Development and characterization of intelligent cellulose acetate-based films using red cabbage extract for visual detection of volatile bases

摘要

Visual pH-sensing cellulose acetate (CA)-based films was incorporated with different concentrations of red cabbage extract (RCE). The films were characterized by color, barrier and thermal properties, microscopic and topographic characteristics, mechanical performance, detection capacity of volatile ammonia, and time-dependent color stability and lighting. The RCE incorporation into CA-based films promoted a color-changing capacity with an increased light barrier and exhibited a plasticizer effect on the mechanical properties of the films. Moreover, the surface patterns of films were heterogeneous and irregular due to the presence of RCE aggregates, which increased as the extract concentration enhanced. The intelligent films showed excellent performance to detect volatile ammonia after 15 min of contact time, despite lower thermal stability and oxygen barrier. The detection of volatile ammonia was fitted well to a statistical model (p < 0.05; R-2 = 0.89) as a function of contact time and RCE concentration. The storage time and incidence of lighting influenced the color and the colorimetric transition of films after 30 days. Regarding biodegradability, sensitivity, simplicity, and low cost, these results suggested that CA intelligent films added with RCE have a great potential application as a volatile base sensor to monitor food degradation.