SOPs are written documentation and protocols for how your facility will handle and produce food safely. ... They document routine operations within the facility to ensure that employees perform those operations consistently and correctly.

https://log10.com/sop-for-food-processing-industry/

Standard Operating Procedures (SOPs) are an important component of your food safety system because they ensure consistency in daily operations. They contain detailed, written instructions of routine operations. Some examples of SOPs include: labelling chemicals, storing utensils, receiving raw materials.

https://www.gov.mb.ca/agriculture/food-safety/at-the-food-processor/food-safety-program/pubs/fs_21.pdf

Kindly check FAO data http://www.fao.org/global-soil-partnership/glosolan/soil-analysis/standard-operating-procedures/en/

Also check http://www.fao.org/ag/agn/CDfruits_en/b_contenidos/4_safety/mater_4/pres4.6.ppt

Yes.

https://www.gov.mb.ca/agriculture/food-safety/at-the-food-processor/food-safety-program/pubs/fs_21.pdf

you can refer this!

I would be surprised if anyone published the actual industrial SOP as this would likely be considered an Intellectual Property or at least commercially sensitive.

Have a look at below Journals maybe you will find something useful:

DOI: 10.1080/10408398.2015.1087963

DOI: 10.1016/j.ijbiomac.2018.11.247

DOI: 10.1016/j.foodchem.2015.02.045

Good Luck.