Development of a bifunctional edible coating for formaldehyde scavenging and preservation of aquatic products

BACKGROUND Although exogenous and endogenous formaldehyde in squid has led to severe health threat, an in-depth study on natural edible scavengers for formaldehyde in squid is still lacking. RESULTS Response surface methodology (RSM) combined with experimental verification approaches was applied to obtain an optimal 'recipe' to achieve formaldehyde removal rate of >85%: 6 mg mL(-1) tea polyphenols, 20 mg mL(-1) chitosan, 3:2 (v/v) tea polyphenols and chitosan, a pH value of 3 and 60 min treatment time. Apart from the capability of removing formaldehyde, the scavenger derived from natural food exhibited a significant preservation effect (extension of preservation time up to 40%) on squid during chilled storage, and was safe and environmentally friendly. Meanwhile, a synergetic effect of the two components on scavenging formaldehyde was unraveled by multimolecular infrared spectroscopy. CONCLUSION An edible and bifunctional reagent composed of tea polyphenols and chitosan was developed for simultaneously removing artificially added or endogenous formaldehyde and for preservation of squid. The bifunctional coating shows promise as a formaldehyde scavenger and green preservative for aquatic products. (c) 2021 Society of Chemical Industry.