Table 2.

Application of ELISA methods in gelatin source authentication.

ELISA type	Antibodies used	Targeted species	Main results	References
Indirect and competitive indirect	Polyclonal anti-peptide antibodies	Distinguishing porcine from bovine gelatins	For discovering bovine gelatin present in porcine gelatin samples to a dilution of 2–4 parts per 1000, competitive indirect ELISA proved more suitable.	[60]
Sandwich ELISA	Polyclonal antibodies from immunization of gelatin in rabbit (pAb2-pAb1) and in goat (pAb3-pAb3)	Identifying porcine and bovine gelatins in food processing for individuals at risk of gelatin allergy	Porcine gelatin (alkaline process) was the primary target of the pAb2-pAb1 ELISA technique whereas bovine and porcine gelatin were the primary targets of the pAb3-pAb3 ELISA (alkaline process). All commercial products that were stated to include gelatin were successfully detected by both ELISA methods.	[61]
Indirect ELISA	Anti-peptide polyclonal antibodies	Analyzing the porcine gelatin content of an edible bird's nest	The established ELISA method detected spiked samples containing at least 0.5 ng/μg porcine gelatin.	[62]
Indirect ELISA	Anti-peptide (collagen α2) polyclonal antibodies	Verification of the source of the gelatin in confectionary products	The detection limit of the specially designed ELISA was 0.05 μg/mL, and it demonstrated little cross-reactivity to both fish and chicken gelatin.	[63]
Indirect ELISA	Anti-peptide polyclonal antibodies	Analyzing the porcine gelatin content of an edible bird's nest	The sequence using collagen α1 was discovered to be sufficient for authenticating edible bird's nest with a detection limit of 0.052 g/mL among three porcine species-specific peptides.	[64]