Preservation properties of in situ modified CaCO3–chitosan composite coatings

• Published in: Food chemistry 2015-09, Vol.183, p.217-226
• Main Authors: Sun, Tong, Hao, Wen-ting, Li, Jian-rong, Dong, Zhi-jian, Wu, Chao-ling
• Format: Article
• Language: English
• Subjects: CaCO3; Chitosan - chemistry; Chitosan composite coatings; Food Preservation - methods; In situ modification; Preservation; Sciaenops ocellatus
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.03.036

•In situ modified CaCO3–chitosan composite coatings were prepared with different modifiers.•Modification in situ could avoid nonuniform dispersion and original size of nano particles.•In situ modifier sodium stearate can imporve the microstructure and properties of coatings.•The shelf life of Sciaenops ocellatus is extended by in site nano CaCO3–chitosan coating. To improve the dispersibility, hydrophilia constraints of primitive particle size, and reduce the economic cost, in situ modified CaCO3–chitosan composite coatings were prepared by tape-casting with different modifiers. The coating structures were characterised, and the preservation properties of the coatings were evaluated by fresh indices of Sciaenops ocellatus. The results revealed that the coatings were homogeneous and compact when the in situ modifier was sodium stearate. Besides, the amide I group of chitosan disappeared and hydrogen bonds were formed between the nano-CaCO3 and the chitosan. Meanwhile, the preservation effects to S. ocellatus of the coatings modified in situ by sodium stearate and sodium citrate were better. This was because the coatings effectively prevented oxygen and bacteria from reaching S. ocellatus, and thus inhibited the degradation of the proteins and lipids. The in situ modified method is conducive to chitosan coating properties, which will be widely used in the food preservation field.