Application of an active/intelligent double-layer film based on geraniol loaded zein elecrtsopun nanofibers and bacterial nanocellulose containing blood orange anthocyanins for protein rich foods

• BNC based pH indicator was prepared by adding Blood orange anthocyanins (BOA). • The active zein NFs were fabricated by incorporating geraniol loaded nanoliposomes. • Active/intelligent bilayer film was used for packaging of protein rich foods. • BNC-BOA smart label was successful in spoilage/freshness monitoring of all samples. • The effect of active NFs was observed on the shelf-life extension of some meats. This study aimed to design and produce an active and intelligent packaging system based on zein nanofibers (NFs) containing geraniol-loaded nanoliposomes (NLPs) and bacterial nanocellulose (BNC) films incorporating blood orange anthocyanins (BOA). Initially, the zein NFs containing geraniol NLPs as the active layer were produced by electrospinning. Then, a pH-sensitive colorimetric indicator as the intelligent layer was designed by immobilizing BOA onto BNC films. The designed indicator exhibited a distinct color transition across a broad pH range. Color stability was optimal under refrigerated conditions and in the absence of light. The colorimetric indicator demonstrated high sensitivity to ammonia vapors and exhibited a desirable rate of color change upon exposure to basic compounds. Finally, the efficacy of the active/intelligent film was evaluated in extending the shelf life and detecting spoilage in protein rich products, including shrimp, fish fillet, chicken fillet, and ground beef. Upon product spoilage, the indicator’s color transitioned from red to gray or pink and subsequently to blue. High correlation coefficients were observed between spoilage indices (pH, TVB-N, TBARS, and psychrophilic bacterial counts) and the colorimetric changes of the indicator, with the highest correlations observed in shrimp and fish. The active NFs were able to marginally extend product shelf life, with the most pronounced effect observed in ground beef. Overall, the results of this research validated the feasibility of utilizing the active/intelligent system containing blood orange anthocyanin as a colorimetric indicator for spoilage detection in meat products. However, the impact of geraniol NLPs on extending product shelf life was limited.