“…The most common use of natural colorant‐responsive films is in the design of smart packaging and indicators of the food quality including TTIs (Maciel et al., 2012), pH (Andretta et al., 2019; Jayakumar et al., 2019; Pourjavaher et al., 2017), gases and volatile compounds (Saliu & Della Pergola, 2018; Xiao‐wei et al., 2018; Zhai et al., 2019), freshness (Apriliyanti et al., 2018; Cao et al., 2019; Zhai et al., 2017), integrity (Biji et al., 2015), chemical array, toxin, and microbial sensors (Rai et al., 2019), and as well as the development of colorimetric sensors (Balbinot‐Alfaro et al., 2019a; Biji et al., 2015; Park et al., 2015; Poyatos‐Racionero et al., 2018; Rai et al., 2019; Xiao‐wei et al., 2018; Yousefi et al., 2019).…”