Application of waterborne rosin polymer coating for preserving strawberry during storage

A water-soluble rosin polymer (RP) was prepared via polymerization of rosin and maleic anhydride. The structure of the RP was characterized via Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The RP was used as a film-forming agent on strawberries to improve their postharvest quality at room temperature. The effectiveness of this treatment was evaluated based on the impact of the RP coating on the following parameters: weight loss, total soluble solids (TSS), firmness, respiration rate, malondialdehyde (MDA) content, anthocyanin content, and total phenolic content (TPC). The samples that coated with the RP exhibited delayed respiration and loss of firmness compared with the control. Correspondingly, the samples coated with the RP had lower weight loss (14.78%), MDA content (8.13 × 10 −2 μmol/g), anthocyanin content (37.86 mg/100 g), TPC (3.41 × 10 −4 mg/100 g), and higher TSS (8.09%). The results indicated that the RP preservative could effectively maintain the freshness of fruits.