Optimization of mechanical and water barrier properties of avocado seed starch based film and its application as smart pH indicator by adding blue butterfly pea flower extract

This study investigated the properties of films based on avocado (Persea americana) seed starch. A full factorial experimental design was performed using different amounts of starch (3–5 %) and glycerol (0.75–1.75 %) to investigate the mechanical, water solubility and swelling, water vapor permeability, and opacity properties of the films. The optimum film formulation with maximum mechanical strength, minimum water solubility and water vapor permeability was found to be 4 % starch and 1 % glycerol. An application study was conducted with blue butterfly pea flower (Clitoria ternatea) extract added at 10 % by volume of the film solution to test its use as a spoilage indicator in packaging chicken breast meat. The deterioration of chicken breast meat was monitored using pH changes and total mesophilic aerobic bacteria count. During storage at room temperature, the film's color transitioned from blue to green as the meat deteriorated, correlating with pH changes and microbial growth. •Avocado seed starch and glycerol were used in biopolymer film production.•The concentrations of avocado seed starch and glycerol affected the properties of films.•Blue butterfly pea flower extract was added to the film to produce a color indicator film.•The indicator film showed color change during the spoilage of chicken breast meat.