Anthocyanin extracts from different plants were used to develop intelligent gelatin films. Red cabbage, sweet potatoes, roselle, butterfly pea, husks, and peelings from mangosteen and red dragon fruit were used. Anthocyanin extracted from butterfly pea had the highest pH sensitivity, which suggested that the distinct color change at each pH. The intelligent gelatin films were prepared using a casting method from gelatin, glycerol, butterfly pea anthocyanin (BPA) extracts, or resazurin, at pH 6. The thickness of the films ranged between 43 and 48 μm. Significant decreases for tensile strength (7.0–2.4 MPa) and water vapor permeability (8.4–2.4 $\times$10^-11 g m m^-2 s^-1 Pa^-1) were observed when adding BPA extract (P < 0.05). The gelatin film with BPA extracts was dark blue, while the film with resazurin was violet/purple. The control film had a smooth surface that was compact without any porous structures when observed using a scanning electron microscope. The film with BPA extracts showed the highest antioxidant activity and showed greater pH sensitivity as compared to the film with resazurin, which suggested that changes in the films’ color occurred at different pH levels. Therefore, the film with BPA extracts was considered a promising film for intelligent packaging. This film used for packaging will serve as an effective pH indicator for the consumer. However, further investigation of its performance is necessary before its application is used in real food systems.

来自不同植物的花色苷提取物用于开发智能明胶膜。使用了红甘蓝，地瓜，玫瑰茄，蝴蝶豌豆，果壳以及山竹果和红火龙果的果皮。从蝴蝶豌豆中提取的花色苷具有最高的pH敏感性，这表明每个pH都有明显的颜色变化。智能型明胶薄膜是采用流延法从明胶，甘油，蝴蝶豌豆花青素（BPA）提取物或刃天青制成的，其pH值为6。薄膜的厚度范围为43至48μm。抗拉强度（7.0-2.4 MPa）和水蒸气渗透性（8.4-2.4）显着降低$\times$10 ^-11  g毫米^-2 s ^-1 Pa ^-1添加BPA提取物时观察到）（P <0.05）。含BPA提取物的明胶薄膜为深蓝色，而含刃天青的薄膜为紫色/紫色。当使用扫描电子显微镜观察时，对照膜具有致密的光滑表面，没有任何多孔结构。与含刃天青的膜相比，含BPA提取物的膜显示出最高的抗氧化活性，并显示出更高的pH敏感性，这表明膜的颜色变化发生在不同的pH水平下。因此，含有BPA提取物的薄膜被认为是用于智能包装的有前途的薄膜。用于包装的这种薄膜将为消费者提供有效的pH指示剂。但是，在将其应用到实际食品系统中之前，有必要对其性能进行进一步研究。