Preparation and characterization of Aloe vera polysaccharide-based packaging film and its application in blueberry preservation

In this study, AVP-HMBCa-CNCs films were prepared based on Aloe vera polysaccharide (AVP), using β-hydroxy-β-methylbutyrate calcium (HMBCa) and nanocellulose (CNCs) as cross-linking and reinforcing agents, respectively, whose effect on freshness preservation of blueberry was investigated. The films were prepared by casting and solvent volatilization. The effects of HMBCa concentration on the physicochemical properties and bioactivity of the films were explored with SEM, FTIR, XRD and TG, showing that HMBCa addition concentrations of 0.1 to 0.5 mg mL−1 exhibited excellent mechanical and barrier properties. In the meantime, adding HMBCa not only improves transparency and reduces solubility, but also boosts the film's antioxidant and antibacterial ability. In addition, AVP-0.25HMBCa-CNCs film showed excellent performance in terms of hardness, respiration rate, weight loss, relative conductivity, total soluble solids and titrable acidity of blueberry. Besides, thermal metrology provides valuable information for edible film storage technology. Therefore, as a transparent edible film, AVP-HMBCa-CNCs film has great potential for green and food preservation.