关键词: 可食膜；乳清分离蛋白；竹叶抗氧化物；物理性能；表征；抗氧化

Abstract: An edible packaging material with good performance was prepared using whey protein isolate (WPI) as a film-forming substrate with the addition of bamboo leaf antioxidant (BLA) and sodium caseinate (SC). The effects of film-forming material composition, pH, and glycerol concentration on the film physical properties such as tensile strength at break, elongation at break, water vapor transmission rate, and light transmittance were investigated. The results showed that the tensile strength and elongation at break of the film with a BLA:SC:WPI ratio of 1:1:10 (m/m) and glycerol concentration of 0.04 g/mL formed at pH 8–9 were 18.4 MPa and 32.8%, respectively, water vapor transmission rate 10.86 g/(m2·d), and light transmittance 90.2%, indicating good physical properties of the film. Fourier transform infrared (FTIR) spectral analysis showed good compatibility between the film-forming materials. Scanning electron microscopic (SEM) analysis showed that the surface of the film was smooth, and the cross section was regular and uniform. When applied to actual samples (dried squid), the prepared edible film showed good antimicrobial and antioxidant effects. This study provides a reference for the development of edible films.

Key words: edible film; whey protein isolate; antioxidant of bamboo leaves; physical properties; characterization; antioxidant