts on other polymers and will bind polymers together forming cross-linkages which change the texture and structure of the proteins.

However, it is banned as a food additive in several countries due to concerns about its safety.
What is a safe alternative which will have the same textural/binding effect on meat proteins but without the possible risk?
I use salt and STTP when I make burgers and bakso, (that’s the hard meatballs).
Sodium Tripolyphosphate (STPP)
There is an article on it that may be of interest.
https://journal.ugm.ac.id/istapproceeding/article/view/32675