We would like to have a neutral foaming cleaning agent to clean FISH OIL and GELATIN residues. We will also need a validation method to test residue.
I recommend you evaluate Liquinox detergent. Liquinox is a neutral pH range, high foaming concentrated cleaner. You dilute it 1:100 or 10 mL/L to use it. For fish oil and gelatin I would use a hot solution to clean with followed by a hot rinse. I am sure you are aware that fish oil can have a very persistent odor. Using a neutral range cleaner to remove fish oils, you may need to clean more than once, or you may need to clean once very thoroughly. You may need to use a very hot water solution for the best results. Be sure your first rinse is as hot as or hotter than your cleaning solution so as to avoid hitting the surface with a cold rinse that will break the emulsion of residual oil and cause it to redeposit.
Review the cleaning validation references for Liquinox - once you know which residue detection method you want to use, please let us know and we will send you the details of that method. I believe Pramod Patel of Emcure has developed a residue detection method for the anionic surfactant in Alconox powdered detergent- I believe an HPLC method. You can use this same method to detect the anionic surfactant in Liquinox as a residue detection method. Note that if you were willing to use the still very mild pH Alconox powder (pH 9.5), that hot 1% Alconox could be used for this cleaning purpose as well. I am recommending Liquinox because you asked for a neutral cleaner.