Abstract
Chitosan biguanidine hydrochloride (CBg) was prepared as a novel multifunctional biodegradable polymer with antimicrobial and excellent water-solubility properties, and used as a crosslinker to prepare carboxymethyl cellulose (CMC)/alginate (A)/CBg edible coating. FTIR confirmed the successful preparation of CBg and CMC/A/CBg films. Wide-angle X-ray diffraction showed that the amorphous structure of CMC/A had some degree of order after CBg addition. The film thickness and solubility were decreased after CBg addition due to the formation of a dense crosslinked structure. CBg addition significantly improved the thermal properties of the films as detected from the calculated IPDT values from TGA curves. Water vapor permeability was reduced to 54% of the value of CMC/A when CBg was added by15 wt%. The addition of CBg didn't change the transparency of CMC/A films. The mechanical properties and antibacterial properties were significantly enhanced after the addition of CBg. CMC/A/CBg were coated on tomato fruits, and the shelf-life studies showed that the storage weight loss was significantly reduced, and the spoilage was inhibited after coating. These results suggest that CMC/A/CBg edible coating might be a promising candidate in food preservation industries.
•Chitosan biguanidine hydrochloride (CBg) was used as a crosslinker for carboxymethyl cellulose (CMC)/alginate (A) system.•Films exhibited a reduced water vapor permeability and good color properties with CBg addition.•Films mechanical, thermal and antibacterial properties were improved with increasing the CBg percent.•Tomato spoilage was inhibited during the storage period when coated with CMC/A/CBg films.•The mass loss of tomatoes was significantly reduced for coated tomatoes.